Aqueous humour ghrelin levels of eyes with and without glaucoma

Abstract Purpose Ghrelin is a recently described acylated peptide, which works as a somatosecretagogue and modulates smooth, skeletal and cardiac muscles contraction, including that of the eye’s muscle. Our purpose was to determine the levels of ghrelin and des‐acyl‐ghrelin in human aqueous humour collected from control and glaucoma patients undergoing cataract surgery. Methods Blood and aqueous humour samples were collected from 24 patients (9 with open angle glaucoma and 15 from age matched cataract patients with no associated disease). The samples were analysed by ELISA to determine the levels of ghrelin and des‐acyl‐ghrelin. Results There was a significant reduction of ghrelin levels in the glaucoma patients group, when compared to control (2.28±1.04 vs 4.26±2.56 fmol/ml, respectively), while those of des‐acyl‐ghrelin were similar (19.19 ± 6.64 vs 18.83 ± 4.92 fmol/ml, respectively). Both levels were not correlated to the duration of fasting. The ratio blood/aqueous humour of ghrelin and des‐acyl‐ghrelin were similar in all the groups. Conclusion Ghrelin aqueous humour levels are significantly reduced in glaucoma patients, while the levels of des‐acyl‐ghrelin are maintained. So the intraocular secretion of ghrelin may be impaired in glaucoma patients, even if they have normal IOP levels.