Prevention of visual field defect after macular hole surgery by passing air used for fluid-air exchange through water

PURPOSE: To evaluate the effect on peripheral visual field defects occurrin g after macular hole surgery of passing air that is used for fluid-air exch ange through water before infusion to the eye. METHODS: We used Goldmann perimetry to measure the visual fields of patient s who underwent vitrectomy to manage idiopathic full-thickness macular hole s using either room air or humidified air for fluid-air exchange. We retros pectively studied visual fields measured in 39 patients (group 1) who under went vitrectomy without humidification of air and prospectively studied vis ual fields measured in 33 patients (group 2) who consecutively underwent vi trectomy with humidified air for fluid-air exchange. RESULTS: In group 1, nine patients (23%) had peripheral visual field defect s, most often located in the inferior or inferotemporal quadrant. No patien ts (0%) in group 2 had a visual field defect after vitrectomy. The differen ce between groups 1 and 2 in the proportion of patients with visual field d efects after vitrectomy was statistically significant (P = .003). CONCLUSIONS: Passing air used for fluid-air exchange through water seems to prevent visual field defects after vitrectomy for macular hole surgery. Vi sual field defects that occur after room air is used may result from desicc ation of the retina by room air. (C) 1999 by Elsevier Science Inc. All righ ts reserved.