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Theodore Gancayco, MD

Theodore-Gancayco-White-Coat-72Dr. Theodore Gancayco is a board certified retina specialist and vitreoretinal surgeon who specializes in medical and surgical diseases of the retina.

He has been practicing ophthalmology in the Washington, D.C., area for over 20 years and has performed thousands of surgeries and laser procedures for the treatment of retinal diseases such as diabetic retinopathy and macular degeneration.

He has been recognized as a Washingtonian “Top Doctor” and he is a clinical instructor for residents of the Georgetown University Family Practice Program. He is past president of the Philippine Medical Association and has led medical missions to the Philippines.

Chad Marcantonio, MD

Dr Chad MarcantonioChad Marcantonio, MD, is a board certified comprehensive ophthalmologist who completed his medical school, internship, and residency at Georgetown University. He treats a wide variety of eye conditions and has a particular interest in cataract surgery.

Dr. Marcantonio spent 3 years in Cleveland where he served as a clinical and surgical instructor for the Cleveland Clinic Ophthalmology Program and was honored with the surgical teaching award 2 years in a row. He also served as a clinic instructor for Case Western medical students and served as a clinical rotation for Ohio State optometry students.

In addition to treating patients here at Washington Eye Specialists, he also sees patients in the Glen Burnie location for our partner practice, OMNI Eye Specialists.

Dr. Marcantonio lives in Annapolis, MD, with his family. 

Nguyen Waterman, OD

Nguyen-Water-White-Coat-72Dr. Nguyen Waterman practices comprehensive eye care including routine eye exams, contact lens fittings, glaucoma and cataract evaluations, as well as pre and post-op surgery care. She also specializes in macular degeneration, diabetic eye, and strabismus evaluations. Dr. Waterman has a passion for treating dry eye patients and those who suffer from eye related allergies.

Prior to joining Washington Eye Specialists, Dr. Waterman worked at Kaiser Permanente where she focused on promoting preventative care of the patient. This entailed working hand in hand with internal medicine to ensure patients with hypertension, diabetes, and other systemic conditions were well monitored. She also participated in telemedicine consults reading retinal photos as a screening measure for diabetic patients.

Additionally Dr. Waterman previously worked at Texas Tech University Health Science Center, where she was responsible for teaching clinical skills to first and second year medical students as they rotated through the different sections. Dr. Waterman also worked as a civilian optometrist at the William Beaumont Army Medical Center where she received the Achievement Medal for Civilian Service in her care of the military community and their family members.

Dr. Waterman attended Washington University in St. Louis where she worked in the Department of Cell Biology and Physiology. After graduating cum laude from Washington University in St. Louis with a degree in Biochemistry, Dr. Waterman attended the University of Missouri in St. Louis Optometry School where she graduated on the Dean’s List.

While in optometry school Dr. Waterman was awarded the Mary M. Gilbert scholarship, a Merit Scholarship, and was a member of the Beta Sigma Kappa International Honor Society. She was also awarded an American Academy of Optometry research stipend and a National Eye Institute Summer Research Fellowship at the University Of Houston School Of Optometry. During her summer fellowship, she published an abstract on corneal healing at the Association for Research in Vision and Ophthalmology (ARVO).


  • Fluent in English and Vietnamese
  • Speaks some Spanish