Mark Williams, MD
Retina Specialist · Orange, CANPI 1780118802
Payments from drug & device makers
Across 85 payments — averaging $66.72 each. Meals, travel, consulting and speaking fees, gifts and royalties reported by drug and device makers.
- Bausch & Lomb, A Division Of Bausch Health US, LLC$2K
- Regeneron Healthcare Solutions, Inc.$747
- Alcon$704
- Genentech USA, Inc.$539
- Apellis Pharmaceuticals, Inc.$353
- Astellas Pharma US Inc$323
- plus $1K from 15 others
What the payments were for
- Travel & lodging$1,07419%
- Food & beverage$4,59781%
Most of this is food and beverage — typically meals provided during product presentations at a clinic or hospital. Nationally that is the single largest category of reported payments by count.
General payments by program year
Who reported the general payments
Companies are grouped under their corporate parent — a single manufacturer often files under several CMS reporting entities. Research and ownership payments are counted separately and are not in this table.
| Company | Payments | Total |
|---|---|---|
| Bausch & Lomb, A Division Of Bausch Health US, LLC | 13 | $1,578 |
| Regeneron Healthcare Solutions, Inc. | 15 | $747 |
| Alcon | 7 | $704 |
| Genentech USA, Inc. | 11 | $539 |
| Apellis Pharmaceuticals, Inc. | 5 | $353 |
| Astellas Pharma US Inc | 5 | $323 |
| Alimera Sciences, Inc. | 4 | $303 |
| Astellas Pharma Global Development | 3 | $194 |
| Genentech, Inc. | 1 | $127 |
| Amgen | 1 | $116 |
| Dompe US, Inc. | 1 | $107 |
| Bausch & Lomb Americas Inc. | 5 | $100 |
| Ocular Therapeutix, Inc. | 1 | $86 |
| Merz Pharmaceuticals, LLC | 1 | $81 |
| Sight Sciences, Inc. | 1 | $72 |
| AbbVie | 3 | $64 |
| Glaukos Corporation | 2 | $59 |
| Biogen | 2 | $37 |
| ANI Pharmaceuticals, Inc. | 2 | $33 |
| Mallinckrodt Hospital Products Inc. | 1 | $25 |
| Novartis | 1 | $24 |
What the payments were tied to
Products named in the reported payments. Only payments of $100 or more are attributed here — the typical reported payment nationally is a meal worth about $16, and listing those product-by-product would be noise.
How this compares
$5,671 in reported general payments places this provider in the 55th percentile of 187 retina specialist providers in California.
Medicare billing
What this is not: this is the amount Original Medicare Part B allowed for services this provider billed in 2024. It is not their income. It excludes Medicare Advantage — now more than half of all Medicare enrollment — along with Medicaid and all commercial insurance, and it is gross practice revenue before staff, rent, supplies and malpractice premiums. CMS also suppresses any figure covering ten or fewer patients, so low-volume providers appear smaller than they are.
Most prescribed under Part D
| Drug | Claims | Cost to plans & patients |
|---|---|---|
| Prednisolone Acetate | 117 | $3,500 |
| MoxifloxacinMoxifloxacin Hcl | 76 | $1,960 |
| Difluprednate | 13 | $1,550 |
| Atropine Sulfate | 39 | $1,167 |
| Ketorolac Tromethamine | 49 | $862 |
| ErythromycinErythromycin Base | 82 | $767 |
| Brimonidine Tartrate | 42 | $296 |
| Latanoprost | 29 | $216 |
| Dorzolamide-TimololDorzolamide Hcl/Timolol Maleat | 15 | $108 |
Paid to pharmacies, not to this prescriber.
Other retina specialist in Orange
- Dante PieramiciSanta Barbara$15.1M
- Margaret ChangSacramento$13.2M
- Hani Salehi-HadHuntington Beach$12.2M
- Payam AminiPasadena$9.9M
- Joel PearlmanSacramento$8.3M
- Dilsher DhootSanta Barbara$8.2M
- Ashkan PirouzFullerton$6.9M
- Roger GoldbergWalnut Creek$5M
- Sean AdreanFullerton$2.9M
- Nathan SteinleSanta Barbara$2.6M
Where these figures come from
- Payments: CMS Open Payments, program years 2019–2025 (publication P06302026_06032026).
- Billing: Medicare Physician & Other Practitioners, data year 2024. Original Medicare Part B only.
- Identity: NPPES NPI Registry, July 2026.