Refractive change and optical biometry dynamics after 25-gauge vitrectomy in pseudophakic eyes

To investigate the refractive change and optical biometry dynamics after 25-gauge vitrectomy without gas tamponade for macular pathology in pseudophakic eyes.

A prospective observational case series.

Patients with pseudophakic eyes who were scheduled for vitrectomy owing to macular pathology by an experienced surgeon (T.S.) at the Hayashi Eye Hospital between March 2019 and February 2020.

The primary endpoint was the change in manifest refraction spherical equivalent (MRSE) between baseline (preoperatively) and 3 months postoperatively. The secondary endpoint was the change in optical biometry parameters obtained by swept-source optical coherence tomography-based biometers between baseline and 3 months postoperatively. Optical biometry parameters included corneal curvature and axial length, evaluated by the IOLMaster 700, and intraocular lens position-that is, lens decentration, lens tilt, and aqueous depth (AQD)-evaluated by the CASIA2.

Thirty-four eyes of 34 patients were enrolled. The mean MRSE values at baseline and 3 months postoperatively were -0.70 ± 1.21 diopter (D) and -0.82 ± 1.27 D, respectively, showing a significant myopic shift of -0.12 ± 0.41 D postoperatively (p = 0.043). There was no significant difference between the pre- and postoperative values of the optical biometry parameters, except for the AQD (4.28 ± 0.34 mm vs 4.27 ± 0.34 mm; p = 0.019).

The results suggest that replacing the vitreous by the aqueous during vitrectomy induces an average myopic shift of -0.12 D.