Why Fellowship Training Matters
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What fellowship training is, how it differs from residency training, and how general and subspecialty eye doctors work together for your care.

Every ophthalmologist is a highly trained eye physician and surgeon
All ophthalmologists complete medical school, a year of internship and three years of ophthalmology residency. Residency trains them to diagnose and treat the full range of eye disease, including cataract surgery and the medical and laser treatment of glaucoma.
Some ophthalmologists then choose an optional fellowship: usually one to two more years focused on a single area, such as glaucoma, cornea, retina or pediatric eye care. Fellowship does not replace residency. It adds depth in one subspecialty, while comprehensive ophthalmologists bring breadth across the whole eye. Both are valuable, and patients are often best served when the two work together.
How eye physicians are trained
Medical school
Four years to earn a medical degree (MD or DO).
Internship
One year of general medical training in a hospital.
Ophthalmology residency
Three years of hands on training in medical and surgical eye care, followed by board certification.
Fellowship (optional)
Usually one to two years of focused training in one subspecialty, such as glaucoma.
Comprehensive ophthalmologists
Comprehensive ophthalmologists care for the whole eye and see the widest variety of conditions.
- Routine and medical eye exams
- Cataract surgery
- Diagnosing and treating glaucoma, diabetic eye disease, dry eye and many other conditions
- Coordinating care and referring to a subspecialist when extra expertise helps
Fellowship trained subspecialists
Fellowship trained subspecialists spend extra years concentrating on one part of the eye or one group of diseases.
- Large volume of complex and advanced cases in that area
- Training in advanced and newer procedures for that subspecialty
- Experience with uncommon forms of disease
- Often involved in teaching or research in that field
What glaucoma fellowship training adds
Glaucoma fellows spend their fellowship focused on diagnosing and treating glaucoma, from early disease through the most advanced cases. Training typically includes interpreting detailed optic nerve and visual field testing, managing glaucoma that is hard to control, and performing the full range of glaucoma procedures, including minimally invasive glaucoma surgery (MIGS), trabeculectomy and tube shunts.
Dr. Philip Ngai completed his glaucoma fellowship at the Hamilton Glaucoma Center at the Shiley Eye Institute, UC San Diego. Dr. Thomas Vo completed his fellowship in cornea, cataract and refractive surgery at Weill Cornell in New York City.
When a subspecialist may help
Many patients with glaucoma or cataracts are cared for very well by a comprehensive ophthalmologist. A subspecialist may be helpful when:
- Glaucoma is advanced, or keeps progressing despite treatment
- Eye pressure is hard to control with drops or laser
- Surgery is being considered beyond standard treatment
- Cataract and glaucoma need to be treated together
- The diagnosis is unusual or uncertain
If you are unsure, your eye doctor can help you decide whether a subspecialty opinion makes sense for you.
Take the next step. It’s easy.
Related care to consider
Fellowship training FAQs
Is a fellowship trained doctor better than one without a fellowship?
Not in general. Every board certified ophthalmologist is trained to provide excellent medical and surgical eye care. A fellowship adds extra depth in one area, which matters most for complex or advanced cases in that area.
How long is a glaucoma fellowship?
Most glaucoma fellowships last one year, after the three years of ophthalmology residency.
Do I need a glaucoma specialist if I have glaucoma?
Not always. Many people with glaucoma are managed well by a comprehensive ophthalmologist or optometrist. A glaucoma specialist is often involved when glaucoma is advanced, progressing or needs surgery.
How do comprehensive and fellowship trained doctors work together?
They often share care. A comprehensive eye doctor may follow you for routine care and refer you to a subspecialist for a specific problem or procedure, then continue your care afterward.
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3000 Big Dalton Ave, Baldwin Park, CA 91706 ยท Monday to Friday, 8am to 5pm, and some Saturdays
