Abstract Purpose: To analyze the correspondence between refractive astigmatism and corneal astigmatism in pseudophakic eyes with non-toric intraocular lenses. Setting: Yeouido St. Mary hospital, Seoul, South Korea Design: Evaluation of a diagnostic test instrument. Methods: This retrospective study included 95 eyes of 95 patients. Corneal astigmatism was measured with an automated keratometer (RK-5, Canon) and Scheimpflug tomography (Pentacam HR, Oculus). Refractive astigmatism was compared to keratometric astigmatism (based on anterior corneal measurements only), Equivalent K Reading and total corneal astigmatism (both based on anterior and posterior corneal measurements). Vector analysis was carried out by Næser’s polar value method. The accuracy was defined as the average magnitude of the vectorial difference in astigmatism (DA). Each corneal measurement was optimized in retrospect by a multiple linear regression equation between refractive and corneal astigmatism. Results: Keratometric astigmatism overestimated with-the-rule (WTR) refractive astigmatism and underestimated against-the-rule (ATR) refractive astigmatism. Several measurements based on both corneal surfaces values did not show any statistically significant difference with respect to refractive astigmatism. The mean corneal astigmatism by total corneal refractive power (TCRP) at 4.0 mm (zone/pupil) produced the lowest mean arithmetic DA and the highest percentage of eyes with a DA ≤0.50 diopter. After optimization, the accuracies of automated KA and TCRP 4.0 mm (zone/pupil) were similar. Conclusions: Total corneal astigmatism measured by the Scheimpflug tomography at 4.0 mm zone centered on pupil, accurately reflects the refractive astigmatism in pseudophakic eyes. However, the accuracy of total corneal astigmatism is not different from automated KA after optimization.

To compare surgical and refractive outcomes between phacotrabeculectomy (P-Trab) and phaco with Ex-PRESS (P-Ex-PRESS) for glaucoma at 6-month follow-up. This prospective randomized controlled trial included 81 eyes; 43 (53%) and 38 (47%) were assigned to the P-Ex-PRESS and P-Trab groups, respectively. Refraction, intraocular pressure (IOP), and best-corrected visual acuity were measured. Refractive change was described by analyzing the magnitude of the cylinder, and polar analysis assessed the change in trend of astigmatism [with-the-rule, against-the-rule (ATR), oblique] evaluating mean astigmatism in centroid form. All patients showed statistically significant postsurgical decrease in IOP (P<0.05). There were no differences neither between the groups for postoperative IOP or visual outcomes, nor in astigmatism before or after surgery (P=0.61, P=0.74). In both groups, the mean pre- and postoperative astigmatism was ATR and OBL, respectively. Pre- and postoperative centroids in the P-Ex-PRESS group were 0.44±1.32 D at 177˚ and 0.35±1 D at 8˚, respectively, (P=0.5) and in the P-Trab group, 0.16±1.5 D at 141˚ and 0.39±1.38 D at 29˚, respectively (P=0.38). Both P-Ex-PRESS and P-Trab showed comparable antihypertensive efficacy in treating open-angle glaucoma in a 6-month period. Pre- and postoperative astigmatism did not differ between groups. The groups showed comparable results for final visual acuity.