Comparison Of Change In Aqueous Depth In Patients Undergoing Phacovitrectomy In One Eye And Phacoemulsification In The Fellow Eye

The role of the vitreous on the effective lens position (ELP) is controversial in eyes undergoing pars plana vitrectomy. This information is relevant because changes in ELP may affect the residual refractive error in eyes undergoing simultaneous cataract surgery or phacovitrectomy. We compared the change in aqueous depth, a proxy of the ELP, between eyes of patients undergoing phacovitrectomy in one eye and phacoemulsification in their fellow eye.

The study was conducted in OMIQ (Oftalmologia Mèdica i Quirúrgica) Research facilities, a private institution in Barcelona, Spain.

Post-hoc analysis of a prospective study in which patients with bilateral cataracts and unilateral epiretinal membrane grades 2 or 3 underwent phacovitrectomy and membrane peeling in one eye and phacoemulsification in their fellow eye. Axial length was measured using the same biometer (Lenstar 900®, Haag-Streit); intraocular lens (IOL) was calculated by the same formula (Barret Universal II) and targeting emmetropia, and both eyes were implanted with the same IOL (AcrySof® IQ Vivity®, Alcon Healthcare). Mean change in aqueous depth in mm was compared between groups (vitrectomized and non-vitrectomized) six months after surgery, and also determined using mixed-effects models.

We included 20 vitrectomized and 20 non-vitrectomized eyes of 20 patients, 11/20 (55%) of whom were female, with a mean age of 71.6 years. At baseline, there was no statistically significant difference between groups in spherical equivalent, axial length, keratometry or lens thickness. The mean change in aqueous depth was +1.51 mm in vitrectomized vs +1.42 mm in non-vitrectomized eyes (p=0.33). On mixed-effects models, vitrectomy had no effect on aqueous depth change (p≥0.10). The percentage of eyes within +/-0.50D and the mean residual spherical equivalent did not differ between groups (p≥0.37).

There were no statistically significant differences in aqueous depth difference between eyes undergoing phacovitrectomy and those undergoing simple phacoemulsification. Vitreous absence had a minor effect on ELP or residual spherical equivalent in these patients.