Refractive Outcome after Phacoemulsification Using Optical Biometry versus Immersion Ultrasound Biometry

Abstract

Purpose: To compare refractive outcome after phacoemulsification using optical biometry versus immersion ultrasound biometry (US) .Patients and methods: A prospective, comparative, non-randomized interventional study included 100 eyes divided into 2 groups: Group (A): (Immersion US biometry) included 50 eyes. Axial Eye Length (AEL) was measured by immersion B scan (immersion A-scan with B- mode guided image). It was further subdivided into Group A1 (AEL ≥ 25 mm) and Group A2 (AEL < 25 mm). Group B (Optical biometry) included 50 eyes. AEL was measured using optical biometry. It was also subdivided into Group B1 (AEL ≥ 25) mm and Group B2 AEL < 25. Intra ocular lens (IOL) power was calculated using Haigis formula targeting post-operative refraction –0.5 to -1 D. Phacoemulsification with posterior chamber IOL was performed. The 2 groups were compared preoperatively for AEL, Keratometic measurements, uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA) and density of cataract. They were compared postoperatively for UCVA, BCVA, spherical equivalent (SE) and mean absolute error (MAE). Results: The study included (100 eyes). Group A1 included 9 eyes (18%) and Group A2 included 41 eyes (82%). Group B1 included 18 eyes (36%) and Group B2 Included 32 eyes (64%). Preoperative comparisons revealed insignificant statistical differences between the 2 groups in the mean AEL, IOL power, preoperative UCVA and BCVA, degree and density of cataract, and K readings. Post operatively there was insignificant statistical differences between the 2 groups in the mean of UCVA and BCVA. There was insignificant statistical differences between subgroups A1and B1 and subgroups A2 and B2 in the median of SE and MAE. Conclusion: The immersion B scan biometry and optical biometry gave comparative results with precise final post-operative refractive outcome.