Purpose: To evaluate the affect of removing the crystalline lens and implanting an intraocular lens on the axial elongation of a neonatal eye.
Methods: Monocular lensectomy coupled with the implantation of a monofocal or multifocal intraocular lens was performed on 21 neonatal rhesus monkeys. Fellow eyes were randomized to part-time occlusion therapy or no treatment. Longitudinal axial elongation of the pseudophakic eyes was then compared to that of the fellow eyes, to the eyes of 19 monkeys made monocularly aphakic as neonates, and to the eyes of 39 normal monkeys.
Results: At 5 weeks of age, aphakic and pseudophakic eyes were significantly shorter than their fellow eyes (P < 0.01). After 1 year of follow-up, the mean axial lengths of the pseudophakic and aphakic eyes were 2.0 +/- 0.2 mm and 2.3 +/- 0.2 mm, respectively, shorter than their fellow eyes. This axial length difference persisted through a second year of follow-up. The difference between the mean axial lengths of the aphakic and pseudophakic eyes was not significant (P > 0.10). Part-time occlusion of the fellow eyes did not affect axial elongation.
Conclusions: Removing the crystalline lens and implanting an intraocular lens in a neonatal monkey eye retards its axial elongation.