Short-term refractive and corneal astigmatism after canal-based microinvasive glaucoma surgery

Q: What is the main purpose of this study?

To assess short-term changes in refractive and corneal astigmatism after Hydrus Microstent implantation during microinvasive glaucoma surgery.

Q: How was refractive and corneal astigmatism measured?

Subjective refraction was obtained mandatorily, and keratometry with Pentacam was obtained optionally preoperatively and at 3 months, analyzed using 3D power vectors and vectorial parameters.

Q: What were the key findings about astigmatism after Hydrus Microstent alone versus combined surgery?

When used as a stand-alone procedure, the Hydrus Microstent was neutral regarding refractive astigmatism. Combined implantation with phacoemulsification induced significant changes in refractive astigmatism, while corneal anterior and posterior astigmatism remained stable.

Sep 30, 2026

Uploaded by jayni

Purpose: investigate refractive and corneal astigmatism changes after Hydrus Microstent implantation during microinvasive glaucoma surgery. Setting: one German medical center. Methods: retrospective, non-randomized observational cohort; mandatory subjective refraction and optional keratometry (Pentacam) preoperatively and at 3 months. Results: 90 eyes included; refractive cylinder showed no time variation in either cohort, but multivariate analysis revealed significant astigmatism change in the phacoemulsification cohort. Blurring power vector decreased with combination surgery, while corneal anterior and posterior astigmatism vectors remained stable. Conclusions: the stent alone is neutral for refractive astigmatism; combined implantation with phacoemulsification can alter refractive astigmatism via lens-exchange-related internal factors.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages13

Reading Time33 min

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Abstract

Purpose and Setting

Methods

Results

Conclusions

Introduction

OPEN ACCESS Citation: Englisch CN, Boden KT, Messias A, Roberts PK, Trouvain AM, Szurman P, et al. (2026) Short-term refractive and corneal astigmatism after canal-based microinvasive glaucoma surgery. PLoS One 21(1): e0340377 . [https://doi.org/10.1371/journal.pone.0340377](https://doi.org/10.1371/journal.pone.0340377) Editor: Nader Hussien Lotfy Bayoumi, Alexandria University Faculty of Medicine, EGYPT Received: May 28, 2025 Accepted: December 20, 2025 Published: January 8, 2026 Copyright: © 2026 Englisch et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data availability statement: All relevant data are within the manuscript and its Supporting Information files. Funding: The author(s) received no specific funding for this work. RESEARCH ARTICLE Short-term refractive and corneal astigmatism after canal-based microinvasive glaucoma surgery Colya N. Englisch1,2*, Karl T. Boden André M. Trouvain1, Peter Szurman 1,3, André Messias1, Philipp K. Roberts1, 1,3, Achim Langenbucher2, Philip Wakili1* 1 Eye Clinic Sulzbach, Knappschaft Hospitals Saar, Sulzbach/Saar, Germany, 2 Department of Experimental Ophthalmology, Saarland University, Homburg/Saar, Germany, 3 Klaus Heimann Eye Research Institute (KHERI), Sulzbach/Saar, Germany * [colya.englisch@uni-saarland.de](colya.englisch@uni-saarland.de) (CNE); Philip.Wakili@Knappschaft-Kl[iniken.de](iniken.de) (PW) Abstract Purpose To investigate changes in refractive and corneal astigmatism after Hydrus Microstent (Alcon Inc. , Geneva, Switzerland) implantation during microinvasive glaucoma surgery. Setting One German medical center. Design Retrospective, non-randomized, observational cohort study. Methods Subjective refraction was obtained mandatorily and keratometry (Pentacam, OCULUS Optikgeräte GmbH, Wetzlar, Germany) optionally preoperatively and after 3 months (D90) . Refractive astigmatism was analyzed using three-dimensional (3D) power vectors, including the spherical equivalent, M, the Jackson cross-cylinder projections to the 0° and 90° meridian (J0) and to the 45° and 135° meridian (J45), and the blurring power vector B. Corneal anterior and posterior surface astigmatism was investigated using the vectorial parameters J0 , J45 , and B. A 3D power vector timecourse analysis of refractive astigmatism was performed using multivariate pairwise testing, and linear mixed-effects models, accounting for patient ID as a random effect, were used for the remaining analyses. PLOS One | [https://doi.org/10.1371/journal.pone.0340377](https://doi.org/10.1371/journal.pone.0340377) January 8, 2026 1 / 13 Competing interests: The authors have declared that no competing interests exist. Results A total of 90 ocular hypertension/glaucoma eyes were included. Sixty eyes were implanted with a Hydrus Microstent and phacoemulsified, and 30 eyes underwent implantation as a stand-alone procedure. Univariate analysis of the refractive cylinder showed no variation over time in any cohort (Phacoemulsification: CD0 =–1.3 ± 0.9 D vs. CD90 =–1.2 ± 1.2 D, P = 0.6; Stand-alone: CD0 =–1.6 ± 1.3 D vs. CD90 =–1.6 ± 1.2 D, P = 0.9), and no relevant time–by–group interaction was observed. Multivariate astigmatism analysis (M, J0 , J45) indicated a significant change in the phacoemulsification cohort (P = 0.0003), in contrast to the stand-alone procedure cohort (P = 0.5) . In thephacoemulsification cohort, B significantly declined from 2.9 ± 2.8 D to 1.2 ± 1.0 D (P< 0.0001) but remained stable in the stand-alone group (2 .7 ± 3.5 D to 2.8 ± 3.4 D, P = 0.07) . Corneal astigmatism analysis, based on 55 eyes from 37 patients, showed that the magnitudes of the J0 and J45 vectors remained stable over time for both the anterior (D0: J0 =–0.12 ± 0.07 D, D90: J0 =–0.21 ± 0.07 D, P =

FAQs

What is the main purpose of this study?

To assess short-term changes in refractive and corneal astigmatism after Hydrus Microstent implantation during microinvasive glaucoma surgery.

How was refractive and corneal astigmatism measured?

Subjective refraction was obtained mandatorily, and keratometry with Pentacam was obtained optionally preoperatively and at 3 months, analyzed using 3D power vectors and vectorial parameters.

What were the key findings about astigmatism after Hydrus Microstent alone versus combined surgery?

When used as a stand-alone procedure, the Hydrus Microstent was neutral regarding refractive astigmatism. Combined implantation with phacoemulsification induced significant changes in refractive astigmatism, while corneal anterior and posterior astigmatism remained stable.

Sep 30, 2026

Uploaded by jayni