Ophthalmologic Knowledge Base
Inflammatory affections in dry eye disease are not only found in the lacrimal gland. Even in the clinically inflammation free and primary tear deficient non-Sjogren's dry eye an elevation of inflammatory cytokines (ILia, IL6, IL8, TNFa) is found in the tear film and inside the tissue of the conjunctiva 48 . The ability of conjunctival epithelial cells to release inflammatory cy-tokines has been reported 12 . This indicates a shift of the cellular immune response into the direction of an inflammatory Thi response similar to the inflammatory affections in the lacrimal gland and may similarly lead to a destruction of the epithelium and the underlying extracellular matrix 48,58 . The primary affection seems to lie in the epithelial cells, similarly
Common mechanisms in immune mediated dry eye disease. Different types of dry eye disease share an immune modulated inflammatory process that can similarly occur in the lacrimal gland (e.g. in Sjogren's syndrome) and at the ocular surface. It appears to start from epithelial defects resulting in a loss of immunological tolerance. Epithelial cells produce inflammatory cytokines (e.g. TNF-a, IL-i, IL-6, IFN-g), upregulate MHC class II and co-stimulatory molecules on their surface and allow uncontrolled antigen (AG) influx through defects. Together this leads to an uncontrolled activation of normal resident mucosal T cells into the inflammatory Thi type that also pro- Fig. 6.6. Common mechanisms in immune mediated dry eye disease. Different types of dry eye disease share an immune modulated inflammatory process that can similarly occur in the lacrimal gland (e.g. in Sjogren's syndrome) and at the ocular surface. It appears to start from epithelial defects resulting in a loss of...
If the eye sometimes wanders like this, but at other times looks ahead normally, usually you need not worry. The eye will grow straighter in time. But if the eye is always turned the wrong way, and if the child is not treated at a very early age, she may never see well with that eye. See an eye doctor as soon as possible to find out if patching of the good eye, surgery, or special glasses might help. IMPORTANT The eyesight of every child should be checked as early as possible (best around 4 years). You can use an 'E' chart (see Helping Health Workers Learn, p. 24-13). Test each eye separately to discover any problem that affects only one eye. If sight is poor in one or both eyes, see an eye doctor.
Ocular toxoplasmosis appears to have a weak but important association with glaucoma. However, there is no prospective study that has examined the relationship between toxoplasmosis and glaucoma. Unlike herpetic uveitis, which is frequently associated with glaucoma, ocular toxoplasmosis in a retrospective study found the highest incidence (38 percent) of elevated intraocular pressure in patients with active ocular toxoplasmosis (Westfall et al., 2005). There was, however, no associated glaucomatous nerve damage. The elevated intraocular pressure appeared to resolve with resolution of the retinochoroiditis. A prospective study will be required to further examine any possible association.
Chronic allergic ocular disease encompasses several disorders, such as seasonal atopic conjunctivitis, perennial atopic conjunctivitis, atopic keratoconjunctivitis (AKC) and vernal keratoconjunctivitis (VKC) 7 . Seasonal atopic conjunctivitis (SAC) is a time-limited disease and in most cases conjunctivitis is only one manifestation of additional allergic reactions (rhinitis, hay fever or a hay fever like symptomatology, and in severe cases conjunctivitis is associated with different forms of pulmonary affection). Atopic keratoconjunctivitis is a severe, bilateral, ocular allergic disease affecting adults. A familial history for atopy and an association with systemic atopic dermatitis are common. Symptoms commonly include itching, burning, and tearing. Signs include involvement of mainly upper conjunctiva in the form of a papillary conjunctivitis. The corneal epithelium reveals mild to moderate inflammatory changes that can result in scarring and neovasculariza-tion leading to...
Cataract and age-related macular degeneration (AMD) represent the two most frequent disease states leading to vision loss worldwide. Both diseases usually occur in older adults. Oxidative stress with accumulation of free radical damage to the lens and retina has been considered causative to development of both cataract and AMD. Thus, the role of dietary and supplementary antioxidants, including vitamin E, -carotene, other carotenoids, vitamin C, and selenium, in preventing or slowing such age-related eye diseases has been extensively investigated. The DRI panel (1) in 2000 noted the existence of nine epidemiological studies (138-146) and one clinical intervention study (147) relating vitamin E status and supplementation to risk of cataract. The epidemiological studies were inconclusive, and the intervention study (147) showed no effect at 50mg -T per day.
A cataract is any opacity of the lens or its capsule. That is, the lens or its capsule loses its transparency light cannot pass through the lens. The result is increasing loss of vision finally resulting in blindness unless treated. A person who has cataracts will usually be affected in both eyes. b. Signs Symptoms. A cataract may appear as a white or yellow discoloration in the lens. Any cataract that develops over a period of time (from months to years) is usually yellowish or light brown in color. A traumatic cataract usually appears white if it develops over a short period of time. This type of cataract is usually due to a metallic foreign body striking the lens such as a BB shot, darts, or rocks. A traumatic cataract may also be caused by overexposure to heat (glassblowers' cataract) or steel fragments. Opacities may develop anywhere in the lens the location of the cataracts plus the pattern or shape may give an indication as to the cause. For example, a typical...
The lens of the eye, behind the pupil, becomes cloudy, making the pupil look gray or white when you shine a light into it. Cataract is common in older persons, but also occurs, rarely, in babies. If a blind person with cataracts can still tell light from dark and notice movement, surgery may let him see again. However, he will need strong glasses afterward, which take time to get used to. Medicines do not help cataracts. (Now sometimes during surgery an artificial lens is put inside the eye so that strong eyeglasses are not needed.)
Uveitic eyes with glaucoma should be evaluated for the feasibility of implantation of a glaucoma drainage device (GDD) at the time of PPV. Anterior segment inflammation can cause early failure of trabeculectomies and also severe complications of fibrosis surrounding anteriorly placed tubes of GDDs 3 . Placement of the GDD in the posterior segment through the pars plana can avoid these severe complications. Excellent cleanup of the peripheral vitreous and posterior cortical vitreous is necessary to prevent aspiration of vitreous with possible retinal complications.
Amniotic membrane transplants (AMT) were first used in ophthalmology by De Rotth in 1940, who reported partial success in the treatment of conjunctival epithelial defects after symble-pharon 4 . Human amniotic membrane is derived from placenta, which consists of the inner amniotic membrane made of a single layer of amnion cells fixed to collagen-rich mes-enchyme six to eight cells thick loosely attached to chorion. It is composed of three layers a single epithelial layer, thick basement membrane, and avascular stroma. Human amniotic membrane is nonimmunogenic and has a unique combination of anti-inflammatory proteins and growth factors that promote wound healing. otic membrane is placed over the entire anterior surface of the globe, tacked down to conjunctiva, with 8-0 nylon interrupted sutures. A bandage soft contact lens is applied over this, and the amnion melts over the ensuing 4 weeks, typically revealing a total healing of the previously persistent epithelial defect.
The importance of this cannot be overemphasised, and that knowledge may help to give you the incentive you need to stop or drastically reduce your smoking habit. This chapter will discuss the physical consequences of diabetes, in particular the short-term complications which include hypoglycaemia, hyperglycaemia and diabetic ketoacidosis (DKA) and how they can be avoided and treated. The chapter will also discuss the long-term complications, which may include heart disease, eye disorders, kidney disease, nerve disorders and foot and leg problems.
We have reported 5, 22, 23 the efficacy and safety of HSO (Oxane HD) as a heavier-than-water endotamponade in the treatment of persistent macular holes, after failure of vitrectomy, ILM peeling, long-acting gas endotamponading, and prone positioning. Oxane HD was removed after 3 months. The main outcome measures were anatomic success rate (closure of the macular hole) and best corrected visual acuity (BCVA). Anatomic closure of the macular hole was achieved in all patients. Postoperative BCVA improved, ranging from 20 40 to 20 100 with regard to preoperative BCVA ranging from 20 100 to 20 600. In our series OCT images showed that HSO, due to its specific gravity, achieved effective endotamponading of the foveal region in the upright position, allowing a good anatomic and functional recovery (Fig. 2.2). Therefore, HSO can be a safe and effective tool in the treatment of persistent macular hole.
The possibility ofdeveloping long-term complications is one ofthe most frightening aspects of diabetes. Prolonged periods of high blood sugar increase the risk of complications in people with diabetes. Common ailments include cardiovascular disease (such as high blood pressure and atherosclerosis), eye disorders, kidney disease, nerve disorders, and foot and leg problems. Most of these conditions result from years of chronic high blood sugar levels. The good news is that many ofthe possible problems can be treated, and often the treatment is most effective when the complications are noticed at an early stage. This is why you will be asked to go for regular medical check-ups.
Patients with retinal detachment who had developed PVR grade C or greater (anterior or posterior) 22 and who were to undergo vitrectomy and silicone oil exchange were recruited. A total of 157 patients were randomized to surgery with or without adjunctive 5FU and LMWH. Forty-five to fifty patients had not had previous vitreoretinal surgery. There were no significant differences in primary (retinal re-attachment without further vitreoretinal intervention at 6 months) or secondary (complete or posterior retinal re-attachment, visual acuity, hypotony, cataract, keratopathy) outcome measures although there was a lower incidence of macular pucker in the treatment group that marginally failed to reach statistical significance (p 0.068). No toxic effects of the adjunctive treatment were observed. Based on these results adjunctive 5FU and LMWH was not recommended for cases of established PVR.
This section of inquiry focuses upon disorders of complex visual processing.20 These disorders are very complicated. They can be screened and evaluated based on history and neurological examination, but a comprehensive appraisal of defects and quantification of these defects requires neuropsychologic, neuroimaging, or neuro-ophthalmologic evaluations. There are some very simple
(caption continued from the previous page) antirhodopsin by the immunogold procedure with silver intensification. The gold particles and the melanin granules in the retinal pigment epithelium (R) appear as bright white dots. Original magnification, X160. In the normal retina, rhodopsin labeling is restricted to the outer segments (*), while in the RP retinas the labeling is present in the tiny rod outer segments (short arrows) and the surface membranes of the rod inner segments (long arrows), somata (open arrows) and neurites (arrowheads). N, inner nuclear layer. (*) in bottom two panels, inner limiting membrane. Reprinted from ref. 13 with permission of the Association for Research in Vision and Ophthalmology.
The pathogen maybe exogenous or endogenous. Of the former, we distinguish between those caused by trauma or surgery the latter may follow trabeculectomy or other types of surgery (most commonly cataract extraction). Such postoperative endophthalmitis may be acute (presenting within a few weeks of surgery) or chronic. eyes with the same inclusion criteria as those in the Endophthalmitis Vitrectomy Study (EVS) acute postoperative endophthalmitis occurring within 6 weeks of cataract extraction with intraocular lens implantation or of secondary intraocular lens implantation. Treating eyes with endophthalmitis of other etiologies or chronicity requires a somewhat modified strategy, including timing and surgical details. These are not discussed here.)
Individuals routinely using Class 3 or Class 4 lasers in any research, development, testing, and evaluation (RDTE) effort where adequate protective measures are not feasible should be tested. Those people who are involved in only one laser test of short duration would not normally receive preplacement or termination eye examinations. They would be examined only if an injury caused by laser radiation was suspected. (2) Hazardous laser equipment. Certain laser equipment, such as tripod-mounted, hand-held or airborne laser range finders, designators, or illuminators may be determined to be of sufficient hazard to operators and related personnel that the Surgeon General may require such persons to be examined. The warning page of the operator's and maintenance manuals for each laser device shall indicate which types of user or related personnel should be examined. Operators of currently fielded tactical laser systems are not required to receive this eye examination. (b)...
Fuchs' heterochromic iridocyclitis is frequently diagnosed in young patients. The disease is usually unilateral even though bilateral cases have been rarely reported. Pain and redness are absent. Small stellate keratic precipitates are uniformly scattered over the endothelium. Different infectious conditions such as toxoplasmosis have been described during FHC, but the putative role of a pathogen is still under debate. Recently, Barequet et al. have analysed the aqueous humor and the anterior capsule of the lens obtained during cataract surgery in a patient with FHC. HSV DNA was identified in the ocular fluid but not in the lens capsule 5 . More specific data are needed before drawing further conclusions about the pathophysiology of the disease.
The Ruff-Light Trail Learning Test assesses visuospatial learning and memory in adults. The test was specifically developed to avoid requiring the patient to possess drawing skills, keen eyesight, good motor control, and refined visuospatial integration. Thus, it is very useful in traumatically brain-injured persons.90 This test makes a direct measure of immediate visual memory as well as visuospatial learning. It also has a delayed recall section, and it allows for the development of learning curves over the course of the testing. It has been standardized for use with individuals ages 16 to 70 years, and normative data are available for two age groups 16 to 54 years and 55 to 70 years. It is not validated for individuals under the age of 16.
Activities, mental health and peripheral vision all significantly improved following surgical intervention. Most importantly, no complications occurred. Since cataract and floaters sometimes coexist in elderly patients, Mossa et al. suggested combined phacoemulsification and deep anterior vitrectomy via a posterior capsulorhexis 20 . They reported on a series of 10 eyes and called this procedure floaterectomy. However, this procedure is not appropriate for the safe and controlled removal of posterior located floaters which are more likely to cause symptoms. Possible intraoperative posterior segment complications cannot be treated adequately with this approach 27 .
This test consists of showing children 30 pictures of objects that have been cut up and placed in different positions. Norms exist in order to assess children as young as age 5 years.134 The child is required to visually examine each picture and decide what it would be if it were assembled and write down the name of the particular object, such as fish, ball, or key. Test items are arranged in increasing difficulty, and most children can complete the test in approximately 15 min. It is sensitive to posterior brain damage. Poor performance on this test can be due to poor visual acuity, low intellectual functioning, psychiatric disease, and poor effort.12
The surgical procedure was technically uncomplicated in all patients. No severe postoperative complications occured in our small group of patients. Nuclear sclerosis requiring lens removal developed in 2 of 5 phakic patients. These two patients were 50 and 57 years old. In 3 younger phakic patients (40 years, 40 years, 46 years) no cataract progression was observed during the follow up period of 13 months and VA remained stable. No cataract surgery related complications occured. Objectively, their visual acuity - tested with standardized methods - had remained the same. Two patients who underwent cataract extraction, stated that this complication and the subsequent operation would not have changed their initial decision for the vitrectomy. No PVD occured in the follow-up period in any of the 3 eyes having an attached posterior hyaloid prior to surgery. He reported diminished productivity and inability to read for extended periods. Ocular history was otherwise unremarkable. On initial...
What is the central question that we can answer after the analysis of previously published small case series and our small group of patients Due to the small number of patients included we most certainly can not comment on the frequency rate of complications. A much higher complication rate after pars plana vitrectomy for secondary vitreous opacities due to branch retinal vein occlusion, uveitis, vasculitis, sickle cell retinopathy and other severe ocular disorders was reported in an early article of Peyman et al. published in 1976 23 . In these early vitrectomy years complications of vitrectomy were markedly higher than nowadays with markedly improved instrumentation and techniques. But this experience caused the very restraining and conservative indication for vitrectomy in eyes with good visual acuity. Today, iatrogenic tears, retinal detachment and other complications in this group of patients seem to be low, but will definitely occur with increasing number of patients. The...
The patients' presenting complaints are usually floaters, decreased visual acuity and sometimes dimness of vision. In the absence of macular edema, however, central vision remains excellent in most cases and is not a good functional parameter for monitoring disease activity, whereas visual field changes more appropriately identify activity of the disease 32,33 .
We have recently shown that apart from central visual impairment due to macular edema, visual field changes are more frequently found than acknowledged in BC and have probably more deleterious effects on visual function than recognized so far 38 . These visual field changes probably are a consequence of retinal dysfunction rather than from choroidal or optic nerve disease and are seen in parallel to massive fluo-rescein exudation 35 (Fig. 15.3 e). In our hands computerized visual field testing is a routine follow-up examination and significant visual field changes are considered an indication to introduce therapy, despite full visual acuity. This attitude may explain why the rate of cystoid macular edema is relatively low in our centre
Almost 80 of patients have posterior segment involvement, which is symptomatic in one-third of the patients. There can be a decrease of visual acuity, blurred vision and floaters. Posterior lesions consist of a typical multifocal bilateral choroiditis associated in all cases with a mild vitreous inflammatory reac-tion.The lesions, circular in shape, vary in number from less than 20 to more than 50 per eye. Chorioretinal lesions involve the midzone and or periphery, more prominently in the temporal and the superonasal quadrants as well as the posterior pole. Lesion size ranges from 100 mm to 1,500 mm, with most of the lesions measuring 200-500 mm. Linear clustering of chorioretinal lesions gives the typical pearls on a string aspect of this choroiditis (Fig. 15.6). Active chorioretinal lesions appear as deep, creamy lesions on ophthalmoscopy, with early hypofluorescence and late staining on fluores-cein angiography. Resolved chorioretinal lesions are partially atrophic and partially...
Common symptoms in cone dystrophy include photophobia, loss of visual acuity, color vision, and central visual fields. Electro-diagnostic tests are used to distinguish cone, cone-rod, and macular dystrophies. Simplex cases are most commonly reported followed by autosomal dominant inheritance, and autosomal recessive X-linked forms are also described. Genetic studies, to date, have shown that autosomal dominant cone and cone-rod dystrophies are genetically heterogeneous with 13 different genomic regions so far reported. Four genes have been described in cone and cone-rod dystrophies and include peripherin ftDS (52,53) GUCA1A associated with autosomal dominant cone dystrophy (76), GUCY2D associated with cone-rod dystrophy (77), and CRX associated with autosomal dominant cone-rod dystrophy (69).
Whether an individual with diabetes is cared for principally by a general practice team or by a hospital diabetes specialist team, it is now widely recognised that care is best provided by groups of health-care professionals with their own particular skills, working closely together. The teams include a consultant physician, diabetes specialist nurse, dietitian, chiropodist, general practitioner and practice nurse. They can also call upon the skills of a psychologist, ophthalmologist, nephrologist, neurologist, vascular and orthopaedic surgeons, obstetricians, midwifes and other specialists as necessary.
Preoperative visual acuity ranged from 20 800 to 20 40 with a reading vision of 1.1 to 0.5 logRAD. Three patients were unable to read. Two patients without reading ability preoperatively were able to read after surgery. Reading was possible in a total of 8 patients at the 6-month follow-up (1.3 to 0.4 logRAD). In all eyes but two, re-vascularization was visible on ICG angiography as early as 3 weeks after surgery. Autofluorescence of the pigment epithelium was coincident with re-vasculariza-tion of the graft and persisted throughout the follow-up.
A congenital model of ocular toxoplasmosis has been reported in which infected dams are inoculated during gestation (Hay et al., 1984). Unfortunately, a wide range of clinical disease occurred in this model. Murine congenital toxoplasmosis differs significantly from human disease. In the murine model there is significant opaque cataract formation, even with lens autolysis. This can be seen by examination using a 35-diopter lens, and documented with a Zeiss operating microscope (Dutton et al., 1986a). Even though ME49 strain infection of mice is a reliable model for Toxoplasma cysts in the brain, it is unusual to find evidence of intraocular toxoplasmosis even with PCR amplification. Antibodies in the same model against interferon-y, TNFa, or CD4 and CD8 cells result in frequent demonstration of parasite in association with more severe ocular lesions (Gazzinelli et al., 1994).
Hyoscine n-butylbromide (Buscopan) is an anticholinergic agent that has been used as a muscle relaxant for the barium enema examination as well as for CT and MR colonography in Europe. It has not received approval for use in the USA. Buscopan has a different mechanism of action than glucagon and is less expensive. Hypotonia of the colon is induced by its action on the postganglionic parasympathetic receptors in smooth muscle. Contraindications to the use of anticholinergic agents include glaucoma, severe prostatic hyperplasia, unstable heart disease, bowel obstruction or ileus, and myasthenia gravis. Anticholinergics can cause side effects such as tachycardia, dry mouth, acute urinary retention, and acute gastric dilatation.
Visual acuity, colour vision, pupillary responses, funduscopy and fluorescein angiogra-phy were all normal. The only additional abnormal finding was an abnormal focal ERG indicating retinal dysfunction around the optic disc at the origin of the visual field defect. Most probably AIBSE and MEWDS are the same disease with the exception of the usual fundus findings that were not found in this and other reports on AIBSE. As indicated by Hamed et al., the retinal lesions may already have subsided at the time of examination or were subclinical Visual loss found in 90 of cases drop in visual acuity from slight to severe, visual field changes and blind spot enlargement
Consistently favorable anatomic and visual outcomes can be achieved by long-acting gas tamponade with strict face-down posturing as originally advocated 25 . In a comparative study of 52 eyes, use of 16 perfluoropropane gas resulted in anatomical closure in 97 and improvement in visual acuityby a mean of 3.1 lines, whereas use of air resulted in closure in only 53.3 and improved mean acuity by only 1.3 lines 34 . In another comparative series of 149 eyes, tamponade by 16 perfluoropropane and face-down posturing for 2 weeks resulted in an anatomical closure rate of 94 , compared with 65 following tamponade by lower concentrations of perfluoropropane and shorter durations of posturing visual outcomes paralleled the rates of macular hole closure 35 . tomical and visual outcomes comparable to those of longer tamponade with a more rapid recovery of visual acuity postoperatively. In a nonrandomized comparative trial of 62 eyes, tamponade by 23 sulfahexafluoride and face-down posturing for 6...
Myotonic Dystrophy The gene involved in myotonic dystrophy encodes a protein kinase whose function is still uncharacterized. The disease is characterized by progressive muscle deterioration, cardiac arrhythmia, frontal baldness, cataracts, and testicular atrophy. Because the disease shows anticipation, symptoms range from mild to a severe neonatal condition.
The anterior cavity of the eye is anterior to the lens. The anterior chamber is anterior to the iris and posterior to the cornea. The posterior chamber is posterior to the iris and anterior to the lens. The anterior cavity contains the aqueous humor secreted by the ciliary body. Too much aqueous humor results in glaucoma. The posterior cavity of the eye is posterior to the lens and suspensory ligaments and anterior to the retina. This cavity contains gelatinous substances called vitreous humor which maintain the globular shape of the eyeball.
Poor performance on this test can be caused by impaired visual acuity, psychiatric disorder, significant pain, impairment of visual attention, and fatigue.12 This test may not detect brain damage located in the left hemisphere, and it requires the administration of other neuropsychological tests to improve the overall neuropsychological screening. This test consists of a series of three geometric figures that the patient must match to one of four sets of designs.135 It is a multiple-choice test of visual recognition. Of the four sets of designs, one of the designs is an exact replica of the stimulus figure, while the others may vary to a subtle degree. This is a visual recognition test, and it is sensitive to posterior brain injury, particularly in the left parietal lobe. One of its strengths is that it can be administered to patients who are unable to speak English, as the patient only must point to one of four sets of figures on a sheet of cardboard. Visual memory plays little role...
Attempts to replace diseased RPE by autologous IPE cells in suspension did not result in a long-term improvement in visual acuity 10, 11, 12 19 , although a small case series report stated that in non-exudative AMD, RPE suspension transplants showed no evidence of rejection and were associated with the disappearance of drusen 1 . Still, so far no conclusive long-term prevention of retinal and choroidal atrophy from cell transplantation has been demonstrated 22 . We have recently reported on functional and anatomical outcome after free graft translocation in 45 patients, the majority of whom had neovascular AMD 6 . Re-vascularization was observed as early as 3 weeks after surgery. Preoperative distant visual acuity ranged from 20 800 to 20 40. Comprehensive evaluation of reading ability using the Radner test demonstrated reading ability in 31 out of 45 eyes preoperatively. Visual outcome after free graft translocation was unrelated to the type of AMD. Patients without intraoperative or...
Most of the vitreous opacities are located anterior to areas of vitreous liquefication, and are therefore far in front of the retina. Opacities may only cause symptoms if they are close to the retina in front of the posterior pole, or if they are large and dense enough. Visible vitreous opacities vary in shape, size, and density and are fibrous in appearance. Because of the extreme mobility of the gel, the appearance and location of these opacities vary considerably. Typical ring-shaped opacities are rare. Opacities are often located at the margin of the lacuna and become symptomatic when they form condensation along the visual axis. The related symptoms are multiple and vague. Only in a few cases the complaints are clearly associated with the presence of large fibrous masses. Centrovitreal location of opacities can reduce visual acuity by impeding the visual axis. However, it is important that vitreous floaters, whether secondary to posterior vitreous detachment or to syneresis and...
A 9-year-old male is referred to the pediatric clinic because of progressive mental retardation, diminished visual acuity, and bone deformity in the thorax. ID CC A 2-year-old white male is brought to the ophthalmologist for an evaluation of eye clouding. Treatment Supportive ophthalmologic, skeletal, and cardiovascular treatment. Consider bone marrow transplant.
In patients with active ocular BD, FA discloses diffuse fluorescein leakage from the retinal capillaries, the larger engorged vessels, and the optic disc. Late staining of the vasculature, as a sign of large zones of capillary nonperfusion, collateral vascular formation, secondary retinal teleangiectasia, and retinal neovascularization could also be present 135,156 . In addition, FA demonstrates central retinal changes which are responsible for poor vision, such as macular is-chaemia, cystoid macular edema, macular hole, and epiretinal membranes 12 .
Biomedical engineering encompasses multiple disciplines, including physics, chemistry, biology, electronics, mechanics, and materials. The devices and procedures developed by biomedical engineers reflect this multidisciplinary field, and can include anything from computers that analyze blood, lasers for eye surgery, and advanced imaging systems, to miniature implantable pumps and tissue-engineered artificial organs.
PE anxious Eye exam reveals bilateral exophthalmos, lid lag, stare (due to lid retraction), and convergence weakness smooth, nontender diffuse goitre bruit over thyroid no cervical lymphadenopathy fine tremor of fingers of outstretched hands onycholysis and palmar erythema ( THYROID ACROPACHY) nontender purplish edematous plaques on shin ( PRETIBIAL MYXEDEMA).
PE normal visual acuity erythematous palpebral conjunctiva watery eyes remains of thick mucus found on inner canthal area no corneal infiltrate on slit-lamp exam normal anterior chamber mild preauricular lymphadenopathy. Conjunctivitis is a common disease of childhood that is mostly viral (adenovirus) and self-limiting it occurs in epidemics, and secondary bacterial infections (staphylococci and streptococci) may result. Visual acuity is not affected.
Viral eye diseases are common and are associated with different well-known forms of uveitis. Different animal and cellular models have been used to study herpetic ocular infections 7i, i6 . However, experimental models and clinical observations support the notion of an infectious, especially a viral, aetiology in different autoimmune conditions. One of the major characteristics of herpetic ocular infections is the dual occurrence of a replicative lytic reaction followed or accompanied by subsequent ocular inflammation. This duality is undoubtedly the patho-physiologic basis of viral uveitis and retinitis in
(Marles and Farnsworth, 1995) Gymnemic acids III, IV, V, VII, and gymnemoside B tested for antidiabetic activity (Yoshikawa et al., 1997a, b) A polyol conduritol A suppresses cataracts (Miyatake et al., 1994) Extracts from fruits have antidiabetic activity (Handa et al., 1989)
Multiple sclerosis and Parkinson's disease are associated with abnormal latency periods. Lesions of the optic nerve, optic tract, and cerebral cortex visual center(s) can be identified with a visual-evoked response exam. Visual field defects due to retinal damage, macular degeneration, and glaucoma may be detected by VER.
Wolf, Cowen, and Paige reviewed in detail their own cases and those reported by others, particularly Janku (1923) and Torres (1927), of T. gondii-like encephalomyelitis and chorioretinitis in infants (Wolf and Cowen, 1937, 1938 Wolf et al., 1939a, 1939b, 1940 Cowen et al., 1942 Paige et al., 1942). Joseph Janku (1923), an ophthalmologist from Czechoslovakia, was credited earlier with finding a T. gondii-like parasite in a human eye (Janku, 1923). The following description of the case of Janku is taken from the English translation published by Wolf and Cowen (1937) Ocular disease Before 1950, virtually all cases of ocular toxoplasmosis were considered to result from congenital transmission (Perkins, 1961). Wilder (1952) identified T. gondii in eyes that had been enucleated. The significance of this finding lies in the way this discovery was made. These eyes were suspected of being syphilitic, tuberculous, or of having tumors. Wilder was a technician in the registry of Ophthalmic...
The main clinical characteristics of ARN syndrome were defined by the American Uveitis Society and include focal, well-demarcated areas of retinal necrosis located in the peripheral retina (Fig. 10.5), rapid, circumferential progression of necrosis, evidence of occlusive vas-culopathy and a prominent inflammatory reaction in the vitreous and anterior chamber 32 . Mild optic disk edema may be present early in the course of the disease and increases progressively. A granulomatous anterior uveitis with secondary glaucoma may be associated. Retinitis progresses rapidly in the absence of treatment, but classically spreads to the posterior pole. An exudative retinal detachment occasionally develops if inflammation is important
PE White hair, including eyelashes and eyebrows eye exam shows nystagmus and poor development of macula with blue iris poor visual acuity (20 350) skin is pink-white with lack of pigmentation throughout body numerous actinic (solar) keratoses on face and scalp as well as on dorsum of hands ulcerated lesion with indurated edges on dorsum of hand with hyper-pigmentation. Treatment Surgery and or chemotherapy for skin cancers, avoidance of sun exposure, management of visual impairment.
Finally it is useful to try to classify the case into any of the known entities (MEWDS, APMPPE, multifocal choroiditis, etc.) in order to anticipate evolutionary patterns and determine a therapeutic approach (monitoring only versus therapeutic intervention using corticos-teroid and or immunosuppressive therapy). In the case of severe visual impairment, even if the condition is known to recover spontaneously, e.g. APMPPE, corticosteroids with or without immunosuppressants should probably be given as it is not known whether a well-known entity is going to develop into an atypical intermediary form possibly more deleterious to the chori-oretina than initially anticipated.
A 70-year-old man complains of the sudden onset of visual loss in his right eye accompanied by a headache. He has a history of hypertension and diabetes mellitus. On physical examination, visual acuity in the left eye is 20 20 while visual acuity in the right eye is 20 90. Fun-duscopic exam shows the right disc to be pale and swollen with some hemorrhages. Which of the following is the most likely diagnosis
Short-sighted within-host evolution posits that the parasites responsible for the morbidity and mortality of the host are selected for as a consequence of within-host evolution since that produces a local advantage for their survival within the host. The host dies and the rate of transmission would decrease. This is an example of evolutionary myopia in which the long-term consequences of killing a host would not matter to the parasite.22,23 Natural selection is a local phenomenon that happens at a given time and place and goes perfectly with this model. Bacteria such as Neisseria meningitidis that normally live attached to human pharyngeal epithelial cells sometimes invade the central nervous system (CNS) and kill the host. Their replication in the CNS is favored since competition is low and defenses are not as abundant as in the tonsillar areas.19
Frontal balding typical facial wasting bilateral cataracts distal muscle weakness in both upper and lower limbs difficulty releasing grip after handshake percussion over tongue and thenar eminence reveals myotonia mildly reduced deep tendon reflexes normal sensory exam moderately atrophic testicles equinovarus deformity of both feet.
Which of the following occurs in the treatment of glaucoma with a (3-adrenergic antagonist 3 i 6. A 65-year-old male complains of losing his vision Retinal examination reveals optic nerve cupping. Peripheral vision loss is observed on visual field tests, and his intraocular pressure is increased. Following treatment with a drug, lie lias improved visual acuity and decreased intraocular pressure.
Screening studies the congenital model as described does not seem to be appropriate because, in spite of low postnatal mortality, it has the disadvantage that ocular morbidity, discovered by cataract manifestation, is only present in 5 percent of the pups (Hutchison et al., 1982). Nevertheless, the use of different mouse and Toxoplasma strains, as well as new sensitive screening methods, may further develop such a model to be suitable for drug testing. Approximately 50 of offspring infected, 5.3 of these developed cataract acute uveitis in a small proportion of eyes
Interstitial cystitis (IC) is a syndrome whose pathogenesis and etiology remain a mystery. Even the diagnosis of this entity is difficult and considered one of exclusion. There are four currently proposed etiologies for this syndrome inflammation, vascular insufficiency, epithelial leak, and deficiency of proteoglycans (i.e., glycosaminoglycans-GAG-). Dimethysulfoxide (DMSO), after being approved for use in 1977, has been shown to induce remission in 35-40 of the patients (128) and is a mainstay of treatment (129). However, no controlled clinical studies have been performed. DMSO is a derivative of lignin, which is a product of the wood-pulp industry. Its therapeutic properties include anti-inflammatory properties, analgesic properties, collagen dissolution, muscle relaxation, and mast-cell histamine release. The usual dose is a 50 solution instilled for 5-10 min. This therapy can be used as a one time dose, repeated weekly for 6-8 wk, or continued weekly for 4-6 mo. Some even...
Congenitally infected children developed scars subsequent to birth during the next 20 years (Koppe et al., 1986). It is estimated that 85 percent of infants untreated and without ocular lesions at birth will subsequently develop ocular toxoplasmosis (Koppe et al., 1974 Wilson et al., 1980). Microphthalmos and microcornea can occur as a consequence of severe congenital eye disease (Suhardjo et al., 2003). Nystagmus and strabismus and amblyopia secondary to congenital toxoplas-mosis are more complex than even most expert ophthalmologists realize (O'Neill, 1998). There is a tendency for clinicians not to struggle with the complex care involved in trying to achieve optimal visual outcome in congenital infection. Less initially severe but still disabling disease such as anterior uveitis (Cano-Parra et al., 2000) secondary to T. gondii is likely underdiagnosed because of the limitations of current non-invasive diagnostic tests.
Aldose reductase is an enzyme that causes accumulation of sorbitol at the cellular level in various diabetic conditions. Sorbitol accumulation directly leads to tissue damage and promotes the macro- and microvascular complications of diabetes because excess intracellular sorbitol levels decrease the concentration of various protective organic osmolytes. This is seen in the animal model of cataracts that contain decreased levels of taurine, a potent antioxidant and free-radical scavenger. Interestingly, inhibitors of aldose reductase have restored levels of protective osmolites and prevented diabetic complications by diminishing sorbitol reduction (13).
While the authors would recommend routine use of hyoscine butylbromide prior to CT colonography, some caution needs to be exercised prior to administration. Glaucoma, cardiac ischaemia and urinary retention may all be precipitated and minor self limiting effects of dry mouth and blurred vision are also associated. Consequently, patients should be questioned about any relevant past medical history and advised not to drive for a short time following administration.
Immunological analysis showed an altered distribution or gly-cosylation of membrane-bound mucins on apical conjunctival epithelial cells of patients with dry eye symptoms compared with normal patients, which correlated with rose bengal staining, another sign of dry eye disease 3 . Reduced membrane-bound and soluble mucin levels probably impair the spreading capability of the tear film, contributing to tear film break-up.
Carotenoids, along with other antioxidants, may play a role in preventing age-related cataracts. In the Nurses' Health Study, an increased intake of spinach and kale (foods rich in the carotenoid lutein) was associated with a moderate decrease (22 ) in risk of cataract.47 In the Health Professionals' Study, broccoli and spinach consumption were consistently associated with a lower risk of cataract. Men in the highest quintile of lutein and zeaxanthin intake (carotenoids found in green vegetables) had a 19 lower risk of cataract, relative to men in the lowest quintile.48
The peroxidase-based or rhodamine fluorescent (Fig. 5B,C) TUNEL assay is performed according to the manufacturer's instructions to detect fragmentation of DNA associated with apoptosis in fresh frozen rabbit corneal sections or formalin-fixed mouse whole-eye sections (see Note 6). Counterstain can be excluded in the TUNEL assay to allow more sensitive detection of keratocytes because of the unambiguous localization of the keratocyte cells in the stroma. Corneas that had a flap formed with a microkeratome or have LASIK that includes flap formation and laser ablation of the underlying bed have keratocytes undergoing apoptosis on the anterior and posterior sides of the flap (Fig. 5D) (see Notes 7 and 8).
This situation is well illustrated by a case recently seen in our centre presenting with macular chorioretinal atrophy (Fig. 14.9 a). The 42-year-old male patient had presented an acute decrease of visual acuity and a central scotoma in his left eye 3 weeks after a flu-like febrile illness that occurred while the patient was staying in Southeast Asia. He consulted an Emergency Ophthalmology Department and a drop of visual acuity to 0.1 was noted OS with full vision OD. The ICGA showed severe central choriocapillaris non-perfusion (Fig. 14.9b). A complete uveitis work-up was performed but was negative in particular there was no evidence of syphilis and tuberculosis and no action was undertaken. Two weeks later a decrease of visual acuity and scotoma occurred OD and the patient was seen in a neighbouring country and again no action was undertaken as the diagnosis made was APMPPE. During the whole episode the patient complained of moderate to severe headaches. The patient was seen in our...
Dry eye disease is a widespread disruption of the normal homeostasis of the ocular surface that affects, depending on the tests applied for diagnosis in various studies, up to 10-30 of the population 56 . It is not homogeneously distributed in the population but more likely affects elderly people and preferentially women, which may point to certain risk factors such as age or hormonal status. It is caused, according to a definition of the American National Eye Institute (NEI) 30 , by an alteration of the tear film either due to aqueous deficiency or to increased evaporation. This condition leads to a disruption of the cellular and morphological integrity of the ocular surface and eventually Fig. 6.5. Clinical photo of severe dry eye disease. A severe dry eye shows dryness of the ocular surface with epithelial staining (if different kinds of vital stains such as fluorescein or rose bengal are applied). The corneal reflex is disturbed and the transparency of the cornea is decreasing....
Operations for abscess drainage, amputations, cataract operations, tonsillectomy, neck tumor excision, lithotomy, obstetrical procedures, bowel obstructions, hemorrhoids, and anal fistulas were described in the Susruta-samhita long before they were ever adopted in Western medicine. A special chapter in the book is dedicated entirely to the pathology and treatment of fractures.
There is evidence that, in some individuals, attention can be substantially impaired following traumatic brain injury, and the attentional dysfunction may affect driving skill. Recent research suggests that the attentional deficit causes impairment in the driver's ability to cope with time pressure.63 In terms of assessment, some evidence suggests that the Useful Field of View (UFOV), a measure of visual information processing, is a good predictor of vehicle crash risk in older adults. Recent research suggests that traumatic brain injury survivors have higher UFOV scores than young adults, which indicates a greater functional loss of peripheral vision in these individuals. Previous studies in older adults have shown that people with UFOV deficits are more likely to experience vehicle crashes.64,65 Further recent research suggests that virtual reality testing may provide an innovative medium for direct evaluation of basic cognitive function such as divided attention and its impact on...
Over the past several decades, attention has focused on the negative health consequences of alcohol. In addition to ocular anomalies among children with fetal alcohol syndrome, epidemiological studies indicate that chronic alcoholism is associated with a higher risk of cataract, keratitis and colour vision deficiencies. Not until the past few decades have we begun to explore the dichotomy of the health effect of alcohol. Many studies have attributed any beneficial effect of alcohol to red wine. Specifically, the last decade has witnessed a significant increase in our understanding of the health benefit of moderate wine consumption.
Visual recovery following surgical closure of macular holes may be gradual. Although substantial improvement in visual acuity occurs soon after cataract extraction, further improvement may be observed for up to 2 years 79 . Visual recovery is inversely correlated with vision in the fellow eye, tending to be greater where vision in the fellow eye is subnormal 80 . Bilateral visual function improves in a significant proportion of patients after macular hole surgery, particularly where vision in the fellow eye is subnormal 30 . Successful closure improves stereoacuity 81 and has a beneficial effect on patients' subjective perception of visual function 82 , but the effect of macular hole surgery on patients' quality of life has yet to be fully evaluated. of symptoms, but is not dependent on the age of the patient. Anatomic and visual outcomes are inversely correlated to the stage of the hole and are greatest following surgery for small stage 2 holes 13 . The closure rate in patients...
Although randomized studies are still lacking, clinical experience indicates that macular oedema usually resolves, often with dramatic improvements in vision, within 4-6 weeks of injection. Cataract development and pressure elevations, which usually respond to medical therapy, may occur. Finally, injection of the commercial preparation has been associated with a sterile endophthalmitis, which could markedly confuse the postoperative picture. Although intravitreal triamcinolone appears to be capable of providing rapid improvement in vision, its use should be limited to selected cases until more is known about its effect in uveitis patients undergoing PPV.
Christian Science was a good experience for me. And there was always testimony of healing and how you saw it interact in your life. You sort of shared in conducting that experience and where you found quotes within the bible that would help you along that turning point. I heard stories of people getting over cancer, people who were born blind seeing without glasses.
By 1915, Osborne and Mendel and also McCollum and Davis had between them distinguished two types of accessory factors based on their solubilities and called them 'fat-soluble A' and 'water-soluble B'. Fat-soluble A was present in butterfat and egg yolk a deficiency of this substance produced an infectious eye disease (xerophthalmia) and growth retardation in young rats. Water-soluble B was present in wheat germ and milk powder its deficiency produced the avian form of beriberi in pigeons. In 1920, the terminal '-e' was dropped from the word 'vitamine' and fat-soluble A and water-soluble B were renamed vitamin A and vitamin B, respectively. The anti-scurvy factor was named vitamin C. For some time it was considered probable that the anti-rickets factor might be identi
In patients with underlying immunosuppres-sion or immune defects, such as with bone-marrow transplantation or HIV, toxoplasmic chorioretinitis is often associated with concurrent toxoplasmic encephalitis (TE) or disseminated infection (for review, see Montoya et al., 2004). However, even in AIDS patients toxoplasmic chori-oretinitis is encountered relatively infrequently (Holland et al., 1988a), so most of the human cases of ocular toxoplasmosis are found in immunocompetent patients. Indeed, T. gondii is one of the most frequently identified causes of uveitis and the most commonly identitified pathogen infecting the retina of otherwise immunocompetent individuals (Holland, 1999) and, regardless of whether ocular toxoplasmosis is due to a reactivated congenital infection or to an infection that is acquired after birth, it usually presents in the immunocompetent host as a more-or-less localized eye disease (Montoya et al., 2004). Therefore, an animal model, particularly one that may be...
The various treatment strategies discussed above have one major feature in common they generally suppress the immune system, but not only the autoaggressive immune response. Furthermore, the pharmaceutical and even some biological agents are burdened with severe side effects, which might even accumulate with duration of treatment. Although most of the side effects are dose dependent and can be reduced by combining different therapeutic agents, the side effects will limit efficiency of therapy in most patients, often resulting in loss of visual acuity for the sake of the patients' safety. It is therefore important to develop highly specific therapies, such as the induction of antigen specific mucosal tolerance. In this case the antigen which is attacked by the immune system is applied orally, and in that manner induces regulatory cells downregulating the autoaggressive immune response.
Mucosal tissues consist of two sheets (Fig. 6.1). The superficial sheet represents a unilayered or, at the ocular surface, a multilayered arrangement of epithelial cells. They usually have a strong mechanical connection by intercellular adherence junctions (e.g. desmosomes and zonulae adherentes) and are sealed by an apical tight junction complex that prevents entrance of foreign materials including potential antigens. Impairment of the epithelial integrity is a major reason for a deregulation of mucosal immunity and is observed in dry eye disease and in allergic eye disease but is also caused by the surgical trauma during corneal transplantation.
The probability of a complicated outcome is only part of the concept of risk. The consequences of an adverse outcome must also be considered. Outcome data should be applied to patients in their particular clinical context. For patients undergoing corneal transplantation the consequences of success or failure can be quite different from patient to patient. For patients with corneal disease in one eye and a normal contralateral eye very little is to be gained by the patient in a functional sense from a successful outcome. Visual ability is determined by how good the vision is in the better eye rather than the level of vision in the poorer eye. Grafts in anything but the favourable circumstances of keratoconus or stromal dystrophy are best avoided when vision is normal in the contralateral eye. Other patients have much to gain from achieving a functioning graft in high risk situations. Those with most to gain are those with poor vision due to corneal disease in an only...
Pathophysiological events in allergic eye disease. Allergic eye disease is an inflammatory process that starts with the activation of mast cells (mc) by allergens crosslinking IgE bound to the high affinity IgE receptor on mc. This initially leads to degranulation of mc with release of vasoactive substances resulting in vascular exudation and edema. In the chronic forms this is accompanied by a release of Th1 and Th2 cytokines by mc. These cytokines activate several other cell types such as (counterclockwise in the figure) stromal fibroblasts, vascular endothelial cells, eosinophils (eos), conjunctival epithelial cells (ec), dendritic cells (dc) and lymphocytes (Ic). The activated cells in turn produce further mediators that reinforce the inflammatory process. Activated cells produce adhesion molecules (dendriform lines) like ICAM-1, VCAM-1, E-selectin and chemokines (small circles) and or their receptors (dendriform lines and excavated squares) that allow The inflammatory...
Blood behind the cornea is a danger sign. It usually results from an injury to the eye with a blunt object, like a fist. If there is pain and loss of sight, refer the person to an eye specialist immediately. If the pain is mild and there is not loss of sight, patch both eyes and keep the person at rest in bed for several days. If after a few days the pain becomes much worse, there is probably hardening of the eye (glaucoma, p. 222). Take the person to an eye doctor at once.
Asami T, Terasaki H, Kachi S, et al. (2004) Ultrastructure of internal limiting membrane removed during plasmin-assisted vitrectomy from eyes with diabetic macular edema. Ophthalmology 111 231-237. Burk SE, Da Mata AP, Snyder ME, et al. (2000) Indocyanine green-assisted peeling of the retinal internal limiting membrane. Ophthalmology 107 2010-2014. Charles S. (1977) Fluid-gas exchange in the vitreous cavity. Ocutome Fragmatome Newsletter 2 1 Coll GE, Change S, Sun J, et al. (1995) Perfluo-rocarbon liquid in the management of retinal detachment with proliferative vitreoretinopathy. Ophthalmology 102 630-638. 9. Da Mata AP, Burk SE, Foster RE, et al. (2004) Long-term follow-up of indocyanine green-assisted peeling of the retinal internal limiting membrane during vitrectomy surgery for idiopathic macular hole repair. Ophthalmology 111 2246-2253. 14. Fujii GY, de Juan E, Humayun MS, et al. (2002) A new 25-gauge instrument system for transconjunctival sutureless vitrectomy surgery....
Freidmann and Knox (1969) described three types of chorioretinal lesions found in a cohort of patients with no other clinical manifestations of T. gondii infection. Of these patients, 56 percent had 'large destructive lesions'. This type of lesion is characterized by its size a large destructive lesion is usually larger than the optic disk and is likely to be associated with vision loss and or complications such as retinal detachment, cataracts, cystoid macular edema, glaucoma, and chronic intraocular inflammatory reactions. 'Punctate inner lesions' accounted for 27 percent of the patients these were described as being smaller and less likely to be associated with vitreous traction. 'Punctate deep lesions' appeared in 17 percent of the patients this type of lesion is always located in the macula or peripapillary area. Because the infected tissue is separated from the vitreous by uninvolved retinal layers, punctate deep lesions are usually not associated with vitreous inflammation.
All patients are re-examined on the first postoperative day and then within 7 days of surgery at our center or by the referring ophthalmologist. Topical antibiotic, steroid, and cycloplegic drops are administered in the standard fashion as for other vitrectomy procedures.
Laboratory and diagnostic studies should be conducted as part of the initial evaluation to assess the patient's risk or presence of comorbidities. Such laboratory studies should include a fasting lipid profile, fasting insulin and glucose, and liver function tests. Should the history and physical examination suggest the presence of pseudotumor, a head CT scan should be ordered and consultation with a pediatric ophthalmologist arranged. Orthopedic complaints should lead to the use of relevant X-ray studies such as hip films to assess for slipped capital femoral epiphyses, and knee films to assess for the presence of Blount's disease. A sleep study should be ordered for patients with a history of apnea or snoring. An echocardiogram is important in patients whose degree of obesity may be causing cor pulmonale. Pulmonary function testing is indicated particularly for patients who complain of respiratory symptoms or shortness of breath with exercise. Indirect calorimetry is helpful in...
Aspirin therapy has been shown to be safe in patients with diabetes, does not promote the progression of ophthalmic disease, and ophthalmological studies have not demonstrated any association between aspirin use and worsening of retinopathy. In fact, some studies have shown a benefit of aspirin in reducing the rate of microaneurysms in the early stages of diabetic retinopathy.
Laser treatment developed in recent years can do a great deal to repair the damage caused by diabetic retinopathy. It is normally directed at the peripheral part of the retina, well away from the macula, and can remove hard exudates and prevent new blood vessels from growing. The earlier the treatment is given, the more successful it is, which is why it is essential that you should have your eyes checked at least once a year. An optician, a specialist ophthalmologist or a doctor who is skilled at this type of examination can do eye checks.
The major strength of this test is its easy administration and the fact that it can be given at the patient's beside. Not only is it sensitive for patients who have sustained traumatic brain injuries, but also it has been shown to be sensitive to early attentional changes in those afflicted with cerebral AIDS. It may not be appropriate for individuals who demonstrate poor vision or those who are severely anxious at the time of testing. Patients with significant motor impairment or psychomotor retardation may perform poorly on this test.12
Astigmatism--refractive error which prevents the light rays from coming to a single focus on the retina because of different degrees of refraction in the various meridians of the cornea. b. Cataract--a lens opacity a loss of transparency of the lens of the eye, resulting in partial or total blindness. Surgery results in improvement of vision in 95 percent of those affected. k. Glaucoma--a group of eye diseases characterized by abnormally high intraocular pressure (pressure in the eyeball). This pressure can damage the optic nerve and, if untreated, lead to a gradual loss of vision -- and eventually blindness. l. Hyperopia (farsightedness)--a refractive error in which the focal point of light rays from a distant object is behind the retina. o. Myopia--a refractive error which the focal point for light rays from a distant object is anterior to the retina. r. Presbyopia-- old sight, physiologically blurred vision, often occurs soon after 40 if at all.
The Susruta-samhita is mainly a surgical compendium but also includes medicine, pathology, anatomy, biology, obstetrics, ophthalmology, hygiene, and psychology. The document contains descriptions of about 1,120 diseases. It also attempted to outline the philosophy of medical teaching what sort of student should be selected, how he should be trained, the oath he should take, and the qualifications a physician should have before entering into practice. The oath in the Susruta-samhita has been noted to be strikingly similar to that of Hippocrates and this has led many scholars to compare other points of the Greek and Indian medical systems. The two systems shared many fundamental beliefs such as the 3 stages of fever and that the body was composed of humors, whose derangement led to the development of disease.
Dilation is achieved within 5 min (after applying 1 drop of Mydriacyl per eye) and lasts for up to 2 h. The eye should be evaluated within 15 min after application of the dilating drops. Under high magnification, a slit beam is passed across the anterior segment. Oblique illumination by the slit beam, will provide an optical cross-section of the lens and cornea. If opacification of the lens is detected, direct illumination along the visual access will allow the cataract to be visualized against the fundus reflex (red reflex). This is often useful in determining its density and position.
The National Adult Reading Test (NART) has been restandardized against the Wechsler Adult Intelligence Scale-Revised (WAIS-R).26 This restandardization allows the reading score taken from the NART to be used to predict the WAIS-R full-scale, verbal, and performance IQs, which are predicted from the number of errors made on the NART. This allows the estimation of a predicted full-scale IQ within the interval of 69 to 131. If a person has a language disturbance following a brain injury, the NART may underestimate premorbid ability. Therefore, patients who are aphasic, dyslexic, or who have articulatory or visual acuity defects probably should not be screened using this instrument.27 Moreover, the standardization sample did not include subjects of more than 70 years age.
Visual acuity is clearness or sharpness of vision. A visual acuity test should be a routine examination of all patients. There are several special charts of test letters used, but the most commonly used chart is the Snellen chart. The patient is seated twenty feet from the chart. He places a clean card in front of one eye without putting pressure on the eye globe. The chart has several rows of progressively smaller letters. The patient is asked to read the letters down the chart as far as possible. A patient who can read the letters on the 20 20 line from a distance of twenty feet is said to have 20 20 vision in that eye. The same process is repeated for the other eye. If the patient normally wears glasses for distance, the test should be repeated with his glasses on. Results should then be recorded as uncorrected and corrected.
It must be emphasized that the decision whether to undergo surgery is the patient's the ophthalmologist should inform the patient about the condition and the risks benefits of each treatment option in a way that allows the patient to make a choice that he is comfortable with 9 . The authors strongly believe that the primary line of treatment for the vast majority of eyes with endophthalmitis should be vitrectomy i.e., purely medical treatment is the exception, not the rule (Fig. 5.6). The decision whether surgery
Because of overlapping visual fields and the fact that ocular toxoplasmosis is usually active unilaterally not bilaterally - a change in vision may not be initially detected unless unilateral daily screening occurs. An Amsler Grid, a graph paper like grid of boxes, mounted to a flat surface may help compliance with self-vision screening. In addition to decreased vision in the area of reactivation, patients will likely have floaters or other media opacity related complaints that will vary depending on the degree of inflammation when the lesion was active and may persist after resolution of the underlying reactivation secondary to inflammatory debris being trapped within the vitreous.
A wide-angle viewing system using a binocular indirect ophthalmomicroscope (BIOM) or contact lens has become popular because the surgeon can see a wider area of the fundus simultaneously (Fig. 7.11) 37 . By viewing a wider area of the fundus, the surgeon can recognize the fundus pathology better and can treat lesions more safely and efficiently. The focus of the new BIOM system can be adjusted by the surgeon using a foot-pedal, while the focus needs to be adjusted by a handle in the old BIOM model. The new contact lens for a wide angle viewing system has a smaller diameter (Fig. 7.12) 28 . The reduction of the diameter of the lens has made it possible to visualize the scleral port directly so that the insertion of surgical instruments through the scleral port can be accomplished without any problems.
Peeling of the posterior vitreous cortex from the retinal surface can result in iatrogenic retinal tears. In the MMHS, retinal tears occurred in 3.2 of eyes and were effectively treated intraop-erativelyby retinopexy 13 . Retinal detachments occurred in 5.6 of eyes in the MMHS and in 11 of eyes in the VMHS 73 . Retinal detachments generally occur within the first 6-8 weeks postoperatively and have a high success rate of anatomic re-attachment following further surgery 13 . Although retinal detachment does not preclude improved final visual acuity, involvement of the macula and the development of proliferative vitreo-retinopathy indicate poorer prognosis 13 . The development of cataract is almost inevitable following macular hole surgery. Lens opacity has been reported in 46 of eyes at 3 months postoperatively 75 , and in greater than 80 by 2 years 33 . Since the development of cataract is predictable, combined cataract and vitrectomy surgery for macular hole has been advocated in...
Doses of TGF- 2 suggested a beneficial effect on visual outcome 44 , studies of nonbovine (recombinant) TGF- 2 demonstrated no significant benefit to vision. In a randomized controlled trial including 130 eyes, application of recombinant TGF-P resulted in anatomical closure in 78 of eyes compared with 61 in the placebo group (p 0.08), but there was no statistically significant difference in visual acuity between the groups 45 . Although the adjunctive use of APCin macular hole surgery results in a significantly higher rate of anatomical hole closure, no significant effect on functional outcome has been demonstrated. In a randomized controlled trial of surgery in 110 eyes the adjunctive use of APC resulted in 98 primary closure versus 82 in the control group (p 0.009), but visual acuity was not significantly different between the two groups 46 and subsequent study suggested relatively high rates of the late re-opening of macular holes.
Gram-positive bacteria cause by far the most cases of acute endophthalmitis after cataract surgery. The number of Gram-negative cases is decreasing and current data suggest an incidence of considerably less than 10 11 . A survey of studies investigating the microbiologic aspects of postoperative endophthalmitis reveals that co-agulase-negative staphylococci represent about half of all culture-positive acute endophthalmitis cases, followed by Staphylococcus aureus and P-hemolytic streptococci 1, 9, 11 . Figures 6.5-6.7 give an idea of the microbiologic view of endo-phthalmitis.
Snellen visual acuity is the most widely used measure of vision testing. This parameter is often misleading in patients with visually disturbing vitreous floaters. Floaters are not recognized as a disease. The clinician cannot understand the complaints of affected patients who then feel frustrated and misunderstood. Other measures, including contrast sensitivity, stereopsis, reading speed, colour discrimination, visual field, and glare testing, have demonstrated that visual acuity is a descriptor of one simple aspect of vision rather than a comprehensive assessment of visual function. Standard clinical tests, such as Snellen visual acuity, are unable to quantify many aspects of a visual disturbance and how the disability interferes with day-to-day functioning and overall quality of life. Nevertheless, objective testing is necessary to help quantify the degree of disability and to define criteria used to recommend surgical intervention. Further tests should be established that may...
Knowledge of the normal appearance of anatomic structures in the image and visual acuity in noting deviations from the normal are the tools that the radiologist uses in making his interpretations. Because an essential point in the radiographic diagnosis often appears in an inconspicuous portion of the image, a systematic analysis and evaluation of the entire image is necessary. This requires the entire image to be diagnostically informative and to have translucent silver deposits representative of the anatomic structures. The radiographic images must represent the true anatomic situation, and their appearance should always be fairly consistent. Standardized projections of an anatomic part always portray the structures in the same manner.
The overall primary success rate of surgery was 84.4 and the complete anatomical attachment rate at 6 months was 98 . There was no significant difference in the rate of PVR - in the treatment group 7 developed PVR compared with 4.9 in the placebo group, or in mean final visual acuity. Notably, in patients with macular sparing retinal detachments the final visual acuity was significantly worse, raising the possibility of a toxicity effect of the adjunctive medications.
The majority of full-thickness macular holes are unilateral. Since many affected individuals have normal visual acuity in their fellow eye at the time of presentation, the risk of macular hole development in the fellow eye is an important consideration in clinical management. While a stage 1 macular hole is associated with an estimated 40-50 risk of progression to a full-thickness hole, the presence of a complete posterior vitreous detachment, as indicated by a Weiss ring, is associated with a risk of progression of less than 1 . In normal fellow eyes without a Weiss ring the incidence of macular holes has been estimated as 7.5 at 18 months and 15.6 at 5 years after presentation 18 . In clinically normal fellow eyes, abnormalities in focal electroretinogra-phy and in color contrast sensitivity 18 suggest that subclinical foveal dysfunction appears to be predictive of an increased risk of macular hole development.