Observation Of Changes In Retinal Vessel Density In Myopic Adolescents With Orthokeratology Based On Optical Coherence Tomography Angiography

Purpose: To use optical coherence tomography angiography(OCTA)to obseve the changes in macular blood flow density in adolescents with low to moderate myopia,after treatment with orthokeratology or the use of ordinary glasses.Methods: Every subject was measured for comperhensive examination.And according to the above measurement and the compliance of children and their parents,40 patients who matched the inclusion criteria accepted treatment of orthkeratology(experiment group)and the other 30 subjects were selected to wear ordinary glasses(control group).During regular follow-up reviews,adolescents were measured respectively at pre-wear,1,3month and 6month after treatment.The follow-up included uncorrected distance visual acuity,axial length,superficial vessel density,deep vessel density,central retinal thickness,foveal avascular zone,foveal avascular zone perimete and foveal vessel density in a 300-μm-wide region around foveal avascular zone.The collected data were analyzed using statistical methods.Results: The experiment group showed a significant improvement in best uncorrected distance visual acuity after wearing orthokeratology,compared to the control group(P<0.01),while the axial length did not show a significant difference between two grouos(P >0.05).By one month,the superficial vessel density had significantly increased in the fovea and superior retina,and the deep vessel density had significantly increased inferiorly in experiment group compared to control group(P <0.05).By three months,there were significant increases in the superficial vessel density in the fovea and inferior retina,and the deep vessel density in the Parafovea and superior and inferior retina in experiment group(P <0.05),while the increase in the superficial vessel density and the deep vessel density in the fovea were obseved by six months.(P<0.05).The vessel density in a 300-μm-wide region around foveal avascular zone significantly increased at every follow-up in the experiment group compared to control group(P <0.05).No significant differences in the central retinal thickness,foveal avascular zone area,foveal avascular zone perimete and vessel density in a300-μm-wide region around foveal avascular zone were obseved between the experiment and control groups(P >0.05).No significant differences in t the retinal nerve fifiber layer,radial peripapillary capillaries density were obseved between the experiment and control groups(P >0.05).Correlation analysis showed a weak positive correlation between the foveal avascular zone area and the foveal avascular zone perimete with the axial length,which was statistically significant(P<0.05);there was no statistically significant correlation between the retinal nerve fifiber layer and radial peripapillary capillaries density with the axial length(P>0.05).Conclusion: The best uncorrected distance visual acuity is significantly improved and safe for young people with mild to moderate myopia with orthokeratology.Short-term orthokeratology weared can increase local retinal vessel density in the macular region in adolescents with low-to-moderate myopia,however,there is no effect on the structural domain of the retina.Figure [10] Table [17] Reference [65]...