Hypotony maculopathy and photoreceptor folds with disruptions after vitrectomy for epiretinal membrane removal: two case reports

Abstract Background Hypotony maculopathy has been classically reported as a complication of glaucoma surgery or ocular trauma. There have been only a few reports of hypotony maculopathy following pars plana vitrectomy (PPV). Here, we report two cases of hypotony maculopathy occurring after PPV for epiretinal membrane (ERM) removal and characteristic photoreceptor folds observed on optical coherence tomography (OCT). Case presentation A 53-year-old Korean woman (case 1) underwent phacoemulsification and posterior chamber lens implantation combined with 25-gauge PPV for ERM removal in the right eye. On the following day, she had severe ocular hypotony, with an intraocular pressure (IOP) that was unmeasurable using a pneumatic tonometer. Despite normalization of IOP, macular retinal and photoreceptor folds with photoreceptor disruptions developed, and Henle’s fiber layer hyperreflectivity was identified. Thereafter, retinal and photoreceptor folds gradually disappeared but photoreceptor disruption and Henle’s fiber layer hyperreflectivity did not improve until 1 year postoperatively, with persistent central visual field distortion and visual acuity worse than that at the preoperative state. A 20-year-old Korean man (case 2) underwent an additional 25-gauge PPV for ERM removal in the left eye. Examination on the following day showed ocular hypotony and retinal folds with peripheral choroidal detachment. Although IOP was normalized, further OCT revealed photoreceptor folds and photoreceptor disruptions. Since then, the photoreceptor folds resolved; however, the photoreceptor disruption remained in the macula at the 1-year follow up, with persistent distorted vision and visual acuity worse than that at the preoperative state. Conclusions Early hypotony after vitrectomy for ERM could result in maculopathy leading to irreversible visual decline and metamorphopsia. Photoreceptor folds on OCT are characteristic features and the predominant mechanism of central visual loss in cases of hypotony maculopathy.