This study aims to evaluate the effect of subthreshold 577 nm micropulse laser photocoagulation in the treatment of initial and refractory cases of Center-Involved Diabetic Macular Edema.

Diabetic Retinopathy (DR) is a common and specific microvascular complication of diabetes that affects 17-54% of people with diabetes aged between 49 and 60 years.

Diabetic macular edema (DME) is one of the most common causes of visual loss in today's society. It affects about 10% of diabetic individuals and 29% of those who have had the condition for more than 20 years.

In micropulse mode, the laser emits short pulses, thereby reducing thermal energy in the target area.

This strategy has two properties: a shorter exposure time and a subvisible clinical endpoint, delivering energy by dividing the beam into a series of short pulses (100-300 µs). Every single pulse has an "on and off" duration (duty cycle (DC)), enabling tissues to cool down before the next pulse.

Inclusion Criteria:

• Age ≥18 years.
• Both sexes.
• Patients with type 1 or 2 diabetes mellitus (DM), best-corrected visual acuity (BCVA) of 20/400 or better, and center-involved DME [defined as a central macular thickness (CMT) of >250 but <700µm measured by spectral-domain optical coherence tomography].
• Patients with any level of non-proliferative diabetic retinopathy or proliferative diabetic retinopathy with adequate panretinal photocoagulation (PRP) and no signs of disease activity determined by fluorescein angiography (FA).

Exclusion Criteria:

• Monocular eyes.
• Chronic renal failure or renal transplant because of diabetic nephropathy.
• Glycated hemoglobin (HbA1c) of more than 10%.
• Vitreomacular traction syndrome.
• Epiretinal membrane.
• PRP within 4months before the treatment.
• Intraocular surgery within 6months, including cataract or vitreoretinal operation.
• Rubeosis iridis.
• Severe glaucoma.
• High-risk proliferative diabetic retinopathy.
• Poor dilation.
• Increased foveal avascular zone.
• Any condition that could interfere with optical coherence tomography (OCT) measurement or visual acuity.

This prospective cohort comparative study was conducted at the Ophthalmology Department of Sohag Teaching Hospital, with approval from the institutional ethical committee.

The data will be available upon a reasonable request from the corresponding author after the end of study for one year.

After the end of study for one year.

The data will be available upon a reasonable request from the corresponding author.