Comparison Between Outcomes of Closure of Idiopathic Macular Hole Using Autologus Tenon Capsule Graft and Internal Limiting Membrane Flap Techniques (Pilot Study)

Macular hole (MH) is a full-thickness defect of the neurosensory retina at the fovea, causing central visual loss. The incidence of idiopathic MH increases with age and is more common in females. Vitreomacular traction is the main pathophysiological factor leading to MH formation.

Pars plana vitrectomy with internal limiting membrane (ILM) peeling has been considered the standard technique for MH repair, achieving high anatomical closure rates. However, for large and refractory holes, conventional ILM peeling may not be sufficient.

The inverted ILM flap technique was developed as an alternative for large MHs (≥400 µm). This method allows the peeled ILM to be inverted and placed over the hole to serve as a scaffold for glial proliferation, enhancing closure rates and improving visual outcomes.

More recently, Tenon capsule graft has been introduced as an autologous biological scaffold for macular hole closure. Tenon tissue is rich in fibroblasts and extracellular matrix, which may promote retinal repair and facilitate closure in cases resistant to conventional approaches.

Optical coherence tomography (OCT) has become essential for evaluating macular hole dimensions, classifying stages, and confirming closure after surgery. It provides high-resolution images that allow detailed morphologic analysis.

Optical coherence tomography angiography (OCTA) enables noninvasive assessment of retinal and choroidal vasculature. Postoperative OCTA studies have shown changes in foveal avascular zone (FAZ) and vessel density in both superficial and deep plexuses, which may correlate with visual recovery.

Comparative studies between Tenon capsule graft and ILM flap using OCT and OCTA are limited, and further research is required to assess their relative efficacy in terms of anatomical closure, visual improvement, and vascular restoration. This study aims to address that gap.

The aim of this study is to compare the functional visual outcomes, anatomical closure rate and macular perfusion changes assessed by OCT and OCTA after surgical repair of macular hole using Tenon capsule graft versus ILM flap.

The study will be conducted in the ophthalmology department, at Ain Shams University Hospitals, Cairo, Egypt.

Inclusion criteria:

• Patients diagnosed with idiopathic full-thickness macular hole
• ≥400 µm in horizontal diameter

Exclusion criteria:

• Media opacity preventing adequate OCT/OCTA imaging
• Other retinal vascular pathology as retinal vascular occlusion
• Intraoperative complications
• Signal noise ratio using OCTA \<6\10
• Poor fixation of the patient

Group 1: Surgical repair of MH using Tenon capsule graft. Group 2: Surgical repair of MH using ILM Flap.

Sample Size:

Due to the novelty of the procedure and the rarity of cases needing surgical treatment and the expensive cost of intervention. This study is also a pilot study. This study is exempted from sample size calculation.

Study type: Prospective interventional .(Pilot study) Ethical Considerations: Written informed consent will be obtained from patients, after approval of the research ethics committee of the Faculty of Medicine, Ain Shams University, Cairo, Egypt.

Study Tools

Preoperative examination :

All participants will have complete ocular examination including:

• Best corrected visual acuity (BCVA) with Snellen E and then transformation to Log MAR
• Slit-lamp examination
• Fundus examination using 90 D lens
• Intraocular pressure measurement by Goldmann applanation tonometry
• Preoperative OCT to assess MH base diameter and narrowest diameter and thickness of edges to calculate MH indices
• OCTA (OptovueInc, Fremont, CA). Sequential optical coherence tomography scans of a specific retinal region will be performed (central 3x3 Macular area Superficial, deep capillary plexus and choriocapillaris) and images will be processed in order to obtain motion contrast of erythrocytes within the vessel, thereby providing detailed imaging of the retinal capillary network. Capillary plexus density (CPD) of vessels in SCP, DCP and the size of the FAZ will be detected by OCTA en-face images.

Operative technique:

In all patients (Group A \& B), PPV will be performed using a 23-gauge, transconjunctival, microincision vitrectomy system. Diluted triamcinolone acetonide (40 mg/ml) will be used to visualize the vitreous. After core vitrectomy, posterior hyaloid detachment will be attempted with the vitrectomy cutter in the suction mode. Then, the ILM will be stained using 0.05% Brilliant Blue G (OCUBLUE PLUS, India).

In Group A: tenon capsule graft will be attempted.

In Group B: free flap ILM peeling will be attempted

SF6 gas will be used as tamponade in both groups

More than one vitreoretinal surgeon will participate

Postoperative assessment:

Patients will be examined one day and three months after surgery. Postoperative assessment will include the following with each assessment: Full ophthalmic examination (UCVA, BCVA, anterior segment assessment, Goldman applanation tonometry measurement (in all follow up visits except 1st day postoperative), fundus examination).

Postoperative OCT to assess Anatomical closure and type of closure Post-operative macular scans by OCTA (OptovueInc, Fremont, CA). Sequential optical coherence tomography scans of a specific retinal region will be performed (central 3x3 Macular area Superficial, deep capillary plexus and choriocapillaris) and images will be processed in order to obtain motion contrast of erythrocytes within the vessel, thereby providing detailed imaging of the retinal capillary network. Capillary plexus density (CPD) of vessels in SCP, DCP and the size of the FAZ will be detected by OCTA en-face images

Primary outcome:

• Improvement in BCVA

Secondary outcome:

• OCT parameters of healing and type of healing
• OCTA parameters of macular vessel density

Statistical Analysis and Statistical Package Data will be collected and analyzed with proper statistical tests.