Findings from a recent study published in Retina mapped drive times from every U.S. census tract to the nearest medical or surgical retina specialist. The finding: Roughly 1 in 20 residents sit beyond a 60-minute drive.
Give me some background first.
Neovascular age-related macular degeneration (nAMD), proliferative diabetic retinopathy (PDR), rhegmatogenous retinal detachment (RRD), and endophthalmitis all call for urgent surgery or a long run of intravitreal injections.
Why proximity matters: Prior research has linked longer travel distances with reduced injection frequency and documented loss to follow-up among patients receiving anti-VEGF therapy for nAMD.
And the gap?
Previous research found that about 90% of surgical retina practices were located in urban zip codes, compared with just 5% in rural areas.
What this means: A rural patient may live a short drive from a specialist practicing in an urban zip code, and an urban address does not guarantee an easy trip.
Now, talk about the study.
A team at the University of Michigan and Harvard Medical School ran a population-based, cross-sectional analysis built on drive-time service areas rather than practice locations. Data were collected in April 2025.
How they built the map:
- The team pulled specialists from the American Society of Retina Specialists (ASRS) and American Academy of Ophthalmology (AAO) directories and cross-referenced them against the Centers for Medicare and Medicaid Services (CMS) Doctors and Clinicians National File
- They then checked each by hand against private practice websites, academic department profiles, health network listings, and physician profiles to catch sites the directories missed
Following this: The team mapped every practice location and calculated 15-, 30-, and 60-minute drive times using real-world traffic conditions. They then added local demographic data from the 2019–2023 American Community Survey.
The cutoff: Inadequate access meant a geographic area that fell outside every 60-minute service area. Odds ratios (ORs) were scaled per 10-percentage-point increase in each tract-level variable, and the primary model adjusted for urbanicity.
Who was included in the study?
The final list held 2,516 active, fellowship-trained retina specialists. Of those, 2,257 (89.7%) were surgical retina and 259 (10.3%) medical retina.
- The team excluded retired, deceased, emeritus, and non-clinical physicians.
Demographics: 2,090 (83.1%) were men and 426 (16.9%) women, though medical retina skewed less male, with women making up 27.0% of that group versus 15.8% of surgical retina. Mean medical school graduation year was 1997 (standard deviation [SD] 12.0, range 1960 to 2020).
Worth noting: Physicians practiced at a mean of 2.9 locations (SD 1.7; median 3, interquartile range 2 to 4). The authors tied the specialty's broad geographic coverage to that multi-site practice model.
On the population side: U.S. census tracts served as the unit of analysis, and the study left out territories such as Puerto Rico.
And the findings?
Nationally: There were 7.57 retina specialists per 1 million U.S. residents.
Drive times broke down like this:
- 62.5% of residents lived within 15 minutes of a specialist
- 21.4% between 15 and 30 minutes
- 11.1% between 30 and 60 minutes
- 5.0% (roughly 16.5 million people) lived beyond 60 minutes
Of importance: 33.5% of rural residents and 20.3% of suburban residents lived beyond a 60-minute drive, compared to 1.6% of urban residents.
Tell me more.
In the primary, urbanicity-adjusted model, rural areas carried 19.66 times the odds of inadequate access compared with urban areas (95% confidence interval [CI], 18.75 to 20.62).
Suburban areas carried 11.03 times the odds (95% CI, 10.60 to 11.49).
Sociodemographic associations held on top of that. For every 10-percentage-point increase in the share of residents who were:
- Medicare-aged residents (≥ 65 years): OR 1.61 (95% CI, 1.58 to 1.64)
- Racial homogeneity, by index: OR 1.15 (95% CI, 1.14 to 1.16)
- Hispanic or Latino residents: OR 1.08 (95% CI, 1.07 to 1.09)
- Uninsured residents: OR 1.05 (95% CI, 1.02 to 1.08)
- Associate's degree or greater: OR 0.89 (95% CI, 0.88 to 0.90)
Tell me more.
The proportion of very low-income residents was associated with inadequate access before adjusting for urbanicity (OR 1.07) and not after (OR 1.00; 95% CI, 0.99 to 1.02; p = 0.73).
And one that emerged: Hispanic or Latino proportions registered nothing in the unadjusted model (OR 0.99; p = 0.09) and turned into a modest risk factor only once urbanicity was accounted for.
Regional density: The Northeast led at 9.68 specialists per million, followed by:
- South (7.76)
- Midwest (7.50)
- West (7.18)
On the state level: Washington D.C. (43.15), Delaware (25.85), and Maryland (16.53) topped the list, while North Dakota (5.13), Oklahoma (5.26), and Alaska (5.45) sat at the bottom.
Limitations?
Drive time captures one piece of access. Cost, appointment availability, and weather conditions were not evaluated.
A bigger assumption: The analysis presumed patients had a personal automobile and could travel to appointments safely, which the authors flagged as shaky for anyone with visual impairment from advanced retinal disease.
Other considerations:
- The team could not account for how much time each specialist spends at a primary versus satellite site, or what share of a practice is devoted to non-retinal care
- The team excluded U.S. territories to stay consistent with prior national ophthalmic access studies
The authors argued these limitations likely made 5.0% an underestimate of the population with inadequate access. And running the other direction: Tele-retina services and anti-vascular endothelial growth factor (VEGF) injections delivered by non-retina-trained ophthalmologists went uncaptured, and may have partly offset that.
Anything else?
One finding that stands out: the suburbs. Sitting inside a micropolitan statistical area did not guarantee reasonable access, with 1 in 5 suburban residents beyond a 60-minute drive despite their relative proximity to urban centers.
Did they propose any solution to closing the gap?
The authors floated several strategies: satellite clinics with part-time retina coverage, hub-and-spoke partnerships between comprehensive ophthalmologists and retina specialists, fellowship programs that steer graduates toward underserved regions, loan forgiveness and rural practice incentives, and expanded mobile clinic, tele-retina, and at-home screening infrastructure.
And lastly: the take home.
For clinicians practicing in rural and suburban communities, about a third of rural patients and a fifth of suburban patients face a drive of more than an hour to reach retina care.
Early recognition and prompt referral carry extra weight where that drive is long, particularly for time-sensitive presentations like RRD and endophthalmitis.
As such: Identifying which patients will struggle to make the trip, and pointing them toward satellite clinics or tele-retina options where those exist, is worth building into the referral conversation.