Calculation of Intraocular Lens Optical Power with Enhanced Depth of Focus

Autor: K. B. Pershin, N. F. Pashinova, A. Yu. Tsygankov, E. A. Antonov
Rok vydání: 2022
Zdroj: The EYE GLAZ. 24:25-31
ISSN: 2686-8083
2222-4408
Popis: Relevance. The new Increased Depth of Focus (EDOF) Intraocular Lens (IOL) technology is designed to improve the correction of visual acuity at a medium distance without compromising distance vision correction and provides a restoration of visual acuity in the distance and at an average distance, but at the same time a lower frequency of side optical phenomena and better contrast sensitivity compared to other multifocal IOLs (MIOL). Regardless of the technology used and the type of lens, the result of surgery and patient satisfaction depend on the optimization of the calculation of the optical strength of the IOL. To date, there is no consensus in the available literature on the choice of a formula for calculating the optical power of known EDOF IOLs.Aim. 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.
Databáze: OpenAIRE
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