Biometric error analysis after cataract surgery performed by residents, in patients with high myopia with SRK/T formula and Wang-Koch formula adjustment

Abstract

ABSTRACT Objective To evaluate intraocular lens power calculation and postoperative refractive errors in patients with high myopia undergoing cataract surgery, comparing predicted target refraction and actual postoperative refraction measured 30 days after surgery with SRK/T formula. Methods This retrospective analysis comprised 39 eyes of 31 patients undergoing cataract surgery through phacoemulsification with in-the-bag IOL implantation. Axial length was measured by partial coherence interferometry or immersion ultrasound biometry, with measurements greater than 26 mm and preoperative myopia greater than -6.0 D Manifest refraction was performed at the 1-month postoperative visit, and the spherical equivalent was analyzed. Results After analysis of 39 eyes of 31 patients undergoing cataract surgery with a mean axial length of 30.4 (standard deviation of 2.2) mm, the mean preoperative refractive spherical equivalent was -15.6 (standard deviation of 7.6) D, ranging from -24.0 to -13.4 D. At 30 days postoperatively, the mean spherical equivalent was -0.35 (standard deviation of 1.1) D, ranging from -2.4 to 2.50 D. Conclusion We encountered a correlation between the absolute refractive error and the dioptric power of the intraocular lens. Against expectations, in our study, ultrasound biometry yielded better results than the optical biometer device, probably due to the small number of patients undergoing optical biometry, suggesting that well-performed immersion biometry can still produce satisfactory results.

Keywords

• Biometry
• Intraocular lens
• Refractive errors
• Myopia
• Cataract extraction