Comparison Of The Characteristics Of High Myopia And Open-angle Glaucoma And The Aqueous Oxidative Stress Level In High Myopia

Purpose: To analyze the difference in the basic structural characteristics between patients with high myopia and open-angle glaucoma,and to explore the possible relationship between high myopia and the incidence of open-angle glaucoma(POAG)by measuring the oxidative stress levels in the aqueous humor of highly myopic eyes.Methods: The subjects selected were 35 highly myopic patients,17 patients with POAG,12 highly myopic patients with POAG and 27 cataractous eyes.Corneal endothelial cell density,coefficient of variation,percentage of hexagonal cells were measured using specular microscopy and thickness of the retinal nerve fiber layer(RNFL)was measured by optical coherence tomography in each group.Aqueous humor samples were collected from 19 highly myopic eyes and 18 eyes with cataract during cataract surgery.The concentration of 8-hydroxydeoxyguanosine(8-OHdG)in the aqueous humor was measured using enzyme-linked immunosorbent assay.Results: There was no statistically significant difference in corneal endothelial cell density,hexagonal cell percentage and coefficient of variation between the control group and the high myopia group(P>0.05).And the values of corneal endothelial cells between the highly myopic patients and highly myopic patients with POAG were not significantly different(P>0.05).Compared with the control group,patients with high myopia showed increased RNFL thickness in the temporal quadrant while reduced RNFL thickness in the remaining quadrants and average RNFL thickness(P <0.05).Highly myopic patients with POAG showed reduced RNFL thickness in the temporal and inferior quadrants compared to the patients with high myopia(P <0.05).There was no difference in the quadrants and average RNFL thickness between the groups of POAG and high myopia with POAG(P>0.05).The level of 8-OHdG in the aqueous humor of the high myopia group was higher than that of the control group,but there was no significant difference(P> 0.05).Conclusion: The change of RNFL thickness especially that in the temporal quadrant in highly myopic eyes may have important diagnostic significance in the early determination of POAG.The role of oxidative damage mechanisms in affecting the risk of POAG in high myopia needs further investigation.