Characteristic Study Of Internal Carotid Artery Stenosis And Retinal Structure And Function In Patients With Ischemic Stroke

Chapter 1.Characteristics of retinal microvascular and nerve changes in patients with internal carotid artery stenosis and ischemic strokePurpose:To compare retinal thickness,vascular density,ganglion cell complex(GCC)and retinal nerve fiber layer(RNFL)thickness in bilateral eyes of patients with unilateral internal carotid artery stenosis(ICAS).Methods:Cross-sectional study.From December 2019 to December 2021,a total of 27 patients with unilateral ICAS≥70%and no stenosis or a stenosis<50%in the contralateral internal carotid artery were recruited.All patients underwent ophthalmic routine examinations and optical coherence tomography angiography(OCTA).Bilateral retinal thickness,vascular density,and GCC thickness were compared,and the presence or absence of ischemic stroke was used to perform subgroup analysis.For data statistics,the Paired-samples T test or the Wilcoxon signed-rank test were used.Results:The vessel densities of superficial and deep in the macular retina,FD-300,and inferior temporal and temporal inferior optic disc capillaries in the ipsilateral group had significantly lower levels than the contralateral group in the patients with ICAS≥70%(P<0.05).Furthermore,the microvascular density in the inferior temporal and temporal inferior optic discs and the superficial and deep macular retina,and the inferior GCC thickness were all considerably lower in the ipsilateral group than those in the contralateral group in the ICAS patients with ischemic stroke(P<0.05).There were no significant changes in the retinal microvasculature and nerve of ICAS patients without ischemic stroke.Conclusion:Severe ICAS patients have occurred retinal microcirculatory and ganglion cell damages,and it is more obvious in patients with both ICAS and ischemic stroke.These findings suggest that the combination of retinal microcirculation and ganglion cell damage may be a risk factor for ischemic stroke.However,prospective studies are needed to confirm it.Chapter 2.Analyzing the predictive value of carotid artery diameter and alterations of retinal microvessels and nerves in ischemic strokePurpose:In Chapter 1,we discovered that patients with severe ICAS have retinal microcirculatory and ganglion cell damage,which is exacerbated when combined with ischemic stroke.This finding suggests that ICAS,when combined with damaged retinal microvessels and GCC damage,may be a risk factor for ischemic stroke.As a result,we intend to look for risk or protective factors in this chapter by observing the characteristic changes in retinal nicrovessels and nerves,as well as the situation of ICAS in ischemic stroke.Finally,a more accurate prediction model of ischemic stroke occurrence will be established by combining the characteristics of retinal microvascular and nerve changes with ICAS.Methods:Cross-sectional study.Between December 2019 and December 2021,patients diagnosed with ischemic stroke at our hospital were gathered.In accordance with the inclusion and exclusion criteria,229 patients had a total of 229 eyes,with 101 eyes in the ischemic stroke group and 128 eyes in the control group.All patients had routine ophthalmic examinations as well as optical coherence tomography angiography(OCTA).Retinal VD and the thickness of the retina,RNFL,and GCC were compared between the two groups.For measurement data with a normal distribution,the independent-sample t test was used;otherwise,the Mann-Whitney U test was used.Lastly,binary logistics regression analysis and receiver operating characteristic(ROC)analysis were used to examine the traditional risk factors,ICAS,and OCTA parameters.Results:IS patients with ipsilateral ICAS have a higher occurrence and severity.There was a decrease in VD of parafovea,FD-300,nasal optic disc,thinning of RNFL around nasal optic disc,and increased A1 in IS patients(P<0.05).A1 increase was a risk factor for IS(OR:1.298),while the rest were protective factors(OR:0.668,0.736,0.857,0.502,0.619,respectively).The incorporation of traditional risk factors,ipsilateral ICAS status,and OCTA-related parameters could significantly improve IS diagnostic accuracy(AUC:0.933,sensitivity:0.921,specificity:0.871).Conclusion:We discovered that patients with IS had abnormal retinal microcirculation and nerve damage prior to clinically visible fundus lesions.Retinal OCTA parameters can provide more information about microvascular changes for IS,and combining internal carotid artery diameter with retinal microvascular and nerve results can improve IS diagnostic accuracy.Although this study suggests that the retinal OCTA parameter can be used as a predictive biomarker of IS,its potential as a predictor of IS needs to be further clarified in prospective studies with larger sample sizes.Chapter 3.Preliminary research on retinal function in ischemic stroke patientsPurpose:We discovered in the first two chapters that patients with IS not only have retinal microcirculation disorders,but also changes in neural structure.Hence,in this chapter,we preliminarily investigate the retinal function of IS patients using the RETeval device.Methods:Cross-sectional study.Patients who had been given an IS diagnosis in our hospital were gathered from October 2021 to June 2022.The inclusion and exclusion criteria resulted in a total of 36 eyes across 36 patients,with 10 eyes in the IS group and 26 eyes in the control group.Routine ophthalmic examinations and full-field electroretinogram(FERG)with the RETeval device were performed on all patients.The amplitude and implicit time of FERG waves in the two groups were compared.For measurements with a normal distribution,the independent-sample t test was used;otherwise,the Mann-Whitney U test was used.Results:The IS and control groups did not differ statistically significantly in terms of FERG parameters.(P>0.05).Conclusion:Despite reduced retinal microcirculation perfusion and GCC damage in IS patients,retinal photoreceptor cells were not damaged obviously.The RETeval device can evaluate retinal function in patients with IS more quickly and safely than traditional visual electrophysiographs.The sample size should be increased in the future to determine the feasibility of using the RETeval device in patients with IS.