AIM:To investigate the retinal vascular caliber, retinal nerve fiber layer(RNFL)thickness, and optic disc changes in patients after pars plana vitrectomy and adjunctive intraoperative procedures.

METHODS:We examined 40 eyes in 40 patients who had undergone unilateral pars plana vitrectomy and adjunctive intraoperative procedure at three time points:prior to surgery, and at 3mo and 6mo after the operation. The diameters of central retinal arteries and veins were measured using retinal photographs. The central retinal arteriolar equivalent(CRAE)and central retinal venular equivalent(CRVE)were calculated using the revised Parr-Hubbard formula. RNFL thickness was obtained using Stratus optical coherence tomography. The cup-to-disc vertical ratio of the optic disc was evaluated using stereo optic disc photography.

RESULTS:There were no significant differences between the eyes of individual patients before the operation. Cup-to-disc vertical ratios of the optic disc were significantly increased 3mo and 6mo postoperatively(P<0.01, P<0.01), and there was a significant difference between the operative eye and fellow eye at the same time points(P<0.01, P<0.01). Changes in CRAE and CRVE in the operative eyes were significantly larger than the fellow eyes 6mo post-operatively(P<0.01, P<0.01). The RNFL thickness showed no significant changes.

CONCLUSION:Whereas there were no changes in RNFL thickness, vitrectomy and adjunctive intraoperative procedures induced changes in the cup-to-disc vertical ratio of the optic disc and retinal vessel diameter for at least 6mo after surgery.