Abstract
Purpose :
To determine whether infant monkeys compensate for imposed myopic defocus when they are exposed to long-wavelength ambient lighting.
Methods :
Starting at 25±2 days of age, infant monkeys were reared under long-wavelength (630 nm; 260 lux) LED ceiling lighting (RL). Six of these animals were reared with unrestricted vision (NRL monkeys); 5 animals were reared with +3.0 D lenses in front of one eye and plano lenses in front of their fellow eye (+3&pl RL monkeys). Refractive development, corneal power, and vitreous chamber depth were measured by retinoscopy, keratometry, and ultrasonography, respectively. Control data were obtained from monkeys housed under typical indoor fluorescent lighting and reared with either monocular +3 D lenses (+3&pl IL animals, n=7) or reared with unrestricted vision (NIL animals, n=34).
Results :
At 130 days of age, the median refractive error for the NRL monkeys (+3.25 D) was significantly more hyperopic than that for the NIL monkeys (+2.44 D; P=0.01). The median ametropias for the treated (+5.38 D) and control eyes (+3.81 D) of the +3&pl RL monkeys were more hyperopic than those for the +3&pl IL monkeys (treated: +4.31 D, p=0.07; control: +3.06 D p=0.09), however these differences were not statistically significant. The +3&pl RL monkeys exhibited hyperopic anisometropias (+1.44±0.37 D) that were also similar to those found in the +3&pl IL monkeys (+1.44±0.48 D, P=1.00). All of the hyperopic changes were associated with shorter vitreous chamber depths.
Conclusions :
Long-wavelength lighting induces hyperopic shifts during refractive development, which suggests that chromatic cues are important for normal emmetropization. However, the reductions in chromatic cues associated with long-wavelength quasi-monochromatic lighting did not prevent the infant monkeys from compensating for optically imposed myopic defocus.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.