Long-term follow up of en face optical coherence tomography of the inner retinal surface following internal limiting membrane peeling for idiopathic macular holes.

Abstract

To evaluate sequential changes in the inner retinal surface using en face spectral domain optical coherence tomography (SD-OCT) following internal limiting membrane (ILM) peeling for idiopathic full thickness macular holes. Retrospective, interventional study on 45 eyes of 42 patients with type 1 macular hole closure after a single procedure and a minimum post-operative follow up of 6months. Best corrected visual acuity (BCVA), fundus photographs, B scan and en face SD-OCT scans were analysed pre-operatively, at 2, 6, 12months post-operatively and then yearly. The presence or absence of concentric macular dark spots (CMDS) on the ILM slab of en face SD-OCT, their distribution pattern and course in terms of number and size of the dark spots was qualitatively assessed at each follow up. CMDS was identified in a total of 26 eyes (57.78%). Of these, it was detected in 21 eyes at 2months and the remaining by 6months. At the time of first detection, the distribution was classified as type 1 in 9 eyes (35%), type 2 in 7 eyes (27%) and type 3 in 10 eyes (38%). There was apparent increase in the number and size of the CMDS in 16 eyes (62%) no later than 12months follow up, while 10 eyes (38%) remained stable. There was no decrease or resolution noted in any patient. The mean post-operative follow up was 19.4months (range 6-69months). Inner retinal defects in the form of CMDS can be picked up on en face SD-OCT between 2-6months post-operatively. They remain stable or become more prominent upto 12months follow up, but do not regress once present. En face SD-OCT is recommended in all cases where ILM is peeled to assess CMDS.