A retrospective analysis of the intraocular lens power calculation in cases of sulcus fixation.

PURPOSE

To evaluate the refractive results in patients with intraocular lenses fixated in the sulcus of posterior chamber. Sulcus fixation causes a more anterior position of IOL than had been intended during the preoperative power calculation. A lack of correction of the IOL's power results in a myopic shift.

MATERIAL AND METHODS

27 patients (27 eyes) who underwent cataract surgery by phacoemulsification and foldable IOL MA60BM sulcus fixation due to a posterior capsule rupture at the Department of Ophthalmology, Medical University of Warsaw. The position of the IOL was confirmed by ultrabiomicroscopy. The study included patients with axial lengths ranging from 22 to 25 mm. Patients who suffered from a corneal astigmatism of > 1,00 Dcyl prior to the surgery were excluded from the study. The study also excluded patients with vitreous loss as this causes the anterior chamber to become deeper after vitrectomy, and consequently the IOL might sit in a more posterior position. The difference between the predicted and the postoperative refraction was evaluated.

RESULTS

The mean visual acuity was significantly better after cataract surgery. The best corrected visual acuity (BCVA) was 1.0, which occurred in 19 cases (70%). The myopic shift, which was assessed as a mean difference between the predicted and the postoperative refraction after sulcus fixation, was 1.25 D.

CONCLUSIONS

In order to avoid a myopic shift in the case of sulcus fixation, the IOL power calculation should be adjusted accordingly. The authors recommend that the IOL power should be reduced by approximately 1.25 to 1.50 D in emetropic eyes.