Overnight lens removal avoids changes in refraction and eye growth produced by plano soft contact lenses in infant marmosets.

Infant marmosets were fitted with zero-powered (plano) soft contact lenses from 4 to 8 weeks of age worn either continuously (24 h per day) (n = 4), for 12 h (n = 4), or for 8 h (n = 3) per day to determine whether limiting the daily duration of lens-wear could significantly reduce or eliminate the effects of continuous lens-wear on ocular growth and refractive state. As in macaques (Hung, L. F., & Smith, E. L. (1996). Extended-wear, soft, contact lenses produce hyperopia in young monkeys. Optometry and Vision Science, 73, 579-584), eyes fitted with contact lenses worn continuously developed more hyperopic refractions (mean +3.22 +/- 1.49 D SE) compared to their fellow untreated eyes, inconsistent changes in vitreous chamber depth (-0.02 +/- 0.09 mm SE) and flatter corneas (mean decrease in corneal power 4.22 +/- 0.39 D SE). Eyes wearing lenses for only 12 h per day showed similar but reduced effects compared to the 24-h group. Most importantly, ocular growth, corneal power and refraction were unaffected in the 8-h group. Future studies using contact lenses in infant primates should employ a reduced daily duration of lens-wear to eliminate the undesirable effect of contact lens-wear per se on ocular development.