Study On Fundus Morphological Differences From Diffuse Chorioretinal Atrophy To Patchy Chorioretinal Atrophy In Pathological Myopia

Objective:To study the fundus morphological differences and its influencing factors in the progression from diffuse chorioretinal atrophy to patchy chorioretinal atrophy in pathological myopia.To provide measurable parameters for clinical diagnosis,treatment and disease prediction of pathological myopia.Methods:A total of 91 patients(137 eyes)with pathological myopia were collected from the Third Affiliated Hospital of Nanchang University.The subjects were selected strictly according to the inclusion and exclusion criteria.The relevant examination and data collection were based on the results of optometry,fundus photography,DRI-OCT Atlantis OCT and IOL-Master.According to fundus morphology and META-PM classification,the cases were divided into two groups,included C2 stage:diffuse chorioretinal atrophy(DCA group),C3 stage:patchy chorioretinal atrophy(PCA group).The observation indicators included:Age,axial length,diopter,best corrected visual acuity(BCVA),choroidal thickness,retinal thickness,retinal nerve fiber layer thickness,optic nerve head(ONH)area,the location and area of Bruch’s membrane opening(BMO),posterior scleral morphology,temporal scleral margin morphology.The influence and correlation of the above indicators between the two groups were compared.To discuss the progress indexes and correlation from DCA group to PCA group.Results:There were 97 eyes in the DCA group and 40 eyes in the PCA group in this study.Compared with the DCA group,the PCA group had longer axial length,greater diopter,and worse best-corrected visual acuity,and the differences were statistically significant(t=-3.39,t=-2.07,t=2.28,all P<0.05).There was no statistically significant difference in the age of the patients.The choroidal thickness in the central area,the1st ring(EDTRS Grid)nasal side,the 1st ring temporal side,the 2nd ring nasal side,and the 2nd ring temporal side area in the PCA group were thinner than those in the DCA group,and the difference was statistically significant(t=3.61,t=4.23,t=4.03,t=1.99,t=2.63,all P<0.05);there was no significant difference in choroidal thickness between the other areas.The temporal retinal thickness of the 1st ring in the PCA group was thinner than that in the DCA group,and the difference was statistically significant(t=2.14,P<0.05).The thickness of the nerve fiber layer above the PCA group was thinner than that of the corresponding area in the DCA group,and the difference was statistically significant(t=2.19,P<0.05);there was no statistical difference between the other areas.The ONH area in the PCA group was larger than that in the DCA group,and the difference was statistically significant(t=-2.50,P=0.02<0.05).There was no significant difference in the BMO area between the two groups.The posterior scleral morphology of the two groups was mainly type II,the differences were statistically significant(X~2=8.69,P=0.03<0.05).There was no significant difference in the distribution of temporal scleral margin morphology between the two groups.Conclusion:Compared with DCA,PCA had longer axial length,higher diopter,and decreased best-corrected visual acuity;the central,nasal,and temporal choroids were thinner;the temporal retina was thinner;the superior nerve fiber layer was thinner;The optic disc area is larger.The two types of the posterior sclera were mainly distributed in type II,among which type II and type III posterior sclera were more likely to develop from DCA to PCA.There was no significant correlation between scleral limbal shape.