Abstract
Purpose :
Gap junctions are involved in multiple retinal signaling pathways including visual acuity regulation and light adaptation which were thought to be related to myopia. This study evaluated the effect of gap junction mediated retinal network in refraction development.
Methods :
Pigmented guinea pigs (3w old) were raised with normal vision (NC groups) or with form deprivation (FDM groups) for 4w. The FD eye was daily subconjunctival injected 18-β-glycyrrhetinic acid (18-β-GA, a gap junction antagonist, low dose: 40μg/100μl, high dose: 120μg/100μl), or its vehicle (DMSO), with injection volume of 100μl. The ocular biometry including refraction, vitreous chamber depth (VCD) and axial length (AL) was measured at the onset and on day 14 and 28. Retinal functions were monitored by electroretinography (ERG) on day 21.
Results :
Though the applied dosages of 18-β-GA did not alter the ERG responding, they were sufficient to affect the refraction development in guinea pigs. The refraction of NC+ DMSO, NC+low dose and NC+ high dose was -0.67±0.65D,-2.18±1.41D and -3.38±2.04D respectively at day 14; and -0.85±0.69D, -3.07±2.42D and -5.44±2.07D respectively at day 28 (p<0.001, repeated one-way ANOVA). The elongation of VCD and AL was consistent with refractive changes (VCD: p=0.065;AL: p=0.004, repeated one-way ANOVA). The application of 18-β-GA enhanced FDM as well. The refraction of FDM+ DMSO, FDM+low dose and FDM+ high dose was -5.15±1.68D,-6.82±1.89D and -6.47±2.39D respectively at day 14; and -8.94±2.04D, -10.81±2.41D and -11.16±2.68D respectively at day 28 (p=0.16, repeated one-way ANOVA). However, retinal gap junction blocking did not increase VCD and AL elongation in FDM groups(VCD: p=0.498; P=0.230, repeated one-way ANOVA).
Conclusions :
Retinal gap junction blocking induces myopia and increases FDM in guinea pig with a dosage did not alter retinal functions, indicating the retinal network mediated by gap junction plays important role in refraction development.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.