Transfer from blue light or green light to white light partially reverses changes in ocular refraction and anatomy of developing guinea pigs.

Relative to the broadband white light (BL), postnatal guinea pigs develop myopia in a monochromic middle-wavelength light (ML, 530 nm) environment and develop hyperopia in a monochromic short-wavelength light (SL, 430 nm) environment. We investigated whether transfer from SL or ML to BL leads to recuperation of ocular refraction and anatomy of developing guinea pigs. Two-week-old guinea pigs were given (a) SL for 20 weeks, (b) SL recuperation (SLR, SL for 10 weeks then BL for 10 weeks), (c) ML for 20 weeks, (d) ML recuperation (MLR, ML for 10 weeks then BL for 10 weeks), or (e) BL for 20 weeks. Two weeks after transfer from ML to BL (MLR group), ocular refraction increased from 1.95 +/- 0.35 D to 2.58 +/- 0.24 D, and vitreous length decreased from 3.48 +/- 0.06 mm to 3.41 +/- 0.06 mm. Two weeks after transfer from SL to BL (SLR group), ocular refraction decreased from 5.65 +/- 0.61 D to 4.33 +/- 0.49 D, and vitreous length increased from 3.18 +/- 0.07 mm to 3.26 +/- 0.11 mm. The MLR and SLR groups had final ocular refractions that were significantly different from those of the ML and SL groups at 20 weeks (ML vs. MLR: p < 0.0001; SL vs. SLR: p < 0.0001) but were still significantly different from the BL group (BL vs. MLR: p = 0.0120; BL vs. SLR: p = 0.0010). These results suggest that recuperation was not complete after return to BL for 10 weeks.