Anatomical and physiological outcomes of nocturnal normobaric hyperoxia treatment in a patient with diabetic macular edema

Abstract

PURPOSE: Diabetes Mellitus (DM) is one of the most prevalent metabolic diseases worldwide and can lead to ocular complications such as diabetic retinopathy (DR). As chronic hyperglycemia leads to endothelial pathologies in the retina, diabetic macular edema (DME) develops and worsens visual acuity. Current treatment methods include laser photocoagulation, intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections, and surgical interventions. This case report explores the effects of nocturnal normobaric hyperoxia (NNBH) treatment in a patient with DME. METHODS: A 64-year-old pseudophakic man with bilateral DME regularly treated with anti-VEGF injections was instructed to self-administer 40% fraction of inspired oxygen (FiO2) at 5 liters per minute (LPM) for 6 to 8 hours per day during sleep. Retrospective data of visual acuity (VA), optical coherence tomography (OCT) imaging, and number of injections during a one-year time frame prior to starting NNBH was compared with newly collected data of a one-year time frame while on NNBH. RESULTS: The patient was treated with a total of 12 anti-VEGF injections in the year prior to starting NNBH treatment. After one year of supplemental oxygen, subject’s VA stabilized to 20/20 in both eyes. When comparing average values of OCT data prior to NNBH and during NNBH, all measurements including central macular thickness (CMT), maximum macular thickness (MMT), foveal volume (FV), and total macular volume (TMV) decreased anywhere from 5.4% to 20.3%, reflecting a stabilization of the retina bilaterally. Subject did not require any intravitreal injections during NNBH treatment. After one month of planned cessation of NNBH, DME recurred. CONCLUSION: This model case demonstrates NNBH may be a novel treatment approach in reducing DME and improving VA in patients with DR. NNBH can be a cost-effective, convenient, and accessible therapy for patients with complications from diabetic retinopathy.