Mechanism of ‘Flap Closure’ after the inverted internal limiting membrane flap technique

Abstract

Purpose4 macular hole closure types are known: U‐type, V‐ type, irregular and flat open. After the inverted ILM flap technique some macular holes are covered only with a thin layer of the inverted ILM flap shortly after surgery (flap closure). The aim of this paper is to describe functional and anatomical results in eyes closed with ‘flap closure’.MethodsData of 190 eyes after vitrectomy with the inverted ILM flap technique were reviewed in order to spot eyes, in which the hole was open and covered only with a thin layer of the inverted ILM flap 1 week postoperatively. Swept Source OCT performed preoperatively and at 1 week, 1, 3, 6, and 12 months after surgery was anlyzed.ResultsFlap closure was noted in 50/190 eyes (26.3%) 1 week after surgery. Preoperatively, the minimum hole diameter was 544.04 μm and maximum diameter at the base was 1001.42 μm, in those eyes. Visual acuity improved from 0.91 logMAR to 0.54 logMAR 12 months after surgery. Final closure type of most eyes primarily closed with the inverted ILM flap technique was U‐type closure. Photoreceptor defects improved during the observation period (50 eyes – 1 week, 41 eyes – 1 month, 34 eyes – 3 months, 23 eyes – 6 months, 19 eyes – 12 months). Restoration of the external limiting membrane preceeded restoration of the photoreceptors. Retinal nerve fiber layer defects were noted in 16 eyes 1 month postoperatively. No new retinal nerve fiber layer defects were noted during the rest of follow‐up.ConclusionsMacular holes closed only with a thin layer of the inverted ILM flap preopeartively, improve their architecture up to 12 months after surgery. Visual acuity improvement was noted in those cases. ‘Flap closure’ is a new closure type, which probably enables closure of large macular holes, which would remain open without the use of the inverted ILM flap technique.