Purpose: To investigate the magnitudes and the axis orientations of anterior, posterior, and total central corneal astigmatism in eyes with keratoconus.
Design: Retrospective case series.
Methods: This study comprised 137 eyes of 137 keratoconic patients (97 men and 40 women; mean age ± standard deviation, 36.9 ± 12.2 years). The magnitude and the axis orientation of each corneal astigmatism were determined with a rotating Scheimpflug system.
Results: The mean magnitudes of anterior, posterior, and total central corneal astigmatism were 3.93 ± 2.74 diopters (D), 0.93 ± 0.64 D, and 3.90 ± 2.75 D, respectively. With-the-rule (WTR), against-the-rule (ATR), and oblique astigmatism of the anterior corneal surface was found in 90 eyes (65.7%), 33 eyes (24.1%), and 14 eyes (10.2%), respectively, whereas the corresponding astigmatism of the posterior corneal surface was found in 14 eyes (10.2%), 15 eyes (10.9%), and 108 eyes (78.8%), respectively. We found a significant correlation between the magnitudes of anterior and posterior corneal astigmatism (Pearson correlation coefficient r = 0.769, P < .001).
Conclusions: The mean magnitudes of anterior and posterior corneal astigmatism were approximately 4 D and 1 D, respectively, in eyes with keratoconus. Approximately 65% and 80% of eyes showed that WTR anterior astigmatism and ATR posterior astigmatism, respectively. The presence of posterior corneal astigmatism is not necessarily negligible for the accurate astigmatic correction of toric intraocular lens implantation or rigid gas-permeable contact lens wear for keratoconus.
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http://dx.doi.org/10.1016/j.ajo.2015.08.016 | DOI Listing |
Purpose: To evaluate the clinical outcome of laser-assisted surgical correction of high hyperopic or mixed astigmatism using small incision intrastromal lenticule rotation (SMILERO) alone or combined with photorefractive keratectomy (PRK).
Methods: This retrospective case series enrolled 25 eyes with high astigmatism that underwent SMILERO surgery. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), uncorrected near visual acuity (UNVA), manifest refraction, central corneal thickness, and corneal higher order aberrations were analyzed before surgery and after 3, 6, and 12 months of follow-up.
Purpose: To evaluate a new regression-derived nomogram for high myopic astigmatism in small incision lenticule extraction (SMILE) surgery.
Methods: In this prospective study, data from 180 eyes with myopic astigmatism ranging from -2.50 to -4.
Purpose: To compare the clinical outcomes, surgical workflow, and patient satisfaction following small incision lenticule extraction (SMILE) performed with the VisuMax 800 in one eye and the VisuMax 500 in the contralateral eye (both Carl Zeiss Meditec).
Methods: This was a prospective, single-site clinical study of patients undergoing SMILE for myopia and myopic astigmatism between February 2022 and August 2023. Each patient underwent bilateral treatment using the VisuMax 800 (VM800 group) in one eye and the VisuMax 500 (VM500 group) in the contralateral eye.
Purpose: To evaluate residual refractive errors after intraocular lens (IOL) extraction and the safety and effectiveness of refractive correction procedures.
Methods: The eligibility criteria for this systematic review were patients who had undergone cataract or clear lens extraction and had experienced residual refractive error. All study designs were considered for inclusion and non-English publications, non-peer reviewed articles, books, and systematic reviews were excluded.
Korean J Ophthalmol
January 2025
Department of Ophthalmology, Seoul National University Bundang Hospital, Seongnam, Korea.
Purpose: To evaluate the accuracy of toric intraocular lens (IOL) axis prediction between two preoperative measurement devices: the optical biometry (IOLMaster 500 or 700) and the dual Scheimpflug topography (Galilei G4).
Methods: Medical records of 64 eyes from 44 patients who underwent phacoemulsification and posterior chamber toric IOL (Zeiss AT TORBI 709M) implantation between July 2017 and January 2022 were reviewed. All patients underwent preoperative evaluation by optical biometry (IOLMaster 500 or IOLMaster 700) and Galilei G4.
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