Early Changes in OCT Biomarkers After the First Intravitreal Anti-VEGF Injection in Treatment-naïve DME

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

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

• Best corrected visual acuity (BCVA): Snellen visual acuities will be presented as Snellen decimal notation.
• Intraocular pressure (IOP) measured by I-Care rebound tonometer.
• Slit lamp examination of the anterior segment and angle of the anterior chamber.
• 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:

• Before injection (within one week before the procedure).
• Two weeks after injection.
• 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).