Amino acid and vascular endothelial growth factor levels in subretinal fluid in rhegmatogenous retinal detachment

PURPOSE To study the concentrations of amino acids and vascular endothelial growth factor (VEGF) in subretinal fluid (SRF) of cases with rhegmatogenous retinal detachment (RRD). The relevance of the results with postoperative anatomic and functional success in RRD was investigated. METHODS Fifty-three patients were included in this prospective study. The study group consisted of 46 patients who had scleral buckling surgery with the diagnosis of RRD, and SRF was obtained during the surgery. The control specimens consisted of vitreous samples of seven patients who were diagnosed with pars plana vitrectomy without RRD. Study cases were divided into three groups, corresponding to the duration of retinal detachment. Clinical characteristics, including best corrected visual acuity (BCVA) and anatomic status at month 6, were recorded. Concentrations of 15 selected amino acids were quantified by using high performance liquid chromatography, and VEGF levels were measured with enzyme immunoassay. RESULTS When compared with the control group, SRF concentrations of aspartate, citrulline, glutamate, and glycine increased significantly in the study group (p<0.05). Statistical analysis showed that concentrations of alanine, isoleucine, leucine, methionine, phenylalanine, threonine, tyrosine, and valine decreased (p<0.05). SRF levels of glutamine, taurine, and serine had no significant change. SRF VEGF levels were significantly higher than the vitreous samples of the controls (p<0.001). Time-dependent changes and interactions between VEGF and amino acids were observed. There was no correlation between the concentrations of amino acids or VEGF with the parameters of BCVA and anatomical success. CONCLUSIONS Significant changes occur in concentrations of amino acids and VEGF in SRF of cases with RRD. Our results suggest that several mechanisms contribute to the pathophysiology.