A morphological study of form-deprived super-high myopia in guinea pigs

Objective To establish an animal model of form-deprived super-high myopia in guinea pigs and to investigate the fundus histopathological changes. Methods Twenty 2-week-old guinea pigs were randomized into form-deprived group( n = 12) and control group( n = 8). Refraction and axial length were measured before form deprivation,and at 4,6,10 and 14 weeks,respectively. The thickness and morphological changes of retina,choroid and sclera were examined with light microscope after 14 weeks. Results The degree of myopia gradually increased after form deprivation,reached- 10. 00 D after 10 weeks and exceeded- 20. 00 D after 14 weeks. Axial length increased accordingly. The retina,choroid and sclera were obviously thinner with characteristic pathological changes in form-deprived group than those in control group. Conclusion Super-high myopia in guinea pigs could be successfully induced by long-term monocular form deprivation,reaching more than- 10. 00 D after 10 weeks. The sclera,choroid and retina in super-high myopia eyes became much thinner with characteristic structural changes in sclera and choroid. The significantly thinning of photoreceptor layer in retina might play an important role in super-high myopia.