Nocturnal Normobaric Hyperoxia in patients with Diabetic Macular Edema: A Case Series

Abstract

Purpose : Diabetic macular edema (DME) is the most common cause of moderate visual loss in people with diabetes mellitus. It is believed to be partially caused by retinal ischemia and is typically treated with anti-VEGF injections and/or focal laser photocoagulation. A previous prospective study showed that 24-hour per day normobaric hyperoxia improved anatomic and visual outcomes in patients with DME. We hypothesize that 6-8 hours per night of normobaric hyperoxia would be sufficient to effectively improve outcomes in patients with DME.

Methods : Three long-term patients of the Beth Israel Deaconess Medical Center Eye Clinic were treated with nocturnal normobaric hyperoxia for an average of 10 months. Patients received oxygen at the rate of 5 L/min via face mask using a portable oxygen concentrator for at least 5 hours per night during sleeping hours. All patients were known to be highly compliant and kept meticulous records of their oxygen use. Patients followed up on a monthly basis for visual acuity testing via the Early Treatment Diabetic Retinopathy Study (ETDRS) protocol and spectral domain optical coherence tomographySD-OCT macular scans.

Results : There were no adverse events and patients tolerated treatment well. Average macula edema decreased from a baseline of 380 μm to 297 μm (p < 0.05). There was also a decrease in the number of injections required to manage their ME, from 12 injections per year (1 per month) to 1 injection per year. Average visual acuity improved by 2 lines (ETDRS). No progression in DR scale was observed in any of the patients.

Conclusions : Long-term nocturnal normobaric hyperoxia is a relatively inexpensive, tolerable, and effective treatment for DME. This study offers preliminary support for the use of normobaric hypoeroxia to treat DME. Further study is required to confirm these results in a larger randomized control trial.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.