A.E. George

Ocular lesions associated with HIV infection in India: a series of 100 consecutive patients evaluated at a referral center

PURPOSE To document the ocular disorders seen in patients known to be infected with human immunodeficiency (HIV) virus at a referral eye clinic in India. METHODS The first 100 individuals known to be HIV-positive at a referral eye clinic between 1993 and 1998 were enrolled in a prospective study. They underwent complete ocular and systemic evaluation. RESULTS Most of the patients (76%) were in the 20-to 40-year age group. Heterosexual exposure to commercial sex workers was the most common risk factor (70%) for HIV infection. Cytomegalovirus (CMV) retinitis (17%) and HIV retinopathy (15%) were the most common HIV-associated ophthalmic lesions. Pulmonary tuberculosis (67%) and oropharyngeal candidiasis (66%) were the most commonly associated systemic infections. Ocular involvement was most common in children who contracted the disease through perinatal transmission (66.7%) and in homosexual patients (60%). Ocular involvement was comparatively less common in patients who contracted the disease through blood transfusions (33%) or exposure to commercial sex workers (24.3%). CONCLUSIONS This study shows that the spectrum of ocular lesions associated with HIV infection in India is different from that seen elsewhere in the world. The prevalence of CMV retinitis and HIV retinopathy is lower in India, and there have been no cases of ocular Kaposi sarcoma. Adnexal infections, albeit rare, were seen in our series. The nonavailability and cost of therapy influenced the visual prognosis in these patients.

Ocular lesions in 1,000 consecutive HIV-positive patients in India: a long-term study

BackgroundOcular lesions in patients on highly active antiretroviral therapy (HAART) have shown changes in disease prevalence and pattern. Although they have been described in the Western population, there are not many such studies in the HAART era from India. This study aims to present the clinical profile, systemic correlation, and visual outcome in HIV-positive patients in relation to HAART in comparison with pre-HAART Indian studies and current Western data. Ocular findings and systemic correlation in 1,000 consecutive patients with HIV seen at a tertiary eye care center were analyzed. This study uses a prospective observational case series design.ResultsAge range of the patients was 1.5 to 75 years. Ocular lesions were seen in 68.5% of the patients (cytomegalovirus (CMV) retinitis was the commonest). The commonest systemic disease was pulmonary TB. Mean interval between HIV diagnosis and onset of ocular lesions was 2.43 years. CD4 counts range from 2 to 1,110 cells/mm3. Immune recovery uveitis (IRU) was seen in 17.4%. Interval between HAART initiation and IRU was 4 months to 2.5 years. Recurrence of ocular infection was seen in 2.53% (post-HAART) and > 20% (pre-HAART). Overall visual outcome showed improvement in about 14.3% and was maintained in 71.6% of the patients.ConclusionsCMV retinitis is the commonest ocular opportunistic infection in India, even in the HAART era. Newer manifestations of known diseases and newer ocular lesions are being seen. In contrast to Western studies, in our patients on HAART, ocular lesions do not always behave as in immunocompetent individuals. Ocular TB needs to be kept in mind in India, as well as other neuro-ophthalmic manifestations related to cryptococci, especially in gravely ill patients. Occurrence and frequency of various ocular opportunistic infections in developing nations such as India have significant variations from those reported in Western literature and need to be managed accordingly.

Ocular and systemic lesions in children with HIV.

The spectrum of ocular lesions in children with HIV infection is different from that seen in adults. Ocular lesions in pediatric AIDS patients have not been studied in India. We analyzed the clinical profile, demographic characteristics, ocular and systemic lesions in children with AIDS seen in a referral eye institute in India. The clinical profile and demographic features were studied and complete ocular examination was done. Systemic findings were evaluated at an AIDS care center and recorded in a precoded proforma. Out of the 218 cases of HIV infection seen at our hospital between December 1993 and October 1999, 12 (5.50%) were below 15 years of age. Seven (58.33%) were males and 5 (41.66%) were females with the mean age of 6.5 years and median age of 6.2 years. Vertical transmission was the most common mode of infection (58.33%). Seven (58.33%) of these patients had systemic infection, the most common being pulmonary tuberculosis (42.85%). Ocular lesions were found in 6 (50%) patients. The most common ocular lesions were anterior uveitis and cytomegalovirus retinitis (CMV) (33%) followed by retinal detachment (16.66%) and vitreous hemorrhage (16.66%). High prevalence of ocular lesions in pediatric AIDS patients in India in a referral eye centre was observed. The most common lesions were anterior uveitis followed by CMV retinitis. The management in such cases was often challenging in a developing country like India.

Simulation of Sand Transport in a Horizontal Well

An important application of horizontal well technology in Canada is recovering oil from marginal heavy oil reservoirs in Saskatchewan and Alberta. These reservoirs are often poorly consolidated ; as a result, recovery operations are susceptible to sand production which potentially poses a serious problem as the sand particles deposit and partially block the horizontal well. This work presents a mathematical treatment of the transport process of oil and sand particles inside a horizontal well. In particular, the model described in this paper formulates the transport process mechanistically. Equations of mass and momentum conservation for the solid phase (sand particles) and the fluid phase (oil) are formulated. The oil is assumed to be Newtonian, and the sand particles are assumed to be spherical in shape and uniform in size. In addition, the model incorporates empirical correlations to describe the interaction between the two phases. The system of equations is solved numerically to determine the distribution of sand particles and oil, their pressure and velocity distributions as a result of the presence of a constriction inside the horizontal well. Simulation results obtained provide insight into the mechanisms involved in the transport process, thus enhance the understanding of the flow of sand and oil inside a horizontal well. This, in tum, yields some guidelines for production operations involving horizontal wells in unconsolidated and poorly consolidated reservoirs.

Tubercular Sclerouveitis Masquerading as an Ocular Tumor: A Case Report

Purpose: To report the diagnosis of a case of tubercular sclerouveitis, which masqueraded as an ocular tumor. Design: Case report. Methods: Retrospective medical chart review including serological, radiological, and histopathological investigative results. Results: A patient presented with recurrent episodes of sclerouveitis in his right eye. Serological investigations for infective and connective tissue disorders were negative. Radiological investigation was suggestive of a scleral perforation. The eye was enucleated and histopathological examination showed chronic inflammation. Polymerase chain reaction of the ocular tissue was positive for IS1160 for Mycobacterium tuberculosis. Conclusion: Infective scleritis should be suspected in cases of scleritis that progress despite treatment. Polymerase chain reaction is instrumental in diagnosing challenging cases.

Incidence and Management of Glaucoma in Vogt Koyanagi Harada Disease.

Purpose:To analyse the prevalence, incidence, and risk factors of glaucoma in Vogt Koyanagi Harada (VKH) disease and study the changes in visual acuity and intraocular pressure (IOP) with treatment. Materials and Methods:Retrospective chart analysis of 448 eyes of 224 patients of Indian origin diagnosed with VKH disease from January 1990 to December 2013, who had a minimum follow-up of 3 months was performed. Results:Seventy-one eyes (15.8%) developed sustained elevation in IOP. The prevalence of glaucoma at presentation was 15.8% and the cumulative incidence of glaucoma was 11.7%. The mechanisms of glaucoma were open-angle glaucoma in 46 eyes, (64.8%), angle closure in 21 eyes (29.6%), and of combined mechanisms in the remainder (4 eyes, 5.6%). Acute angle-closure crisis developed in 9 eyes (12.6%). Uveal effusion (odds ratio 9.47; confidence interval, 4.08-20.03) and increased number of recurrences (odds ratio 1.31; confidence interval, 1.13-1.53) were found to be significant risk factors for the development of glaucoma. Successful control of IOP was achieved in 64% at 12 months using medical/ laser treatment for glaucoma and was 50 % at 12 months following surgical management. Conclusions:Glaucoma is a frequent complication of uveitis in VKH disease. Presence of uveal effusion and increased number of recurrences of inflammation are significant risk factors.

Paediatric choroidal neovascular membrane secondary to toxoplasmosis treated successfully with anti-vascular endothelial growth factor

The purpose of this report was to evaluate the role anti-VEGF in management of CNVM secondary to ocular toxoplasmosis. Young female diagnosed as a case of bilateral ocular toxoplasmosis presented with complaints of diminution of vision in the right eye. Fundus examination showed an active CNVM adjacent to toxoplasmosis scar. In view of active CNVM, patient was administered intravitreal ranibizumab. A total of 2 injections of intravitreal ranibizumab were given. Fundus showed a scarred CNVM adjacent to the toxoplasma scar with no clinical signs of activity. Anti-VEGF therapy has been successfully used to improve visual and anatomical outcome in juxtafoveal (deleted subfoveal)CNVM secondary to toxoplasmosis.

Analysis of Scaled Steamflood Experiments

Canadas heavy oil and oil sands deposits are estimated to contain as much oil as the conventional oil resources of the entire world. Heavy oil deposits, in particular those in southwestern Saskatchewan and southeastern Alberta, represent an attractive target for exploitation as the in-place heavy oils are mobile under reservoir conditions. These reservoirs typically have good porosity, high permeability (1-5 darcies), high initial oil saturation (> 65%), and the oil viscosity ranges from 1000 to 1500 cp; but the pay thickness is between 3-10 metres and often underlain by bottom water zone (bottom water). Primary recovery in these reservoirs typically amounts to less than 5% of the initial oil in place (IOIP). In a few cases, where the conditions are more favorable, use of horizontal wells has increased primary recovery to 15-20% prior to water coning. This still leaves up to 80% of the oil in place unrecovered. Using a scaled physical model of the Aberfeldy reservoir (Saskatchewan), steamflood experiments were performed to investigate steamflood recovery performance using horizontal injection and production wells. This paper reports results of analyses made for two types of experiments; one was for steamflooding a homogeneous reservoir (base case run), and the other was for steamflooding a reservoir having a 20% net pay bottom water layer. Analyses include comparisons between steam zone volumes obtained experimentally and theoretically, and heat distribution (heat injected, heat loss, heat accumulated, and heat produced) during a steamflood. The scale up of laboratory results to predict prototype field performance is also presented. The analytical heat loss model, based on the simultaneous solution of two heat conduction equations, showed a 3.1% difference from experimental results. Scaled-up experimental data, for the base case run (horizontal injector and producer), showed that approximately 20% of the initial oil in place (IOIP) was recovered after 0.8 PV of steam (CWE) had been injected. For a reservoir having a 20% net pay bottom water, after 0.8 PV of steam (CWE) had been injected, heat accumulated in the formation was found to be approximately 3776.6 kJ. Of this, 2000 kJ of energy was stored in the matrix, and the fluids in the reservoir contained 1776.6 kJ of energy. The increase in the oil recovery for a reservoir having 20% net-pay bottom water layer depends on how the energy contained in the fluids is managed.

Clinical Profile of Scleritis in Children

ABSTRACT Purpose: To describe the clinical pattern of scleritis in patients ≤16 years of age at a tertiary care eye hospital in India. Methods: The medical records of 24 eyes of 20 children with scleritis were included in this retrospective study. Collected data included age, subsets of uveitis, best corrected visual acuities (BCVA), detailed laboratory investigations and treatment. Results: Mean age at presentation was 12.2 ± 2.5 years. Scleritis was unilateral in 80% patients and an equal gender distribution was observed. Posterior scleritis (41.7%) was the most common subtypes of scleritis and nodular scleritis was the most common type of anterior scleritis (33.3%). Necrotizing scleritis was seen in 16.7% eyes. Tuberculosis was the only systemic association and found in three (15%) patients. Conclusions: Clinical profile of scleritis in children can be different from that of adults.

Uveitis in Patients with Retinitis Pigmentosa: 30 Years’ Consecutive Data

ABSTRACT Purpose: To describe the clinical pattern of uveitis in patients with retinitis pigmentosa (RP) at a tertiary care eye hospital over a period of 30 years. Methods: The medical records of 32 eyes of 22 patients of RP with uveitis were included in this study. Collected data included age, subsets of uveitis, best corrected visual acuities (BCVA), detailed laboratory investigations, and treatment. Results: Mean age at presentation was 53.4 ± 18.8 years, and mean age of diagnosis of RP was 39.2 ± 21.4 years. Uveitis was bilateral in 10 (45.5%) patients. The most common of uveitis in current study was anterior uveitis (56.2%), followed by intermediate uveitis (43.8%). Cataract developed in 12 (37.5%) eyes, and three eyes had raised intraocular pressure. Ten patients (45.5%) required oral steroid, and one patient required oral methotrexate. Conclusions: Uveitis in RP patients is rare, but not uncommon. Coexistence of these disorders might support the inflammatory pathway in etiology of RP.