Diabetic macular edema (DME) is a leading cause of vision loss in patients with diabetes. Anti-VEGF agents are widely used to improve vision and reduce retinal swelling. However, treatment cost remains a major barrier in many healthcare systems.

This study evaluates the real-world effectiveness and safety of a ranibizumab biosimilar in patients with DME. Medical records of adult patients treated at a tertiary ophthalmology center will be reviewed. Changes in best-corrected visual acuity (BCVA) and central macular thickness (CMT) will be analyzed from baseline to final follow-up, along with treatment burden and safety outcomes.

The findings aim to provide evidence on visual and anatomical outcomes following biosimilar anti-VEGF therapy in routine clinical practice.

This study is a retrospective observational cohort designed to evaluate the real-world effectiveness and safety of intravitreal ranibizumab biosimilar in patients with diabetic macular edema (DME). Medical records of adult patients diagnosed with type 1 or type 2 diabetes mellitus who received at least one injection of ranibizumab biosimilar at the Retina Unit, Department of Ophthalmology, Benha University Hospitals, between January 2022 and April 2026 will be reviewed. Eligible cases will include eyes with center-involving DME confirmed by optical coherence tomography (OCT) and a minimum follow-up period of 3-6 months. Baseline demographic, systemic, and ocular characteristics, including age, sex, diabetes duration, HbA1c level, lens status, prior ocular treatment, best-corrected visual acuity (BCVA), and central macular thickness (CMT), will be collected. Follow-up data will include changes in BCVA and CMT, number of injections received, and treatment regimen (loading dose, pro re nata, or treat-and-extend protocols). Outcomes will assess mean changes in BCVA and CMT from baseline to final follow-up, as well as the proportion of eyes achieving clinically meaningful visual and anatomical improvement. Safety outcomes will include ocular adverse events such as endophthalmitis, intraocular inflammation, retinal detachment, and intraocular pressure elevation, as well as systemic thromboembolic events. Statistical analysis will be performed using SPSS software, with appropriate parametric or non-parametric tests applied based on data distribution, and a p-value <0.05 considered statistically significant. The study will be conducted following Institutional Review Board approval and in accordance with the Declaration of Helsinki, with all data anonymized to ensure patient confidentiality.

Inclusion Criteria:

• • Age ≥18 years

  • Diagnosis of type 1 or type 2 diabetes mellitus
  • Center-involving diabetic macular edema confirmed by OCT
  • Received at least one intravitreal ranibizumab biosimilar injection
  • Minimum follow-up duration of 3-6 months

Exclusion Criteria:

• • Macular edema due to causes other than diabetes

  • Prior anti-VEGF treatment within specified washout period
  • Significant media opacity affecting imaging
  • Coexisting retinal pathology affecting vision (e.g., AMD, RVO)
  • Prior vitreoretinal surgery
  • Incomplete records or inadequate follow-up

Adult patients with type 1 or type 2 diabetes mellitus diagnosed with center-involving diabetic macular edema confirmed by optical coherence tomography (OCT), who received at least one intravitreal injection of ranibizumab biosimilar at the Retina Unit, Department of Ophthalmology, Benha University Hospitals, between January 2022 and April 2026. Eligible eyes had a minimum follow-up duration of 3-6 months with available baseline and follow-up data for best-corrected visual acuity (BCVA) and central macular thickness (CMT). Patients with other causes of macular edema, prior recent anti-VEGF therapy within the washout period, significant media opacity affecting imaging, coexisting retinal pathology affecting vision, prior vitreoretinal surgery, or incomplete records were excluded. The population reflects a real-world retrospective cohort treated in routine clinical practice.