Dr. Mahan received his medical degree and completed his internship at Oklahoma University College of Medicine and Health Sciences Center in Oklahoma City. He served in the United States Air Force as a flight surgeon before completing an ophthalmology residency at Wilford Hall USAF Medical Center in San Antonio, Texas. He subsequently completed a glaucoma fellowship under the mentoring of Dr. Richard Simmons of Boston in affiliation with New England Glaucoma Research Foundation, the Massachusetts Eye and Ear Infirmary, and Harvard Medical School.
Dr. Mahan has been board certified by the American Board of Ophthalmology since 1988. He specializes in the treatment and surgery of glaucoma and cataracts. He has held teaching appointments at ophthalmology residency training programs over his career. His professional memberships include the American Medical Association, the American Academy of Ophthalmology and the Chandler-Grant Society. He is a graduate of the Tennessee Medical Association Physician Leadership College and has served in leadership positions on the board of the Tennessee Academy of Ophthalmology, Coffee County Medical Society, and at Harton Regional Medical Center.