Effects of confined space and near vision stimulation on refractive status and vitreous chamber depth in adolescent rhesus monkeys

This study aimed to investigate the effects of sustained near vision stimulation, on the refractive development and elongation of the vitreous chamber in adolescent rhesus monkeys. A total of 12 adolescent rhesus monkeys (1.5–2.0 years old) were randomly assigned to 3 groups. In groups A ( n =4) and B ( n =4), monkeys were reared in close-vision cages for 8 and 4 h d −1 , respectively; tiny granules were added on the cage floor to avoid visual deprivation and to encourage near gaze. In group C ( n =4), monkeys were reared in open-vision cages, with non-granule food as a control. Vitreous chamber depth, refractive status, and corneal refractive power were assessed over 18 months. Paired t -test was used to compare the differences and a P -value