Namperumalsamy Venkatesh Prajna

Comparison of natamycin and voriconazole for the treatment of fungal keratitis.

OBJECTIVE To conduct a therapeutic exploratory clinical trial comparing clinical outcomes of treatment with topical natamycin vs topical voriconazole for fungal keratitis. METHODS The multicenter, double-masked, clinical trial included 120 patients with fungal keratitis at Aravind Eye Hospital in India who were randomized to receive either topical natamycin or topical voriconazole and either had repeated scraping of the epithelium or not. MAIN OUTCOME MEASURES The primary outcome was best spectacle-corrected visual acuity (BSCVA) at 3 months. Other outcomes included scar size, perforations, and a subanalysis of BSCVA at 3 months in patients with an enrollment visual acuity of 20/40 to 20/400. RESULTS Compared with those who received natamycin, voriconazole-treated patients had an approximately 1-line improvement in BSCVA at 3 months after adjusting for scraping in a multivariate regression model but the difference was not statistically significant (P = .29). Scar size at 3 months was slightly greater with voriconazole after adjusting for scraping (P = .48). Corneal perforations in the voriconazole group (10 of 60 patients) were not significantly different than in the natamycin-treated group (9 of 60 patients) (P >.99). Scraping was associated with worse BSCVA at 3 months after adjusting for drug (P = .06). Patients with baseline BSCVA of 20/40 to 20/400 showed a trend toward a 2-line improvement in visual acuity with voriconazole (P = .07). CONCLUSIONS Overall, there were no significant differences in visual acuity, scar size, and perforations between voriconazole- and natamycin-treated patients. There was a trend toward scraping being associated with worse outcomes. Application to Clinical Practice The benefit seen with voriconazole in the subgroup of patients with baseline visual acuity of 20/40 to 20/400 needs to be validated in a confirmatory clinical trial. Trial Registration clinicaltrials.gov Identifier: NCT00557362.

The Antioxidants in Prevention of Cataracts Study: effects of antioxidant supplements on cataract progression in South India.

Aim: To determine if antioxidant supplements (β carotene and vitamins C and E) can decrease the progression of cataract in rural South India. Methods: The Antioxidants in Prevention of Cataracts (APC) Study was a 5 year, randomised, triple masked, placebo controlled, field based clinical trial to assess the ability of interventional antioxidant supplements to slow cataract progression. The primary outcome variable was change in nuclear opalescence over time. Secondary outcome variables were cortical and posterior subcapsular opacities and nuclear colour changes; best corrected visual acuity change; myopic shift; and failure of treatment. Annual examinations were performed for each subject by three examiners, in a masked fashion. Multivariate modelling using a general estimating equation was used for analysis of results, correcting for multiple measurements over time. Results: Initial enrolment was 798 subjects. Treatment groups were comparable at baseline. There was high compliance with follow up and study medications. There was progression in cataracts. There was no significant difference between placebo and active treatment groups for either the primary or secondary outcome variables. Conclusion: Antioxidant supplementation with β carotene, vitamins C and E did not affect cataract progression in a population with a high prevalence of cataract whose diet is generally deficient in antioxidants.

Expression of Innate and Adaptive Immune Mediators in Human Corneal Tissue Infected With Aspergillus or Fusarium

BACKGROUND Filamentous fungi of the genera Aspergillus and Fusarium are major causes of corneal ulcers in the United States and in the developing world and result in significant visual impairment and blindness. METHODS RNA was extracted from 110 patients with corneal ulcers in southern India within 1 week of infection with either Fusarium solani or Aspergillus flavus, and gene expression was determined by quantitative polymerase chain reaction. Posttransplant corneas from later stage disease (>2 weeks after infection) were also examined. RESULTS Expression of Dectin-1, Toll-like receptor 2 (TLR2), TLR4, TLR9, and NOD-like receptor protein (NLRP)3 messenger RNA was elevated >1000-fold compared with uninfected donor corneas, whereas Dectin-2 was constitutively expressed in uninfected corneas. Furthermore, interleukin 1β (IL-1β) expression was elevated >1000-fold, whereas IL-1α expression was not increased. Expression of IL-8, IL-17, and tumor necrosis factor α was also elevated. CD3(+)and CD4(+) T cells were detected in infected posttransplant corneas. Expression of IL-17 and interferon γ was elevated but not that of IL-4. There were no significant differences in the host response between Aspergillus- and Fusarium-infected corneas at any time point. CONCLUSIONS There is a common innate and adaptive immune response to these filamentous fungi, which includes the generation of T-helper 1 and T-helper 17 cells.

Identification of Mutations in the SLC4A11 Gene in Patients With Recessive Congenital Hereditary Endothelial Dystrophy

OBJECTIVE To identify Solute Carrier family 4 (sodium borate cotransporter) member 11 (SLC4A11) gene mutations associated with autosomal recessive congenital hereditary endothelial dystrophy (CHED2). METHODS DNA extraction from blood, polymerase chain reaction amplification, and direct sequencing of all the exons of the SLC4A11 gene were performed for 26 affected members of 20 unrelated families with CHED2. RESULTS Of 10 mutations observed, 6 were novel, 1 of which involves a complete deletion of exon 6, identified for the first time, to our knowledge, in SLC4A11. The mutations cosegregated with the disease phenotype and were absent in 200 ethnically matched control chromosomes analyzed. CONCLUSIONS This study increases the number of SLC4A11 gene mutations and confirms the role of this gene in causing CHED2. Clinical examination did not reveal any considerable variability in disease expressivity in patients carrying SLC4A11 mutations. Extensive linkage analysis may reveal the modifier genes involved in causing CHED2 in the SLC4A11 mutations unidentified in 9 families. CLINICAL RELEVANCE In India, there is a high frequency of CHED2, possibly related to consanguineous marriages. Counseling could be provided to explain the drawbacks of consanguineous marriages to assist in reducing this devastating disorder.

A randomised clinical trial comparing 2% econazole and 5% natamycin for the treatment of fungal keratitis

Aim: To compare 2% econazole and 5% natamycin in the management of fungal keratitis. Methods: A randomised clinical trial was performed using 2% econazole or 5% natamycin as the two treatment arms on patients presenting with culture positive fungal keratitis to the cornea service at Aravind Eye Care System, Madurai, India. Results: 116 patients were recruited, and 112 continued in the study. There were no significant differences between the two arms at baseline or for success (defined as a healed or healing ulcer) at final visit (p = 0.79). Conclusions: 2% Econazole appears to be as effective as 5% natamycin for the management of fungal keratitis.

Activity of antibiotics against Fusarium and Aspergillus

Background/aims: To study the susceptibility of Fusarium and Aspergillus isolated from keratitis to amoxicillin, cefazolin, chloramphenicol, moxifloxacin, tobramycin and benzalkonium chloride (BAK). Methods: 10 isolates of Fusarium and 10 isolates of Aspergillus from cases of fungal keratitis at Aravind Eye Hospital in South India were tested using microbroth dilution for susceptibility to amoxicillin, cefazolin, chloramphenicol, moxifloxacin, tobramycin and BAK. The minimum inhibitory concentration (MIC) median and 90th percentile were determined. Results: BAK had the lowest MIC for both Fusarium and Aspergillus. Chloramphenicol had activity against both Fusarium and Aspergillus, while moxifloxacin and tobramycin had activity against Fusarium but not Aspergillus. Conclusions: The susceptibility of Fusarium to tobramycin, moxifloxacin, chloramphenicol and BAK and of Aspergillus to chloramphenicol and BAK may explain anecdotal reports of fungal ulcers that improved with antibiotic treatment alone. While some of the MICs of antibiotics and BAK are lower than the typically prescribed concentrations, they are not in the range of antifungal agents such as voriconazole, natamycin and amphotericin B. Antibiotics may, however, have a modest effect on Fusarium and Aspergillus when used as initial treatment prior to identification of the pathological organism.

In Vitro Natamycin Susceptibility of Ocular Isolates of Fusarium and Aspergillus Species: Comparison of Commercially Formulated Natamycin Eye Drops to Pharmaceutical-Grade Powder

ABSTRACT The Clinical and Laboratory Standards Institute susceptibility method prohibits the use of pharmacy preparations, but obtaining pure powders is difficult. The activity of natamycin against isolates of Aspergillus and Fusarium species isolated from keratitis was assessed by using both powder and pharmacy eye drop preparations. Eye drop preparations may be a viable option for testing natamycin activity.

Corticosteroids for bacterial corneal ulcers.

Aims: The aim of the study was to conduct a preliminary clinical trial to assess whether adjunctive topical corticosteroids improve outcomes in bacterial keratitis and, if no difference was found, to determine the feasibility and sample size necessary for conducting a larger trial to answer this question. Methods: In this single centre, double-masked clinical trial, 42 patients with culture-confirmed bacterial keratitis at Aravind Eye Hospital in India were randomised to receive either topical prednisolone phosphate or placebo. All patients received topical moxifloxacin. The primary outcome was best spectacle-corrected visual acuity (BSCVA) at 3 months, adjusting for enrolment BSCVA and arm. Other pre-specified outcomes included re-epithelialisation time, infiltrate/scar size and adverse events. Results: Compared with placebo, patients in the steroid group re-epithelialised more slowly (hazard ratio 0.47, 95% CI 0.23 to 0.94). There was no significant difference in BSCVA or infiltrate/scar size at 3 weeks or 3 months. To have 80% power to detect a two-line difference in acuity, 360 cases would be required. Conclusions: Although corticosteroid treatment resulted in a statistically significant delay in re-epithelialisation, this did not translate to a significant difference in visual acuity, infiltrate/scar size or adverse events. To assess the effect of steroids on acuity, a larger trial is warranted and feasible. Trial registration number: NCT00324168

Comparative proteomics of human male and female tears by two-dimensional electrophoresis

The proteomic profile of tear fluid is of fundamental interest in eye research. In this study we optimized the tear sample preparation method for two-dimensional (2D) analysis and determined the protein profile of tear fluid from healthy males and females. To find the most efficient method for tear sample preparation, four widely applied precipitation methods and ultrafiltration were compared. Of these, TCA precipitation & ultrafiltration resulted in efficient sample concentration and desalting. Use of a nonionic wetting agent, Tergitol NP7, in rehydration solution during isoelectric focusing improves protein separation in 2D gel electrophoresis considerably. Using this optimized method, tear protein profile was analyzed from healthy males and females. Of the thirty six tear proteins identified by LC-MS/MS, seven tear proteins were found to be significantly up regulated in the healthy female tear samples when compared to the male tear samples. These results indicate that the tear protein profile differs with respect to the sex. Mostly, the up regulated proteins are involved in the local immune defense; implying that there may be a sex difference in the ability to defend against infection at the anterior segment of the eyes of normal individuals.

Identification of Human Corneal Epithelial Stem Cells on the Basis of High ABCG2 Expression Combined With a LargeN/C Ratio

Till date there is no exclusive marker for human corneal epithelial stem cells (CESCs). In this study, our strategy is to combine high expression of ABCG2, a putative SC marker with high N/C ratio to develop a specific method for identification of CESCs.