PURPOSE: To determine the accuracy of intraocular lens (IOL) power calculations in eyes with high myopia and to suggest adjusted constants for these cases. SETTING: Centre for Ophthalmology, Eberhard-Karls-University, Tuebingen, Germany. METHODS: Patients with high myopia having phacoemulsification with implantation of an AcrySof MA60MA IOL (power range +5.00 to -5.00 diopters [D]) were evaluated. Optical biometry (IOLMaster) and IOL calculations were performed before and after IOL implantation. Because of different optic principal planes of negative-diopter and positive-diopter IOLs, separate constants were calculated for these groups. RESULTS: Fifty eyes (32 patients) were evaluated. Thirty eyes (mean AL 31.15 mm +/- 1.69 [SD]) had implantation of a positive-diopter IOL (mean power +3.10 +/- 1.50 D) and 18 eyes (mean AL 33.20 +/- 2.25 mm), a negative-diopter IOL (mean power -3.20 +/- 1.70 D). Postoperatively, the mean spherical equivalent was -1.42 +/- 1.33 D and -0.41 +/- 1.81 D, respectively. The difference in optimized constants between positive- and negative-diopter IOLs was significant for all formulas. Power calculation with the SRK II formula showed a wide range of deviation of postoperative refraction from target refraction. Calculation with the Haigis, SRK/T, Holladay 1, and Hoffer Q formulas showed a mean deviation of 0.00 D with an SD of 0.88, 0.92, 1.03, and 1.15, respectively. CONCLUSIONS: Results indicate that the SRK II formula cannot be recommended for IOL power calculation in highly myopic patients. With optimized constants, the SRK/T, Haigis, Hoffer Q, and Holladay 1 formulas produced small deviation of postoperative refraction from target refraction.
PURPOSE: To determine the accuracy of intraocular lens (IOL) power calculations in eyes with high myopia and to suggest adjusted constants for these cases. SETTING: Centre for Ophthalmology, Eberhard-Karls-University, Tuebingen, Germany. METHODS:Patients with high myopia having phacoemulsification with implantation of an AcrySof MA60MA IOL (power range +5.00 to -5.00 diopters [D]) were evaluated. Optical biometry (IOLMaster) and IOL calculations were performed before and after IOL implantation. Because of different optic principal planes of negative-diopter and positive-diopter IOLs, separate constants were calculated for these groups. RESULTS: Fifty eyes (32 patients) were evaluated. Thirty eyes (mean AL 31.15 mm +/- 1.69 [SD]) had implantation of a positive-diopter IOL (mean power +3.10 +/- 1.50 D) and 18 eyes (mean AL 33.20 +/- 2.25 mm), a negative-diopter IOL (mean power -3.20 +/- 1.70 D). Postoperatively, the mean spherical equivalent was -1.42 +/- 1.33 D and -0.41 +/- 1.81 D, respectively. The difference in optimized constants between positive- and negative-diopter IOLs was significant for all formulas. Power calculation with the SRK II formula showed a wide range of deviation of postoperative refraction from target refraction. Calculation with the Haigis, SRK/T, Holladay 1, and Hoffer Q formulas showed a mean deviation of 0.00 D with an SD of 0.88, 0.92, 1.03, and 1.15, respectively. CONCLUSIONS: Results indicate that the SRK II formula cannot be recommended for IOL power calculation in highly myopic patients. With optimized constants, the SRK/T, Haigis, Hoffer Q, and Holladay 1 formulas produced small deviation of postoperative refraction from target refraction.
Authors: V Vasavada; S K Shah; V A Vasavada; A R Vasavada; R H Trivedi; S Srivastava; S A Vasavada Journal: Eye (Lond) Date: 2016-08-05 Impact factor: 3.775
Authors: Jasmine K M Lam; Tommy C Y Chan; Alex L K Ng; Vanissa W S Chow; Victoria W Y Wong; Vishal Jhanji Journal: Graefes Arch Clin Exp Ophthalmol Date: 2016-06-16 Impact factor: 3.117