Dehydration injury as a possible cause of visual field defect after pars plana vitrectomy for macular hole

PURPOSE: To present the hypothesis that a visual field defect after pars plana vitrectomy for macular hole may be caused by dehydration injury to the nerve fiber layer during the fluid air exchange. METHODS: In a consecutive nonrandomized series of 45 operations on 35 eyes of 34 patients with full-thickness macular hole, the surgical method was changed with postoperative visual field testing performed. RESULT: The incidence and location of the postoperative visual field defect was affected only by changing the location of the infusion cannula. CONCLUSION: Dehydration injury of the nerve fiber layer during the fluid air exchange should be considered as a possible cause of visual field defect after pars plana vitrectomy for macular hole.