{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,27]],"date-time":"2026-07-27T14:57:00Z","timestamp":1785164220463,"version":"3.55.0"},"reference-count":29,"publisher":"Public Library of Science (PLoS)","issue":"1","license":[{"start":{"date-parts":[[2026,1,8]],"date-time":"2026-01-08T00:00:00Z","timestamp":1767830400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS One"],"abstract":"\n Purpose<\/jats:title>\n To investigate changes in refractive and corneal astigmatism after Hydrus Microstent (Alcon Inc., Geneva, Switzerland) implantation during microinvasive glaucoma surgery.<\/jats:p>\n <\/jats:sec>\n \n Setting<\/jats:title>\n One German medical center.<\/jats:p>\n <\/jats:sec>\n \n Design<\/jats:title>\n Retrospective, non-randomized, observational cohort study.<\/jats:p>\n <\/jats:sec>\n \n Methods<\/jats:title>\n \n Subjective refraction was obtained mandatorily and keratometry (Pentacam, OCULUS Optikger\u00e4te GmbH, Wetzlar, Germany) optionally preoperatively and after 3 months (D90). Refractive astigmatism was analyzed using three-dimensional (3D) power vectors, including the spherical equivalent,\n M<\/jats:italic>\n , the Jackson cross-cylinder projections to the 0\u00b0 and 90\u00b0 meridian (\n J<\/jats:italic>\n 0<\/jats:sub>\n ) and to the 45\u00b0 and 135\u00b0 meridian (\n J<\/jats:italic>\n 45<\/jats:sub>\n ), and the blurring power vector\n B<\/jats:italic>\n . Corneal anterior and posterior surface astigmatism was investigated using the vectorial parameters\n J<\/jats:italic>\n 0<\/jats:sub>\n ,\n J<\/jats:italic>\n 45<\/jats:sub>\n , and\n B<\/jats:italic>\n . A 3D power vector time-course 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.\n <\/jats:p>\n <\/jats:sec>\n \n Results<\/jats:title>\n \n 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: C\n D0<\/jats:sub>\n \u2009=\u2009\u20131.3\u2009\u00b1\u20090.9 D vs. C\n D90\u2009<\/jats:sub>\n =\u2009\u20131.2\u2009\u00b1\u20091.2 D,\n P<\/jats:italic>\n \u2009=\u20090.6; Stand-alone: C\n D0<\/jats:sub>\n \u2009=\u2009\u20131.6\u2009\u00b1\u20091.3 D vs. C\n D90<\/jats:sub>\n \u2009=\u2009\u20131.6\u2009\u00b1\u20091.2 D,\n P<\/jats:italic>\n \u2009=\u20090.9), and no relevant time\u2013by\u2013group interaction was observed. Multivariate astigmatism analysis (\n M<\/jats:italic>\n ,\n J<\/jats:italic>\n 0<\/jats:sub>\n ,\n J<\/jats:italic>\n 45<\/jats:sub>\n ) indicated a significant change in the phacoemulsification cohort (\n P<\/jats:italic>\n \u2009=\u20090.0003), in contrast to the stand-alone procedure cohort (\n P<\/jats:italic>\n \u2009=\u20090.5). In the phacoemulsification cohort,\n B<\/jats:italic>\n significantly declined from 2.9\u2009\u00b1\u20092.8 D to 1.2\u2009\u00b1\u20091.0 D (\n P<\/jats:italic>\n \u2009<\u20090.0001) but remained stable in the stand-alone group (2.7\u2009\u00b1\u20093.5 D to 2.8\u2009\u00b1\u20093.4 D,\n P<\/jats:italic>\n \u2009=\u20090.07). Corneal astigmatism analysis, based on 55 eyes from 37 patients, showed that the magnitudes of the\n J<\/jats:italic>\n 0<\/jats:sub>\n and\n J<\/jats:italic>\n 45<\/jats:sub>\n vectors remained stable over time for both the anterior (D0:\n J<\/jats:italic>\n 0\u2009<\/jats:sub>\n =\u2009\u20130.12\u2009\u00b1\u20090.07 D, D90:\n J<\/jats:italic>\n 0\u2009<\/jats:sub>\n =\u2009\u20130.21\u2009\u00b1\u20090.07 D,\n P<\/jats:italic>\n \u2009=\u20090.12; D0:\n J<\/jats:italic>\n 45\u2009<\/jats:sub>\n =\u2009\u20130.05\u2009\u00b1\u20090.05 D, D90:\n J<\/jats:italic>\n 45\u2009<\/jats:sub>\n =\u2009\u20130.01\u2009\u00b1\u20090.05 D,\n P<\/jats:italic>\n \u2009=\u20090.5) and posterior surfaces (D0:\n J<\/jats:italic>\n 0\u2009<\/jats:sub>\n =\u20090.12\u2009\u00b1\u20090.01 D, D90:\n J<\/jats:italic>\n 0\u2009<\/jats:sub>\n =\u20090.13\u2009\u00b1\u20090.01 D,\n P<\/jats:italic>\n \u2009=\u20090.3; D0:\n J<\/jats:italic>\n 45<\/jats:sub>\n \u2009=\u2009\u20130.01\u2009\u00b1\u20090.01 D, D90:\n J<\/jats:italic>\n 45\u2009<\/jats:sub>\n =\u2009\u20130.01\u2009\u00b1\u20090.01 D;\n P<\/jats:italic>\n \u2009=\u20090.9), without significant effects of time, group, or their interaction.\n <\/jats:p>\n <\/jats:sec>\n \n Conclusions<\/jats:title>\n The Hydrus Microstent is neutral in refractive astigmatism when used as a stand-alone procedure. In contrast, combined implantation with phacoemulsification can induce changes in refractive astigmatism. Keratometry analysis confirmed that both anterior and posterior corneal astigmatism remain stable, indicating that refractive changes are likely due to internal factors associated with lens exchange rather than the stent itself. Therefore, when implanted alone, the Hydrus Microstent is unlikely to compromise the results of prior refractive treatments.<\/jats:p>\n <\/jats:sec>","DOI":"10.1371\/journal.pone.0340377","type":"journal-article","created":{"date-parts":[[2026,1,8]],"date-time":"2026-01-08T18:27:06Z","timestamp":1767896826000},"page":"e0340377","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":2,"title":["Short-term refractive and corneal astigmatism after canal-based microinvasive glaucoma surgery"],"prefix":"10.1371","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-6746-3681","authenticated-orcid":true,"given":"Colya N.","family":"Englisch","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0277-2525","authenticated-orcid":true,"given":"Karl T.","family":"Boden","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andr\u00e9","family":"Messias","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Philipp K.","family":"Roberts","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0005-0997-6151","authenticated-orcid":true,"given":"Andr\u00e9 M.","family":"Trouvain","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9636-7346","authenticated-orcid":true,"given":"Peter","family":"Szurman","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Achim","family":"Langenbucher","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3587-6382","authenticated-orcid":true,"given":"Philip","family":"Wakili","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2026,1,8]]},"reference":[{"issue":"2","key":"pone.0340377.ref001","article-title":"Causes of blindness and vision impairment in 2020 and trends over 30 years, and prevalence of avoidable blindness in relation to VISION 2020: the Right to Sight: an analysis for the Global Burden of 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