To evaluate the difference between the predicted postoperative refraction and the actual postoperative refraction after simultaneous vitrectomy and cataract surgery with sulcus fixation of an intraocular lens (IOL).

The records of patients with simultaneous vitrectomy and cataract surgery with sulcus IOL implantation (group 1) and with in-the-bag IOL implantation (group 2) were reviewed. We compared the spread between the predicted and actual refractive errors in the two groups.

Group 1 consisted of 19 eyes in 19 patients and group 2 consisted of 23 eyes in 20 patients. The spread between the predicted and actual refraction (spread = actual-predicted) was -0.71 ± 1.02 D in group 1 ( p = 0.012) and -0.07 ± 0.74 D in the group 2 ( p = 0.86). The actual refractive errors in group 1 shifted toward myopia from the predicted in-the-bag refraction when compared with group 2.

For the implantation of an IOL in the sulcus after simultaneous vitrectomy and cataract surgery, the IOL power should be approximately 1.0 D less than the power for in-the-bag fixation.