The expression of MMP-2 in sclera of form deprived eyes in guinea pigs

Objective To investigate changes in matrix metalloproteinase-2 (MMP-2) in sclera of guinea pig eyes with form deprivation myopia. Methods Form deprivation was established monocularly in 16 guinea pigs (18 days of age) for 8 weeks. Six guinea pigs with age matching that of the experimental group were used as normal control. Ocular measurements including refraction, axial length, thickness and dry weight of the posterior sclera were performed prior to and after the form deprivation. MMP-2 at the posterior sclera was measured using immunohistochemistry after the form deprivation with the levels of expression compared among the deprived, fellow and normal control eyes. Results The deprived eyes showed myopia of (-7.00±1.03)D in relative to the normal control eyes after 8 weeks of form deprivation. The posterior sclera was significantly thinner in the deprived eyes [the difference value was (13.8±8.2)μm,P0.01]. The dry weight of the posterior sclera was smaller in the deprived eyes than both the fellow and normal control eyes [the difference value was (0.13±0.07)mg,P0.05]. The level of expression in MMP-2 was higher in the deprived eyes than both the fellow and normal control eyes. Conclusion Form deprivation myopia in guinea pig eyes is associated an increasing amount of MMP-2 in the posterior scleral tissue, indicating an increased degradation of the extracelular matrices.