PSEUDOPHAKIA RETARDS AXIAL ELONGATION IN NEONATAL MONKEY EYES

Purpose. To evaluate the affect of removing the crystalline lens and i mplanting an intraocular lens on the axial elongation of a neonatal ey e. Methods. Monocular lensectomy coupled with the implantation of a mo nofocal or multifocal intraocular lens was performed on 21 neonatal rh esus monkeys. Fellow eyes were randomized to part-time occlusion thera py or no treatment. Longitudinal axial elongation of the pseudophakic eyes was then compared to that of the fellow eyes, to the eyes of 19 m onkeys made monocularly aphakic as neonates, and to the eyes of 39 nor mal 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 aph akic eyes were 2.0 +/- 0.2 mm and 2.3 +/- 0.2 mm, respectively, shorte r than their fellow eyes. This axial length difference persisted throu gh a second year of follow-up. The difference between the mean axial l engths of the aphakic and pseudophakic eyes was not significant (P > 0 .10). Part-time occlusion of the fellow eyes did not affect axial elon gation. Conclusions. Removing the crystalline lens and implanting an i ntraocular lens in a neonatal monkey eye retards its axial elongation.