Changes in biological parameters and scleral collagen content in guinea pigs with lens-induced myopia

Abstract

Objective To study the changes in scleral collagen and the role of these changes in the development of lens-induced myopia (LIM).Methods Experimental study.Thirty-six three-week-old male pigmented guinea pigs were randomly assigned to the lens-induced group (n=24)and the normal control group (n=12).The lens-induced guinea pigs were fitted with a-10 D lens on the right eye.After 4 weeks of lens wear,refractive state,axial length,dry weight and thickness of the posterior sclera and front/equator sclera,and the concentration of hydroxyproline and amino acid in the same area of the posterior sclera after hydrochloric acid hydrolysis were measured in both groups.Data were analyzed using t test.Results Axial myopia was successfully induced in the lens-induced guinea pigs after 4 weeks (t=-14.90,P＜0.01).Axial length was longer in the LIM eyes compared with the control eyes (t=14.76,P＜0.01) and the dry weight and thickness of the posterior sclera of the LIM eyes decreased (t=3.98,6.67,P＜0.01).Amino acid were also lower (t=3.29,P＜0.01).Conclusion The lens-induced myopic eye has an elongated axial length,a thinner posterior sclera with decreased dry weight and collagen synthesis.These factors reduce the load-bearing capacity of the sclera and induce the eye to change shape. Key words: Myopia; Sclera; Collagen; Hydroxyproline ; Models,animal