Effects of Long-Wavelength Lighting on Refractive Development in Infant Rhesus Monkeys.
Level 5 - mechanism / opinion, no new human data
Animal experimental study (non-human primates)
PubMed 26447984 · doi:10.1167/iovs.15-17025
What was done
Infant rhesus monkeys starting at 25 ± 2 days of age wore continuous long-wavelength-pass (red) filters over both eyes (BRL, n = 7) or one eye (MRL, n = 6) until 146 ± 7 days of age. Comparators were 6 monkeys reared with binocular neutral density (ND) filters and 33 untreated control monkeys reared under typical indoor lighting. Refractive development, corneal power, and vitreous chamber depth were evaluated with retinoscopy, keratometry, and ultrasonography, followed by an observation period after filter removal.
What was found
At the end of rearing, median refractive error in BRL monkeys was +4.25 diopters (D), significantly more hyperopic than ND monkeys (+2.22 D; P = 0.003) and normal monkeys (+2.38 D; P = 0.0001). MRL monkeys developed hyperopic anisometropia of +1.70 ± 1.55 D versus -0.013 ± 0.33 D in normal controls (P < 0.0001). Hyperopia in treated eyes was associated with shorter vitreous chambers. Monkeys recovered from the induced hyperopic shifts after filter removal.
Why it matters
These results demonstrate that long-wavelength-dominated lighting does not promote myopia in infant primates and suggest that altering chromatic cues can disrupt normal emmetropization.
Limits
The study is restricted to a small cohort of infant rhesus monkeys under artificial laboratory filter conditions, which may not directly translate to human visual environments or lighting exposures.
Cited by
- partial The lack of long-wavelength light exposure is a contributing driver in the development of myopia.