Study of guinea pig refractive status and ocular length during the early recovery from lens-induced myopia

Objective: To investigate changes in refractive status and ocular length in guinea pigs during the early time of myopic recovery for the causes of recovery. Methods: Exp guinea pigs wore a -5.00 D lens on one eye from 4-18 days, which was then removed for 48 hours. At 18 and 20 days of age, each eye was evaluated for refractive status and ocular length of the eye. Results: The right eyes treated with -5 D lenses for 12 days developed (-2.00± 1.50) D (P=0.04) of myopia and had an increase in axial length of (0.033±0.025) mm compared to the left eyes (P=0.04). After 48 hours of recovery, the difference between the two eyes was reduced to (-0.72±0.86) D(P=0.13), but the ocular length still had significant difference (0.031±0.022) mm (P=0.04). During the myopia recovery early period, the refractive status and ocular length changed in the same direction in the left eyes but in the opposite way in the right eyes. Conclusions: Guinea pigs treated with -5. 00 D lenses for 12 days developed explicit relative axial myopia. After removal of the lens for 48 hours, myopia significantly recovery can be due to the thickening of choroid and the reduction in ocular growth.