Determinants of glaucoma awareness and knowledge in urban Chennai.

Aim: To assess the awareness and knowledge levels about glaucoma and its determinants in an urban population of Chennai in south India. Materials and Methods: Chennai glaucoma study (CGS) was a population based prevalence study to estimate the prevalence of glaucoma in a rural and urban south Indian population. A total of 3850 subjects aged 40 years or above participated in the urban arm of CGS. A systematic random sample of 1926 (50.0%) subjects completed a questionnaire that assesses their awareness and knowledge level of glaucoma. Respondents “having heard of glaucoma” even before they were contacted/recruited for the study were defined as “aware” and respondents having some understanding of the eye disease were defined as “knowledgeable”. Results: Overall 13.5% were aware of glaucoma, the age-gender adjusted rate for awareness was 13.3% (95% CI: 11.57 to 15.03). Two clinicians graded knowledge on glaucoma, based on the subject's knowledge of risk factors, definitions and treatment aspects of glaucoma. Overall 8.7% had some knowledge about glaucoma. Among those who had knowledge 0.5% had good knowledge about glaucoma, 4% had fair knowledge and 4.2% had poor knowledge. We observed a very good agreement between the clinicians in grading knowledge (k =0.92). Determinants of glaucoma awareness and knowledge were higher levels of education, females, age, religion and family history of glaucoma. Conclusion: Awareness and knowledge about glaucoma was very low among the urban population of Chennai. We have found that younger subjects and men were less aware of glaucoma. Subjects with lower levels of education were less aware and knew less about glaucoma than their counterparts. The study findings stress the need for health education for effective prevention of blindness due to glaucoma.

Genotype-phenotype correlation analysis in retinoblastoma patients from India.

BACKGROUND: Genetic analysis has a beneficial impact on retinoblastoma management enabling definite risk assessment. However, information regarding genotype-phenotype correlation in retinoblastoma is limited. AIM: To analyze the retinoblastoma susceptibility gene for mutations in retinoblastoma patients and correlate the genotypes the phenotypes. METHODOLOGY: Eleven retinoblastoma patients, who underwent molecular genetic studies were classified into high, moderate or low disease severity groups based on phenotype. RESULTS: Seven patients had high disease severity and four moderate disease severity. Eleven truncating mutations were detected; six were in the N-terminus region of the retinoblastoma protein and two in the A/B pocket (p=0.03). CONCLUSIONS: No significant association between mutation type and disease severity could be established in the present study. However a positive correlation between location of the mutations in certain domains of the retinoblastoma protein and disease severity was observed. To the best of our knowledge this is the first genotype-phenotype correlation study in retinoblastoma patients from India.

Karyotyping in retinoblastoma--a statistical approach.

PURPOSE: Karyotype analysis in hereditary retinoblastoma is considered to be of marginal value in risk prediction due to uncertainties in the assessment of 13q14 deletions. However, it is a low cost genetic test for retinoblastoma in developing countries. In the present study, the results of karyotype analysis were refined by a statistical method to overcome limitations. METHODS: Karyotype analysis was performed by trypsin-Giemsa banding and naked eye karyotyping for 33 bilateral, 25 unilateral and one regressed retinoblastoma patients. The percentage of metaphases with 13q14 deletions in each case was plotted on a scatter diagram. Normalization of the data was achieved by log transformation and the results were statistically analyzed by one-sample 't' test using SPSS version 9.0. RESULTS: Seven samples had 13q14 deletion percentages above the cutoff value. One-sample 't' test showed significance (p< 0.001). By this method, two unilateral and five bilateral patients had 13q14 deletions, constituting 11.8 % of cases. CONCLUSION: For accuracy, statistical analysis should be considered as an adjunct in karyotyping.