Vitreous growth hormone and visual dysfunction

Growth factors have been found in vitreous fluid, in which they regulate retinal function and provide markers of ocular dysfunction. Since growth hormone (GH) has recently been discovered in the vitreous of human eyes, the possibility that vitreal GH concentrations might differ in different ocular disease states was assessed. GH-immunoreactivity in the vitreous of cadaver controls and in the vitreous of patients with ocular dysfunction was quantified by ELISA. In non-diabetics, vitreous GH concentrations were comparable in patients with subretinal hemorrhage (SH), vitreous hemorrhage (VH), vitreous debris (VD), retinal detachment (RD), central retinal vein occlusion (CRVO), macular hole (MH), dislocated crystalline lens (DCL) or epiretinal membrane (ERM). The GH concentration, corrected for protein content, in the vitreous of diabetic patients was, however, lower than that in cadaver controls with no history of ocular disease and lower than that in non-diabetic patients with ocular dysfunction. Vitreous GH concentrations in diabetic patients with proliferative diabetic retinopathy (PDR) did not differ from those without PDR. The presence of GH in the human vitreous suggests that vitreous GH may have roles in normal ocular function and be involved in the pathogenesis of ocular disease. Low GH concentrations in the vitreous of diabetic patients may correlate with retinal neurodegeneration and may provide a marker to follow its progression.