Effect of Gas Tamponade on the Intraocular Lens Position and Refractive Error after Phacovitrectomy: A Swept-Source Anterior Segment OCT Analysis.

Abstract

To investigate the intraocular lens (IOL) position and refractive outcomes after cataract surgery and phacovitrectomy using swept-source anterior segment OCT (SS-ASOCT). Retrospective case series. Patients underwent cataract surgery (group A: 34 eyes), phacovitrectomy without gas tamponade (group B: 20 eyes), and phacovitrectomy with gas tamponade (group C: 22 eyes). Various parameters associated with the anterior chamber and lens were measured by SS-ASOCT (CASIA2; Tomey Corp, Nagoya, Japan) before and after surgery. Axial lengths were measured by optical biometry (IOLMaster; Carl Zeiss, Oberkochen, Germany). The refraction (spherical equivalent) was measured 1 week and 1 month after surgery. Refractive outcomes and the parameters measured by SS-ASOCT were statistically evaluated. The overall mean median absolute error (MedAE) was 0.34 diopters (D) at 1 month postoperatively. The MedAE was greater in group C (0.47 D) than in group A (0.31 D) and group B (0.20 D). The overall mean refractive prediction error (ME) was -0.22±0.62 D at 1 month postoperatively. The ME was significantly greater in group C (-0.82±0.64 D) than in group A (0.08±0.39 D) and group B (-0.07±0.45 D) (P < 0.001, P < 0.001), indicating a greater myopic shift in group C. The forward movement of the IOL position was significantly correlated with a greater ME at 1 month (R = 0.53, P < 0.001). Forward fixation of the IOL caused myopic refractive errors even after the gas had disappeared in eyes that underwent phacovitrectomy with gas tamponade.