Effect of Trabeculectomy on Mean and Centroid Surgically Induced Astigmatism

• Published in: Journal of clinical medicine Vol. 11; no. 1; p. 240
• Main Authors: Ando, Wakako, Kamiya, Kazutaka, Kasahara, Masayuki, Shoji, Nobuyuki
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 03.01.2022; MDPI
• Subjects: Approximation; Automation; Cataracts; Clinical medicine; Cornea; Eye surgery; Glaucoma; Hospitals; Lasers; Patient satisfaction; Statistical analysis; Sutures; Trends; trabeculectomy; corneal astigmatism; surgical induced astigmatism; arithmetic mean; centroid; glaucoma
• ISSN: 2077-0383; 2077-0383
• DOI: 10.3390/jcm11010240

This study aimed to investigate the arithmetic mean of surgically induced astigmatism (M-SIA) and the centroid of surgically induced astigmatism (C-SIA) after standard trabeculectomy. We comprised 185 eyes of 143 consecutive patients (mean age ± standard deviation, 67.7 ± 11.6 years) who underwent trabeculectomy and completed at least a 3-month routine follow-up. In all cases, the scleral flap was made at the nasal-superior location. Corneal astigmatism was measured with an automated keratometer. We calculated the M-SIA and the C-SIA using vector analysis and applied the astigmatism double angle plot. The magnitude of corneal astigmatism increased significantly, from 1.17 ± 0.92 D preoperatively to 1.77 ± 1.05 D postoperatively (paired -test, < 0.001). The M-SIA was 1.12 ± 0.55 D, and the C-SIA was 0.73 D @64° ± 1.02 D in the right eye group, and the M-SIA was 1.08 ± 0.48 D and the C-SIA was 0.60 D @117° ± 1.03 D in the left eye group. The C-SIA showed an astigmatic shift toward the nasal-superior location of the scleral flap creation. Our results revealed that trabeculectomy induced the SIA in the direction of the scleral flap location and that the C-SIA was much lower than the M-SIA in eyes undergoing trabeculectomy.