Intraocular lens power calculation and optimized constants for highly myopic eyes.

Full Abstract

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.

Author information

Author/s: Petermeier, Katrin (K); Gekeler, Florian (F); Messias, Andre (A); Spitzer, Martin S (MS); Haigis, Wolfgang (W); Szurman, Peter (P);

Affiliation: University Eye Hospital, Centre for Ophthalmology, Eberhard-Karls University, Tuebingen, Germany. katrin.petermeier(-atsign-)med.uni-tuebingen.de

Journal and publication information

Publication Type: Journal Article; Research Support, Non-U.S. Gov't

Journal: Journal of cataract and refractive surgery (J Cataract Refract Surg), published in United States. (Language: eng)

Reference: 2009-Sep; vol 35 (issue 9) : pp 1575-81

Dates: Created 2009/08/17; Completed 2009/10/23;

PMID: 19683155, status: MEDLINE (last retrieval date: 10/23/2009, IMS Date: )

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