Purpose To investigate the incidence, clinical features and risk factors of premacular membrane (PMM) formation after primary rhegmatogenous retinal detachment (RRD) repair with scleral buckling (SB) alone.

Methods This institutional, prospective and consecutive case series included phakic eyes with RRD, treated with SB alone within 7 days from the occurrence of symptoms, with a follow-up of 6 months. Spectral-domain optical coherence tomography images were reviewed. The association of PMM development and morphology with preoperative and intraoperative RRD features was analysed.

Results Ninety-two patients with a mean age of 56±13 years completed the 6 months follow-up period. Postoperatively, eyes with any PMM stage were 30 out of 92 (32.6%) at 1 month and 47 out of 92 (51,1%) at both 3 months and 6 months. Over the follow-up period, 17 out of 47 PMMs (36.2%) progressed to later stages. Progression of PMMs to later stages were observed only in RRDs involving the macular region (17 out of 35 eyes, 48.5%), while none of the PMMs in macula-sparing detachments progressed to later stages (p=0.020). The risk factors significantly associated with postoperative new onset of PMM were preoperative RRDs involving the macular region (p=0.001), cryopexy time (p=0.045), presence of horseshoe tears (p=0.003), worse preoperative visual acuity (p=0.004) and subretinal fluid drainage (p=0.047).

Conclusion The incidence of postoperative PMM formation after RRD repair with SB alone was high. In retinal detachments involving the macular region PMM were more severe, tending to anatomical progression and functional deterioration. Activation of foveal Müller cell in detachments involving the macula may be a key factor in PMM progression.