Purpose: To compare the refractive results of 4 different options for the Barrett True-K formula in eyes with previous myopic excimer laser surgery.
Setting: IRCCS-Fondazione Bietti, Rome, Italy.
Design: Retrospective case series.
Methods: Biometric measurements obtained with a rotating Scheimpflug camera (Pentacam) were entered into the Barrett True-K formula. Clinical history (laser-induced refractive change) and the measured posterior corneal curvature were entered as optional. Four variants of the Barrett True-K formula were investigated: (1) with history and measured posterior corneal power, (2) with history and predicted posterior corneal power, (3) no history with measured posterior corneal power, and (4) no history with predicted posterior corneal power. The prediction error (PE) was calculated as the difference between the measured and predicted postoperative refraction values.
Results: In 50 eyes (50 patients), the Barrett True-K formula with history and measured posterior corneal power resulted in the lowest standard deviation of the PE (0.52 diopters [D]), lowest median (0.245 D) and mean (0.413 D) absolute errors, and highest percentage of eyes with a PE within ±0.25 D (54%), ±0.50 D (70%), and ±0.75 D (84%). The Barrett True-K no-history formula with predicted posterior corneal power yielded the worst refractive outcomes. When the 4 options were compared, statistically significant differences were detected among the median absolute errors (P = .0017) and the percentage of eyes with a PE within ±0.25 D (P < .0001).
Conclusions: Using historical data and measured posterior corneal power improved the refractive accuracy of the Barrett True-K formula in eyes with previous myopic excimer laser surgery.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1097/j.jcrs.0000000000000205 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
[Development and validation of a risk prediction model for early postoperative high intraocular pressure after implantation of posterior chamber intraocular lens].
Zhonghua Yi Xue Za Zhi
January 2025
Ophthalmology Center, the Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou310009, China.
To develop and validate a predictive model for assessing the risk of early postoperative high intraocular pressure (HIOP) following posterior chamber intraocular lens implantation. The clinical data of patients who underwent posterior chamber intraocular lens implantation at the Second Affiliated Hospital of Zhejiang University School of Medicine between May 2023 and April 2024 were retrospectively reviewed. Patients were divided into a modeling group and a validation group with a 7∶3 ratio using computerized random allocation.
View Article and Find Full Text PDFRepeatability of Pentacam HR in Keratoconus According to Two Different Scan Protocols: 25-3D Scan and 50-Cornea Fine.
J Clin Med
January 2025
Eye Clinic, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, 25121 Brescia, Italy.
This study aims to evaluate the repeatability of the Pentacam HR, comparing two different measurement modes (50-cornea fine and 25-3D scan) in patients affected by keratoconus. Multicenter retrospective study, conducted at Eye Clinic of the ASST-Spedali Civili-University of Brescia, Italy, and St. Paul's Eye Unit, Royal Liverpool University Hospital, United Kingdom.
View Article and Find Full Text PDFA Pilot Case Series on the Use of a Large Mushroom-Shaped Corneal Graft for the Surgical Management of Post-Penetrating Keratoplasty Ectasia and Endothelial Failure.
J Clin Med
January 2025
Eye Unit, Department of Medical and Surgical Specialties, Radiological Sciences, and Public Health, University of Brescia, 25123 Brescia, Italy.
: The aim of this study was to evaluate the effect of a surgical technique for managing post-penetrating keratoplasty (PK) ectasia complicated by late endothelial failure (LEF). : A single-center pilot case series was conducted regarding consecutive patients affected by post-PK ectasia with late graft failure. Using a microkeratome, a single donor cornea was dissected to prepare a two-piece graft, comprising a larger anterior lamella made up of anterior stroma and a smaller posterior lamella made up of posterior stroma, Descemet's membrane, and endothelium.
View Article and Find Full Text PDFEstablishment of an Ex Vivo Human Corneal Endothelium Wound Model.
Transl Vis Sci Technol
January 2025
UCL Institute of Ophthalmology, University College London, London, UK.
Purpose: A human model able to simulate the manifestation of corneal endothelium decompensation could be advantageous for wound healing and future cell therapy assessment. The study aimed to establish an ex vivo human cornea endothelium wound model where endothelium function can be evaluated by measuring corneal thickness changes.
Methods: The human cornea was maintained in an artificial anterior chamber, with a continuous culture medium infusion system designed to sustain corneal endothelium and epithelium simultaneously.
Intraocular lens power calculation in cataract patients with keratoconus: Bayesian network meta-analysis.
Int Ophthalmol
January 2025
Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Laboratory, No.1, Dong Jiao Min Xiang, Dong Cheng District, Beijing, 100730, China.
Purpose: To compare the accuracy of intraocular lens (IOL) power calculation formulas in cataract patients with keratoconus (KC).
Methods: This study followed the Preferred Reporting Items for Systematic Reviews and Meta-analysis statementand and was registered on PROSPERO (CRD42024568997). Pubmed, Web of Science, Cochrane Library, and EMBASE were searched for retrospective and prospective clinical studies published until October 2024.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!