Optical Coherence Tomography Angiography (OCTA) Changes in Patients With Epiretinal Membranes (ERM) With and Without Peeling of the Internal Limiting Membrane (ILM)
Condition: Epiretinal Membrane of Both Eyes
MeSH terms: Epiretinal Membrane
Study type: Interventional

Summary: 
      Main objective

      The objective is to compare two surgical options in vitrectomies for epiretinal membranes
      using parameters of optical coherence tomography angiography.

      Background

      State of the art treatment for epiretinal membranes consists of pars plana vitrectomy,
      staining of the epiretinal membrane with a blue colouring dye and epiretinal membrane
      peeling. The vitrectomized space is filled with fluid (balanced salt solution) during the
      procedure and the fluid can optionally be replaced with air as a final step. After ERM
      peeling (but before the selection of the tamponade), the internal limiting membrane (the
      innermost layer of the retina) is either peeled as well or left untouched and the question
      which method should be preferred has been a hot topic in recent years. The investigators want
      to investigate possible effects of the used method (peeling vs. nonpeeling) on retinal
      perfusion parameters represented by OCTA. Two epiretinal membrane patient groups will
      therefore be formed: The first group's (group 1) ILM will be peeled, the second group's
      (group 2) ILM will not be peeled. After recruitement, patients will therefore be
      electronically randomized to one of the two groups. The groups will then be compared by the
      means of OCTA.

      Study design

        -  Since there are no previous data on our research question, this investigation is defined
           as a pilot study.

        -  40 patients with epiretinal membranes will be included. This appears to be a reasonable
           number given the incidence of epiretinal membranes. Previous studies that compared
           peeling versus nonpeeling in ERM used similar sample sizes. The detectable effect size
           was calculated at d = 0.91. We intend to complete this pilot study within 9 months.

        -  Randomization will be performed using electronic randomization. 20 patients each will be
           randomized to either group 1 or group 2.

        -  Both eyes in each patient will be imaged.

        -  No treatment decisions will be made based on OCTA findings. Treatment decisions will be
           made according to the clinic's standard of care.

        -  Three follow-up visits specific to the study are needed. These visits will be scheduled
           one week, one month and three months after surgery. All other preoperative and follow-up
           visits will be decided by the treating physician and follow the clinic standard of care.

      Examinations

        -  Distance visual acuity using ETDRS (Early Treatment Diabetic Retinopathy Study) standard
           at 4 meters as per clinic standard of care.

        -  Tonometry as per clinic standard of care.

        -  Slit-lamp evaluation as per clinic standard of care.

        -  Arterial blood pressure.

        -  Axial eye length.

        -  Heidelberg Spectralis conventional OCT.

        -  The following 2 AngioVue scans will be taken:

      A. One 3mm x 3mm, 304 x 304 A-scan OCTA of the macula B. One 6mm x 6mm, 304 x 304 A-scan OCTA
      of the macula

      Hypothesis

      The null hypothesis of our investigation indicates that there are no statistically
      significant differences in OCTA perfusion parameters based on the used option.

      The alternative hypothesis states that there are statistically significant differences in
      OCTA perfusion parameters based on the used option.

      Primary Objective

      To demonstrate possible differences in OCTA perfusion parameters based on the used option.

      Secondary Objectives

      To assess the feasibility of the AngioVue optical coherence tomography angiography system in
      evaluating subtle changes in the retinal perfusion of patients with epiretinal membranes.
    


Intervention name(s): ILM nonpeeling; ILM peeling
Intervention type(s): Procedure; Procedure
Intervention description(s): ILM is not peeled after ERM removal; ILM is peeled after ERM removal
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment