Factors influencing refractive outcomes after combined phacoemulsification and pars plana vitrectomy

Abstract

PURPOSE: To evaluate the factors influencing the refractive outcomes of combined phacoemulsification, foldable intraocular lens (IOL) implantation, and pars plana vitrectomy (PPV). SETTING: Department of Ophthalmology, Seoul National University Hospital, Seoul, Korea. METHODS: One hundred fifty-four consecutive patients who had combined phacoemulsification, IOL implantation, and PPV between September 2001 and August 2004 were enrolled in a prospective study. Refractive, keratometric, and axial length measurements were performed preoperatively and 4 months postoperatively. The factors influencing the postoperative refractive outcomes were analyzed. RESULTS: The mean refractive prediction error (ie, actual minus predicted spherical equivalent [SE]) was −0.06 diopters (D) ± 0.75 (SD). In long eyes (preoperative axial length more than 24.5 mm), the mean predicted SE and actual SE were −0.81 ± 0.76 D and −1.24 ± 0.79 D, respectively; the difference was significantly different (P = .001, paired t test). Patients with a preoperative visual acuity worse than 5/200 and those with preoperative foveal detachment had a significant postoperative myopic shift (P = 0.024 and P = 0.002, respectively; paired t test). Postoperative refractive error was not influenced by the intraocular air or gas tamponade during surgery (P = 0.336, paired t test). CONCLUSIONS: The combined surgery included a small biometric error that was within the tolerable range in most cases. However, myopic shifts developed in patients with long axial lengths, poor preoperative visual acuity, and the preoperative presence of foveal detachment.