| Objective:Analyzing the characteristics of OCTA images in patients with severe NPDR in order to study the changes of retinal blood vessels and nerves in patients with severe NPDR And explore the clinical value of OCTA in the early diagnosis of DR.Methods:This study is a retrospective study.Clinical data of patients with NPDR admitted to the outpatient department of our hospital from September 2021 to October 2022 were collected,including 94 eyes in all.Data such as age,gender,eye type,intraocular pressure,BCVA,Opal ultra-wide Angle fundus photography,slit lamp and fundus examination after dilation were recorded.The retinal vascular images obtained by OCTA were manually stratified and a series of parameters such as retinal VD,FAZ area and FAZ perimeter were calculated by Image J software.According to the International Clinical Grading Standard for diabetic retinopathy(2002),patients that are chose are divided into five groups,including 26 eyes of healthy group,22 eyes of NDR group,18 eyes of mild NPDR group,13 eyes of moderate NPDR group and 15 eyes of severe NPDR group.The severe NPDR group is set as the observation group.Healthy group,NDR group,mild NPDR group and moderate NPDR group are set as control A,B,C and D group separately.Results:At the SCP level,the FAZ area is the largest in eyes with severe NPDR compared to healthy eyes and eyes with other stages of DR.The difference is statistically significant(P<0.01).The FAZ perimeter is the largest in eyes with severe NPDR.The difference is statistically significant(P<0.01)compared to normal and NDR eyes,but the difference is not statistically significant(P>0.01)compared to eyes with mild NPDR and eyes with moderate NPDR.Severe NPDR eyes has the lowest blood flow density,with statistically significant differences from normal,NDR and mild NPDR eyes(P<0.01)but no statistically significant differences from moderate NPDR eyes(P>0.01).At the MCP level,the FAZ area is the largest in eyes with severe NPDR compared to healthy eyes and eyes with other stages of DR.The difference is statistically significant from normal,NDR,and mild NPDR eyes(P<0.01)but statistically insignificant from moderate NPDR eyes(P>0.01).The FAZ perimeter is the largest in eyes with severe NPDR,with statistically significant differences from normal,NDR,mild NPDR,and moderate NPDR eyes(P <0.01).The blood flow density is the smallest in eyes with severe NPDR,with statistically significant differences from normal,NDR,and mild NPDR eyes(P<0.01)but not statistically significant with moderate NPDR eyes(P>0.01).At the DCP level,the FAZ area is the largest in eyes with severe NPDR,with statistically significant differences from healthy eyes and eyes with other stages of DR(P<0.01)but no statistically significant differences from NDR eyes,mild NPDR eyes and moderate NPDR eyes(P>0.01).The blood flow density was the smallest in eyes with severe NPDR,with statistically significant differences from normal eyes,NDR eyes and mild NPDR eyes(P>0.01)but not statistically significant differences from eyes with moderate NPDR(P<0.01).Statistically significant differences exist in Log MAR at each stage of DR(P<0.01),and a two-by-two comparison revealed that visual acuity is better in eyes with severe NPDR than in eyes with moderate NPDR but worse than in the remaining eyes.There is statistically different from normal and NDR eyes(P<0.01),but there is not statistically different from eyes with mild NPDR and eyes with moderate NPDR(P>0.01).Conclusions.1,Eyes with severe NPDR had the largest FAZ perimeter at the SCP level and MCP level in the macula among all NPDR stages.Eyes with severe NPDR had the largest FAZ area at the SCP level,MCP level,and DCP level among all NPDR stages.And eyes with severe NPDR had the smallest VD at the SCP level,MCP level,and DCP level among all NPDR stages.This indicated that when the disease did not evolve to PDR,with the increase of retinal severity,the area of the central nonvascular area of macula was larger,the vascular damage of the retina in macular area was more serious and the vascular density was lower.2.Patients’ visual acuity became significantly worse when there was a rational change of retinal vascular disease,while patients’ visual acuity was not significantly changed when there was no pathological change of retinal vascular. |
