Improving intraocular lens power prediction in combined phacoemulsification and vitrectomy in eyes with macular oedema

Abstract

Purpose: To report the accuracy of intraocular lens (IOL) power estimation in eyes that have undergone phacovitrectomy for retinal diseases with accompanying macular oedema. Methods: A retrospective study was conducted in 23 eyes of 23 patients at Soonchunhyang University Hospital, Seoul, Korea. The relationship between preoperative planned refraction and postoperative achieved refraction was evaluated by simple linear regression analysis. Pre- and postoperative macular thicknesses were measured using optical coherence tomography (OCT). The estimated IOL power of the ultrasound axial length (AL) and the adjusted AL (increased amount of macular thickness added to ultrasound AL) were compared using a paired t-test. Results: The pre- and postoperative refractions were -0.28 +/- 0.14 dioptres (D) and -0.74 +/- 0.48 D, respectively (P = 0.000). The postoperative refraction showed better correlation with the target refraction of the implanted IOL calculated with the adjusted AL (R = 0.608, P = 0.002) compared with the original planned refraction (R = 0.142, P = 0.518). The IOL power calculated with the adjusted AL was 0.59 +/- 0.56 D less than the original IOL power (P = 0.000). Conclusion: Postoperative myopic shift can be corrected by adding the amount of macular thickness measured on OCT to the ultrasound AL, or by simply implanting an IOL 0.50 D less than the IOL targeted for emmetropia.