Prognostic factors in fluid–gas exchange after primary idiopathic macular hole surgery

Purpose This retrospective study aimed to evaluate the prognostic factors associated with the success of fluid–gas exchange in patients who had undergone failed primary idiopathic macular hole (IMH) surgery. Methods In total, 19 eyes of 19 patients with failed IMH surgery who then underwent fluid–gas exchange were included. Of those, 18 eyes had macular hole (MH) closure (successful, 15 eyes; unsuccessful, 3 eyes). Demographics, pre-operative characteristics, and pre-procedural characteristics were assessed. The patients were divided into successful (U or V-type closure) and unsuccessful groups (W-type or unclosed), following fluid–gas exchange. One eye was unclosed after fluid–gas exchange; therefore, this patient underwent additional vitrectomy for MH closure (unsuccessful). Results The outcomes of the fluid–gas exchange were categorized as unclosed or as U-type, V-type, or W-type closure. None of the patients experienced complications after the procedure. The successful group showed a significantly lower pre-operative and pre-procedural minimum diameter, base diameter, and macular hole volume, and higher pre-operative and pre-procedural macular hole index, hole form factor, and tractional hole index values. Moreover, a better visual prognosis was observed in the successful group. Conclusion These findings suggest that indices predicting favorable results of primary surgery for IMH are useful for predicting the success of fluid–gas exchange in patients with failed primary MH surgery.