Методы расчета оптической силы интраокулярной линзы с увеличенной глубиной фокуса

Abstract

Perpose. Retrospective analysis of the accuracy of 7 formulas for optical power calculation of a new extended depth of focus intraocular lens. Methods. The retrospective study included 34 patients (62 eyes) with implantation of a new EDOF Tecnis Symfony IOL ZXR00. The mean age of the patients was 61.9 ± 9.4 (39–87) years. IOL optical power range was +5.0 to +30.0 D, target refraction was –0.25 to 0.25 D. The average follow-up period for the patients was 12.3 ± 1.8 months. The SRK/T, Barrett Universal II, Haigis, Hoffer Q, Holladay 2, Olsen, and Kane formulas were retrospectively analyzed for effectiveness using appropriate constants. Each formula was optimized for the study group of patients to achieve an average refractive error as close to zero as possible. For each formula, the mean error (ME), mean absolute error (MAE), standard deviation (SD), median absolute error (MedAE), maximum absolute error (MaxAE), and percentage of eyes within the error range of 0.25, 0.5, 1.0, and 2.0 D were calculated. Results. The optimized constants were LF = 2.21, a0 = 1.43, a1 = 0.39, a2 = 0.12, personalized ACD = 5.68, ACD (Hoffer Q/Holladay 2) = 5.68/5.66, A-constant (SRK/T/Kane) = 119.5/119.4. For the SRK/T, Barrett Universal II, Kane and Haigis formulas the lowest MAE is shown. Application of the Hoffer Q and Holladay 2 formulas are associated with the highest MAE. The Barrett Universal II, SRK/T, Kane, and Haigis formulas were characterized by the highest percentage of reaching refraction of ±0.25 D (64, 62, 59, and 53 %, respectively). For all of the formulas examined, the frequency of reaching refraction of ±1.00 D was greater than 90 % and within ±2.00 D greater than 97 %. Conclusion. This study was the first to retrospectively compare seven formulas for calculating the optical power of a new intraocular lens with an enhanced depth of focus. The SRK/T, Barrett Universal II, Haigis, and Kane formulas are recommended for calculating the optical power of the indicated IOL in clinical practice. Keywords: cataract, phacoemulsification, EDOF, Symfony, IOL optical power calculation, constant optimization.