Observation On Macular Microcirculation Changes In Non-proliferative Diabetic Retinopathy Patients With Different Degrees Of Myopia By OCTA

Objective:The optical coherence tomography angiography（OCTA）technique was used to observe the macular microcirculation changes in non-proliferative diabetic retinopathy（NPDR）patients with different degrees of myopic and to measure the central macular thickness（CMT）,subfoveal choroidal thickness（SFCT）,and analysed the relevant indicators,Thus to provide more clinical evidence on the protective mechanism of myopia against diabetic retinopathy（DR）.Methods:Retrospective study.Seventy-one inpatients（105 eyes）with a clear diagnosis of NPDR in the ophthalmology department of Xi’an Central Hospital from January 2022 to December 2022 were selected for the study.According to spherical equivalent（SE）,all patients were divided into myopic group（SE≤-0.5D）and non-myopic group;and the myopic group was further divided into mild myopic group（SE≤-0.50D and>-3.00D）,moderate myopic group（SE≤-3.00D and>-6.00D）and high myopic group（≤-6.00D）.Patients’gender,age,duration of diabetes,eye category,glycosylated hemoglobin,SE and axial length（AL）were recorded.Patients were examined with the instrument（Zeiss CIRRUS HD-OCT 5000）after adequate pupil dilatation,and the Angiography 3×3mm mode was selected for scanning to obtain OCTA images.Images with image quality≥8 were accepted.The area of the superficial capillary plexuses（SCP）in the macular central recess,the paracentral macular recess（1～3mm）and the 3mm×3mm macular area in terms of vascular density（VD）,perfusion density（PD）and foveal avascular zone（FAZ）were acquired automatically by using the software（version:Cirrus 9.0）,and were recorded as VD₁,VD_1-3,VD3,PD1,PD_1-3,PD₃,FAZ respectively;and the paracentral macular zone was divided into temporal（T）,superior（S）,nasal（N）and inferior（I）,and data were recorded as T_VD,S_VD,N_VD,I_VD and T_PD,S_PD,N_PD,I_PD.The Macular Cube 512 x 128 mode was selected and the CMT was recorded,then the depth enhanced imaging mode（EDI-OCT）of HD Cross was selected and the horizontal and vertical SFCT was measured manually 3 times and the results were averaged and recorded.The data were analysed using SPSS version 23.0 statistical software.Results:1.In the corresponding regions,the VD₁,VD_1-3,VD₃,PD₁,PD_1-3,PD₃of myopic NPDR patients were lower than those of non-myopic NPDR patients.2.The FAZ of myopic NPDR patients were larger than those of non-myopic NPDR patients.3.The VD₁,VD_1-3,VD₃,PD₁,PD_1-3,PD₃ in NPDR patients with high myopic were lower than those with mild and moderate myopic.And the VD₁,VD_1-3,VD₃,PD₁,PD_1-3,PD₃ in NPDR patients with moderate myopic were lower than those with mild myopic.4.The FAZ in NPDR patients with high myopic were larger than those with mild myopic.And the FAZ in NPDR patients with moderate myopic were larger than those with mild myopic.5.Vascular density in myopic NPDR patients varied in different quadrants of the macular.The S_VD,N_VD,S_PD,N_PD in NPDR patients with high myopic were lower than those with mild and moderate myopic.And the FAZ in NPDR patients with moderate myopic were larger than those with mild myopic.The T_VD,I_VD T_PD,I_PD with high myopic were lower than those with moderate myopic.But there were no differences in VD and PD levels in different quadrants between NPDR patients with moderate myopia and those with mild myopia.6.In NPDR patients with different degrees of myopic,the higher the degree of myopia,the smaller the VD and PD,the larger the FAZ,and the thinner the CMT and SFCT.Conclusion:1.Myopic patients have lower VD,PD levels.2.The decline in retinal VD and PD levels in myopic NPDR patients is asynchronous in different quadrants.3.In NPDR patients with different degrees of myopic,VD,PD,and CMT and SFCT of the macular SCP decreased with increasing myopia,FAZ increased with increasing myopia.