Association Between Retinal Thickness And Clinical Symptoms In Patients With Spinocerebellar Ataxia Type 3

Objective: The aim of this study is to investigate the changes in peripapillary retinal nerve fiber layer(p RNFL)and the thickness of macular internal limiting membrane-retinal pigment epithelium(ILM-RPE)in spinocerebellar ataxia type 3(SCA3),and to analyze the association between retinal thickness and clinical symptoms in SCA3 to identify the possible role of retinal thickness as a potential biomarker in assessing the severity of symptoms in SCA3.Method: 1.Patients with ataxia who attended the Affiliated Hospital of Hangzhou Normal University from November 2020 to December 2022 were recruited.After dynamic mutation screening,28 patients diagnosed with SCA3 were enrolled,and 19 sex and age-matched healthy controls were collected.2.The recruited patients were assessed with the Scale for the Assessment and Rating of Ataxia(SARA),the International Cooperative Ataxia Rating Scale(ICARS),the Berg Balance Scale(BBS),Pittsburgh Sleep Quality Index(PISQ)and Epworth Sleepiness Scale(ESS).3.All SCA3 patients and healthy controls underwent peripapillary and macular optical coherence tomography(OCT),intraocular pressure measurement,fundoscopy,exophthalmos measurement and visual acuity assessment of both eyes.4.IBM SPSS25.0 was used to analyze the differences in retinal thickness in different regions between the SCA3 and healthy controls,and the association between retinal thickness and the severity of clinical symptoms in SCA3 patients.Results: The present study found that compared with healthy controls,the p RNFL thickness in all sectors,except for the nasal quadrant,was significantly thinner in SCA3 patients(P<0.05);and the thickness of ILM-RPE in the macular areas decreased in all quadrants(P < 0.05).Throuth peripapillary OCT,p RNFL thicknesses(superior,inferior and average)were inversely correlated with SARA and ICARS scores,the thinner the p RNFL thicknesses,the more severe the ataxia symptoms.Furthermore,the correlations between higher SARA scores and lower p RNFL thickness in superior quadrant was observed on binomial logistic regression(OR=0.922,95%CI 0.853-0.997,P =0.043).The ILM-RPE thickness and cube volume was found to be negatively correlated with PSQI scores and positively correlated with sleep efficiency by macular OCT.Furthermore,binomial logistic regression identified lower ILM-RPE thickness was significantly associated with worse PSQI scores(OR=0.911,95%CI 0.834-0.996,P =0.041),and lower cube volume in ILM-RPE was significantly associated with worse PSQI scores(OR=0.09,95%CI 0.010-0.831,P =0.034)and worse sleep efficiency(OR=0.073,95%CI0.006-0.954,P =0.046).Conclusion: Compared with healthy controls,the retinal thicknesses of SCA3 patients were thinner,and were correlated with clinical symptoms.Of which,the changes of p RNFL thicknesses(superior,inferior and average)were correlated with ataxia symptoms;the changes of ILM-RPE thickness in macular area are related to sleep disorders.Which provided potential biological markers for future assessment of disease severity and progression in SCA3 patients.