Our Medical Doctors

Alexander Chang, MD

Dr. Alexander Chang, M.D., was born in Hong Kong and arrived in this country at the age of eight. He grew up in Cleveland, Ohio; the youngest of six children. Dr. Chang earned his Bachelor’s degree at Case Western Reserve University in 1972 graduating Phi Beta Kappa and loved the school so much that he then earned his Medical degree at Case Western Reserve University School of Medicine in 1976. Dr. Chang completed his ophthalmology training at the University of Pittsburgh and has been practicing ophthalmology in Pittsburgh ever since. In 1990, he founded Chang Eye Group.

Dr. Chang is a highly respected and leading cataract surgeon in the tri-state area and has performed well over 10,000 cataract surgeries. He also provides medical eye care for patients with glaucoma, diabetes, and macular degeneration.

Dr. Chang is affiliated with St. Clair Memorial Hospital, as well as Ellwood City Hospital, Ellwood City, PA. Because Dr. Chang’s practice is privately owned he is able to accept insurance from both Highmark and UPMC.

Rose Ngan, MD

Dr. Rose Ngan, M.D., earned her Bachelor’s degree at the University of Michigan in 2001 and her Medical degree from the University of Washington Medical School in 2006. She completed ophthalmology training at the University of Rochester Medical School. Dr. Ngan has received a number of academic honors and has served as a medical researcher at both University of Washington and University of Michigan. She has been listed as an author of research papers published in prestigious journals such as The American Journal of Ophthalmology and the Journal of Investigative Medicine. Dr. Ngan has received awards for her professional presentations. She has been a literacy volunteer and an English teacher in the Global Service Corps.

Dr. Ngan provides medical eye care for patients with glaucoma, diabetes, and macular degeneration and performs cataract surgery.

Michael Alunni, MD

Michael Alunni, M.D., graduated with honors from Jefferson Medical College Of Thomas Jefferson University in 2005. He received his medical degree from Sidney Kimmel Medical College . His residency was completed at UPMC Eye Center and achieved his fellowship graduation from Allegheny Ophthalmic and Orbital Associates. Dr. Alunni is a member of the American Board of Ophthalmology.

Having more than 13 years of diverse experiences, especially in ophthalmology, glaucoma and cataracts, Dr. Michael A Alunni affiliates with many hospitals including Allegheny General Hospital, St Clair Hospital, and Upmc Passavant.

Erik Happ, MD

Dr. Erik Happ, M.D., earned his medical degree from Hahnemann University, completed a general surgery internship at the National Naval Medical Center and Flight Surgery Training at the Naval Operational Medicine Institute. After serving five years in the United States Navy, he completed his ophthalmology residency at the University of Pittsburgh’s Eye and Ear Institute followed by a fellowship in the departments of Ophthalmology and Neurosurgery at AGH.

He is an avid supporter of the non-profit Hawaiian Eye Foundation, SEE International and American. These organizations are dedicated to promoting the preservation, restoration, and improvement of vision for underserved people of the Pacific Basin through charitable service, education, and research programs. He has traveled with the support of these foundations several times to Vietnam to treat patients who have no access to subspecialty care and provide invaluable training for local physicians and surgeons. He also helped establish a fellowship program in the United States to train Vietnamese ophthalmologists and is co-director of the oculoplastic and orbital surgery fellowship program at AGH.

Dr. Happ is a member of the North American Neuro-ophthalmology Society, American Academy of Ophthalmology and Society of US Naval Flight Surgeons.

Our Optometrists

Michele Schraeder, OD

Dr. Michele Schraeder, O.D. earned her Bachelor’s degree at the Indiana University of Pennsylvania and earned her Doctor of Optometry degree at Pennsylvania College of Optometry. She has been with the Chang Eye Group since completing her optometry training in 1997. Dr. Schraeder is a member of the American Optometric Association, the Western Pennsylvania Optometric Association, and is certified by the National Board of Contact Lens Examiners.

As a contact lens specialist, Dr. Schraeder often fits specialized contact lenses that correct astigmatism or both near and far vision (multifocal). She also provides primary eye care to patients of all ages and performs special testing such as A-scans, retinal photos, and OCT. Dr. Schraeder provides pre-op and post-op care to patients who choose to undergo LASIK.

Kristi Weatherly, OD

Dr. Kristi Weatherly, O.D. graduated Magna Cum Laude from the Clarion University of Pennsylvania with a Bachelor of Science Degree. She earned her Doctor of Optometry Degree from the Pennsylvania College of Optometry with honors in clinical excellence in primary care. Dr. Weatherly is an active member of the American Optometric Association (AOA), Pennsylvania Optometric Association (POA), and Western Pennsylvania Optometric Society (WPOS). She is certified by the National Board of Contact Lens Examiners and has participated in numerous research projects concentrating on contact lens complications and anterior segment disease. Dr. Weatherly focuses her practice on primary eye care, contact lenses, pediatrics, cataract and LASIK co-management and low vision. Dr. Weatherly welcomes patients of all ages.