Endocrine Abstracts

Purpose: Congenital leptin deficiency (CLD) is an extremely rare condition. The effects of the disease and leptin treatment on ocular structures are unknown in this patient group. In our study, we planned to compare the ocular findings of patients who received leptin replacement therapy due to leptin deficiency with the control group

Methods: In this prospective, cross-sectional comparative study, six patients with a diagnosis of congenital leptin deficiency and fifteen healthy controls were included. All participants underwent optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) imagining. Measurements of axial length, central corneal thickness, thickness of subfoveal choroid, retinal nerve fiber layer (RNFL) and macular vessel densities of the superficial capillary plexus and deep capillary plexus were compared.

Results: In the leptin group, 4 patients were on leptin replacement therapy for 23 years and two patients were on leptin replacement therapy for 4 years. The mean axial length (P =0.23), anterior chamber depth (P =0.011), and central corneal thickness (P =0.000) measurements were significantly lower in the leptin group than the control group. The mean of subfoveal choroidal thickness (EDI) (P =0.002), and nasal RNFL thickness (P =0.008), were significantly increased in the leptin group. Perifovea superficial capillary plexus density were significantly decreased in the leptin group (45.02 ± 3.12) compared to controls (48.44 ± 3.61, P =0.005).

Discussion: In this study, the ocular findings of patients with CLD and the effect of long-term leptin replacement therapy on ocular structures were evaluated for the first time in the literature. In our study, mean superficial retinal capillary plexus values of patients with congenital leptin deficiency were significantly lower than controls. The possible explanation for this result may be chronic hypoxia caused by inappropriate vascular structure and impaired angiogenesis due to leptin deficiency. In addition, the mean of EDI and nasal RNFL thickness measurements were significantly higher in leptin patients compared to controls. These results may be due to the effects of leptin on angiogenesis, cell proliferation, endothelial dysfunction, inflammatory and vascular smooth muscle proliferation. In addition, the increase in the nasal region RNFL layer thickness in the patient group, especially in those using leptin replacement therapy for more than 5 years, compared to the controls suggests the neuroprotective effect of leptin.

Conclusions: This study revealed that CLD can bring about developmental and pathological structural changes in anterior segment of eye and in vessel formation of retinal and choroidal vasculature.