Abstract:  Objective To compare the difference of the changes of corneal topography after direct cyclopexy from after internal cyclopexy. Design Retrospective case series. Participants 27 patients (27 eyes) with cyclodialysis were included in Beijing Tongren Eye Center from January 2018 to December 2020. 17 eyes with lens underwent direct cyclopexy and 10 eyes with intraocular lens or intraoperative combined lens resection underwent internal cyclopexy. Methods All patients were operated by the same surgeon. In the internal cyclopexy group, cyclodialysis was sutured without direct visualization which one of the two long straight needles of a double armed 10/0 polypropylene thread was pierced into the eye through corneal limbus. All patients were examined by ultrasound biomicroscopy (UBM) before and after operation to evaluate the cyclodialysis. Pentacam examination was performed before, 1 week and 1 month after operation to analyze the changes of corneal topography parameters. Main Outcome Measures Pentacam parameters including astigmatism of anterior corneal surface, Rper (mean radius of curvature in the 7-9 mm area of the cornea), index of surface variance (ISV) and index of vertical asymmetry (IVA). Results In the internal cyclopexy group, astigmatism of anterior corneal surface, Rper, ISV and IVA at 1 week after operation was (1.19±0.96) D, (8.10±0.30) mm, (18.50±6.13), (0.15±0.05) respectively; however, in direct cyclopexy group, astigmatism of anterior corneal surface, Rper, ISV and IVA at 1 week after operation was (2.02±1.03) D, (8.05±0.29) mm, (27.00±4.69), (0.18±0.05) respectively. There was significant statistical difference in astigmatism and ISV between the two groups at 1 week after operation (t=2.122, P=0.046; t=3.764, P=0.002). In 10 eyes of internal cyclopexy and 9 eyes of direct cyclopexy group, the differences of all the parameters between two groups in 1 month after operation were no statistically significant (all P>0.05). Conclusion Direct cyclopexy can cause early postoperative astigmatism changes while internal cyclopexy has little effect on postoperative astigmatism.（Ophthalmol CHN, 2022, 31: 146-150）

Key words:  cyclodialysis, corneal topography, astigmatism