Relation between size at birth and age-related cataract.

PURPOSE To determine whether poor fetal growth, as determined by size at birth, is associated with an increased risk of age-related cataract. METHODS A total of 741 men and women born in Sheffield, England between 1922 and 1930 and whose size at birth was available were traced and invited to take part in the study. Of these, 392 (53%) attended for ophthalmic examination. Lens opacity in these volunteers was graded using the Lens Opacities Classification System (LOCS) III. RESULTS After adjusting for age, gender, gestational age, and risk factors for cataract there were no consistent associations between size at birth and age-related cataract. However, the odds ratio for nuclear cataract (opalescence) among subjects whose birth weight was more than 8 lb was 2.4 (95% CI 1.2 to 5.0) compared with those who weighed under 6 lb 12 oz at birth. Risk of cortical cataract by contrast fell with increasing birth weight, but the trend was not significant and became weak after adjusting for gestational age and other risk factors for cataract. No relation was evident between risk of posterior subcapsular cataract and size at birth. CONCLUSIONS There is no consistent association between size at birth and age-related cataract. The higher risk of nuclear cataract with increased birth weight was contrary to the expected trend. The apparent difference in direction of the relation between birth weight and different subtypes of cataract may be a chance finding but warrants further exploration.