Does internal limiting membrane peeling during epiretinal membrane surgery induce microscotomas on microperimetry? Study protocol for PEELING, a randomized controlled clinical trial

Abstract

Background The epiretinal membrane (ERM) is a degenerative condition associated with age, which can cause loss of vision and/or metamorphopsia. The treatment of symptomatic ERM involves surgical removal including a vitrectomy followed by peeling of the ERM using a microforceps. As the internal limiting membrane (ILM) is adherent to the ERM, it is sometimes removed with it (spontaneous peeling). If ILM remains in place, it can be removed to reduce ERM recurrence. However, it is important to clarify the safety of ILM peeling while it increases surgical risks and cause histological disorganization of the retina that can lead to microscotomas maybe responsible for definitive visual discomfort.Methods PEELING is a prospective, randomized, controlled, single-blind and multi-centered trial with two parallel arms. This study investigates the benefit/risk ratio of active ILM peeling among subjects undergoing ERM surgery without spontaneous ILM peeling. Randomization is done in the operating room after ERM removal if ILM remains in place. After randomization, the two groups "active peeling of the ILM" and "no peeling of the ILM" are compared during a total of three follow-up visits scheduled at M1, M6 and M12. Primary endpoint is the difference in microscotomas before surgery and 6 months after surgery. Patients with spontaneous peeling are not randomized and are included in the ancillary study with the same follow-up visits and the same examinations as the principal study. Relevant inclusion criteria involve subjects over 18 years living with idiopathic symptomatic ERM, including pseudophakic patients with transparent posterior capsule or open capsule or lensed patients with age-related cataracts. The calculated sample size corresponds to 53 randomized eyes (1eye/patient) per arm that means 106 randomized eyes (106 randomized patients) in total and a maximum of 222 included patients (116 spontaneous peeling). Discussion ILM peeling is often practiced in ERM surgery to reduce ERM recurrence. It does not impair post-operative visual acuity but it increases the surgical risks and causes anatomical damages. If active ILM peeling is significantly associated with more microscotomas, it may contraindicate the ILM peeling during primitive idiopathic ERM surgery. Trial Registration ClinicalTrials.gov NCT02146144. Registered May 22, 2014. Recruitment is still 4 ongoing Administrative InformationNote: the numbers in curly brackets in this protocol refer to SPIRIT checklist item numbers. The order of the items has been modified to group similar items (see http://www.equator-network.org/reportingguidelines/spirit-2013-statement-defining-standard-protocol-items-for-clinical-trials/). Title {1}: Prospective, randomized, controlled and single-blind study assessing the benefit/risk ratio of internal limiting membrane (ILM) peeling during Epiretinal Membrane (ERM) surgery.

Effects of Ectopic Inner Foveal Layers on Foveal Configuration and Visual Function After Idiopathic Epiretinal Membrane Surgery

“…Previous studies indicated that the Müller cell activation might contribute to its formation. 17 The ILM peeling during the ERM removal will increase the risk of histological disorganization of the retina but with no impairment of VA. 3,25 This procedure can result in significant damage to the Müller cells, promoting the reparation of injury of the Müller cells. Therefore, the presence of EIFL postoperatively may represent a repair response to the surgical damage.…”