Yukari Yaguchi1, Kazuno Negishi2, Megumi Saiki1, Hidemasa Torii1, Kazuo Tsubota1. 1. Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan. 2. Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo, 160-8582, Japan. fwic7788@mb.infoweb.ne.jp.
Abstract
PURPOSE: To compare the accuracy of several methods of intraocular lens (IOL) power calculations used for cataract surgery in eyes treated with phototherapeutic keratectomy (PTK) that results in changes in the anterior corneal surface and axial length; these results make power calculations less predictable. METHODS: We evaluated the medical records of 23 eyes of 13 patients (mean age, 68.8 years; range 62-80 years) who underwent cataract surgery after PTK at Keio University Hospital, Tokyo, Japan. The prediction error, defined as the difference between the estimated postoperative spherical equivalent and the postoperative manifest refraction at the spectacle plane, was calculated using five formulas: SRK/T, Haigis-L, Shammas-PL, Camellin-Calossi, and OKULIX ray tracing software. We compared the median values of the arithmetic and absolute prediction errors among the five formulas. RESULTS: The median arithmetic errors after cataract surgery for the five formulas were 0.70 D (diopter) (range -0.41 to 2.78), -0.96 D (range -2.14 to 0.81), -0.81 D (range -1.89 to 1.15), -0.04 D (range -1.35 to 1.47), and 0.68 D (range -0.61 to 2.50), respectively. CONCLUSION: The Camellin-Calossi formula is a good option for calculating IOL powers in eyes that underwent PTK.
PURPOSE: To compare the accuracy of several methods of intraocular lens (IOL) power calculations used for cataract surgery in eyes treated with phototherapeutic keratectomy (PTK) that results in changes in the anterior corneal surface and axial length; these results make power calculations less predictable. METHODS: We evaluated the medical records of 23 eyes of 13 patients (mean age, 68.8 years; range 62-80 years) who underwent cataract surgery after PTK at Keio University Hospital, Tokyo, Japan. The prediction error, defined as the difference between the estimated postoperative spherical equivalent and the postoperative manifest refraction at the spectacle plane, was calculated using five formulas: SRK/T, Haigis-L, Shammas-PL, Camellin-Calossi, and OKULIX ray tracing software. We compared the median values of the arithmetic and absolute prediction errors among the five formulas. RESULTS: The median arithmetic errors after cataract surgery for the five formulas were 0.70 D (diopter) (range -0.41 to 2.78), -0.96 D (range -2.14 to 0.81), -0.81 D (range -1.89 to 1.15), -0.04 D (range -1.35 to 1.47), and 0.68 D (range -0.61 to 2.50), respectively. CONCLUSION: The Camellin-Calossi formula is a good option for calculating IOL powers in eyes that underwent PTK.
Entities:
Keywords:
Band keratopathy; Camellin–Calossi formula; Granular corneal dystrophy type 2; Intraocular lens power calculation; Phototherapeutic keratectomy
Authors: David Smadja; Marcony R Santhiago; Glauco R Mello; David Touboul; Michael Mrochen; Ronald R Krueger Journal: J Refract Surg Date: 2013-01 Impact factor: 3.573