Dr. Robert T. Chang, MD
Ophthalmology (Glaucoma Specialist (Ophthalmology) Physician)
300 Pasteur Dr
Stanford, CA 94305
Who else practices at this address →
Santa Clara County includes mental health (13% of residents) shortage areas. About shortage areas
- Medicare participating
At a glance
- Medical school
- University of Missouri, Columbia School of Medicine (2002)
- Years since graduation
- 24
- In the NPI registry since
- 2006
- Medicare patients seen, 2024
- 752
Licensed in California since 2009, according to the Medical Board of California. We show license dates only for the states that publish them in bulk; see which states do. For other states, check the state medical board.
The NPI date is when this clinician registered for a National Provider Identifier, the billing number used on health claims. It is not a license, graduation or board-certification date. NPIs were first issued in May 2005 and became required on claims in 2007–2008, so an early date usually means the clinician was already in practice before then. What an NPI is
Education and training
- 2002Medical school: University of Missouri, Columbia School of Medicine
- 2006Registered with an NPI (national billing number; not a license date) — NPIs began in 2005, so practice likely started earlier
Undergraduate school, residency, fellowship, licensing exams and board certification aren’t in public federal data. Board certification can be confirmed with the certifying board (ABMS member boards for MDs, AOA boards for DOs).
Specialties and state licenses
-
Glaucoma Specialist (Ophthalmology) Physician primary
CA license A108857 (first issued 2009; current) -
Ophthalmology Physician
CA license A108857 (first issued 2009; current) · FL license ME99224 · MO license 2004011762
As reported to the NPI registry. To confirm a license is current, check the state medical board.
Where they work
Hospitals
- Stanford Health Care Stanford, CA
Medical groups
- Stanford Health Care (3,122 clinicians)
Hospitals this clinician lists with Medicare, and groups they bill Medicare through (Care Compare). Affiliation doesn’t mean they see patients at every location.
Medicare patients and services
- Medicare patients, 2024
- 752
- Services billed
- 3,165
- Patients’ average age
- 77
| Service | Times | Patients |
|---|---|---|
| Established patient office or other outpatient visit, 30-39 minutes | 377 | 283 |
| Established patient office or other outpatient visit, 20-29 minutes | 366 | 261 |
| Exam of visual field with extended testing | 340 | 295 |
| Imaging of optic nerve | 327 | 320 |
| Ct scan of cornea | 117 | 110 |
| Measurement of corneal curvature and depth of eye | 102 | 100 |
| Established patient office or other outpatient visit, 40-54 minutes | 95 | 86 |
| Established patient complete exam of visual system | 80 | 79 |
| Imaging of retina | 77 | 66 |
| Removal of cataract with insertion of prosthetic lens | 71 | 57 |
Medicare fee-for-service only. CMS leaves out services billed for fewer than 11 patients. These figures describe a practice’s Medicare work; they aren’t a measure of quality.
Medicare prescriptions
| Drug | Prescriptions |
|---|---|
| Latanoprost Other prescribers in Stanford, CA | 369 |
| Prednisolone Acetate Other prescribers in Stanford, CA | 202 |
| Timolol Maleate Other prescribers in Stanford, CA | 131 |
| Dorzolamide-Timolol (dorzolamide hcl/timolol maleat) Other prescribers in Stanford, CA | 107 |
| Brimonidine Tartrate Other prescribers in Stanford, CA | 80 |
| Cyclosporine Other prescribers in Stanford, CA | 79 |
| Rocklatan (netarsudil mesylat/latanoprost) Other prescribers in Stanford, CA | 76 |
| Restasis (cyclosporine) Other prescribers in Stanford, CA | 65 |
| Tafluprost (tafluprost/pf) | 51 |
| Methazolamide | 49 |
Prescriptions filled under Medicare Part D, including refills. CMS leaves out drugs prescribed fewer than 11 times.
Payments from drug and device companies
In 2025, 7 companies reported 49 payments worth $20,483 in total to this clinician.
| Alcon Vision LLC | $13,046 |
|---|---|
| Alcon Research LLC | $4,000 |
| Sight Sciences, Inc. | $1,469 |
| Glaukos Corporation | $1,091 |
| AbbVie Inc. | $788 |
| Bausch & Lomb Americas Inc. | $65.22 |
| Beaver-visitec International, Inc. | $23.90 |
| Consulting Fee | $17,025 |
|---|---|
| Food and Beverage | $2,333 |
| Compensation for services other than consulting (speaking, faculty) | $1,125 |
What the payments were for
| Company | What it was for | Amount |
|---|---|---|
| Alcon Vision LLC Dec 4, 2025 | Consulting Fee Voyager DSLT · Ophthalmology | $4,000 |
| Alcon Vision LLC Oct 9, 2025 | Consulting Fee Voyager DSLT · Ophthalmology | $3,500 |
| Alcon Vision LLC Feb 6, 2025 | Consulting Fee Voyager DSLT; HYDRUS Microstent · Ophthalmology | $3,000 |
| Sight Sciences, Inc. May 15, 2025 | Compensation for services other than consulting (speaking, faculty) OMNI SURGICAL SYSTEM; SION SURGICAL INSTRUMENT · Ophthalmology | $1,125 |
| Alcon Vision LLC May 22, 2025 | Consulting Fee HYDRUS Microstent · Ophthalmology | $1,000 |
| Alcon Research LLC May 22, 2025 | Consulting Fee NGENUITY · Ophthalmology | $1,000 |
| Alcon Research LLC Jan 23, 2025 | Consulting Fee NGENUITY · Ophthalmology | $1,000 |
| Alcon Research LLC Apr 10, 2025 | Consulting Fee NGENUITY · Ophthalmology | $1,000 |
| Alcon Research LLC Sep 4, 2025 | Consulting Fee NGENUITY · Ophthalmology | $1,000 |
| Glaukos Corporation Oct 29, 2025 | Consulting Fee | $800 |
All 11 payments other than meals, newest first
| Company | What it was for | Amount |
|---|---|---|
| Alcon Vision LLC Dec 4, 2025 | Consulting Fee Voyager DSLT · Ophthalmology | $4,000 |
| Glaukos Corporation Oct 29, 2025 | Consulting Fee | $800 |
| Alcon Vision LLC Oct 9, 2025 | Consulting Fee Voyager DSLT · Ophthalmology | $3,500 |
| Alcon Research LLC Sep 4, 2025 | Consulting Fee NGENUITY · Ophthalmology | $1,000 |
| Alcon Vision LLC May 22, 2025 | Consulting Fee HYDRUS Microstent · Ophthalmology | $1,000 |
| Alcon Research LLC May 22, 2025 | Consulting Fee NGENUITY · Ophthalmology | $1,000 |
| Sight Sciences, Inc. May 15, 2025 | Compensation for services other than consulting (speaking, faculty) OMNI SURGICAL SYSTEM; SION SURGICAL INSTRUMENT · Ophthalmology | $1,125 |
| Alcon Research LLC Apr 10, 2025 | Consulting Fee NGENUITY · Ophthalmology | $1,000 |
| AbbVie Inc. Feb 10, 2025 | Consulting Fee DURYSTA · EYE CARE | $725 |
| Alcon Vision LLC Feb 6, 2025 | Consulting Fee Voyager DSLT; HYDRUS Microstent · Ophthalmology | $3,000 |
| Alcon Research LLC Jan 23, 2025 | Consulting Fee NGENUITY · Ophthalmology | $1,000 |
Each payment as the company reported it, with the products it named. Meals are counted in the totals above but not listed one by one.
From CMS Open Payments. A payment is not evidence of wrongdoing; many are for consulting, teaching or meals. Clinicians can review and dispute their records with CMS.