ABSTRACT
OBJECTIVE: To identify genetic disorders associated with ophthalmologic abnormalities; type and frequency of various ophthalmologic abnormalities associated with selected genetic and inherited disorders; and devise a suitable classification for ophthalmologic abnormalities. METHODS: Pediatric cases referred with mental retardation, congenital malformations and suspected genetic and metabolic disorders were enrolled prospectively. Relevant clinical details (including an ophthalmologic examination) and investigations were recorded. RESULT: Of the 1308 patients enrolled, 679 (51.9%) had ophthalmologic abnormalities. 458 cases (67.45%) out of these 679 had mental retardation and 20 (2.94%) had neuroregression. Environmental (12.22%) and chromosomal anomalies (10.9%) were the largest etiological groups. Down syndrome was the commonest of the chromosomal anomalies and mongoloid slant and epicanthic folds were its commonest ophthalmologic features. Mucopolysaccharidoses (21.4%), Wilson disease (19.64%), oculocutaneous albinism (16.07%) and lipid storage disorders (14.29%) were the most common inborn errors of metabolism associated with ophthalmologic abnormalities. Of the 39 cases with Mendelian inheritance of disorders, autosomal dominant disorders (56.41%) were the commonest associated with ocular abnormalities. A simple anatomical classification has been devised for various ophthalmologic abnormalities encountered (wherein, positional and adnexal abnormalities were the commonest). CONCLUSION: Up to 50% of cases referred to the genetic services have ophthalmologic abnormalities. Conditions including chromosomal abnormalities, metabolic disorders, Mendelian syndromes and environmental factors are associated with ocular abnormalities. Anatomically, positional and adnexal abnormalities are the commonest.