Study On Macular Blood Flow Density In Patients With Carotid Artery Stenosis By OCTA

Objective:To evaluate the parameters of macular area blood supply in patients with different degrees of carotid stenosis by optical coherence tomography(OCTA),in order to analyze the influence of the degree of carotid stenosis on the macular area blood flow.Methods:From September 2018 to September 2019,50 patients with 100 eyes,including 32 males and 18 females,were diagnosed with unilateral carotid artery stenosis in the department of internal medicine of the fourth affiliated hospital of China medical university.The average age was 62±11.02 years.All patients underwent color doppler ultrasound examination of the carotid artery to determine the degree of carotid artery stenosis,the location and nature of carotid artery plaque.Eyes of all patients in the macular area 3 times 3 mm×3 mm size imaging,respectively calculated the foveal avascular zone(FAZ)area of superficial capillary plexus(SCP)layer,and the blood flow density of SCP layer and deep capillary plexus(DCP)layer of experimental group and control group.The parameters of macular blood flow in patients with different degrees of carotid stenosis were compared,and the correlation between the location and nature of carotid plaques and macular blood flow parameters was analyzed.Results:1.Comparing between the experimental group(eyes on the affected side)and the control group(eyes on the healthy side),the blood flow density of SCP layer in the affected side was decreased in the severe carotid stenosis group(41.10±4.34%)compared with the healthy side(46.93±3.00%),and the difference was statistically significant(P<0.05).There was no significant difference in the blood flow density of SCP layer between the affected eyes(47.04±2.36%)and the healthy eyes(48.25±2.14%)in patients with mild carotid stenosis(P>0.05).There was no significant difference in the blood flow density of SCP layer between the affected eyes(47.19±3.48%)and the healthy eyes(48.67±2.16%)in patients with moderate carotid stenosis(P>0.05).There was no statistically significant difference in blood flow density between the DCP layer of the experimental group(the mild group:52.12±3.02%,the moderate group:51.39±4.15%,the severe group:53.35±2.50%)and the control group(the mild group:53.11±2.87%,the moderate group:51.48±3.47%,the severe group:54.01±2.33%)(P>0.05).The difference of blood flow between the experimental group and the control group in patients with different carotid artery stenosis groups was compared,and the difference of blood flow density in SCP layer in the severe stenosis group(5.83±4.22%)was statistically significant compared with the mild group(1.21±3.43%)and moderate group(1.48±4.57%)(P<0.05).There was no statistically significant difference in blood flow density in the DCP layer of the affected eye among all groups(the mild group:0.99±2.41%,the moderate group:0.10±2.08%,the severe group:0.66±1.20%)(P>0.05).2.There was no statistically significant difference in FAZ area between the experimental group(the mild group:0.296±0.064mm~2,the moderate group:0.300±0.059mm~2,the severe group:0.374±0.100mm~2)and the control group(the mild group:0.275±0.066mm~2,the moderate group:0.293±0.110mm~2,the severe group:0.402±0.096mm~2)(P>0.05).There was no statistically significant difference in FAZ area between different carotid stenosis groups(the mild group:0.021±0.046mm~2,the moderate group:0.008±0.101mm~2,the severe group:0.028±0.054mm~2)(P>0.05).3.The correlation between the characteristics of carotid plaques and macular blood flow density in each group was not statistically significant(P>0.05).The correlation between carotid plaque location and macular blood flow density in each group was not statistically significant(P>0.05).Conclusion:In the severe carotid stenosis group,the blood flow density in the SCP layer of the affected eye decreased,while the DCP layer did not change significantly.There was no significant change in blood flow density in SCP and DCP layer in patients with mild and moderate stenosis.There was no significant change in the FAZ area of the affected eye in all carotid artery stenosis groups.There was no significant correlation between the quality and location of carotid plaques and macular blood flow density.When OCTA measured decreased blood flow density in SCP layer of the affected eyes,it had a predictive effect on the degree of ipsilateral carotid artery stenosis.