Intraocular lens power calculation for cataract surgery after photorefractive keratectomy.
نویسندگان
چکیده
OBJECTIVE To assess intraocular lens (IOL) power calculations in patients undergoing cataract surgery after excimer laser photorefractive keratectomy (PRK) for myopia. METHODS Four eyes of two patients underwent phacoemulsification with IOL implantation after PRK for myopia. The estimated refractive error that would have been induced had the IOL predicted for emmetropia been implanted was calculated using SRK-II, SRK/T, Holladay, and Binkhorst formulas. Manual keratometry and videokeratography-simulated keratometry values measured before surgery were used. Keratometry values calculated by subtracting the refractive change induced by the excimer laser PRK from the manual keratometry or videokeratography-simulated keratometry values measured before PRK were also used. Both spectacle and corneal plane calculations were performed. RESULTS Manual keratometry and videokeratography-simulated keratometry values underpredicted the IOL power. Corneal plane manual or videokeratography refraction-derived keratometry calculations were most accurate using the SRK/T formula, while spectacle plane calculations were most accurate using the SRK-II formula. In both methods the calculated refractive error was within 0.52 diopters (D) for the emmetropic lens power predicted. Statistical analysis was not performed. CONCLUSIONS Refraction-derived keratometric values provided the most accuracy in calculating IOL powers. Our results suggest the SRK/T formula was the most accurate for corneal plane calculations, while the SRK-II formula was the most accurate for spectacle plane calculations.
منابع مشابه
Clinical and theoretical results of intraocular lens power calculation for cataract surgery after photorefractive keratectomy for myopia.
OBJECTIVES To describe the refractive results of cataract surgery after photorefractive keratectomy (PRK) for patients with myopia, and to find a more accurate method to predict intraocular lens (IOL) power in these cases. DESIGN Nonrandomized, retrospective clinical study. PATIENTS AND METHODS Nine patients (15 eyes) who underwent cataract surgery after prior PRK to correct myopia were ide...
متن کاملIntraocular Lens Power Calculation after Corneal Refractive Surgery
PURPOSE To determine the accuracy of a method of calculating intraocular lens (IOL) power after corneal refractive surgery. SETTING Department of Ophthalmology, Hospital de Gipuzkoa, San Sebastián, Spain. METHODS The SRK/T formula was modified to use the pre refractive surgery K-value (Kpre) for the effective lens position (ELP) calculation and the post refractive surgery K-value (Kpost) fo...
متن کاملAccuracy of Scheimpflug Holladay equivalent keratometry readings after corneal refractive surgery.
PURPOSE To determine the accuracy of Pentacam Scheimpflug system Holladay equivalent keratometry (K) readings (EKRs) in calculating intraocular lens (IOL) power after corneal refractive surgery, including laser in situ keratomileusis (LASIK), photorefractive keratectomy (PRK), and radial keratotomy (RK). SETTING Jules Stein Eye Institute, David Geffen School of Medicine at University of Calif...
متن کاملمقایسهی کراتومتری پنتاکم وکراتومتری IOL Master در محاسبهی لنز داخل چشمی افراد با قرنیهی طبیعی
Background and Objective: Proper method and machine for corneal evaluation is an important factor in many anterior segment interventions. This study was performed to compare the mean keratometry (K) readings obtained with an IOL Master and Pentacam for intraocular lens power calculation in normal subjects with no history of refractive surgery. Materials and Methods: Mean K values were obtained ...
متن کاملComparison of IOL power calculation methods and intraoperative wavefront aberrometer in eyes after refractive surgery.
PURPOSE To compare preoperative methods for calculating intraocular lens (IOL) power versus the intraoperative wavefront aberrometer in eyes with a history of refractive surgery. METHODS A retrospective study of 46 eyes (33 patients) with previous refractive surgery that underwent subsequent cataract surgery was conducted. Suggested IOL power predicted by ORange intraoperative wavefront aberr...
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ورودعنوان ژورنال:
- Archives of ophthalmology
دوره 121 7 شماره
صفحات -
تاریخ انتشار 1997