Influence of phacoemulsification combined with limbal relaxing incisions for preoperative astigmatism on corneal high-order aberrations

Abstract

Background phacoemulsification combined with limbal relaxing incision (LRI) is reported to be effective for the management of coexisting cataract astigmatism, but the influence of after phacoemulsification with LRI on corneal high-order aberration is still rarely reported. Objective This study was to evaluate the effect of cataract surgery with LRI for preoperative astigmatism or on corneal high-order aberration. Methods A self-controlled serial cases observational study was designed.A total of 35 cataractous eyes of 35 patients with astigmatism ≥1.0 D before cataract surgery were enrolled in Tianjin Medical University Eye Hospital from August 2014 to April 2015 under the informed consent of patients.LRIs were performed on the eyes during the phacoemulsification and IOL implantation.The uncorrected visual acuity (UCVA), BCVA and optometry were recorded before operation and 1 day, 1 week, 1 month, 3 months after operation.Pentacam was employed to measure the maximal and minimal diopters, astigmatism and high-order aberrations within 3 mm of the anterior corneal surface at above-mentioned time points.All the results were compared among different time points.The optometry outcomes and the anterior corneal surface astigmatism change were analyzed using vector analysis method. Results The UCVA was 0.34±0.22, 0.38±0.25, 0.43±0.27, 0.42±0.28 in 1 day, 1 week, 1 month and 3 months after operation, which was significantly higher than 0.08±0.09 before operation; and the BCVA was 0.54±0.27, 0.64±0.29, 0.67±0.29, 0.71±0.32 in 1 day, 1 week, 1 month and 3 months after operation, showing a significant increase in comparison with 0.22±0.51 before operation(F=54.457, P=0.000; F=62.653, P=0.000). The refractive cylindrical error and corneal astigmatism were significantly decreased after operation in comparison with before operation(F=31.061, P=0.000; F=113.043, P=0.000). High order aberrations (HOA) at postoperative 1 day, 1 week, 1 month, 3 months were all higher than those in preoperation (F=11.189, P=0.000) under the 4 mm pupil diameter.Compared with preoperation, the vertical coma, secondary vertical coma and three leaf clover were significantly increased(all at P 0.05) under the 6 mm pupil diameter. Conclusions Phacoemulsification combined with LRI can reduce the corneal astigmatism effectively and steadily, and the increase of corneal aberrations does not affect visual acuity. Key words: Cataract/surgery; Cataract/complication; Astigmatism/surgery; High order aberration; Limbal relaxing incision