Abstract
Purpose :
Scleral extracellular matrix remodeling plays a crucial role in myopia development, but the mechanisms controlling scleral collagen turnover remain unclear. We describe here the time dependent changes that occur in scleral MMP-2 levels during the development of form deprivation myopia (FDM) in mice.
Methods :
C57BL/6 mice (3 weeks old) were randomly divided into form-deprivation (FD) group and age-matched control group. In the FD group, one eye was treated, and the untreated eye formed a second control group (fellow group). Form-deprivation myopia (FDM) was induced by wearing monocular occluder in C57BL/6 mice for either 1, 1.25, 1.5, 1.75, 2, 7 or 14 days, respectively. An eccentric infrared photorefractor (EIR) measured refraction. Optical coherence tomography measured corneal thickness, anterior chamber depth, lens thickness, vitreous chamber depth and axial length. Semi quantitative RT-PCR analysis determined scleral MMP-2 mRNA levels.
Results :
MMP-2 mRNA levels remained stable for up to 14 days in the age-matched control eyes (p>0.05). For up to 1.75 days of form deprivation, the MMP-2 mRNA levels in the FD eyes were not markedly different from the two control groups (p>0.05). After 2 days of form deprivation, the level was 27% higher in the FD eyes than in the fellow eyes (p<0.05), and 50% higher than in the control eyes (p<0.05). After 7 days of form deprivation, the FD eyes level was 74% higher than in the control eyes (p<0.01). After 14 days of form deprivation, the level was 82% higher in the FD eyes than in the fellow eyes (p<0.01), and 110% higher than in the control eyes (p<0.05).
Conclusions :
FDM development in mice is associated with time dependent increases occur in scleral MMP-2 gene expression levels. Accordingly, this model is relevant for clarifying how scleral MMP-2 gene expression is upregulated during myopia development.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.