The effect of internal limiting membrane peeling on the inner retinal layers in patients without macular pathology

Abstract

Background: To examine the effect of internal limiting membrane (ILM) peeling on the inner retinal layers in patients without macular pathology. Methods: A prospective nonrandomized trial of patients undergoing pars plana vitrectomy with ILM peeling for pathology outside of the macula was performed. Optical coherence tomography (OCT) including macular ganglion cell layer (GCL), inner plexiform layer (IPL) and peripapillary retinal nerve fiber layer imaging was performed prior to surgery, 1,3 and 6 months post-operatively and at the end of follow up (ranges between 4-17 months). Patients with any macular pathology on OCT prior to surgery were excluded. The main outcome measure was change in thickness of the GCL and IPL. Results: Ten patients who underwent pars plana vitrectomy with ILM peeling for macula-on retinal detachment were included in the analysis. The mean age was 55 years and the mean follow up was 10.8 months. All patients completed at least 2 post-operative follow up visits that included an OCT as per the protocol (range 2-6 months). There was an immediate reduction in the global (G), infero-temporal (IT), supero-temporal (ST) and superior (S) GCL thickness at the first follow up as compared to the pre-operative state (P=0.028, P=0.027, P=0.026 and P=0.027 respectively). From the first follow up visit onward until the final follow up the thinning persisted, though there was no further statistically significant thinning. Conclusion: Peeling of the ILM causes significant GCL thinning in maculae without pathology prior to surgery. At up to 17 months of follow up, this effect seems to be immediate and non-progressive.