Aim: To investigate the outcome of the inverted Internal Limiting Membrane (ILM) flap technique for extra large idiopathic macular holes (MHs).
Methods: A retrospective non-comparative surgical case series of seven eyes of 7 patients with MHs (base diameter of at least 1000 ?m) was conducted. All the MHs were treated using pars plana vitrectomy and brilliant blue G (BBG)-assisted inverted ILM flap technique. Spectral Domain- Optical Coherence Tomography (SD-OCT) images were used to assess the anatomical outcomes of surgery including the macular microstructure, while Best Corrected Snellen Visual Acuity (BCSVA) was used to evaluate the functional outcomes.
Results: The average MH size was 1241microns and average symptom duration was nineteen months. All eyes achieved successful anatomical closure and there was no occurrence of a flat open type closure. SD-OCT microstructural study revealed a reconstruction of the Ellispod Zone (EZ) and External Limiting Membrane (ELM), in only 3 eyes. There was an improvement in visual acuity in 5 eyes, while 2 eyes maintained the same as pre operative vision. The largest increase in post operative visual acuity gain was a 4-line improvement in Best Corrected Snellen Visual Acuity (BCSVA) noted in one of the 3 eyes with reconstructed EZ and ELM. The 3 months symptom duration in this patient was the shortest in this series.
Conclusion: Inverted ILM flap technique is a safe and effective approach for the management of extra large chronic idiopathic MHs with demonstrably good anatomical and limited functional results in a majority of cases. Postoperative reconstruction of the microstructure is however seen only in a minority of eyes. Despite an absence of the outer retina (EZ and ELM), some eyes still experience an improvement in vision. The symptom duration may play a vital role in functional outcome in this subset of extra large chronic MHs.