Abstract
Purpose:
We have reported that the A2A receptor knockout mice confer a relatively myopia during the first two months of postnatal development. The present studies seek to evaluate the role of the adenosine A2A receptor in form deprivation myopia (FDM) using A2A KO mice.
Methods:
The right eye of A2A KO mice and WT littermates (postnatal days 23) were subjected to form deprivation to induce myopia. Ocular parameters were measured at 4 and 6 weeks after form deprivation. Refraction was measured by eccentric infrared photorefraction (EIR). Corneal radius of curvature was evaluated by a keratometer with a + 20.0 D aspherical lens mounted before it. Ocular dimensions (including anterior chamber depth, lens thickness, vitreous chamber depth and axial length) were measured by a custom-designed optical coherence tomography.
Results:
In WT mice, after form deprivation for 4 and 6 weeks, the treated (T) eyes showed significant myopic shift compared with their fellow (F) eyes (4 w: T: 2.23±1.43D, F: 9.13±1.22D, P<0.001; 6 w: T: 3.06±1.92D, F: 8.28±1.51D, P<0.001) and the myopic shift was correlated with the increase in axial length (4 w: P<0.001; 6 w: P<0.05) and increased vitreous chamber depth (4 w: P<0.01; 6 w: P<0.01), and no significant difference was found in corneal radius of curvature. In A2A R KO mice, after form deprivation for 4 and 6 weeks, the treated (T) eyes showed significant myopic shift compared with their fellow (F) eyes (4 w: T: -0.39±1.63D, F: 5.77±1.73D, P<0.001; 6 w: T: -1.69±1.48D, F: 7.29±1.43D, P<0.001). However, there was significant difference in corneal radius of curvature after form deprivation for 4 and 6 weeks (4 w: T: 1.432±0.023mm, F: 1.440±0.030mm, P<0.05; 6w:T:1.465±0.027mm, F:1.475±0.026mm, P<0.001) and no significant difference in ocular axial length, vitreous chamber depth, anterior chamber depth, and lens thickness between T eyes and F eyes in all groups was found.
Conclusions:
Genetic inactivation of the A2A receptor can induce myopia accompanied with corneal radius of curvature changes compared with WT mice by form deprivation, suggesting that adenosine A2A receptor have a role in development form deprivation myopia in mice.
Keywords: 410 adenosine •
605 myopia •
676 refraction