To evaluate the cause of dark arcuate striae observed in infrared photographs in idiopathic epiretinal membrane (ERM) and macular hole patients after internal limiting membrane (ILM) peeling.

Forty patients (41 eyes) of idiopathic ERM and macular hole who underwent trans pars plana vitrectomy with ILM peeling and gas tamponade were included in the present study. The best corrected visual acuity (BCVA) was recorded at preoperative and postoperative 6 months. Infrared (IR) photography with spectral domain optical coherence tomography (SD-OCT) were obtained at preoperative and postoperative 1 week, 1 month, 3 months, and 6 months. When abnormal findings were visible on IR photographs, additional SD-OCT was performed at the corresponding sites.

Of 40 patients, 4 patients demonstrated dark striae extending from the optic nerve to near macular area in IR photographs at 1 week postoperatively. SD-OCT images of the dark striae region revealed the swelling of retinal nerve fiber layer (RNFL). At postoperative 6 months, however, RNFL swelling previously observed subsided in all 4 cases, while temporal retinal thinning and dimples were observed in 3 cases. The preoperative and postoperative BCVA did not show any statistical difference between the patients with the RNFL swelling and the patients without the swelling.

Swelling of RNFL may occur in idiopathic ERM and macular hole patients after pars plana vitrectomy and ILM peeling, which may present as dark striae in IR photographs.