Purchase this article with an account.
Y Qiao, LF Hung, C-S Kee, R Ramamirtham, EL Smith; Ocular Changes in Anisometropic Infant Rhesus Monkeys . Invest. Ophthalmol. Vis. Sci. 2002;43(13):2927.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: The factors that influence the dimensions of individual ocular components during emmetropization are not well understood. The purpose of this study was to characterize the nature of the ocular changes responsible for the compensating refractive-error alterations in lens-reared monkeys. Methods: Eight infant rhesus monkeys were reared with positive lenses over one eye and negative lenses over the other eye. An alternating occlusion regimen ensured that the monkeys viewed through each eye for half the daily lighting cycle. The lens-rearing procedures were initiated at 3 weeks of age and continued for 3 months. Refractive status, corneal power and the eye's axial dimensions were determined periodically throughout the treatment period by cycloplegic retinoscopy, keratometry and A-scan ultrasonography, respectively. Crystalline lens parameters were also measured and calculated using a video-based phakometer. Ten normal monkeys served as controls. Results: At the end of the treatment period, the lens-reared monkeys exhibited compensating anisometropias that ranged from 1.0 to 6.5 D. The anisometropias were associated with interocular differences in vitreous chamber depth. The monkeys with anisometropias greater than 3 D also exhibited slightly steeper corneas and they tended to have deeper anterior chambers. However, there were no systematic interocular differences in crystalline lens parameters (lens thickness, anterior and posterior radii and equivalent power). Instead lens growths in both eyes of all of the anisometropic monkeys were comparable to that in normal monkeys. Conclusion: The ocular changes associated with compensating anisometropic growth appear to reflect selective alterations in axial growth rate, in particular, the axial elongation rate of the vitreous chamber. The failure to observe lenticular changes suggests that equatorial growth is unaffected or that vision-dependent changes in equatorial diameter do not influence lens development.
This PDF is available to Subscribers Only