Visual outcomes and incidence of pseudophakic cystoid macular oedema in eyes with cataract and idiopathic epiretinal membrane after two-step sequential surgery.

OBJECTIVES To determine whether pars plana vitrectomy (PPV) or cataract surgery should be performed first in concurrent epiretinal membrane (ERM) and cataract treatment with respect to visual outcome and pseudophakic cystoid macular oedema (PCMO) incidence. METHODS Patients who underwent PPV and cataract surgery sequentially at a tertiary medical centre were retrospectively recruited. Best-corrected visual acuity (BCVA) and central macular thickness (CMT) measured from optical coherence tomography (OCT) images collected before and after each surgery were documented. OCT-defined PCMO incidence and its influence on visual outcomes were analysed. RESULTS In total, 259 and 159 eyes received PPV (ERM-CATA) before and after cataract surgery (CATA-ERM), respectively. The ERM-CATA group had better final BCVA (logMAR: 0.274 vs. 0.558, p < 0.001) and greater BCVA gain (logMAR VA change: -0.379 vs. -0.220, p = 0.001) than did the CATA-ERM group. Baseline BCVA was positively correlated with final BCVA (p < 0.001), whereas baseline CMT, final CMT, and postoperative CMT changes were not. PCMO incidence did not differ significantly between the two groups (15.4% vs. 19.5%, p = 0.287), and final BCVA changes did not significantly differ between eyes with and without PCMO. PCMO incidence was much higher (29.40% vs. 16.30%, p = 0.008) in eyes with baseline CMT ≥ 500 μm. CONCLUSIONS When managing ERM and cataract, PPV should be performed before cataract surgery to yield better visual outcomes. Both surgical sequences yield similar PCMO rates. Greater baseline CMT is a risk factor for PCMO after cataract surgery.