Changes Of Corneal Thickness And Topography In Patients With Moderate To Severe Congenital Ptosis Before And After Surgery

Purpose:Through the comparison of corneal thickness,corneal topographic parameters and visual acuity changes before and after ptosis correction surgery in patients with moderate to severe congenital ptosis aged from 3 to 18 years,the corneal changes before and after congenital ptosis surgery were investigated,in order to provide a basis for the causes of corneal changes in patients with congenital ptosis.Method:In this study,A total of45 patients with moderate to severe unilateral congenital ptosis and surgical correction of ptosis were selected in the Ophthalmology department of our hospitalfrom June 2021 to December 2022.The patients were divided into two groups: observation group(ptosis eye),and control group(contralateral eye).The preoperative data of observation group and control group were collected:optical coherence tomography angiography(optical coherence tomography angiography,OCTA)anterior segment function measured corneal thickness in 17zones(C,S5,SN5,N5,IN5,I5,IT5,T5,ST5,S6,S6,SN6,N6,IN6,I6,IT6,T6,ST6),and corneal topography was used to measure corneal curvature K1,corneal curvature K2,corneal astigmatism(cylinder,CYL),surface regularity index(SRI),surface asymmstry index(SAI),and best corrected visual acuity(BCVA).The observation group underwent ptosis correction and collected BCVA,full corneal thickness in zone 17,K1,K2,CYL,SRI,and SAI at 1 month and 3 months postoperatively.SPSS 26.0 was used for statistical analysis,with within-group comparisons using repeated measures ANOVA and between-group comparisons between the observation and control groups using t-test.Results:1.The change of corneal thickness: there was no significant difference in all areas of the observation group at 1 month after surgery compared with that before surgery(P>0.05).At 3 months after operation,the S5 and S6 regions of the observation group were thinner than those before operation and were close to those of the control group,and the difference was statistically significant(P<0.05).In the observation group,there were no significant changes in other regions at 3 months after operation compared with those before operation,and the difference was not statistically significant(P>0.05).In the observation group,there was no significant difference in all regions between 1 month after operation and 3 months after operation(P>0.05).The preoperative C,S5,SN5,ST5,S6,SN6,ST6 in the observation group were significantly thicker than those in the control group,and the difference was statistically significant(P<0.05).There was no significant difference in other areas between the observation group and the control group before operation(P>0.05).2.The changes of corneal topography: the K2,K1,CYL,SAI,SRI of the observation group before surgery,1 month and 3 months after surgery had no significant changes(P>0.05).The preoperative K1,CYL,SRI and SAI of the observation group were higher than those of the control group,and the differences were statistically significant(P<0.05).The preoperative K2 of the observation group was higher than that of the control group,but there was no statistically significant difference between the two groups(P>0.05).3.Changes of BCVA: the BCVA(Log MAR)in the observation group was gradually improved at 1 month and 3 months after operation,but there was no statistically significant difference between the two groups(P>0.05).The preoperative BCVA(Log MAR)of the observation group was significantly higher than that of the control group,and the difference was statistically significant(P<0.05).Conclusion:1.In patients with moderate to severe unilateral congenital ptosis,the corneal area covered by the eyelid before surgery was thicker than that of the contralateral eye.With the increase of recovery time after surgery,the cornea in S5 and S6 regions gradually became thinner and closer to that of the contralateral normal eye,which may be related to the long-term pressure of ptosis on the cornea,leading to corneal hypoxia and edema and then increasing corneal thickness.When the ptosis is corrected,the pressure of the upper eyelid on the cornea is relieved,and the corneal thickness becomes thinner and closer to the contralateral eye.2.In patients with moderate to severe unilateral congenital ptosis,the cornea of the ptosis eye is more irregular and asymmetric than that of the contralateral eye,and the corneal astigmatism is bigger.The fluctuation of corneal topography related parameters after surgical correction may be caused by vertical pressure caused by continuous eyelid edema after surgery.3.In patients with moderate to severe unilateral congenital ptosis,the BCVA of the ptosis eye is worse than that of the contralateral eye.