Abstract
Purpose: :
To examine growth of the human lens in the Indian population and compare this with growth in Western populations by measuring in vitro dimensions together with wet and dry weights. Of particular interest are data on dry weights which are expected to be less variable than wet weights.
Methods: :
Lenses were removed from eye bank eyes and their dimensions were measured, initially with digital calipers and then with a mini-shadowgraph, constructed especially for this purpose. They were then carefully blotted dry and weighed before being placed in 5% buffered formalin. After 1 week fixation, the lenses were dried at 80°C until constant weight was achieved. Lenses with capsular damage or cataract were excluded.
Results: :
Data were obtained for > 100 lenses, aged 0-91, within 24.1 ± 12.9 hours (range, 9.5-91.5 hours) post-mortem. Rapid changes were observed in all parameters in the young lenses, indicative of asymptotic growth, but insufficient data were available at this time to permit logistic analysis. In lenses aged over 20 years, both wet and dry weights increased linearly at 1.39 and 0.52 mg/year, respectively, throughout the rest of life. Allometric analysis indicated that dry weight increased at a faster rate than wet weight, indicative of continued compaction of fibre cells. However, the difference was small and more data are required to confirm the trend. After age 20, the equatorial diameter increased at 0.091mm/year and thickness at .0167mm/year.
Conclusions: :
Over the age range examined, Indian lens growth is very similar to that in Western populations. Compaction appears to continue throughout life.
Keywords: aging • development