Macular Micro Vascular Changes Following Macular Hole Repair : Optical Coherence Tomography Angiography Study

The goal of this prospective interventional study is to to compare the micro vascular and structural changes between surgery with and without ILM flap to repair macular hole.

The main questions it aims to answer are:

* What are the macular micro vascular and structural changes pre and post repair of idiopathic full thickness macular hole and what is the correlation between these changes and visual recovery.
* Is there are any prognostic values of the micro vascular status of the macula could be assessed preoperatively.
* What are the differences regarding these micro vascular and structural changes between repair with and without ILM flap.

Participants will be:

* Subjected to pars plana vitrectomy to repair macular hole.
* Examined by optical coherence tomography angiography pre and post operative

Researchers will compare:

Group A: eyes treated without ILM flap Group B : eyes treated by ILM flap to see if there are differences regarding the micro vascular and structural changes in the macular area.

This study will include 28 eyes with idiopathic full thickness macular hole; they will be divided into two groups:

Group A: 14 eyes will be treated without ILM flap Group B : 14 eyes will be treated by ILM flap

* Sample size: 28 eyes. (based on ELM recovery rate in ILM flap 70% versus 21.4% with inverted flap (Iwasaki et al., 2019), and at power of study 80% and confidence level 95%, sample size is calculated using openEpi software to be 14 eyes in each group
* Study setting: Ophthalmology Department, Fayoum University and the Research Institute of Ophthalmology
* Data Collection :

  * History :

    1. Demographic data ( age , gender )
    2. General medical history ( DM, HTN )
    3. Symptom duration
    4. Previous ocular history
  * Clinical examination:

    1. Best corrected visual acuity using snellen chart (converted to log MAR for statiscal analysis).
    2. Slit lamp biomicroscopy for anterior segment examination.
    3. Posterior segment examination using binocular indirect ophthalmoscope and indirect slit lamp bio microscopy (+90 volk lens for detailed evaluation of macula)
    4. Axial length measurement
  * Optical Coherence Tomography:

We use SD- OCT and OCTA for pre and post-operative evaluation of retinal layers microstructure and vasculature.

* Surgical Procedure

All eyes in this study will be subjected to pars plana vitrectomy procedure with these main steps:

* 23 G trocar system will be used
* Posterior vitreous detachment will be induced with the aid of triamcinolone acetate injection, and core vitrectomy will be done
* Brilliant blue stain will be injected, and ILM forceps will be used for ILM peeling

Patients will be divided then into two groups:

Group A: Only wide ILM peeling up to the arcades well be done Group B: ILM peeling with flap well be done

* Shaving of the vitreous base, and then fluid air exchange
* SF 6 gas tamponade will be used

  • Study procedures:

  o Regular clinical assessment pre and at 1 and 6 months post-operative including:
* Best corrected visual acuity measurement using Snellen chart with conversion to log. MAR notation for statistical analysis
* Posterior segment examination using binocular indirect ophthalmoscope and indirect slit lamp bio microscopy (+90 volk lens for detailed evaluation of macula)

  * Standard Optical coherence tomography of the macula at 1 and 6 months post-operative using (SD-OCT) scans (512 A-scans, 20°×20°) with the following protocol:

Macula thickness map for measurement of central retinal thickness, and photoreceptor inner segment/outer segment complex.

o Optical coherence tomography angiography of the macula at 1 and 6 months post-operative studying Superficial Capillary plexus, Deep Capillary plexus and Fovea avascular zone.

Eligibility Criteria:
Inclusion Criteria:

* Idiopathic full thickness Macular hole without retinal detachment

Exclusion Criteria:

* Previous pars plana vitrectomy
* High myopia with axial length ≥ 26 mm.
* Uncertain symptom duration or ≥ 6 month .
* History of same eye trauma
* Poor image quality.
* Patients with diabetic retinopathy or other retinal diseases, e.g. ischemic, inflammatory.
* Any patient with significant cataract which needs combined phaco-vitrectomy.