Comparison of the Postoperative Refractive Errors Measured by Ultrasound and Partial Coherence Interferometers after Phacovitrectomy

Purpose: To compare the accuracy of refractive outcome measured by Ultrascan (Alcon, Fort Worth, TX, USA) and partial coherence interferometers after phacovitrectomy. Methods: We performed a retrospective study in 74 eyes of 74 patients who underwent phacovitrectomy. SRK-T formula was used to predict intraocular lens (IOL) power. The difference between the predicted and postoperative refractive outcomes for the 2 methodologies (Ultrascan and IOL Master [Zeiss, Carl Zeiss, Jena, Germany]) were compared. The predicted refractive outcome was defined as the estimated refractive error when the selected IOL was inserted. Results: The axial length measured using IOL Master was statistically longer than when measured using Ultrascan (23.85 ± 0.15 mm, 23.56 ± 0.15 mm, p < 0.001). Based on keratometry, statistically significant difference between the 2 groups was not observed. The postoperative refractive error was more accurate when using the IOL Master than Ultrascan (0.08 ± 0.74, 0.47 ± 0.69, p < 0.001). However, in cases of vitreous hemorrhage, the postoperative refractive error was 0.42 ± 0.49 with the IOL Master and 0.07 ± 0.54 with the Ultrascan. Conclusions: Generally, IOL Master is a more accurate method for calculating the IOL power prior to phacovitrectomy. However, in cases of vitreous hemorrhage, Ultrascan appears superior to IOL Master when calculating the IOL power. J Korean Ophthalmol Soc 2015;56(7):1059-1064