Born in Troy, Ohio, Dr. Kosier received her Bachelor of Science and Medical Degrees from the Ohio State University in Columbus, Ohio. Dr. Kosier completed her Internal Medicine residency at Morristown Memorial Hospital in Morristown, New Jersey and her Ophthalmology residency at William Beaumont Hospital in Royal Oak, Michigan.
Dr. Kosier established her private surgical practice in Lancaster, Ohio, in 1988, and is a member of the Fairfield Medical Center Staff. Her specialties include small incision cataract surgery, eyelid surgery, evaluation and management of glaucoma and macular degeneration, and general ophthalmology. She is a Diplomat of the American Board of Ophthalmology. She is a member of the American Academy of Ophthalmology, Ohio Ophthalmology Society, and American Society of Cataract and Refractive Surgeons.