The Use of Amniotic Membrane or Internal Limiting Membrane for Large or Refractory Macular Holes: A Prospective Study

The Use of Amniotic Membrane or Internal Limiting Membrane for Large or Refractory Macular Holes: A Prospective Study

The Use of Amniotic Membrane or Internal Limiting Membrane for Large or Refractory Macular Holes: A Prospective Study

Prospective, randomized, unmasked interventional study. To evaluate anatomical and functional results through microperimetry in cases of refractory or large macular holes (MH), using amniotic membrane (AM) or internal limiting membrane ( ILM ).

This study will evaluate functional results through microperimetry of patients undergoing macular hole surgery ( for patients with macular holes ≥ 600 microns and in cases refractory to conventional surgical treatment) using amniotic membrane or internal limiting membrane as an adjunct in the closure process of the hole. The current treatment considered the gold standard for the idiopathic macular holes consists of pars plana vitrectomy (PPV) with removal of the posterior hyaloid (when adhered) and the internal limiting membrane (ILM) with the help of a vital dye and subsequent placement of buffering gas (C3F8 or SF6) in non-expandable concentration. Approximately 44% of the large holes do not close after conventional surgery. To increase the closure rate in these cases, new techniques have been proposed, such as the inverted ILM flap technique and the free ILM flap technique. Many studies demonstrate the effectiveness of these 2 techniques, but with no visual function improvement. The amniotic membrane has been used in some cases as an adjunct in the macular holes closure and as a substrate for cell growth and improvement of visual acuity. Amniotic membranes are supposed to promote epithelialization and have anti-fibrotic, anti-inflammatory, anti-angiogenic and anti-microbial properties. In the present study, the patients who meet the inclusion criteria will be randomized and undergo pars plana vitrectomy surgery with removal of the ILM and a fragment of the ILM itself or an amniotic membrane plug will be put in place approximately 1 -1.5 mm under the adjacent retina, inside the macular hole, with the chorionic face in contact with the retinal pigmented epithelium (RPE). After certifying that the plug is in the correct location, the gas fluid exchange will be performed, with a C3F8 buffering infusion of 12.5% and the patients will perform the face down position for 7 days. The patients included in the study will undergo a complete eye examination, including corrected Visual Acuity measurement (BCVA), performing the Ocular Coherence Tomography ( OCT) using the Zeiss Cirrus 5000 equipment and microperimetry using the macular integrity assessment (MAIA) equipment in the pre-operative. Patients will undergo surgery after complementary exams and adequate pre-anesthetic evaluation. Patients will be evaluated on the 1st and 7th postoperative days and at 1, 3, 6 and 12 months after surgery. The patient will undergo a complete eye examination and postoperative follow-up as described above, and during visits on the 7th day, and in the 1st, 3rd, 6th and 12th month of the postoperative period, OCT will be performed and the microperimetry will be performed in the 1st, 3rd, 6th and 12th postoperative month for evaluation and monitoring of anatomical and functional responses, respectively. The use of the amniotic membrane, due to its anti-inflammatory, anti-fibrotic and substrate properties for cell growth is supposed do increase the rate of closure in the refractory and large holes, as well as promoting a better functional response by providing better reconstitution of the outer retinal layers.The amniotic membrane will be provided for this study by the SorocabaEye Bank (BOS), where it will be prepared and preserved.

Use of Amniotic membrane plug, Use of a internal limiting membrane inverted flap, gas tamponade (C3F8 12,5%)

The vitrectomy technique using pars plana 23-gauge will be performed with removal of the ILM (when present adhered to the macula) and placement of an amniotic membrane plug or a internal limiting membrane flap in the macular hole, with a fluid-air exchange and a buffering gas infusion (C3F8 12, 5%). The amniotic membrane plug will be made with a dermatological punch with a diameter of 1.0 to 2mm depending on the size of the macular hole measured by the OCT, and will be positioned inside de macular hole with the chorionic side facing the RPE ( retinal pigmented epithelium) with a 23 gauge forceps. The chorionic side of the membrane is the sticky one. The internal limiting membrane flap will be created at the same time of peeling and will bem positioned in as inverted flap over and inside the macular hole with a 23 gauge ILM forceps. These technics will be helped with de use of a extra lighting sclerotomy.

Inclusion Criteria: Patients with a macula hole that falls into the two categories below: Patients with idiopathic macular hole (with no history of secondary macular hole) ≥ 600 microns (measured using optical coherence tomography) Patients with an idiopathic macular hole submitted to conventional treatment without closing it (of any size). History of the disease less than 18 months Aged over 18 years old Visual acuity less than 20/32 Exclusion Criteria: History of any previous macular disease other than idiopathic macular hole Macular hole of other causes (secondary) Patients with diabetic retinopathy or other retinal vascular diseases Eyes subjected to intravitreal injection of any medication Visual acuity <20/400 of any retinal cause in the contralateral eye or absence of the globe *Aged under 50 years old Cataract and anti-glaucoma surgery less than 3 months before the study Glaucoma with optic nerve excavation > 0.7 in the studied eye Intraocular pressure > 24 mmHg with the use of maximum medication in the studied eye History of vitreoretinal surgery for a condition other than the idiopathic macular hole (retinal detachment, vitreous hemorrhage) History of retinal detachment of any etiology A patient who manifests himself not being able to perform the head position in the postoperative period A patient with active anterior or posterior uveitis