Gullapalli N. Rao

Angle-closure glaucoma in an urban population in southern india: The andhra pradesh eye disease study

OBJECTIVE To assess the prevalence and features of angle-closure glaucoma (ACG) in an urban population in southern India. DESIGN A population-based, cross-sectional study. PARTICIPANTS A total of 2522 (85.4% of those eligible) persons of all ages, including 1399 persons 30 years of age or older, from 24 clusters representative of the population of Hyderabad city. TESTING The participants underwent an interview and detailed eye examination that included logarithm of minimum angle of resolution visual acuity, refraction, slit-lamp biomicroscopy, applanation tonometry, and gonioscopy; pupil dilatation and stereoscopic fundus evaluation was performed if the risk of angle-closure as a result of dilatation was not believed to be imminent. Humphrey threshold 24-2 visual fields (Humphrey Instruments Inc., San Leandro, CA) were performed when indicated by standardized criteria for disc damage or if intraocular pressure (IOP) was 22 mmHg or more. MAIN OUTCOME MEASURES An occludable angle was defined as pigmented posterior trabecular meshwork not visible by gonioscopy in three quarters or more of the angle circumference. Manifest primary angle-closure glaucoma (PACG) was defined as IOP of 22 mmHg or more or glaucomatous optic disc damage with visual field loss in the presence of an occludable angle. An IOP of 22 mmHg or more or glaucomatous optic disc damage in the presence of an occludable angle secondary to an obvious cause was defined as secondary ACG. RESULTS Manifest PACG and occludable angles without ACG were present in 12 and 24 participants, respectively, with age- and gender-adjusted prevalence (95% confidence interval [CI]) of 0.71% (0.34%-1.31%) and 1.41% (0.73%-2.09%) in participants 30 years of age or older, and 1.08% (0.36%-1.80%) and 2.21% (1.15%-3.27%) in participants 40 years of age or older, respectively. With multivariate analysis, the prevalence of these two conditions considered together increased significantly with age (P < 0.001); although not statistically significant, these were more common in females (odds ratio 1.70; 95% CI, 0.82-3.54) and in those belonging to lower socioeconomic strata as compared with middle and upper strata (odds ratio, 1.82; 95% CI, 0.88-3.74). The odds of manifest PACG were higher in the presence of hyperopia of more than 2 diopters ([D]; odds ratio, 3.69; 95% CI, 0.89-15.2). Only four of 12 participants (33.3%) with manifest PACG had been previously diagnosed, and one of 12 (8.3%) had peripheral iridotomy performed previously. Manifest PACG had caused blindness in one or both eyes in five of these 12 participants (41.7%); best-corrected distance visual acuity less than 20/400 in one or both eyes in four patients, and acuity less than 20/200 in one eye in another patient. Most (83.3%) of those with manifest PACG could be classified as having chronic form of the disease. We may have underestimated manifest PACG because visual fields were per- formed only on those with clinical suspicion of optic disc damage. Secondary ACG was present in two participants. CONCLUSIONS The prevalence of PACG in this urban population in southern India is close to that reported recently in a Mongolian population. A large proportion of the PACG in this population was undiagnosed and untreated. Because visual loss resulting from PACG is potentially preventable if peripheral iridotomy or iridectomy is performed in the early stage, strategies for early detection of PACG could reduce the high risk of blindness resulting from PACG seen in this urban population in India.

The epidemiological features and laboratory results of fungal keratitis: a 10-year review at a referral eye care center in South India.

Purpose. To report the epidemiological features and laboratory results of 1,352 cases of fungal keratitis diagnosed at the L.V. Prasad Eye Institute (LVPEI) in south India. Methods. The medical and microbiology records of 1,352 culture proven cases (1,354 eyes) of fungal keratitis diagnosed at the LVPEI between January 1991 to December 2000 was retrospectively reviewed for demographic features, risk factors, seasonal variation, and laboratory findings. Results. Males (962) were affected significantly more (p < 0.0001) than females (390). Of 1,352 patients, 853 (64.4%) were in the younger age group (16–49 years). Ocular trauma predisposed to infection in 736 (54.4%) of 1,354 eyes. There was a higher incidence of fungal keratitis during the monsoon and winter than summer. A fungal cause was established by smears of corneal scrapings in 1,277 (95.4%) eyes. The potassium hydroxide preparation (KOH), Calcofluor white (CFW), Gram-, and Giemsa-stained smears revealed fungus in 1,219 (91.0%), 1,224 (91.4%), 1,181 (88.2%), and 1,139 (85.1%) eyes, respectively. Fusarium (506, 37.2%) and Aspergillus species (417, 30.7%) predominated the hyaline fungal spectrum (1,133) and Curvularia species (39, 2.8%) were the highest among the dematiaceous isolates (218). Conclusions. To the best of our knowledge, this review presents the epidemiological features and laboratory results of the largest series of fungal keratitis ever reported in the literature. Keratomycosis is predominant in young adults with trauma as the major predisposing factor. With fungal keratitis being a major ophthalmologic problem in the tropical regions of the world, data available on the epidemiological features of a large series would greatly help medical practitioners at primary and secondary health care centers in the management of the disease. A simple KOH preparation of corneal scraping alone is highly beneficial in confirming the diagnosis.

Review of epidemiological features, microbiological diagnosis and treatment outcome of microbial keratitis: Experience of over a decade

Purpose: To review the epidemiological characteristics, microbiological profile, and treatment outcome of patients with suspected microbial keratitis. Materials and Methods: Retrospective analysis of a non-comparative series from the database was done. All the patients presenting with corneal stromal infiltrate underwent standard microbiologic evaluation of their corneal scrapings, and smear and culture-guided antimicrobial therapy. Results: Out of 5897 suspected cases of microbial keratitis 3563 (60.4%) were culture-proven (bacterial – 1849, 51.9%; fungal – 1360, 38.2%; Acanthamoeba – 86, 2.4%; mixed – 268, 7.5%). Patients with agriculture-based activities were at 1.33 times (CI 1.16–1.51) greater risk of developing microbial keratitis and patients with ocular trauma were 5.33 times (CI 6.41–6.44) more likely to develop microbial keratitis. Potassium hydroxide with calcofluor white was most sensitive for detecting fungi (90.6%) and Acanthamoeba (84.0%) in corneal scrapings, however, Gram stain had a low sensitivity of 56.6% in detection of bacteria. Majority of the bacterial infections were caused by Staphylococcus epidermidis (42.3%) and Fusarium species (36.6%) was the leading cause of fungal infections. A significantly larger number of patients (691/1360, 50.8%) with fungal keratitis required surgical intervention compared to bacterial (799/1849, 43.2%) and Acanthamoeba (15/86, 17.4%) keratitis. Corneal healed scar was achieved in 75.5%, 64.8%, and 90.0% of patients with bacterial, fungal, and Acanthamoeba keratitis respectively. Conclusions: While diagnostic and treatment modalities are well in place the final outcome is suboptimal in fungal keratitis. With more effective treatment available for bacterial and Acanthamoeba keratitis, the treatment of fungal keratitis is truly a challenge.

Open-angle glaucoma in an urban population in southern india: The andhra pradesh eye disease study

OBJECTIVE To assess the prevalence and features of open-angle glaucoma in an urban population in southern India. DESIGN A population-based cross-sectional study. PARTICIPANTS A total of 2522 persons (85.4% of those eligible) of all ages, including 1399 persons 30 years of age or older, from 24 clusters representative of the population of Hyderabad city. TESTING The participants underwent an interview and detailed eye examination that included logarithm of minimum angle of resolution visual acuity, refraction, slit-lamp biomicroscopy, applanation tonometry, gonioscopy, dilatation, cataract grading, and stereoscopic fundus evaluation. Automated Humphrey threshold 24-2 visual fields (Humphrey Instruments Inc., San Leandro, CA) and optic disc photography were performed when indicated by standardized criteria for disc damage or if intraocular pressure (IOP) was 22 mmHg or more. MAIN OUTCOME MEASURES Definite primary open-angle glaucoma (POAG) was defined as obvious glaucomatous optic disc damage and visual field loss in the presence of an open-angle, and suspected POAG was defined as suspected glaucomatous optic disc damage without definite visual field loss. Ocular hypertension (OHT) was defined as IOP of 22 mmHg or more without glaucomatous optic disc damage or visual field loss in the presence of an open-angle. Glaucomatous optic disc damage or IOP of 22 mmHg or more secondary to an obvious cause and with an open-angle was defined as secondary open-angle glaucoma. RESULTS Definite POAG, suspected POAG, and OHT were present in 27, 14, and 7 participants, respectively, with age- and gender-adjusted prevalence (95% confidence interval) of 1.62% (0.77%-2.48%), 0.79% (0.39%-1.41%), and 0.32% (0.10%-0.78%) in those 30 years of age or older, and 2.56% (1.22%-3.91%), 1.11% (0.43%-1.78%), and 0.42% (0.11%-1.12%) in those 40 years of age or older, respectively. The prevalence of POAG increased significantly with age using multivariate analysis (P < 0.001). Only two of 27 participants (7.4%) with definite POAG had been previously diagnosed and treated, and 66.7% of the previously undiagnosed had IOP less than 22 mmHg. Fourteen of 27 participants (51.9%) with definite POAG had severe glaucomatous damage based on optic disc and visual field criteria, of which five participants (18.5%) had at least one blind eye as a result of POAG (all with best-corrected distance visual acuity less than 20/400 or central visual field less than 10 degrees); the other 13 participants (48.1%) had moderate glaucomatous damage. Because visual fields and optic disc photography were not performed on all participants, the prevalence of POAG may have been underestimated. Secondary open-angle glaucoma was present in one participant as a result of angle recession. CONCLUSIONS The prevalence of open-angle glaucoma in this urban population in southern India is at least as much as that reported recently from white populations in developed countries. However, the vast majority of persons with glaucoma were undiagnosed in this population, and a large proportion of those having definite POAG already had severe glaucomatous damage.

Ciprofloxacin-resistant pseudomonas keratitis

OBJECTIVE To determine ciprofloxacin resistance of corneal isolates of Pseudomonas and to review the clinical response to topical therapy in cases of ciprofloxacin-resistant Pseudomonas keratitis, where medical therapy was begun with 0.3% ciprofloxacin. DESIGN Retrospective noncomparative case series. PARTICIPANTS Medical and microbiology records of 141 culture-proven cases of Pseudomonas keratitis, examined between January 1991 and June 1998, were reviewed retrospectively. METHODS All isolates of the Pseudomonas species from corneal scrapings were tested for their susceptibility to routinely used antibiotics by the Kirby-Bauer disc-diffusion method. The minimum inhibitory concentration of ciprofloxacin was determined by the agar-dilution method for most of the isolates found resistant to ciprofloxacin. Clinical response to initial therapy with 0.3% ciprofloxacin was determined in cases of keratitis caused by ciprofloxacin-resistant Pseudomonas. MAIN OUTCOME MEASURES Resistance of Pseudomonas isolates to ciprofloxacin and clinical response to initial therapy with 0.3% ciprofloxacin. RESULTS By use of the in vitro antimicrobial susceptibility test, 22 cases of keratitis caused by ciprofloxacin-resistant Pseudomonas were identified. The minimum inhibitory concentration of ciprofloxacin for these isolates was > or =16 microg/ml (mean = 43 microg/ml). Gentamicin resistance occurred in 63.6% of isolates also, but 90.9% ciprofloxacin-resistant isolates were susceptible to amikacin. Fifteen (76.7%) of 19 patients who initially received ciprofloxacin did not show any clinical improvement even after 3 days of intensive medical therapy. The infiltrate resolved in all 8 cases where the antibiotic therapy was modified on the basis of susceptibility test. Four eyes were subjected to penetrating keratoplasty, and three were eviscerated following failure of treatment with ciprofloxacin. CONCLUSION True resistance to ciprofloxacin is emerging in ophthalmology even among Pseudomonas isolates; therefore, the empiric treatment of infectious keratitis with ciprofloxacin monotherapy must be critically reviewed at this time.

Is current eye-care-policy focus almost exclusively on cataract adequate to deal with blindness in India?

BACKGROUND Indias National Programme for Control of Blindness focuses almost exclusively on cataract, based on a national survey done in the 1980s which reported that cataract caused 80% of the blindness in India. No current population-based data on the causes of blindness in India are available. We assessed the rate and causes of blindness in an urban population in southern India. METHODS We selected 2954 participants by stratified, random, cluster, systematic sampling from Hyderabad city. Eligible participants were interviewed and given a detailed ocular assessment, including visual acuity, refraction, slitlamp biomicroscopy, applanation intraocular pressure, gonioscopy, dilatation, grading of cataract, stereoscopic fundus assessment, and automated-threshold visual fields. FINDINGS 2522 participants, including 1399 aged 30 years or more, were assessed. 49 participants (all aged > or =30 years) were blind (presenting distance visual acuity <6/60 or central visual field <200 in the better eye). The rate of blindness among those aged 30 years or more, adjusted for age and sex, was 3.08% ([95% CI 1.95-4.21]). Causes included cataract (29.7%), retinal disease (17.1%), corneal disease (15.4%), refractive error (12.5%), glaucoma (12.1%), and optic atrophy (11.0%). 15.7% of the blindness caused by visual-field constriction would have been missed without visual-field examination. Also without visual-field and detailed dilated-fundus assessments, blindness attributed to cataract would have been overestimated by up to 75.8%. If the use of cataract surgery in this urban population was half that found in this study, which simulates the situation in rural India, cataract would have caused 51.8% (39.4-64.2) of blindness, significantly less than the 80% accepted by current policy. INTERPRETATION Much of the blindness in this Indian population was due to non-cataract causes. The previous national survey did not include detailed dilated-fundus assessment and visual-field examination which could have led to overestimation of cataract as a cause of blindness in India. Policy-makers in India should encourage well-designed population-based epidemiological studies from which to develop a comprehensive long-term policy on blindness in addition to dealing with cataract.

Patient characteristics, diagnosis, and treatment of non-contact lens related Acanthamoeba keratitis.

AIM To review the clinical characteristics, diagnosis, and visual outcome in patients with non-contact lens related Acanthamoebakeratitis and compare the findings with reported series of contact lens associated Acanthamoeba keratitis. METHODS Medical and microbiology records of 39 consecutive patients with a diagnosis ofAcanthamoeba keratitis, at a tertiary eyecare centre in India between January 1996 and June 1998, were analysed retrospectively. RESULTS A majority of the patients presented with poor visual acuity and large corneal stromal infiltrates (mean size 38.20 (SD 26.18) mm). A predisposing factor was elicited in 19/39 (48.7%) patients (trauma 15, dirty water splash three, leaf juice one). None of the patients had worn contact lenses. Most patients (26/39 (66.6%)) came from a low socioeconomic background. Complaint of severe pain was not a significant feature and radial keratoneuritis was seen in 1/39 (2.5%) patients. A ring infiltrate was present in 41.1% of cases. A clinical diagnosis of fungal keratitis was made in 45% of the patients before they were seen by us. However, all patients were diagnosed microbiologically at our institute based on demonstration ofAcanthamoeba cysts in corneal scrapings (34/39) and/or culture of Acanthamoeba(34/39). Treatment with biguanides (PHMB, 15/38 (39.4%), PHMB with CHx, 23/38 (60.5%), one patient did not return for treatment) resulted in healing with scar formation in 27 out of 31(87.0%) followed up patients (mean time to healing 106.9 days). Overall visual outcome was poor with no statistical difference between cases diagnosed within 30 days (early) or 30 days after (late) start of symptoms. The visual outcome in cases requiring tissue adhesive (five) and keratoplasty (three) was also poor. CONCLUSIONS This is thought to be the largest series of cases ofAcanthamoeba keratitis in non-contact lens wearers. In such cases, the disease is advanced at presentation in most patients, pathognomonic clinical features are often not seen, disease progression is rapid, and visual outcome is usually poor. Possible existence of Acanthamoeba pathotypes specifically associated with non-contact lens keratitis and unique to certain geographical areas is suggested.

Amniotic membrane transplantation for ocular surface reconstruction

The amniotic membrane, composed of 3 layers, the epithelium, basement membrane, and the stroma, was first used along with the chorion as a biologic membrane to promote healing of skin burns in 1910. In ophthalmology, it was used in 1940 in the management of conjunctival defects. Its revival in the 1990s was due to its ability to reduce ocular surface inflammation and scarring, promote rapid epithelialization due to the presence of growth factors, and antimicrobial properties. This has resulted in its application in several ocular disorders. A review of the literature shows that amniotic membrane is definitely beneficial in some but not all pathology. The future of amniotic membrane transplantation is very exciting, especially in the field of limbal stem cell research. However, further work is needed to elucidate whether it functions merely as a biologic contact lens or whether it has additional benefits.

Keratomycosis : Clinical and microbiologic experience with dematiaceous fungi

OBJECTIVE To assess the significance of dematiaceous fungi in the causation of keratomycosis. DESIGN Retrospective, noncomparative case series. PARTICIPANTS Eighty-eight cases of dematiaceous fungal keratitis seen at the L. V. Prasad Eye Institute, Hyderabad, India from January 1991 through December 1996. INTERVENTION Only culture-proven cases were analyzed. MAIN OUTCOME MEASURES Predisposing factors, clinical characteristics, microbiology, treatment methods, and outcome. RESULTS Of 557 cases of fungal keratitis seen during the study period, dematiaceous fungi were the etiologic agents in 88 (15.7%), after Fusarium in 210 (37.6%) and Aspergillus species in 170 cases (30.4%), respectively. Trauma was the most common predisposing factor (47.7%). Fifty-three eyes (61.3%) had the classical clinical picture of yellow-white, dry raised infiltrate with feathery hyphate edges at initial examination. The characteristic macroscopic pigmentation was seen in only 24 eyes (27.27%). Septate branching fungal filaments were identified in 78 smears (88.63%) on light microscopy, of which 5 (5.7%) also showed the presence of bacteria. Curvularia species dominated the spectrum (22.7%). Treatment was started in 48 eyes with topical antifungal agents, whereas 37 received both oral and topical antifungal agents. Outcome data were available for 68 cases. Forty-nine (72%) responded to medical therapy, whereas 13 eyes required therapeutic penetrating keratoplasty and 6 eyes had to be eviscerated. CONCLUSIONS This is the largest series of keratitis caused by dematiaceous fungi reported to date. It clearly brings out the clinical importance of this group of corneal infections.

Pseudophakic Bullous Keratopathy: Relationship to Preoperative Corneal Endothelial Status

Pseudophakic bullous keratopathy is one of the complications of intraocular lens implantation. A knowledge of the preoperative status of corneal endothelium may help to minimize the incidence of this complication. The preoperative corneal endothelial status of 118 eyes of 102 patients who received Worst-Medallion intraocular lenses more than five years ago was analyzed retrospectively. This data was then correlated with the postoperative clinical status of the cornea. Twelve eyes (10%) underwent penetrating keratoplasty for irreversible corneal edema, and 28 of the remaining eyes (22%) had clinical evidence of peripheral corneal edema. No correlation was found between the preoperative endothelial cell density or the degree of postoperative cell loss and the development of corneal edema. Significant correlation was found between variation in cell size (pleomorphism) and the development of postoperative corneal edema. Greater density of precipitates on endothelium and abnormality in cell shape postoperatively were also frequently seen in corneas that developed edema subsequently.