Forward fixation of IOL causes myopic refractive errors after phacovitrectomy with gas tamponade

Myopic refractive errors result from forward fixation of the intraocular lens (IOL) even when gas has disappeared in eyes undergoing phacovitrectomy with gas tamponade, a recent study has shown.

This retrospective case series sought to examine the IOL positive and refractive outcomes after cataract surgery and phacovitrectomy using swept-source anterior segment optical coherence tomography (SS-ASOCT). Patients were categorized as follows: those who underwent cataract surgery (group A: 34 eyes) and those who had phacovitrectomy with gas tamponade (group C: 22 eyes) and without (group B: 20 eyes).

The authors used SS-ASOCT before and after surgery to measure various parameters associated with the anterior chamber and lens. Optical biometry was also used to measure axial lengths. Refraction (spherical equivalent) was measured 1 week and 1 month after surgery. The authors statistically assessed refractive outcomes and parameters measured by SS-ASOCT.

At 1 month after surgery, the overall mean median absolute error (MedAE) was 0.34 dioptres (D). Eyes in group C had greater MedAE than those in groups A and B (0.47 vs 0.31 and 0.20 D). On the other hand, the overall mean refractive prediction error (ME) at 1 month postoperatively was –0.22±0.62 D. Group C also had significantly greater ME than groups A and B (−0.82±0.64 vs 0.08±0.39 and −0.07±0.45; p<0.001), which indicated a greater myopic shift in group C.

In addition, the forward movement of the IOL position at 1 month was found to be significantly associated with a greater ME (R, 0.53; p<0.001).