AIM: To analyze the ocular findings of patients who received lifelong leptin therapy due to congenital leptin deficiency (CLD), an extremely rare condition. METHODS: A prospective, cross-sectional comparative study was performed on six patients with CLD and 13 healthy age- and sex-matched controls. The central corneal thickness (CCT), anterior chamber depth (ACD), axial length (AL), keratometry (K1, K2), optical coherence tomography (OCT), and OCT angiography parameters were compared between the leptin and control groups at the baseline visit. The change in these measurements in leptin patients over a two-year period was analyzed. RESULTS: CLD patients had lower mean AL, ACD, and CCT (P≤0.012 for all). Mean K1, K2 (P≤0.047 for both), choroidal thickness (P≤0.001), and central ganglion cell layer (GCL) thickness (P=0.029) were higher in the leptin group. Perifoveal superficial capillary plexus (SCP) density was decreased in all quadrants except the temporal region (P<0.05), and parafoveal deep capillary plexus (DCP) density was decreased in the superior hemisphere, temporal quadrant (P≤0.036 for both) and nasal quadrant (P=0.048) in the leptin group. During the two-year follow-up, no changes in anterior and posterior segment measurements were observed in the leptin patients, except for subfoveal choroidal thickness (P<0.001). CONCLUSION: CLD patients exhibit structural alterations in both the anterior and posterior segments of the eye, including notable changes in retinal and choroidal vasculature. However, there is limited evidence concerning the influence of leptin therapy on the eye.