Outcomes of the Haigis-L formula for calculating intraocular lens power in Asian eyes after refractive surgery

PURPOSE: To report outcomes using the Haigis-L formula to calculate intraocular lens (IOL) power in Asian eyes with long axial lengths (ALs) that had previous myopic laser in situ keratomileusis (LASIK) or photorefractive keratectomy (PRK). SETTING: Singapore National Eye Centre, Singapore. DESIGN: Retrospective case series. METHODS: Patients with ALs greater than 25.0 mm and previous myopic LASIK or PRK who had phacoemulsification were analyzed. The emmetropic IOL power was back-calculated using the 1-month postoperative manifest refraction and compared with the emmetropic IOL power calculated with the Haigis-L formula. The primary outcome measure was the mean arithmetic prediction error, defined as the difference between the actual postoperative refractive error and the intended formula-derived refractive target. RESULTS: Sixty-two eyes (52 patients) were analyzed. The mean arithmetic prediction error was -0.44 diopter (D) +/- 0.98 (SD) and the mean absolute error, 0.87 +/- 0.62 D. The mean arithmetic prediction error was -0.52 +/- 0.96 D in eyes with an AL less than 27.0 mm and -0.36 +/- 1.00 D in eyes with an AL of 27.0 mm or greater (P = .463). The predictability of being within +/- 0.50 D and +/- 1.00 D of target was 35.7% and 63.1%, respectively, overall; 31.6% and 60.5%, respectively, in eyes with an AL less than 27.0 mm; and 39.1% and 65.2%, respectively, in eyes with an AL of 27.0 mm or greater (P = .772). CONCLUSION: The Haigis-L formula was acceptably accurate in predicting and achieving target outcomes after phacoemulsification in Asian eyes with a long AL that had previous myopic LASIK or PRK. (C) 2015 ASCRS and ESCRS