Soluble opsin is present in human vitreous.

The purpose of this research project was to evaluate if intravitreal opsins are present in human vitreous liquid which is, so far, unknown. Therefore a pilot study was conducted including 22 vitreal samples which were harvested at the beginning of a standard 23-gauge three-port pars plana vitrectomy for macular pucker, diabetic vitreous hemorrhage or vitreal floater removal as well as macular hole closure or vitreomacular traction relief from the central vitreous body. No adverse events or serious side effects occurred. All samples were immediately stabilized by human albumin and arginine and subsequently frozen. Short-wavelength cone opsin concentrations were analyzed by enzyme immune essay (EIA) with anti-proteolytic 400 mM arginine, pH 8.7, in the antigen capture phase. Intravitreal short-wavelength cone opsins were detected in all analyzed samples and respective concentrations ranged at levels of 157 pg/ml ± 73 pg/ml (MV ± SD; range: 27 pg/m-286 pg/ml). Eyes with MP/MH/DVH/VMT and VF exhibited intravitreal short-wavelength cone opsin concentrations of 189 pg/ml ± 68 pg/ml (range: 72 pg/ml-286 pg/ml)/96 pg/ml ± 39 pg/ml (range: 50 pg/ml-138 pg/ml)/126 pg/ml ± 88 pg/ml (range: 27 pg/ml-198 pg/ml)/224 pg/ml and 121 pg/ml. Further studies will quantify the intravitreal opsin pattern of all visual opsins and compare these concentrations between different vitreoretinal diseases. This in turn might offer a better pathophysiological understanding and new diagnostic and therapeutic strategies for various eye pathologies. As a hypothesis, soluble opsins might be a biomarker for retinal damage comparable to creatinine for kidney damage.