Sulfur hexafluoride (SF6) versus perfluoropropane (C3F8) tamponade and short term face-down position for macular hole repair: a randomized prospective study

BACKGROUND: To compare early visual and anatomical outcomes after either sulfur hexafluoride (SF6) or perfluoropropane (C3F8) tamponade for macular hole repair. METHODS: 147 eyes affected by primary full-thickness macular hole underwent pars plana vitrectomy with dye assisted removal of the internal limiting membrane and gas tamponade. Prone position was prescribed for 48 h after surgery. All patients were divided into 3 groups depending on the size of the hole: small (<250 µm), medium (>250-<400 µm) or large (>400 µm). Eyes within the same group randomly received either SF6 (70 eyes) or C3F8 (77 eyes). A complete ophthalmic evaluation, including best corrected visual acuity and anatomic status of the macular holes, was conducted preoperatively, at 1 week and 1 month after surgery. Macular hole volume was calculated using optical coherence tomography scans. The Wilcoxon Signed Ranks Test, the Mann-Whitney Test, the Spearman's rank-order correlation coefficient and the study of variance for repeated measures were used for statistical analysis. RESULTS: Mean best-corrected visual acuity improved from 0.92 logMAR to 0.28 logMAR (P < 0.001). A reduction of the dimensions of macular holes was observed in all cases, with a total repair of 90 % (63/70 eyes) in the SF6 group and 91 % in the C3F8 group (70/77 eyes). There was a negative correlation between the initial minor diameter, the volume of the hole and the rate of anatomic success. CONCLUSIONS: Short-term anatomical and visual outcomes were similar in eyes treated with either SF6 or C3F8, independently of the stage of the macular hole. The initial volume and the minor diameter of the hole may be considered as valid tools for predicting surgical success. Age and gender did not appear to have influenced the prognosis.