A retrospective, observational, hospital-based study which will be conducted in the Department of Ophthalmology, Sohag University Hospital, Egypt.

Aim of the work To evaluate early changes in OCT biomarkers and visual acuity in treatment-naïve patients with diabetic macular oedema after the first intravitreal antiVEGF injection.

Patients and methods Study Design A retrospective, observational, hospital-based study which will be conducted in the Department of Ophthalmology, Sohag University Hospital, Egypt.

Patients This study will include 50 eyes with center-involving DME (CI-DME) of patients who received their 1st AntiVEGF injection as a routine treatment in the Department of Ophthalmology, Sohag University Hospital.

Inclusion Criteria

1. Diabetic patients with center-involving DME (CI-DME) who are treatment-naïve.
2. Central macular thickness (CMT) of 300 microns or more will be accepted as CI-DME.

Exclusion Criteria

1. Media opacities affecting OCT imaging (corneal pathologies, dense cataracts, vitreous opacities, etc).
2. Patients with any other retinal vascular diseases (retinal vein occlusion, central serrous chorioretinopathy, age-related macular degeneration, etc).
3. Patients who have had previous intravitreal injections or Laser treatment.
4. Patients who underwent previous vitreoretinal surgeries.
5. Patients with recent history of undergoing cataract surgery.
6. Patients with uncontrolled glaucoma or ocular inflammations (eg: vitritis). 4

Methods

We will analyze the medical records of the study participants before and after injection and the collected data will include:

A. History:

Patient age, gender, duration and treatment of diabetes mellitus, visual impairment history, ocular/systemic comorbidities, topical/systemic drug intake, previous ocular/systemic interventional procedures or surgery.

B. Medical Examination and Laboratory investigations:

Blood Pressure, Lipid profile, HbA1c will be measured.

C. Full ophthalmological examination:

Data recorded from the preoperative ophthalmic examination of the studied eye, which includes:

1. Best corrected visual acuity (BCVA): Snellen visual acuities will be presented as Snellen decimal notation.
2. Intraocular pressure (IOP) measured by I-Care rebound tonometer.
3. Slit lamp examination of the anterior segment and angle of the anterior chamber.
4. Fundus examination by indirect ophthalmoscope and slit lamp biomicroscopy with documentation of the stage of diabetic retinopathy.

D. OCT imaging:

OCT images and data will be collected and analysed from the electronic medical reports for all patients at 3 points:

1. Before injection (within one week before the procedure).
2. Two weeks after injection.
3. One month after injection. 5

The collected OCT data will include the following biomarkers:

• Determining the type of DME (diffuse, cystoid, serous retinal detachment).
• Mean central subfield thickness (CST).
• Presence, location and height of macular Intraretinal cystoid spaces (ICS).
• Presence of Subfoveal neuroretinal detachment (SND) and height of serous macular detachment.
• The presence and size, and localization of hyperreflective foci (HF) within the retina.
• The disorganisation of the inner retinal layers (DRIL).
• The presence of vitreomacular traction.
• The integrity of the outer retinal layers, (ellipsoid zone (EZ) and external limiting membrane (ELM)).

E. Theinjectionprocedure:

The surgical notes will be reviewed from the patient's files to report the injection procedure, preparations and complications.

Inclusion Criteria:

• Diabetic patients with centre-involving DME (CI-DME) who are treatment-naïve.
• Central macular thickness (CMT) of 300 microns or more will be accepted as DME.

Exclusion Criteria:

• Media opacities affecting OCT imaging (corneal pathologies, dense cataracts, vitreous opacities, etc).
• Patients with any other retinal vascular diseases (retinal vein occlusion, central serrous chorioretinopathy, age-related macular degeneration, etc).
• Patients who have had previous intravitreal injections or Laser treatment.
• Patients who underwent previous vitreoretinal surgeries.
• Patients with recent history of undergoing cataract surgery.
• Patients with uncontrolled glaucoma or ocular inflammations (eg: vitritis).

Diabetic macular Oedema patients who are treatment naïve.