Venkatapathy Narendran

Diabetic retinopathy among self reported diabetics in southern India: a population based assessment

Aims: To estimate the prevalence of diabetic retinopathy among self reported diabetics in a population of southern India. Methods: A cross sectional sample of subjects aged 50 years and older was selected using a cluster sampling technique from Palakkad district of Kerala state. Eligible subjects were identified through a door to door survey. Ocular examinations including visual acuity and anterior and posterior segment examinations were performed at preselected sites within clusters. History of diabetes was elicited, and height, weight, and blood pressure were measured for all subjects. Results: Among the 5212 examined people (92% response rate), 68 (26.2%) of 260 people with self reported history of diabetes had diabetic retinopathy. The age-sex adjusted prevalence of diabetes among people aged 50 years and older was 5.1% (95% CI 3.9, 6.3, deff 4.33) and of diabetic retinopathy among the diabetics was 26.8% (95% CI: 19.2, 34.4, deff 1.99). Non-proliferative diabetic retinopathy (94.1%) was the most common form of retinopathy seen. Two eyes were blind (presenting vision <6/60) as a result of retinopathy. Conclusion: Preventive strategies have to be evolved to ensure that blindness due to diabetic retinopathy does not become a public health problem in India. Further studies are required to understand the risk factors for retinopathy and vision loss in this population.

Intravitreal bevacizumab (Avastin) for post laser anterior segment ischemia in aggressive posterior retinopathy of prematurity

Aggressive posterior retinopathy of prematurity (formerly known as fulminate/type II/rush disease) occurs in zone 1 or posterior zone 2. Treatment involves extensive near confluent laser ablation of a large area of avascular retina. Anterior segment ischemia is a rare complication that can occur due to injury to the long posterior ciliary arteries in the horizontal meridians during aggressive posterior laser treatment. The outcome of this rare complication is very poor. This case describes a favorable outcome of intravitreal injection of bevacizumab (Avastin) in a case of anterior segment ischemia.

Aggressive posterior retinopathy of prematurity in large preterm babies in South India

Objective To describe aggressive posterior retinopathy of prematurity (APROP) in a subset of premature babies, having gestational age (GA) of ≥28 weeks and birth weight (BW) of ≥1000 g. Design Retrospective observational case series. Setting and Patients Case records of 99 babies, who were diagnosed to have APROP between July 2002 and October 2010 were reviewed. Fundus fluorescein angiography (FFA) was carried out in 19 babies. Results The mean GA was 31.7 weeks (range 28–35 weeks) and mean BW was 1572 g (range 1000–2310 g). All these babies received supplemental unblended oxygen 3 days or longer after birth. Of the 52 babies who had an eye exam in the neonatal intensive care unit prior to discharge, 35 babies had loss of vascularised retina from zone II to zone I and four babies from zone III to zone I, when examined as an outpatient. FFA revealed large geographic areas of vaso-obliteration (more than 30 disc areas) posterior to the shunt vessels within vascularised retina. Conclusions Features of severe capillary bed loss in the vascularised retina were seen in our cases. Oxygen could be a precipitating factor in causing this retinopathy of prematurity in large babies.

Severe retinopathy of prematurity in big babies in India: history repeating itself?

ObjectiveTo describe the characteristics of babies with severe retinopathy of prematurity (ROP) attending a tertiary referral eye hospital in South India.MethodsData on consecutive preterm infants with severe ROP presenting between July 2002 and October 2007 were retrieved from medical records. Severe ROP was defined as high risk prethreshold disease or worse.Results144 babies with severe ROP were divided into two groups: group 1 had high risk prethreshold or threshold ROP while group 2 had stages 4 or 5 ROP. The overall mean gestational age was 30.7 weeks (range 25–35 weeks) and the mean birth weight was 1410 g (range 650–2310 g). Most babies had received unmonitored supplemental oxygen (ascertained through discussion with the treating pediatricians).ConclusionMore bigger and mature babies are developing severe ROP in South India than in industrialized countries. The characteristics of babies affected are similar to those seen during the first epidemic of ROP which occurred during the 1950s in Europe and North America. Guidelines on oxygenation and screening policies should be jointly developed by pediatricians and ophthalmologists to end this epidemic of avoidable blindness in India.

Screening for retinopathy of prematurity-a comparison between binocular indirect ophthalmoscopy and RetCam 120

AIM To compare the photographic screening for retinopathy of prematurity (ROP) using RetCam 120 with binocular indirect ophthalmoscope (BIO), which is the current gold standard. SETTING AND DESIGN Prospective, comparative study. MATERIALS AND METHODS A total of 87 RetCam examinations were performed on 27 premature babies. They were stored in a separate file after deleting the identifying information. At the same visit using the BIO with scleral depression, an experienced vitreoretinal surgeon evaluated the fundus in detail. A masked examiner then evaluated the RetCam photographs for presence or absence of ROP, the stage and zone of the disease and the presence or absence of plus disease. These data were then compared with the BIO findings to determine the sensitivity, specificity and the positive and negative predictive values of the method. RESULTS ROP was detected in 63 of 87 examinations by BIO and in 56 of 87 RetCam examinations. Nine RetCam examinations were false-negative and two were false-positive. Sensitivity of RetCam was 85.71% (54/63) and specificity was 91.66% (22/24). The positive and negative predictive values were 96.43% and 70.97% respectively. CONCLUSION Nine cases having ROP were missed by the RetCam. All these cases were either in zone 3 or the outer part of zone 2, which later regressed. These were missed mostly because of the restricted mobility of the camera head caused by its size and the barrier caused by the lid speculum arms. No case of threshold ROP was missed. RetCam may replace BIO for screening of ROP.

Fusarium keratitis in South India: causative agents, their antifungal susceptibilities and a rapid identification method for the Fusarium solani species complex.

Seventy Fusarium isolates derived from human keratomycosis were identified based on partial sequences of the β‐tubulin (β‐TUB) and translation elongation factor 1α (EF‐1α) genes. Most of the isolates were confirmed as members of the F. solani species complex (75.71%), followed by the F. dimerum species complex (8.57%), the F. fujikuroi species complex (8.57%), the F. oxysporum species complex (4.29%) and the F. incarnatum‐equiseti species complex (2.86%). A combined phylogenetic tree was estimated including all the 70 isolates. Isolates belonging to different species complexes formed separate clades. In this study, we also report the first isolation of F. napiforme from human keratomycosis. A new method based on a specific EcoRI restriction site in the EF‐1α gene was developed for the rapid identification of F. solani. In vitro antifungal susceptibilities of the isolates to seven antifungals were determined by broth microdilution method. Terbinafine, natamycin and amphotericin B proved to be the most effective drugs, followed by voriconazole. The minimal inhibitory concentrations of clotrimazole, econazole and itraconazole were generally high (≥64 μg ml−1). The interactions between the two most effective antifungals (natamycin and terbinafine) were determined by checkerboard microdilution method. Synergism (71.8%) or no interaction (28.2%) was revealed between the two compounds.

Case of Keratitis Caused by Aspergillus tamarii

ABSTRACT We report a case of Aspergillus tamarii keratitis. Ocular injury was known to be a predisposing factor. Topical natamycin and econazole treatment and subsequent systemic ketoconazole treatment proved effective. The isolate was identified by morphological characteristics and sequence analysis as A. tamarii, a member of Aspergillus section Flavi not hitherto reported from keratomycosis.

Filamentous fungal infections of the cornea: a global overview of epidemiology and drug sensitivity.

Fungal keratitis is a serious suppurative, usually ulcerative corneal infection which may result in blindness or reduced vision. Epidemiological studies indicate that the occurrence of fungal keratitis is higher in warm, humid regions with agricultural economy. The most frequent filamentous fungal genera among the causal agents are Fusarium, Aspergillus and Curvularia. A more successful therapy of fungal keratitis relies on precise identification of the pathogen to the species level using molecular tools. As the sequence analysis of the internal transcribed spacer (ITS) region of the ribosomal RNA gene cluster (rDNA) is not discriminative enough to reveal a species‐level diagnosis for several filamentous fungal species highly relevant in keratitis infections, analysis of other loci is also required for an exact diagnosis. Molecular identifications may also reveal the involvement of fungal species which were not previously reported from corneal infections. The routinely applied chemotherapy of fungal keratitis is based on the topical and systemic administration of polyenes and azole compounds. Antifungal susceptibility testing of the causal agents is of special importance due to the emergence and spread of resistance. Testing the applicability of further available antifungals and screening for new, potential compounds for the therapy of fungal keratitis are of highlighted interest.

Epidemiology of Aspergillus keratitis at a tertiary care eye hospital in South India and antifungal susceptibilities of the causative agents

In recent years, Aspergillus species are reported frequently as aetiological agents of fungal keratitis in tropical countries such as India. Our aim was to evaluate the epidemiological features of Aspergillus keratitis cases over a 3‐year period in a tertiary eye care hospital and to determine the antifungal susceptibilities of the causative agents. This study included culture proven Aspergillus keratitis cases diagnosed between September 2005 and August 2008. Data including prevalence, predisposing factors and demography were recorded, the isolates were identified by morphological and molecular methods and the minimum inhibitory concentration values of antifungal agents towards the isolates were determined by the microdilution method. Two hundred Aspergillus isolates were identified among 1737 culture proven cases. Most of the aspergilli (75%) proved to be A. flavus, followed by A. fumigatus (11.5%). Sixteen (8%) isolates belonged to species that are recently identified causative agents of mycotic keratitis. Most of the infected patients (88%) were adults ranging from 21 to 70 years of age. Co‐existing ocular disease was confirmed in 16.5% of the patients. Econazole, clotrimazole and ketoconazole were notably active against A. flavus. Aspergillus keratitis is a significant problem in patients with ocular lesions in South‐Indian States, warranting early diagnosis and initiation of specific antifungal therapy to improve outcome.

Mycotic Keratitis Due to Aspergillus nomius

ABSTRACT We report the first known case of fungal keratitis caused by Aspergillus nomius. Ocular injury was known as a predisposing factor. The patient was treated with natamycin and econazole eye drops, itraconazole eye ointment, and oral ketoconazole. A therapeutic penetrating keratoplasty was performed 16 days after presentation. A sequence-based approach was used to assign the isolate to a species.