# Pediatric Eye Care Access With and Without a CHLA Class Center

## Main finding

The strongest defensible conclusion is **not** that a CHLA-class children’s eye center “causes” better outcomes, but that metros anchored by one tend to have a very different pediatric eye-care ecosystem: larger multidisciplinary teams, visible orthoptics capacity, fellowship pipelines, regional satellite clinics, and published subspecialty volumes. In contrast, large metros without a clearly documented high-volume children’s-hospital eye program are more often served by smaller hospital clinics and/or private pediatric-ophthalmology practices, with fewer public signals of orthoptic depth, training capacity, or regional referral reach. Nationally, this matters because pediatric ophthalmology is scarce: about **90% of U.S. counties had no pediatric ophthalmologist in 2022**, **90.2% had none in 2023**, and **1 in 7 U.S. children live outside a 60-minute drive to pediatric ophthalmology care**. Those access gaps track lower income, lower internet access, more uninsurance, and lower educational attainment. citeturn16search7turn17view0turn6view0

The evidence is much thinner for **metro-specific orthoptics** and for **metro-specific clinical outcomes** such as amblyopia visual-acuity gains or age at diagnosis. What the literature does show is that access barriers are associated with worse process outcomes: Medicaid-insured children are more likely to face long waits, more likely to be lost to follow-up after amblyopia diagnosis, and, in broader pediatric-eye-care studies, substantially less likely to secure appointments than privately insured peers. Even high-resource centers acknowledge capacity strain and triage lower-acuity referrals away from subspecialty clinics. citeturn12search1turn12search13turn15search12turn13search20

## How the groups were defined

I treated a metro as **high-resource** only when I could verify multiple objective signals of a major children’s-eye program in the gathered sources: a dedicated children’s-hospital ophthalmology division, a visible orthoptist presence, fellowship/training infrastructure, and/or published annual pediatric volume. That standard is clearly met by programs such as **Boston Children’s**, **CHOP**, **Texas Children’s**, **Cincinnati Children’s**, **CHLA**, and also by other children’s hospitals surfaced in the review such as **Children’s National**, **Children’s Hospital Colorado**, **Rady Children’s**, and **Children’s Healthcare of Atlanta**. Boston Children’s has an AUPO-compliant pediatric ophthalmology fellowship with **3 positions** and an AOC-accredited orthoptic fellowship; CHOP has a large division with ophthalmologists, optometrists, orthoptists, regional locations, and both ophthalmology and orthoptic fellowships; Texas Children’s reports **more than 16,000 patients annually** and **more than 1,100 procedures each year**; Cincinnati Children’s reports **more than 22,000** pediatric ophthalmology patients yearly. CHLA explicitly describes itself as one of the country’s leading and largest pediatric ophthalmology programs and highlights in-house orthoptists and extensive subspecialty structure. citeturn21search16turn21search24turn21search21turn21search5turn26view0turn29search1turn21search6turn21search3turn35search6turn35search1turn22search18turn35search10turn23search15turn34search1

I treated a metro as a **lower-resource comparator** when, in the gathered sources, I could verify pediatric ophthalmology services but **could not verify** a comparable high-volume children’s-hospital eye program with public subspecialty volume/training/orthoptics signals. By that rule, **San Antonio**, **El Paso**, and **Las Vegas** are defensible comparators. San Antonio’s reviewed sources show pediatric ophthalmology is available through University Health/UT Health and a private pediatric practice, but I did not locate a CHLA-/CHOP-/Boston-style children’s-hospital eye division with published annual volume or fellowship infrastructure in the sources I gathered. El Paso’s reviewed sources surfaced dedicated private pediatric ophthalmology clinics, including one prominently built around a single named board-certified pediatric ophthalmologist. Las Vegas’ reviewed sources surfaced private-practice pediatric ophthalmology service lines, and Nevada’s statewide pediatric-ophthalmologist supply is small. That does **not** mean no pediatric eye care exists there; it means the public signals of **depth, scale, and orthoptic embeddedness** are materially weaker. citeturn22search13turn23search22turn32view0turn35search0turn35search2turn33search0turn33search8turn18view0

## Side by side comparison across metros and regions

| Metro or region | Anchor service model found in reviewed sources | Objective high-resource signals | Publicly documented scale | Orthoptics signal | Regional pediatric-ophthalmologist supply proxy | What this suggests |
|---|---|---|---|---|---|---|
| **Boston** | Boston Children’s Department of Ophthalmology | AUPO pediatric ophthalmology fellowship with **3 positions**; AOC-accredited orthoptic fellowship; department housed in the largest pediatric medical center in the U.S. | The Boston Orthoptic Fellowship page names **6 orthoptists plus the program director/chief orthoptist** on faculty materials; Boston Children’s also lists multiple ophthalmology locations. citeturn21search16turn25search1turn25search5turn25search12 | Strong, embedded, training-producing orthoptics presence. citeturn25search1turn25search5 | Massachusetts had **32.7 pediatric ophthalmologists per million people younger than 19** in 2023, among the highest state rates. citeturn18view0 | A CHLA-class ecosystem: orthoptics, fellowship pipeline, tertiary referral identity, and high surrounding provider density. |
| **Philadelphia** | CHOP Division of Ophthalmology | Large children’s-hospital division; ophthalmology and orthoptic fellowships; regional satellite locations. citeturn21search21turn21search5turn21search25 | Team page shows **1 division chief, 22 attending physicians, 5 optometrists, and 2 orthoptists** listed, plus additional staff. citeturn26view0 | Strong, explicit orthoptist staffing and formal orthoptic fellowship. citeturn26view0turn21search5 | Pennsylvania had **16.1 pediatric ophthalmologists per million people younger than 19** in 2023. citeturn18view0 | Not just a hospital clinic; effectively a regional pediatric-eye network with orthoptics built into the core team. |
| **Houston** | Texas Children’s Ophthalmology | Dedicated children’s-hospital ophthalmology division; multiple Houston-area sites plus Austin access. citeturn29search1turn21search6 | Texas Children’s reports **>16,000 patients annually** and **>1,100 procedures each year**. citeturn29search1 | Multidisciplinary care is explicit, but the orthoptist headcount was not publicly extractable from the gathered pages. | Texas had **6.8 pediatric ophthalmologists per million people younger than 19** in 2023. citeturn18view0 | Houston likely outperforms the Texas state backdrop because it concentrates one of the state’s major tertiary programs. |
| **Cincinnati** | Cincinnati Children’s Division of Pediatric Ophthalmology | One of the country’s largest pediatric eye centers; multiple regional clinic sites. citeturn21search3turn21search19 | Cincinnati Children’s reports treating **more than 22,000 infants, children and adolescents per year**. citeturn21search3turn35search6 | Orthoptists are mentioned in Cincinnati Children’s materials, but a clean public headcount was not extractable from gathered pages. citeturn21search15 | Ohio had **15.5 pediatric ophthalmologists per million people younger than 19** in 2023. citeturn18view0 | Another clear high-resource referral hub with large published volume and multi-site regional reach. |
| **Los Angeles region** | CHLA Vision Center | Explicitly described as one of the nation’s leading and largest pediatric ophthalmology programs; in-house orthoptists; multiple subspecialty programs. citeturn35search1 | CHLA lists cornea/glaucoma, eye movement, retina, retinoblastoma, and neuro-ophthalmology programs. In the 2022 national county analysis, **Los Angeles County had the most pediatric ophthalmologists of any U.S. county**, accounting for **3.6%** of all U.S. pediatric ophthalmologists. citeturn35search1turn11search2 | Strong orthoptist signal from program description. citeturn35search1 | California had **11.5 pediatric ophthalmologists per million people younger than 19** in 2023; Los Angeles County appears to sit above that state average because it is the top county nationally by raw count. citeturn18view0turn11search2 | This is the closest publicly documented “CHLA-class” archetype in the review. |
| **San Antonio** | Smaller mixed ecology: hospital clinic plus private pediatric practice | Pediatric ophthalmology exists, but I did **not** find a public high-volume children’s-hospital eye-center profile with training and published volume comparable to Boston/CHOP/Texas Children’s/CHLA in the gathered sources. citeturn22search13turn23search22 | One private subspecialty practice publicly lists **2 pediatric ophthalmologists and 2 certified orthoptists**. citeturn32view0 | Orthoptics exists locally, but in the reviewed sources it appears concentrated in a single private practice rather than a large children’s-hospital division. citeturn32view0 | Texas state proxy: **6.8 pediatric ophthalmologists per million children**. citeturn18view0 | Meaningfully better than a true desert, but publicly visible depth is still much thinner than in the high-resource exemplars. |
| **El Paso** | Private pediatric-ophthalmology practices | I did **not** locate a comparable high-volume children’s-hospital eye program in the gathered sources. | One reviewed practice markets itself around **one named board-certified pediatric ophthalmologist**; another private group offers pediatric ophthalmology services. citeturn35search0turn35search2 | No public orthoptist team was identifiable from the gathered sources. | Texas state proxy: **6.8 pediatric ophthalmologists per million children**. citeturn18view0 | A reasonable lower-resource comparator: specialist care exists, but scale and public orthoptics/training depth look much smaller. |
| **Las Vegas** | Private-practice pediatric ophthalmology service lines | I did **not** locate a public CHLA-class children’s-hospital eye program in the gathered sources. | One major practice page centers pediatric care on **one named pediatric ophthalmologist**; AAPOS job materials describe pediatric service lines inside large adult ophthalmology groups. citeturn33search0turn33search8 | No orthoptist team was publicly visible in the gathered Las Vegas pages. | Nevada had **9 pediatric ophthalmologists total**, or **11.3 per million people younger than 19**, in 2023. citeturn18view0 | Pediatric-eye care is present, but the public profile looks fragmented and private-practice based rather than children’s-hospital centered. |

## Stat cards

| Value | Metric or what it measures | Scope and population | Period | Source | Confidence | One-line so what |
|---|---|---|---|---|---|---|
| **1,056 pediatric ophthalmologists** | Total practicing pediatric ophthalmologists identified in public databases | United States | March 2022 | Walsh et al., *JAMA Ophthalmology* 2023. citeturn16search7 | [Measured] | The national pediatric-ophthalmology workforce is small enough that local concentration matters. |
| **2,828 of 3,142 counties** (**90.0%**) | Counties with **zero** pediatric ophthalmologists | U.S. counties | 2022 | Walsh et al., *JAMA Ophthalmology* 2023. citeturn16search7 | [Measured] | Most counties have no local pediatric ophthalmologist at all. |
| **4 of 50 states** (**8.0%**) | States with **zero** pediatric ophthalmologists | U.S. states | 2022 | Walsh et al., *JAMA Ophthalmology* 2023. citeturn16search7 | [Measured] | Entire states can lack in-state pediatric ophthalmology coverage. |
| **1,060 pediatric ophthalmologists** and **586 pediatric optometrists** | Total pediatric-eye-care specialist counts found from public databases | United States | April 2023 | Siegler et al., *JAMA Ophthalmology* 2024. citeturn17view0 | [Measured] | Pediatric ophthalmology remains the larger specialist workforce, but both are sparse. |
| **2,834 of 3,142 counties** (**90.2%**) | Counties with **zero** pediatric ophthalmologists | U.S. counties | 2023 | Siegler et al., *JAMA Ophthalmology* 2024. citeturn17view0 | [Measured] | The 2022 desert pattern did not materially improve in 2023. |
| **2,939 of 3,142 counties** (**93.5%**) | Counties with **zero** pediatric optometrists | U.S. counties | 2023 | Siegler et al., *JAMA Ophthalmology* 2024. **Shared eye-care metric, not orthoptics-specific.** citeturn17view0 | [Measured] | The broader pediatric-eye-care workforce is also highly concentrated. |
| **2,731 of 2,834 counties** (**96.4%**) | Counties without a pediatric ophthalmologist that also lacked a pediatric optometrist | U.S. counties with no pediatric ophthalmologist | 2023 | Siegler et al., *JAMA Ophthalmology* 2024. **Shared eye-care metric.** citeturn17view0 | [Measured] | Where pediatric ophthalmologists are missing, substitute pediatric-eye-care capacity is usually missing too. |
| **1 in 7 children** | Children living **outside a 60-minute drive** to pediatric ophthalmology care | U.S. children | 2025 publication using contemporary service-area analysis | Franco et al., *J AAPOS* 2025 abstract. citeturn6view0 | [Modeled] | Even after allowing an hour of travel, access is still materially incomplete. |
| **$70,230.59 vs $53,263.62**; difference **−$16,966.97** (95% CI **−$18,544.57 to −$14,389.37**) | Median household income in counties **with** vs **without** a pediatric ophthalmologist | U.S. counties | 2022 | Walsh et al., *JAMA Ophthalmology* 2023. citeturn16search7 | [Measured] | Pediatric ophthalmology is concentrated in wealthier counties. |
| **8.0% vs 4.7%** | Families without internet service in counties with **0** vs **≥1** pediatric ophthalmologist | U.S. counties | 2022 | Walsh et al., *JAMA Ophthalmology* 2023. citeturn16search7 | [Measured] | Access gaps stack with digital-access barriers. |
| **5.7% vs 4.1%** | Children/uninsured proportion in counties with **0** vs **≥1** pediatric ophthalmologist | U.S. counties, persons younger than 19 | 2022 | Walsh et al., *JAMA Ophthalmology* 2023. citeturn16search7 | [Measured] | Pediatric-eye-care scarcity and insurance vulnerability co-occur. |
| **$78,388.67 vs $57,714.03**; difference **−$20,675.00** (95% CI **−$21,550.90 to −$19,799.10**) | Mean household income in counties with **both** pediatric ophthalmologist and pediatric optometrist vs **neither** | U.S. counties | 2023 | Siegler et al., *JAMA Ophthalmology* 2024. **Shared eye-care metric.** citeturn17view0 | [Measured] | Places with the deepest pediatric-eye-care ecosystems are also much better resourced socioeconomically. |
| **Massachusetts: 32.7 per million** | Pediatric ophthalmologists per million people younger than 19 | Massachusetts | 2023 | Siegler et al., Table 1. citeturn18view0 | [Measured] | Parent-state context for Boston is exceptionally strong. |
| **Pennsylvania: 16.1 per million** | Pediatric ophthalmologists per million people younger than 19 | Pennsylvania | 2023 | Siegler et al., Table 1. citeturn18view0 | [Measured] | Philadelphia sits in a mid-to-high state-supply environment. |
| **Ohio: 15.5 per million** | Pediatric ophthalmologists per million people younger than 19 | Ohio | 2023 | Siegler et al., Table 1. citeturn18view0 | [Measured] | Cincinnati’s strong center exists in a state with solid but not elite pediatric-ophthalmology supply. |
| **California: 11.5 per million** | Pediatric ophthalmologists per million people younger than 19 | California | 2023 | Siegler et al., Table 1. citeturn18view0 | [Measured] | California overall is moderate, but Los Angeles County is a major concentration node within the state. |
| **Texas: 6.8 per million** | Pediatric ophthalmologists per million people younger than 19 | Texas | 2023 | Siegler et al., Table 1. citeturn18view0 | [Measured] | Texas statewide supply is relatively thin; Houston’s large center likely compensates locally. |
| **Nevada: 9 pediatric ophthalmologists; 11.3 per million younger than 19** | State pediatric-ophthalmology supply | Nevada children | 2023 | Siegler et al., Table 1. citeturn18view0 | [Measured] | Las Vegas may be the state’s main access node, but the statewide workforce is small. |
| **Los Angeles County: 3.6% of all U.S. pediatric ophthalmologists** | Share of U.S. pediatric-ophthalmologist workforce in one county | Los Angeles County | 2022 | Summary of Walsh et al. findings. citeturn11search2 | [Estimate] | CHLA sits inside the single biggest county concentration of pediatric ophthalmologists in the country. |
| **Suffolk County: 1.8% of all U.S. pediatric ophthalmologists** | Share of U.S. pediatric-ophthalmologist workforce in one county | Suffolk County, Massachusetts | 2022 | Summary of Walsh et al. findings. citeturn11search2 | [Estimate] | Boston’s core county is also a nationally dense workforce node. |
| **>16,000 patients annually** and **>1,100 procedures/year** | Reported pediatric ophthalmology clinical volume | Texas Children’s Ophthalmology, Houston-centered system | Current program description | Texas Children’s Ophthalmology program page. citeturn29search1 | [Measured] | This is exactly the kind of public volume signal that distinguishes a CHLA-class center from smaller markets. |
| **>22,000 infants, children and adolescents per year** | Reported annual pediatric ophthalmology patient volume | Cincinnati Children’s | Current program description | Cincinnati Children’s Ophthalmology. citeturn21search3turn35search6 | [Measured] | The Cincinnati program is clearly functioning as a high-volume regional referral center. |
| **3 fellowship positions** | AUPO-compliant pediatric ophthalmology fellowship size | Boston Children’s / Harvard | Current AUPO listing | Boston Children’s fellowship pages and AUPO listing. citeturn21search16turn21search28 | [Measured] | High-resource centers do not just deliver care; they reproduce the workforce. |
| **At least 6 named orthoptists plus the program director/chief orthoptist** | Publicly visible orthoptics faculty | Boston Children’s Orthoptic Fellowship materials | 2025-2026 pages | Boston Orthoptic Fellowship materials. citeturn25search1turn25search5 | [Measured] | Orthoptics capacity is deep enough to support both care and training. |
| **1 chief, 22 attending physicians, 5 optometrists, 2 orthoptists** | Publicly listed team composition | CHOP Division of Ophthalmology | 2026 webpage viewed | CHOP team page. citeturn26view0 | [Measured] | CHOP has unmistakable multidisciplinary depth. |
| **2 pediatric ophthalmologists and 2 orthoptists** | Publicly listed pediatric team size | Children’s Eye Center of South Texas, San Antonio | 2026 webpage viewed | San Antonio staff page. citeturn32view0 | [Measured] | San Antonio has meaningful local expertise, but at a much smaller scale than the exemplar centers. |
| **1 named board-certified pediatric ophthalmologist** | Publicly emphasized pediatric-ophthalmology staffing | One El Paso pediatric ophthalmology practice | 2026 webpage viewed | Children’s Eye Center of El Paso. citeturn35search0 | [Measured] | El Paso’s reviewed public footprint looks much thinner and more dependent on single-practice capacity. |
| **Median wait 46 days vs 14 days** | Appointment wait time for Medicaid patients vs privately insured patients at non-Medicaid practices | U.S. pediatric-eye-care appointment audit | 2025 publication | Cheung et al., PubMed abstract. citeturn12search1 | [Measured] | Insurance status powerfully changes how quickly a child can get seen. |
| **56% vs 100%** | Medicaid-participating practices providing routine eye care for ages **0-5** vs **6-17** | U.S. Medicaid-participating pediatric-eye-care practices | 2025 publication | Cheung et al., PubMed abstract. citeturn12search1 | [Measured] | The youngest kids can face the tightest access bottlenecks. |
| **52.8 ± 58.3 days vs 25.4 ± 36.5 days** | Average wait for successful appointments at ophthalmologist vs optometrist offices | U.S. pediatric-eye-care appointment access study | 2025 | *J AAPOS* abstract. **Shared eye-care metric.** citeturn13search3 | [Measured] | Even when an appointment is obtained, ophthalmology usually takes longer than optometry. |
| **“Wait times may be longer”** for uncomplicated failed screening referrals | Capacity triage signal from a high-resource children’s hospital | Children’s Hospital Colorado failed-screening guidance | Current webpage | Children’s Hospital Colorado referral guidance. citeturn13search20 | [Measured] | Even strong tertiary centers ration subspecialty bandwidth and redirect lower-acuity volume. |
| **15.8%**, down from **19.2%** | Share of school-age children on Medi-Cal receiving eye-doctor care | California children enrolled in Medi-Cal | 2022-2024 vs 2015-2016 | California policy brief as reported by CalMatters. **Shared pediatric-eye-care metric, not orthoptics-specific.** citeturn14search3turn14search12 | [Low-confidence] | Low-income child eye-care uptake can be poor even in a state that hosts elite tertiary centers. |
| **About 39%** vs **71%** | Comprehensive-exam follow-up after failed vision screening in routine primary-care settings vs an integrated case-managed program | U.S. children after vision screening | Studies summarized in 2024 National Academies report | National Academies chapter citing Hered & Wood and Sight Savers America. **Shared screening metric.** citeturn14search22 | [Estimate] | Screening alone is not enough; system design determines whether kids actually reach treatment. |
| **28.4% vs 10.3%** | Immediate loss to follow-up after amblyopia diagnosis for Medicaid vs private insurance | Children with unilateral amblyopia in one U.S. academic-center study | Patients diagnosed 2015-2018; published 2022 | Hawn et al., *J Pediatr Ophthalmol Strabismus* PDF. citeturn15search12 | [Measured] | Outcome gaps often arise because underserved children disappear before treatment can work. |
| **2.86 vs 2.98 lines improvement; P = .84** | Visual-acuity improvement among children who **did follow up** for amblyopia treatment | Medicaid vs private-insurance subgroups in one U.S. study | Same study period | Hawn et al., published 2022. citeturn15search12 | [Measured] | Once children stay engaged in care, response to treatment may be similar; access and continuity are the bigger problem. |
| **12% supply decline**, **24% demand increase**, **30% workforce inadequacy by 2035**; **77% metro vs 29% nonmetro adequacy** | Projected overall ophthalmology workforce supply-demand gap | United States, all ophthalmology | 2020-2035 projection | Berkowitz et al., *Ophthalmology* 2024 via reproduced PDF. **Overall ophthalmology, not pediatric-only.** citeturn36search20 | [Modeled] | The national ophthalmology pipeline is moving in the wrong direction, especially outside metro areas. |

## Narrative

The numbers point to a fairly consistent story. A CHLA-class center is not just “more doctors in one building.” It is usually a **cluster institution**: subspecialists are concentrated there, orthoptists are built into the workflow, trainee pipelines exist, and clinic locations spread outward to shorten travel inside the catchment. Boston, CHOP, Texas Children’s, Cincinnati Children’s, and CHLA all show some combination of those signals. By contrast, the lower-resource comparators I could verify are structurally different: pediatric eye care exists, but it is thinner, more private-practice based, less visibly orthoptics-rich, and less publicly documented as a regional pediatric tertiary program. citeturn25search1turn26view0turn29search1turn21search3turn35search1turn32view0turn35search0turn33search0

The biggest caveat is that **publicly available metro-level orthoptics data are weak**. Pediatric-ophthalmologist supply can be approximated from the JAMA Ophthalmology state and county analyses, but orthoptists do not have a comparable county-by-county public registry. The American Orthoptic Council’s public-facing verification process is manual and requires contacting the office, which is the opposite of a machine-readable workforce file. So the best orthoptics comparison available here is through **program staffing evidence**, not a true national small-area dataset. That limitation is real, and it prevents a clean answer to “how many counties have zero orthoptists?” citeturn5view0turn4view0

What the access literature does show, though, is that pediatric-eye-care deserts align with the same social gradients that shape many pediatric subspecialties. Counties without pediatric ophthalmologists are poorer, have less internet access, more uninsured children, and weaker transportation access. In the 2023 practitioner-type study, counties with neither pediatric ophthalmologists nor pediatric optometrists had the lowest incomes and education levels. That means any observed advantage of Boston/Philadelphia/Houston/Cincinnati over San Antonio/El Paso/Las Vegas is partly a center effect and partly a **place effect**: richer, more academic, more connected metros attract and retain scarce specialists in the first place. citeturn16search7turn17view0

The outcome story is suggestive, not definitive. I did **not** find a strong metro-vs-metro U.S. literature directly comparing amblyopia cure rates, strabismus severity at presentation, or age at diagnosis by presence or absence of a CHLA-class center. The stronger evidence is one step upstream: access barriers worsen waits, appointment success, and follow-up. Medicaid-insured children faced sharply longer waits in a recent U.S. access study, and children with Medicaid were much more likely to be immediately lost to follow-up after amblyopia diagnosis. In plain terms: the current evidence says lower-resource markets are likely to lose children earlier in the care cascade, but the literature is not yet good enough to quantify how many lines of vision or how many months of diagnostic delay that translates to at the metro level. citeturn12search1turn12search13turn15search12turn17view0

So, if the question is **“What difference does a CHLA-class center make?”**, the best evidence-backed answer is: it appears to make the biggest difference in **system capacity and care pathways**—more multidisciplinary staffing, more orthoptic embedding, more regional referral reach, more ability to absorb complexity, more training, and probably shorter within-region travel because of outreach clinics. But it does **not** erase the national shortage, and it does **not** by itself solve insurance-related access barriers or follow-up failure. Even elite centers still triage limited pediatric-ophthalmology capacity, which is exactly what you would expect in a field where roughly 90% of counties lack a pediatric ophthalmologist and where fellowship recruitment remains fragile. citeturn13search20turn16search7turn17view0turn36search11

## Data gaps

The current evidence still cannot answer several important questions well:

- **True orthoptist geography in the United States.** I did not find a county- or metro-level public orthoptist registry. The AOC public workflow supports manual certification verification, not workforce mapping. citeturn5view0turn4view0
- **Metro-specific pediatric ophthalmology wait times.** I found national and insurance-stratified appointment-access studies, but not a reliable cross-metro dashboard for new pediatric ophthalmology visits. citeturn12search1turn13search3
- **Direct metro-level outcomes.** I did not find a robust U.S. study comparing amblyopia outcomes, strabismus severity at presentation, later diagnosis, or visual loss across metros with versus without major children’s-hospital eye centers. The 2024 JAMA Ophthalmology paper explicitly calls for this work. citeturn17view0
- **Travel-time comparisons inside metros.** The best current evidence is national drive-time modeling, not city-by-city pediatric ophthalmology drive-time estimates. citeturn6view0
- **Medicaid follow-up by metro after school or primary-care screening.** Some state and local signals exist, including California, but they are broader pediatric-eye-care measures and not orthoptics-specific. citeturn14search3turn14search22
- **A clean causal estimate of the “center effect.”** High-resource centers sit in bigger, richer, more academic metros with different referral patterns, insurance mixes, and baseline workforce density, so ecological comparisons remain confounded. citeturn16search7turn17view0