Refractive Outcomes and Anterior Chamber Depth after Cataract Surgery in Eyes with and without Previous Pars Plana Vitrectomy.

To compare the differences in refractive outcome and anterior chamber depth (ACD) after phacoemulsification between eyes with and without previous pars plana vitrectomy (PPV). Patients who had significant cataracts after PPV were included in the study group, and patients with a matched axial length (AL) who had cataracts without PPV were selected as the control group. The performance of new generation intraocular lens (IOL) power calculation formulas (Barrett Universal II, Kane, Ladas Super formulas), and the traditional formulas (SRK/T, Holladay 1, Hoffer Q, Haigis) with and without the Wang-Koch (WK) AL adjustment were compared between the two groups. The postoperative ACD was measured using the Scheimpflug imaging system with manual correction at least three months after surgery. In total, there were 193 eyes from 193 patients in each group. The mean prediction errors (MEs) of the new generation formulas had no significant systemic bias in the study group; the hyperopic shift was displayed in the traditional formulas for eyes with AL > 26mm. However, the difference of MEs between the two groups among all the formulas were not significant. The absolute prediction error (MAE) and median prediction error (Med AE) in the study group were larger than those in the control group among all the formulas. The postoperative ACD of the study group was deeper but not significant than that of the control group. There was no refractive shift in vitrectomized eyes compared with non-vitrectomized eyes no matter in new generation formulas or traditional vergence formulas. The prediction error among all the formulas in vitrectomized eyes were significantly higher than those in non-vitrectomized eyes. The ACD after phacoemulsification in vitrectomized eyes was not significantly different from non-vitrectomized eyes.