The effect of age on the retardation of axial elongation following a lensectomy in infant monkeys.

Objective: To determine the effect of age on the retardation of axial elongation in neonatal monkey eyes following the extraction of the crystalline lens.
Methods: A monocular lensectomy was performed on 4 rhesus monkeys when they were 4 days, 2 weeks, 7.5 months, and 1 year of age. Longitudinal measurements of axial lengths and keratometry readings were made.
Results: The aphakic eye was 1.7 mm shorter than the unmanipulated fellow eye in the monkey undergoing surgery at 4 days of age and 1.1 mm shorter in the monkey undergoing surgery at 2 weeks of age. However, the aphakic eyes were only 0.2 mm and 0.1 mm shorter than their unmanipulated fellow eyes, respectively, in the monkeys undergoing surgery at 7.5 months and 1 year of age.
Conclusions: The retardation of axial elongation following a lensectomy in infantile monkey eyes is age dependent. Little effect is observed in monkeys aged 7.5 months or older.