P Namperumalsamy

Global variation and pattern changes in epidemiology of uveitis

Uveitis, a complex intraocular inflammatory disease results from several etiological entities. Causes of uveitis are known to vary in different populations depending upon the ecological, racial and socioeconomic variations of the population studied. Tropical countries are unique in their climate, prevailing pathogens and in the existing diseases, which further influence the epidemiological and geographical distribution of specific entities. We provide an overview of the pattern of uveitis of 15221 cases in 24 case series reported from several countries over 35 years (1972-2007) and we integrate it with our experience of an additional 8759 cases seen over six years (1996-2001) at a large community-based eye hospital. Uveitis accounted for 0.8% of our hospital-based outpatient visits. The uveitis was idiopathic in 44.6%, the most commonly identified entities in the cohort included leptospiral uveitis (9.7%), tuberculous uveitis (5.6%) and herpetic uveitis (4.9%). The most common uveitis in children below 16 years (616 patients; 7.0% of the total cohort) was pediatric parasitic anterior uveitis, (182 children, 29.5% of the pediatric cohort), whereas the most common uveitis in patients above 60 years (642 patients; 7.3% of the total cohort) was herpetic anterior uveitis, (78 patients, 12.1% of the elderly cohort). Etiologies varied with the age group of the patients. As in other tropical countries, a high prevalence of infectious uveitis was seen in this population.

Proinflammatory cytokines and angiogenic and anti-angiogenic factors in vitreous of patients with proliferative diabetic retinopathy and eales' disease

Purpose: To investigate the mechanism of angiogenesis in proliferative diabetic retinopathy (PDR) and Eales’ disease (ED) on the basis of the levels of proinflammatory cytokines, angiogenic growth factor, and antiangiogenic factor in the vitreous humor. Methods: Twenty-five patients with PDR, 10 patients with ED, and 25 with macular hole (MH) as control subjects were studied. The concentration of the proinflammatory cytokines interleukin-6 (IL-6), IL-8, IL-1&bgr;; chemokine-monocyte chemoattractant protein-1 (MCP-1); angiogenic factor-vascular endothelial growth factor (VEGF); and antiangiogenic factor-pigment epithelium derived factor (PEDF) in the vitreous fluid obtained from the eyes during vitrectomy were measured by sandwich enzyme linked immunosorbent assay (ELISA). Results: IL-6, IL-8, MCP-1, and VEGF levels in the vitreous were significantly higher in PDR (P < 0.0001) and ED (P < 0.0001) than in MH patients. Conversely, the vitreous level of PEDF was significantly reduced in PDR (P < 0.0001) but not in ED. A significant correlation was observed between VEGF and IL-6 in ED patients. Conclusion: The authors demonstrate the importance of VEGF in retinal neovascularization of ED which is an idiopathic inflammatory venous occlusion. Further study is required to understand the interrelationship between VEGF and inflammatory cytokines in PDR and ED.

Clinico-microbiological profile and visual outcomes of post-traumatic endophthalmitis at a tertiary eye care center in South India

PURPOSE To analyze the clinical and microbiological characteristics of eyes with post-traumatic endophthalmitis and factors influencing the visual outcomes in these cases. METHODS We performed a retrospective chart analysis of the clinical and microbiological data of 97 consecutive patients with post-traumatic endophthalmitis presenting to a tertiary eye care hospital in South India. RESULTS Thirty-nine (40.2%) cases were culture-positive, gram-positive cocci (n=24/42, 57.1%) being the commonest isolates. Staphylococcus epidermidis and Pseudomonas aeuruginosa were the commonest single isolates (n=10; 23.8%). Majority of the organisms were sensitive to chloramphenicol (n=27) or ciprofloxacin (n=26). Susceptibility to vancomycin (n=3) and amikacin (n=4) was poor. Cases with negative cultures at presentation were more likely to have improvement in visual acuity compared with culture-positive cases (on multivariate analysis, OR: 3.2, 95% CI: 1.1, 9.0). CONCLUSIONS In this series of post-traumatic endophthalmitis, a high prevalence of resistance of the culture isolates to vancomycin and amikacin was observed.

An outbreak of trematode-induced granulomas of the conjunctiva

PURPOSE To describe the epidemiologic, clinical, and histopathologic features of trematode granulomas of the conjunctiva, eyelid, and anterior chamber in pediatric patients. DESIGN Prospective noncomparative case series. PARTICIPANTS Forty-one children from a southern Indian village with conjunctival granulomas. METHODS The village of Sellananthal was selected for a field visit after analysis of earlier hospital-based allergic conjunctival granuloma cases. Children with ocular diseases were examined, and histories of exposure to assumed risk factors and clinical findings were evaluated. Selected patients were brought to the base hospital for excisional biopsy. Serial sections obtained from the excised nodules were examined for the presence of a parasite. MAIN OUTCOME MEASURES Histopathologic examination of excised conjunctival lesions or response of lesions to local medical therapy. RESULTS In this year-long prospective study, 41 children (16 years or younger; 38 boys and 3 girls) with clinical features of allergic conjunctival granulomas were examined. Thirty-four patients were from a single village located in the southern Indian state of Tamil Nadu; the remaining 7 were from various parts of the same state. All children swam in their villages freshwater pond. Twenty patients with nodules less than 5 mm in diameter received medical treatment; 13 with larger nodules underwent surgical excision of the lesions. Nine of these 13 cases revealed a zonal granulomatous inflammation admixed with eosinophilic leukocytes; 4 of these 9 displayed fragments of the tegument and internal structures of a trematode and Splendore-Hoeppli phenomenon. The remaining 4 of the 13 cases revealed nongranulomatous inflammation made up of lymphocytes, histiocytes, and eosinophils. Eight patients refused surgical treatment. CONCLUSIONS In southern India, one cause of allergic conjunctival granulomas in children seems to be trematode infection. The clustering of cases in a single village and exposure to a village freshwater pond indicate the need for an epidemiologic investigation and study of the parasites life cycle. Sporadic cases from other parts of the state with similar histories of exposure to their local pond or river water suggest a widespread distribution of the etiologic agent.

Spontaneous cataract absorption in patients with leptospiral uveitis

AIMS To describe the occurrence of spontaneous cataract absorption in patients with leptospiral uveitis. METHODS The records of patients with seropositive leptospiral uveitis seen in the uveitis clinic at Aravind Eye Hospital between January 1994 and December 1997 were reviewed retrospectively. RESULTS During the 4 years of the study, 394 eyes of 276 patients with seropositive leptospiral uveitis were identified. Of these, 54 eyes (13.7%) of 41 patients (14.9%) had a final visual acuity of 20/40 or worse attributable to cataract formation. Of these 54 eyes, 41 eyes (75.9%) had visually significant cataract on their first visit to the uveitis clinic, and 13 eyes (24.1%) were noted to have cataract 1–6 months after presentation. Spontaneous absorption was observed in 10 eyes (18.5%) of eight patients (19.5%), and occurred from 6 weeks to 18 months, with a median of 5 months, after the onset of cataract. Of 12 035 consecutive, non-leptospiral, non-traumatic, uveitic, control patients seen during the same 4 years of the study, none showed spontaneous cataract absorption. CONCLUSION Spontaneous cataract absorption occurs in a significant number of patients with leptospiral uveitis, and appears to be unique to this form of non-traumatic uveitis.

Pegaptanib sodium for ocular vascular disease.

Pegaptanib sodium (MacugenTM) is a selective RNA aptamer that inhibits vascular endothelial growth factor (VEGF) 165 , the VEGF isoform primarily responsible for pathologic ocular neovascularization and vascular permeability, while sparing the physiological isoform VEGF 121 . After more than 10 years in development and preclinical study, pegaptanib was shown in clinical trials to be effective in treating choroidal neovascularization associated with age-related macular degeneration. Its excellent ocular and systemic safety profile has also been confirmed in patients receiving up to three years of therapy. Early, well-controlled studies further suggest that pegaptanib may provide therapeutic benefit for patients with diabetic macular edema, proliferative diabetic retinopathy and retinal vein occlusion. Notably, pegaptanib was the first available aptamer approved for therapeutic use in humans and the first VEGF inhibitor available for the treatment of ocular vascular diseases.

Double prepapillary arterial loops associated with superior branch macular artery occlusion.

Prepapillary arterial loops are congenital vascular anomalies that have been noted to cause arterial occlusions. We report a case of superior branch macular artery occlusion in an eye with two independent prepapillary arterial loops, following a Valsalva-like mechanism.