Dr. Brennen was raised in Pittsburgh, Pennsylvania and completed his undergraduate degree at the University of Pittsburgh, where he majored in microbiology and graduated summa cum laude with departmental honors.
He received his medical degree from the University of Pittsburgh School of Medicine in 2006. He completed his ophthalmology residency at the University of Pittsburgh. After his residency, Dr. Brennen completed a two year medical and surgical fellowship at the University of Tennessee/Charles Retina Institute. He joined Retina Associates in 2015 and resides in Washington, DC.
He is a member of the American Academy of Ophthalmology and has served as clinical instructor in medical and surgical retina at the University of Tennessee College of Medicine. He has authored several research publications on macular degeneration and retinal imaging. Dr. Brennen specializes in caring for patients with macular degeneration, retinal vascular disorders, diabetic retinopathy, and retinal detachment.