Effects of Subtenon-injected Autologous Platelet-rich Plasma on Visual Functions in Eyes With Retinitis Pigmentosa

blood is drawn from the patient's antecubital vein and inserted into four 3.0 ml vacutainer tubes that contain trisodium citrate. These four tubes were placed in a centrifuge machine, and centrifugation was carried out at 2500 rpm (580×g) for 8 min within a 30-min blood collection period. As a result of centrifugation, the plasma was separated in the vacutainer tubes from the remaining blood components. Three different layers formed in the tubes: red blood cells at the bottom, aPRP in the middle layer, and aPPP in the top layer. A total of 1.5 ml of the middle layer (which mainly contained platelets) was withdrawn by syringe, and it was immediately injected into the subtenon space of each eye.