Treatment of primary full-thickness macular hole by intravitreal injection of expansile gas

Objective To evaluate the efficacy of intravitreal injection (IVI) of expansile gas to treat primary full-thickness macular hole (FTMH). Methods Prospective interventional case series. Twenty-six eyes of 26 patients in Peking Union Medical College Hospital with primary FTMH underwent IVI of perfluoropropane (C3F8) 0.2 ml, followed by 7-14 days' face-down positioning. The macular hole closure rate, post-operative visual acuity, and the incidence of surgical complications were observed. The correlation between the patients' age, macular hole diameter, pre-operative best-corrected visual acuity (BCVA), status of the vitreous, and the macular hole closure rates were analyzed. Results A total of 17 cases (65.4%) had hole closure after IVI of C3F8 alone. The closure rate of small, medium, and large FTMH was 85.7, 80, and 33.3%, respectively. Pre-operative OCT examination showed that 10 cases (37%) had vitreo-macular traction (VMT), and all of them achieved vitreous-macula separation after IVI of the gas. The diameters of the hole (P = 0.024) and the status of the vitreous (P = 0.038) had a significance difference for hole closure. The mean pre-operative and post-operative BCVA was 0.84 +/- 0.29 and 0.49 +/- 0.36 (logMAR), respectively (P < 0.01). One myope with persistent hole developed rhegmatogenous retinal detachment (RRD) 2 months after the surgery. Another myope with hole closure developed RRD 10 months after the surgery. They achieved hole closure and retinal reattachment after vitrectomy and scleral buckling, respectively. Conclusion Intravitreal injection of C3F8 gas alone was an effective treatment for small-sized and medium-sized primary FTMH, but further large prospective studies are needed.