Hn Madhavan

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.

Newer Emerging Pathogens of Ocular Non-Sporulating Molds (NSM) Identified by Polymerase Chain Reaction (PCR)-Based DNA Sequencing Technique Targeting Internal Transcribed Spacer (ITS) Region

Purpose: To apply Polymerase Chain Reaction (PCR)-based DNA sequencing targeting Internal Transcribed Spacer (ITS) region for identification of non-sporulating molds (NSM) to species level which formed 12% of ocular isolates of fungi in a tertiary eye hospital in South India. Materials and Methods:Fifty ocular filamentous fungal NSM isolates recovered from 45 patients were included in the study. PCR-based DNA sequencing technique targeting ITS region was applied to identify NSM. Results: PCR-based DNA sequencing revealed 23 established pathogens involving 8 genera (Aspergillus, Fusarium, Bipolaris, Pythium, Cochilobolus, Exserohilum, Pseudoallescheria, and Scedosporiumspecies) and 27 emerging pathogens involving 7 genera (Botryosphaeria Lasiodiplodia species, Thielavia tortuosa, Glomerulla singulata, Macrophomina phaseolina, Rhizoctonia bataticola, and Podosporaspecies) reported for the first time in literature related to ocular infections. Fifteen (30%) patients with fungal keratitis caused by NSM failed to respond to standard antifungal therapy. Conclusion: PCR-based DNA sequencing technique is a rapid, reliable, and valuable tool to identify 54% of NSM as newer potential pathogens of fungi causing ocular mycoses.

Ex vivo cultivation of corneal limbal epithelial cells in a thermoreversible polymer (Mebiol Gel) and their transplantation in rabbits: an animal model.

We evaluated the efficacy of autologous expanded corneal epithelial cell transplants derived from harvested limbal biopsy cultured on a thermoreversible polymer (Mebiol Gel) for the management of unilateral limbal stem cell deficiency (LSCD). Corneal limbal biopsies from 12 rabbits were cultured on a thermoreversible polymer Mebiol Gel at 37 degrees C. Cells were harvested from the dishes after 3 weeks by reducing temperature to 4 degrees C. Autologous transplantation was undertaken to reconstruct the experimentally induced limbal stem cell deficiency in the rabbit eyes. The corneas of both eyes of all rabbits were harvested later for molecular studies. Reparative surgery was a total success in seven rabbits, partial success in two, and failure in three eyes. Histology of the seven successful eyes showed the successful growth of the corneal epithelium. Immunohistochemistry and reverse transcriptase polymerase chain reaction showed the cornea phenotype and stem cell-associated markers in the limbus of the seven successful eyes, indicating the homing of these cells into limbus. In the three failure cases and in the two control rabbit eyes, used in the study, histology showed presence of goblet cells and vascularization in the stroma with abortive formation of corneal epithelium. Our results suggest that transplantation of autologous limbal epithelial cells grown in thermoreversible polymer Mebiol Gel may restore a nearly normal ocular epithelial surface in eyes with unilateral LSCD.

Chikungunya virus iridocyclitis in Fuchs' heterochromic iridocyclitis

We are reporting a case of bilateral Fuchs’ heterochromic iridocyclitis with chikungunya virus infection in the left eye. A 20-year-old female was presented with a past history of fever suggestive of chikungunya with bilateral Fuchs’ heterochromic iridocyclitis and complicated cataract. She had a tripod dendritic pattern of keratic precipitates by confocal microscopy in the left eye with a stippled pattern of keratic precipitates in both eyes. The real-time polymerase chain reaction (RT-PCR) assay in the aqueous humor detected 98 copies/ml of chikungunya virus RNA. The patient underwent clear corneal phacoemulsification with in-the-bag intraocular lens implantation in the left eye with a good visual outcome. This is the first report where the presence of chikungunya virus RNA has been associated with a case of bilateral Fuchs’ heterochromic iridocyclitis.

Application of semi-nested polymerase chain reaction targeting internal transcribed spacer region for rapid detection of panfungal genome directly from ocular specimens

BACKGROUND The incidence of fungal endophthalmitis has dramatically increased in recent years and rapid detection of fungi using nucleic acid-based amplification techniques is helpful in management. AIM To evaluate semi-nested polymerase chain reaction (PCR) targeting internal transcribed spacer (ITS) region for detection of panfungal genome in ocular specimens. STATISTICAL ANALYSIS USED Z test for two proportion. MATERIALS AND METHODS Standardization of PCR targeting ITS primers was carried out by determining analytical sensitivity and specificity. The sensitivity and specificity of PCR was determined by serial tenfold dilutions of C. albicans (ATCC 24433) DNA and DNA extracts of laboratory isolates of Aspergillus fumigatus, Fusarium lichenicola (4), other fungal and closely related bacterial strains and also human DNA. Semi-nested PCR was applied onto a total of 168 ocular specimens with clinically suspected fungal etiology during 2003-2005. RESULTS AND CONCLUSIONS PCR was specific and sensitive to detect 1fg of fungal DNA with ITS primers. PCR detected fungal genome in 90 (53.57%) in comparison with the conventional technique, positive in 34 (20.23%) by smear examination and in 42 (25%) by culture. The increase in clinical sensitivity by 28.57% using PCR was found to be statistically significant { P < 0.001 using Z test for two proportion}. The accuracy of the test was found to be 70.85%. PCR proved to be a rapid diagnostic technique for detection of panfungal genome directly from clinical specimens.

Efficacy and safety of 1% rimexolone versus 1% prednisolone acetate in the treatment of anterior uveitis – a randomized triple masked study

Purpose: To evaluate the efficacy and safety of 1% rimexolone versus 1% prednisolone acetate ophthalmic suspension in the treatment of anterior uveitis. Methods: A randomised triple masked, parallel comparison of rimexolone and prednisolone acetate ophthalmic suspensions was carried out on 78 patients with acute, chronic and recurrent anterior uveitis. Treatment regimen included instillation of one or two drops of drug one hourly through the waking hours during the first week, two hourly in the second week, four times a day in the third week, two times a day for the first 4 days and once a day for the 3 days in the last week. The patient was clinically evaluated on the 3–4th, 7–10th, 14th, 21st and 28th days. The patient was also reviewed on the 30th day. Anterior chamber cells and flare reactions were compared for evaluating the efficacy of the drugs. Result: Rimexolone is as effective as prednisolone acetate ophthalmic suspension in the treatment of anterior uveitis. The largest difference found was 0.1 in the flare reaction (statistically insignificant; p=0.3) and 0.2 score units (statistically significant; p=0.01) in the cells. Overall, comparison of the drugs shows no clinical significance in the treatment of anterior uveitis by either drug. Difference in intraocular pressure (IOP) was also statistically insignificant (p>0.05). However, three patients in the prednisolone acetate group and 1 patient from the rimexolone group showed a rise in IOP. Conclusion: Rimexolone 1% ophthalmic suspension is as effective as and safer than prednisolone acetate 1% ophthalmic suspension in the treatment of anterior uveitis.

Diagnostic Value of Specific Local Antibody Production and Nucleic Acid Amplification Technique-Nested Polymerase Chain Reaction (nPCR) in Clinically Suspected Ocular Toxoplasmosis

Objective: The study was to evaluate the diagnostic efficacy of nested polymerase chain reaction (nPCR) using primers targeting B1 gene of Toxoplasma gondii (T. gondii) with Witmer Desmonts coefficient (WDC) technique in intraocular fluids of clinically suspected toxoplasma retino choroiditis (TRC) patients. Materials and Methods: Two hundred and seventy eight specimens from 189 patients (25 TRC patients and 164 controls) consisting of 189 serum samples and 89 intraocular fluids were included in the study. The clinical specimens were categorized into TRC patients (typical TRC lesion-group I & atypical TRC lesion-group II) and controls (voluntary blood donors-group III, patients undergoing uncomplicated cataract surgery-group IV, ocular inflammation of nontoxoplasma origin-group V). Detection of anti T. gondii IgG and IgM antibodies in serum samples and intraocular fluids were performed and WDC was calculated by the standard method. The standardized nPCR was applied on the 89 intraocular fluids. Results: Clinical diagnosis of TRC based on fundus examination was considered to be the “gold standard.” Anti T. gondii IgG/IgM antibodies were detected in serum by ELISA in 95.6% of 25 clinically suspected TRC patients (gp I and II), 28% of gp III, 40.4% of gp IV, and in 58.3% of gpV. Witmer Desmonts coefficient was positive in 72.7% (16/22) and nPCR in 59.1% (13/22) of TRC patients (gp I and II). Both WDC and nPCR were negative in all the controls. The difference in sensitivity of WDC and nPCR was not statistically significant (p = 0.5247). Conclusions: Though both WDC and nPCR were reliable diagnostic techniques for ocular toxoplasmosis, nPCR is more acceptable because of the amount of specimen(s) required, rapidity, cost effectiveness, and direct evidence of T. gondii DNA in the intraocular fluids.

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.

Chronic microsporidial stromal keratitis in an immunocompetent, non-contact lens wearer.

An 82-year-old healthy man with unilateral chronic stromal keratitis, initially diagnosed to have viral keratitis and refractory to medical therapy, showed numerous oval, microsporidial organisms, measuring 4-5 m in length in the corneal biopsy. Penetrating keratoplasty, followed by treatment with systemic albendazole and topical propamidine isethionate resulted in resolution of the infection. Electron microscopy of the keratoplasty specimen demonstrated sporoblasts with diplokaryotic nuclei and multiple coils of the filament. The light and electron microscopic features were consistent with microsporidial keratitis.

Necrotizing nocardial scleritis with intraocular extension: a case report.

Nocardial scleritis is an uncommon but potentially sight-threatening condition with only four cases reported in the literature. Predisposing factors in these patients included cataract surgery in two (1,2), scleral buckling in one (3), and trauma with vegetable matter in the other (4). We report here a case of nocardial scleritis in the absence of predisposing ocular surgery or trauma. Despite intensive medical and surgical therapy, the necrotizing scleritis progressed with intraocular extension of the infection.