To report a case of non-glaucomatous retinal nerve fiber layer (RNFL) defect associated with paravascular inner retinal defect (PIRD) in a patient with idiopathic epiretinal membrane (ERM). Case summary

A 70-year-old male who was diagnosed with ERM in his right eye and pseudoexfoliative glaucoma in his left eye visited our clinic. His intraocular pressure was 14 mmHg in both eyes while using topical hypotensive medications in both eyes. His right eye showed no glaucomatous change of the optic disc head, and also no glaucomatous visual field defect on standard automated perimetry. Red-free fundus photography and swept-source optical coherence tomography showed an ERM and wedge-shaped RNFL defect starting from the PIRD, not the optic disc head. He was diagnosed with non-glaucomatous RNFL defect in the right eye and was told to stop using topical hypotensive medication for the right eye. After 2 years of discontinuing the medication, the IOP was within the normal range, the RNFL defect showed no progression, and the visual field remained stationary. Conclusions

A non-glaucomatous RNFL defect can develop in association with PIRD in patients with idiopathic ERM. Examinations for PIRD as well as evaluation of the optic disc head are therefore necessary in patients with ERM and RNFL defect.