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.