Abstract
Purpose:
To investigate the effects of 430nm monochromatic light on defocus-induced myopia in guinea pigs.
Methods:
Eighteen 2-week-old pigmented guinea pigs were randomly assigned to two groups based on the mode of illumination: short-wavelength light (SL) for 8 weeks and broad-band white light (BL) for 8 weeks. All animals of the two groups were worn -5D lenses on right eye. Biometric and refractive measurements were then performed every 2 weeks. The illuminative parameters of all groups were identical and the light quantum number was 3×10-4μmol·cm-2·s-1.
Results:
After the beginning of the experiment, the right eyes of the two groups decreased in refraction. At the end of the experiment, relative myopia of the right eye was about 2.72D in the SL and about 3.03D in the BL when compared with the fellow eye. But a relative hyperopia, about 1.2D, was induced in the SL compared with the BL group in the end. From 4 to 8 week, there was significant difference in radius of corneal curvature between the two eyes of the SL group. But, there was no significant difference in corneal curvature between the two eyes of the BL group. At the end of the experiment, there was significant difference in radius of corneal curvature between the right eyes of the two groups. The difference was not significant in vitreous length of right eye between the two groups from beginning to the end of experiment. There was no significant difference in vitreous length between the two eyes of the SL group in the end. But finally, significant difference existed in vitreous length between the two eyes of the BL group. There were no significant inter-group or intra-group differences in length of anterior segment and Lens thickness.
Conclusions:
430nm monochromatic light could interfere with the development of defocus-induced myopia in guinea pigs. The effect of the monochromatic light may be achieved by influencing the developments of vitreous chamber and corneal curvature. The recognition of defocus under the monochromatic light may be achieved by the function from only one type of cone.