The change of corneal astigmatism after cataract surgery with different locations of clear corneal incision
ZHANG Min, WU Qiang, WANG Wen-qing, LU Bin, FANG Jian, YU Jia-yi
Published 2011-07-10
Cite as Chin J Pract Ophthalmol, 2011,29(07): 686-688. DOI: 10.3760/cma.j.issn.1006-4443.2011.07.012
Abstract
Objective To analyze the corneal astigmatism before cataract surgery and evaluate the astigmatism changes after cataract surgery performed using clear corneal incisions with different locations. Methods This randomized prospective clinical study comprised 295 eyes of 218 patients underwent phacoemulsification and implantation of foldable intraocular lens through a corneal tunnel incision. Patients were randomly divided into three groups depending on the different locations of the incision: temporal, superotemporal and superior. Corneal topography was performed preoperatively and 1week, 1 month, and 3 months postoperatively. Surgically induced changes were calculated by vector analyses using the Holladay-Cravy-Koch method. Results Preoperatively, in 60.68% of eyes, corneal astigmatism was between 0.5 and 1.5 diopters (D) and in 11.86%, it was 1.5 D or higher. Meanwhile,about 29.49 percent of eyes had with-the-rule (WTR) astigmatism, while 51.19% had against-the-rule (ATR) astigmatism, and the others had oblique astigmatism. At three follow-up visits postoperatively,the mean magnitude of surgically-induced astigmatism (SIA) was lowest in the temporal incision group and highest- in the superior incision group. In addition, an ATR shift was found in the superior incision group. Conclusions Corneal astigmatism less than 1.5 D is present in most cataract surgery candidates. Cataract surgery using temporal clear corneal incision induces significantly less SIA in the early postoperative period. Superior incision may lead to an ATR astigmatism shift.
Key words:
Cataract; Phacoemulsification; Clear corneal incision; Corneal astigmatism
Contributor Information
ZHANG Min
Shanghai No.6 People's Hospital, Shanghai 200233, China
WU Qiang
Shanghai No.6 People's Hospital, Shanghai 200233, China
WANG Wen-qing
Shanghai No.6 People's Hospital, Shanghai 200233, China
LU Bin
Shanghai No.6 People's Hospital, Shanghai 200233, China
FANG Jian
Shanghai No.6 People's Hospital, Shanghai 200233, China
YU Jia-yi
Shanghai No.6 People's Hospital, Shanghai 200233, China