Changes in Blood Flow on Optic Nerve Head After Vitrectomy for Rhegmatogenous Retinal Detachment

To determine the preoperative characteristics and the changes in retinal blood flow following vitrectomy in eyes with a rhegmatogenous retinal detachment (RRD). Twenty-five-gauge vitrectomy without scleral bucking was performed on 31 eyes of 31 patients with macula-on RRD. The retinal blood flow on the optic nerve head (ONH) was assessed by laser speckle flowgraphy (LSFG), and the mean blur rate (MBR) and pulse waveform parameters before and at 10 days, 1, 2, 3, and 6 months after the surgery were examined. Eyes treated by scleral buckling, and eyes with an epiretinal membrane and cataract that underwent surgery were used as controls. The mean preoperative MBR-vessel on the ONH was significantly lower in eyes with RRD than in the fellow unaffected eyes (P < 0.001), but it was not significantly different from the operated eye and the fellow eye in the control group. A significant increase in the mean MBR-vessel on the ONH was observed following vitrectomy in eyes affected by RRD (P < 0.001), whereas no significant difference was observed in the fellow eye, the scleral buckling-treated eyes, and the control eyes. Of the eight pulse waveform parameters, only the flow acceleration index was significantly lower in eyes with a RRD than in the fellow eyes preoperatively, but then it significantly increased with time following vitrectomy. The changes in the MBR-vessel were not correlated with that of other parameters (e.g., the ocular perfusion pressure). These results indicate that the retinal blood flow is reduced in eyes affected by RRD preoperatively, and can recover following successful RRD repair by vitrectomy.