Supplementary Material for: A case of epiretinal membrane masquerading as foveal hypoplasia uncovered by optical coherence tomography angiography

Introduction
This case report describes a patient whose misdiagnosis of foveal hypoplasia was uncovered by optical coherence tomography angiography (OCTA) findings that suggested the presence of an Epiretinal membrane (ERM) over foveal hypoplasia.
Case Presentation
A 67-year-old man with no significant past medical history was referred to our retina clinic with a diagnosis of foveal hypoplasia. He had been experiencing significant vision loss for more than one year. OCT demonstrated absence of the foveal depression in both eyes. A subtle ERM was identified in the left eye OCT, but the presence of an ERM in the right eye OCT was equivocal. As such, it was unclear whether flattening of the fovea was attributable to hypoplasia or ERM based on OCT alone. This prompted further investigation with OCTA, which showed the presence of the FAZ in both eyes. The diagnosis of stage 2 epiretinal membrane OU was made based on OCTA findings. The patient underwent cataract extraction with intraocular lens implantation, pars plana vitrectomy, and epiretinal membrane peel, which resulted in improvement of visual symptoms and visual acuity. Follow up OCT showed normalization of the foveal pit in the right eye greater than the left eye.
Conclusion
This case demonstrates the importance of utilization of OCTA in differentiating true foveal hypoplasia from this foveal “pseudohypoplasia” exhibited by our patient.