Retinal Hemoglobin Oxygen Saturation And Retinal Vascular Diameter In Myopic Eyes

Purpose: To investigate the changes in the retinal hemoglobin oxygen saturation and the retinal vascular diameter in myopic eyes by a scanning laser ophthalmoscope(SLO).Methods: All study subjects were from Joint Shantou International Eye Center.Sixty-one eyes from 61 patients were included in the hemoglobin oxygen saturation measurement group,eighty eyes from 80 patients were included in retinal vascular diameter measurement group.All subjects underwent imaging with an SLO through dual lasers(532 nm and 633 nm).The retinal arteries and veins were labeled by one single clinical ophthalmologist.The diameters of retinal arteries and veins(DA and DV)and central retinal artery and vein equivalents(CRAE and CRVE)were measured.The oxygen saturations of hemoglobin in arteries and veins(SO2A and SO2V),the difference between the SO2 A and SO2V(SO2AV)were estimated from optical densities ratio of vessels on images at the two wavelengths.Spherical equivalent(SE)was calculated and used to categorize refractive status.In the retinal oxygen saturation measurement,normal group,non-high myopia group and high myopia group were defined as-0.5D <SE<+0.5D,-6.0D<SE≤-0.5D and SE≤-6.0D.In the retinal vascular diameter measurement,normal group,mild myopia group,moderate myopia group and high myopia group were defined as-0.5 diopters(D)<SE<+0.5D,-3.0D<SE≤-0.5D,-6.0D<SE≤-3.0D and SE≤-6.0D.Statistical analysis was performed with SPSS.One-way analysis of variance was used to compare retinal vascular diameter and retinal hemoglobin oxygen saturation among different groups,Pearson’s correlation coefficients were calculated to assess the relationship between retinal vascular diameter/retinal hemoglobin oxygen saturation and refractive error and AL.Results: The mean age of the retinal oxygen saturation was 27.05±5.79 years,the mean age of the retinal vascular diameter measurement was 27.61±7.00 years.In the retinal oxygen saturation,the SO2 V in high myopia group was significantly higher than that in normal group and non-high myopia group(high myopia group VS normal group VS non-high myopia group = 73.21 ±21.42% VS 55.81±21.69% VS 56.88±13.83,all P =0.02 < 0.05).The Pearson correlation coefficients among SE and SO2 A and SO2 V were-0.29 and-0.36 respectively(all P < 0.05),while the correlations between AL and SO2 A and SO2 V were 0.272 and 0.296,respectively(all P < 0.05).The Pearson correlation coefficients among SO2 AV,SE and AL were 0.02 and 0.04(all P > 0.05).In the retinal vascular diameter,the Pearson correlation coefficients among SE and DA,CRAE,DV and CRVE were 0.68,0.39,0.51 and 0.39respectively(all P< 0.01),while the correlations between AL and DA,CRAE,DV and CRVE were-0.52,-0.41,-0.42 and-0.47,respectively(all P < 0.01).Conclusion: In current study,there was a negative correlation between the oxygen saturations of hemoglobin in arteries and veins(SO2A and SO2V)and myopic diopters in younger adult individuals.The retinal vascular diameter of myopic eyes decreased with the myopic diopters and AL.