Secondary Macular Holes Post Pars Plana Vitrectomy

Purpose: To report incidence, clinical presentation, and treatment outcome of full-thickness macular hole (FTMHs) diagnosed post pars plana vitrectomy. Methods: We retrospectively reviewed the demographics, best-corrected visual acuity (BCVA), indication for the primary vitrectomy, time to diagnose the secondary FTMH, optical coherence tomographic (OCT) appearance, and treatment outcome of FTMHs, occurring after vitrectomy performed between January 2019 and December 2020. Results: Six of 523 vitrectomized eyes developed FTMHs, an incidence of 1.1%. There were five females and one male, mean age of 56.5 years (range 37-85). The indication for primary vitrectomy was rhegmatogenous retinal detachment (RRD) in three eyes, one eye each for sub internal limiting membrane hemorrhage from a ruptured macroaneurysm, vitreous hemorrhage from polypoidal choroidal vasculopathy (PCV), and pre-insertion of Ahmed glaucoma drainage device (GDD). FTMHs occurred within one week to three months after vitrectomy (time from primary vitrectomy to the identification of the secondary MH was a mean of 1.03 months). Mean BCVA in all six MH eyes was log MAR 0.9 (Snellen: 6/54). Anatomical closure was achieved after one surgery in three eyes, two surgeries in 1 eye, after photodynamic therapy (PDT) in the PCV eye, and one patient declined surgery. The mean BCVA in the four surgically closed MH eyes improved marginally from log MAR 0.82 (Snellen: 6/38) to log MAR 0.72 (Snellen: 6/30), mean follow-up 7.6 months. Conclusion: Post-vitrectomy FTMH is rare, and RRD was the commonest indication for initial vitrectomy. We observed that all secondary MHs were closed successfully using the inverted internal limiting membrane (ILM) flap technique with limited improvement in vision. The visual outcome of these secondary MHs trails behind that of idiopathic MHs.