Experimental autoimmune uveitis (EAU) is a T-cell mediated autoimmune disease that targets the neural retina and serves as a model of human uveitis. EAU can be induced against several retinal proteins in rats, mice, and subhuman primates. These include the S-antigen, a major protein in retinal photoreceptor cells; interphotoreceptor retinoid-binding protein (IRBP); and rhodopsin and other antigens of retinal origin. There are many similarities between clinical uveitis and EAU, but the latter differs in being self-limited, and needs adjuvant for disease induction. The experimental disease can be induced only in susceptible animal strains. Use of the EAU model has helped investigators understand the pathophysiology of the disease and to evaluate disease-modifying strategies, which could be applied in the clinic. There has been significant progress in this field during last decade, but much more understanding is needed before the knowledge can be transferred to clinical practice. A deeper understanding of the immune mechanisms involved in the EAU model may lead to the development of new therapeutic approaches targeted at various components of the immune response by immunomodulation to control uveitis. This review summarises the evidence from the EAU model, which could be of relevance to the clinical management of patients with uveitis.

Purpose: To evaluate the nature and prevalence of ocular manifestations in a group of patients with Human Immunodeficiency Virus (HIV) infection/Acquired Immunodeficiency Syndrome (AIDS) from South India, and to elaborate the impact of the disease on existing health agencies. Methods: We examined 19 consecutive patients with AIDS (Group-A) who presented to our centre. After counselling, HIV screening tests were also performed on 8 individuals related to the patients and those who were seropositive (Group-B) were examined for ophthalmic lesions. Results:In Group-A, HIV retinopathy was present in 34%, CMV retinitis in 39%, Herpes Simplex-related Acute Retinal Necrosis (ARN) and retinitis in 11%, tubercular choroiditis in 11%, while Herpes Zoster retinitis and presumed P. carinii choroidopathy each were observed in 2.5% of the eyes. Results of screening tests in Group-B revealed HIV-seropositive asymptomatic status in 6 (75%) of them with no ocular manifestations. Conclusion: HIV retinopathy and opportuninstic ocular infections were common in AIDS patients. Heterosexuality was the most common mode of transmission. Since no effective management is readily available, prevention through proper counselling appears to be the only defence against AIDS in India.

Purpose: To describe ophthalmic and systemic findings in 70 patients with Human Immunodeficiency Virus (HIV) infection examined at a referral eye centre in India.Methods: A complete ophthalmological examination was performed on each patient. Relevant investigations were carried out on selected patients.Results: Thirty two (45.7%) had ocular lesions, the most common being cytomegalovirus (CMV) retinitis (21.4%). Other lesions included cotton-wool spots (12.8%), chorioretinitis (5.7%), endogenous endophthalmitis (8.5%), anterior uveitis (4.2%), and molluscum contagiosum (1.4%). The most common systemic infection was pulmonary tuberculosis (50%). The others were oral candidiasis (41.4%), Pneumocystitis carinii pneumonia (11.4%), HIV enteropathy (12.8%) and toxoplasmosis (4.2%). Systemic and intravitreal ganciclovir treatment were given in selected cases and the outcome was documented. Conclusion: Our study indicates that ocular lesions in HIV patients in India are less common than in USA and Africa. Unlike HIV patients in USA, the most common ocular lesion among HIV patients in India is CMV retinitis and not the cottonwool spots.

Purpose: To analyse commonly used ocular antibiotics and determine their in-vitro efficacies against bacterial keratitis pathogens. Methods: A retrospective review of microbiology records at the LV Prasad Eye Institute in Hyderabad, India identified 1,633 bacterial keratitis isolates. Antibiotic susceptibility of corneal isolates was determined for various ocular antibiotics using the Kirby-Bauer disc-diffusion method. Results: Cefazolin had coverage against 1,296 (83.0%) of 1,562 isolates tested; chloramphenicol against 1,136 (71.7%) of 1,585 isolates; ciprofloxacin against 1,080 (69.3%) of 1,558 isolates; gentamicin against 1,106 (70.6%) of 1,567 isolates; norfloxacin against 1,057 (67.7%) of 1,561 isolates; vancomycin against 463 (84.3%) of 549 isolates; and framycetin against 105 (36.2%) of 290 isolates. Also included is a breakdown by species, and sensitivity profiles for resistant isolates.Conclusion: This study provides information on the efficacies of ocular antibiotics commonly used against bacterial keratitis pathogens. It also examines the antibiotic susceptibility profiles for corneal pathogens that are resistant to an ocular antibiotic but sensitive to other selected antibiotics. It is hoped that this information will aid in the decision-making of empiric initial treatment of bacterial keratitis.

Purpose: To analyse leading bacterial keratitis pathogens for in-vitro susceptiblity to commonly used ocular antibiotics and to determine trends in antibiotic susceptibility for these pathogens. Methods: A retrospective review of microbiology records from 1991-1997 at the LV Prasad Eye Institute, Hyderabad, India identified the five leading bacterial keratitis pathogens.. Antibiotic susceptibility of corneal isolates was determined for various ocular antibiotics using the Kirby-Bauer disc-diffusion method. Results: Linear regression analyses were performed. Statistically significant trends included a 3.56% increase per year in the percentage of Staphylococcus epidermidis isolates susceptible to chloramphenicol (p = 0.032) [-6.61 - -0.51, 95% CI]; a 9.93% decrease per year in the percentage of Corynebacterium species isolates susceptible to ciprofloxacin (p = 0.050) [0 -19.86, 95% CI]; a 0.69% increase per year in the percentage of Staphylococcus aureus isolates susceptible to gentamicin (p = 0.012) [-11.35 - -2.49, 95% CI]; and a 5.53% increase per year in the percentage of Staphylococcus aureus isolates susceptible to norfloxacin (p = 0.040) [-10.66 - -0.40, 95% CI]. A trend of borderline significance included a 3.77% decrease per year in the percentage of Pseudomonas aeruginosa isolates susceptible to ciprofloxacin (p=0.064) [-0.34 - 7.89]. Conclusion: This study provides information on the trends in antibiotic susceptibility for the leading bacterial keratitis pathogens. It is hoped that this study will provide a rational approach for initial therapy, taking into account changing trends in antibiotic susceptibility

Purpose: To evaluate polymerase chain reaction (PCR) in diagnosis of Chlamydia trachomatis. Methods: In this study PCR assay was used to amplify the 517bp region of common endogenous plasmid in conjunctival specimens from 178 patients with follicular conjuntivitis, and to amplify the 1000bp region of major outer membrane protein (MOMP) gene of C.trachomatis from 71 of these 178 patients. The PCR-amplified products were visualised by agarose gel electrophoresis and ethidium bromide staining and Southern hybridisation with radio-labelled internal probes. The test was compared with a direct immunofluorescence assay using monoclonal antibody for Chlamydia antigen detection. Results: The plasmid PCR assay was positive in 95 (53.37%) of the 178 specimens processed whereas the Chlamydia antigen was detected in 69 (38.76%) of the 178 specimens by direct immunofluorescence assay (p= 0.005). In the 71 specimens processed for both the PCR assays, plasmid PCR was positive in 52 (73.23%) and MOMP PCR was positive in 43 (60.56%) of the specimens (p=0.10). Thirty seven of these 71 specimens which were positive in both PCR assays were also positive in direct immunofluorescence assay. Conclusion: The PCR assays could detect Chlamydia in a significantly larger number of specimens than conventional antigen detection assay, and being marginally more sensitive, the plasmid PCR assay has the potential for wider use in the diagnosis of trachoma.

Purpose: To assess the effect of tenonectomy in further lowering the intraocular pressure (IOP) when combined with trabeculectomy. Methods: The outcomes and complications in 54 eyes of 54 consecutive patients who underwent trabeculectomy with tenonectomy (group I), and 47 eyes of 47 patients who underwent trabeculectomy without tenonectomy (group II) with matching pre-operative variables were analysed. Results: With a mean follow up of 14.7 ± 8.1 months in group I and 17.4± 9.5 months in group II, the post-operative mean IOP in the former group was lower by 2.2 mmHg compared to the latter group (p=0.024). Complications seen were conjunctival buttonhole (one in each group), encysted bleb (two in group I and one in group II), one persistent choroidal detachment, and one ciliary block glaucoma in group I. Conclusion: Tenonectomy when combined with trabeculectomy, results in a lower IOP

Purpose: To estimate the prevalence of bilateral cataract blindness in persons ≥50 years of age in Ahmedabad district, Gujarat. Methods: A total of 1,962 persons ≥50 years of age were examined in clusters of 45 people or less. The survey design used a systematic random cluster sampling. The sample size was calculated assuming a prevalence of bilateral cataract blindness (visual acuity <3/60) of at least 3% and design effect of 1.6, to estimate the actual prevalence of cataract blindness with a sampling error of ≤20 at 80% confidence level. Visual acuity was assessed with glasses, where available, and pinhole was used for visual acuity <6/18. Distant direct ophthalmoscopy in semidark condition with undilated pupil was used to assess the lens status. Results: The age-gender-adjusted prevalence of all blindness was 2.9% in persons ≥50 years of age (6.7% for visual acuity<6/60). The age-gender-adjusted prevalence of bilateral cataract blindness ( visual acuity <3/60) was 1.2% in persons ≥50 years of age. For visual acuity <6/60, the prevalence was 3.1%. The prevalence in females was slightly higher than in males. The prevalence of bilateral and unilateral aphakia and pseudophakia was high. The cataract surgical coverage, an indicator for coverage and service utilization, was 92.9% for persons and 83.1% for eyes. Conclusion: Rapid assessment of cataract blindness in persons ≥50 years of age can be conducted in urban settings with existing resources and at affodable costs, to provide district level data for assessment and monitoring of cataract intervention programs.