Calculation of Intraocular Lens Power with the Srk Ii Formula for Axial High Myopia

Abstract

Aim.

The SRK II formula has been widely used for intraocular lens (IOL) power calculations. The predictability of this formula is evaluated in axial myopic patients. Methods. Planned extracapsular cataract extraction and posterior chamber IOL implantation (PECCE+IOL) were performed on 98 eyes of 98 patients with axial length > 24.5 mm. Cases had no preoperative complications and postoperative visual acuity was at least 0.5 (Snellen). Corneal refractive power and axial length were measured preoperatively and emmetropic IOL power calculations were made using the SRK II formula. Long-term (mean 4.7 months) visual acuities and refractions were noted postoperatively.

Results.

The absolute refractive error was < 1.00 Diopters (D) in 57 eyes (58.2%) and < 2.00 D in 83 eyes (84.7%). The mean absolute error of the SRK II formula in axial myopia was 1.16 D ± 0.78 SD.

Conclusions.

The SRK II formula is not very accurate in axial myopic patients.