Glaucoma can progress without a single symptom: up to 1 person in 2 who has it does not know. The 3 major risk factors are raised intraocular pressure, age and family history.
If your vision is changing, if you carry risk factors or if you simply want your eye health checked, Noria Health Hub can arrange a full check-up or a second medical opinion in Brussels, with a report within 24 h, coordinate your care where needed across more than 40 medical pathways in 48 h, then, if your medical condition allows, arrange surgery within 7 days.
Why glaucoma can advance unseen
In most screening debates, the argument is about whether it is useful to look for a silent disease. In ophthalmology, one mechanical fact changes the terms of that debate. You must have lost between 25 and 35% of retinal ganglion cells before a defect appears on a standard visual field. The symptom arrives after the loss, and the loss is irreversible.
That is why optical coherence tomography, which directly measures the thickness of the nerve fibre layer, changed practice. It sees the loss before the patient does.
Glaucoma screening: the benefit of a systematic programme remains uncertain
This particular feature of glaucoma does not mean that screening every adult has been shown to be beneficial. The US Preventive Services Task Force classifies this screening as grade I, that is, insufficient evidence, for want of a randomised trial measuring long-term vision loss.
What randomised trials have clearly demonstrated, by contrast, is that lowering intraocular pressure slows progression of glaucoma once it is diagnosed. The proven link is the treatment, not the mass screening strategy.
Diabetic retinopathy: screening whose value is solidly demonstrated
Here the data are of another kind, and they are solid.
| What is measured | The result |
|---|---|
| Global prevalence of retinopathy in people with diabetes, meta-analysis | 22.27% |
| Share of certified blindness attributed to diabetic retinopathy in England before the national programme | 17.7% |
| The same share after systematic screening was introduced | 14.4% |
| What that changed in rank | Diabetic retinopathy is no longer the leading cause of blindness in the working-age population in England |
It is one of the few screening programmes in the world whose effect can be shown on a national blindness register. The comparison is before-and-after rather than randomised, but the temporal coherence is strong.
Diabetic retinopathy: some AI systems can run without immediate human reading
Ophthalmology is the first specialty in which a health authority has authorised an autonomous diagnostic device, that is, one returning a result without medical review. The pivotal trial performance is as follows.
| What is measured | The result |
|---|---|
| Sensitivity of the autonomous device for clinically significant diabetic retinopathy | 87.2% |
| Specificity | 90.7% |
| False positives per 100 people screened | About 8 |
| What the device does not do | It screens neither glaucoma, nor macular degeneration, nor other retinal disease |
A specificity of 90.7% is still a specificity, not a certainty. About 8 people in 100 will be referred for nothing, which is the accepted price for not missing the 87.2% of true retinopathies.
Macular degeneration: the risk depends heavily on stage
The prevalence of late age-related macular degeneration is about 0.1% around age 50, and about 9.8% beyond 85. That is a factor of roughly 100 on a single variable, age.
This has a direct consequence for what it is reasonable to offer. A fundus examination in a person of 40 with no risk factor and the same examination in a person of 75 do not follow the same logic, even though the technical act is identical. The same test does not have the same value depending on who takes it.
Cataract: a benefit measured on daily life
Cataract surgery is associated with a reduced risk of falls, with a hazard ratio of about 0.66 in the available analyses. It is one of the few places where an ophthalmic intervention shows a measured effect on an event that is not visual.
The limit must nonetheless be named. Most of these data are observational, and people who have surgery differ from those who do not in autonomy, access to care and general health. The effect is probably real, its exact size uncertain.
How long people wait
| Country | What is measured | The wait |
|---|---|---|
| France | Ophthalmologist appointment, median | 52 days |
| France | The same, mean | 80 days |
| France | The same, 9th decile, that is the 10% who wait longest | 189 days |
| England | Ophthalmology pathway, referral to start of treatment | 18-week target, met for only a share of patients |
The contrast between a median of 52 days and a 9th decile of 189 days is the real lesson of this table. The mean describes nobody, and it is the tail of the distribution that decides what happens to people.
What the studies do not allow us to claim
You will not read here that systematic eye screening preserves sight, because no randomised trial has demonstrated it for glaucoma. We will not claim that an algorithm replaces an ophthalmologist, because the only authorised autonomous device covers a single disease on a retinal photograph. Nothing entitles us to write that a normal examination puts you in the clear either, because glaucomatous disease unfolds over decades.
What we will say is that if you have diabetes, a family history of glaucoma, are over 60, or are strongly short-sighted, your individual situation justifies a documented examination, with measurements that can be compared 2 years from now.
In practice, if this concerns you
You set out your problem, your symptoms or your question. Reports, test results and images already available can be studied before you arrive, so that the pathway is prepared. The aim is not to run every examination as a matter of course, but to select those that can genuinely help confirm a hypothesis, rule out a risk or guide a decision. The findings are then brought together and the next steps organised. Follow-up is coordinated from there.
Need a medical opinion quickly? For a concern that does not call for emergency services, you can ask to speak to a doctor at any time through Noria Health Hub. This on-demand medical consultation is billed separately from the assessment pathway.
Further reading
The companion articles.
What” rel=”noopener” target=”_blank”>https://noriahealth.com/blog/what-a-health-assessment-can-actually-find/”>What a health assessment can actually find
Waiting” rel=”noopener” target=”_blank”>https://noriahealth.com/blog/what-delay-really-costs-what-the-studies-say/”>Waiting for a diagnosis or a treatment, what the studies actually measure
Sources
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Chou R et al., Screening for Glaucoma in Adults, Updated Evidence Report and Systematic Review for the US Preventive Services Task Force, JAMA, 2022. https://doi.org/10.1001/jama.2022.6290
Quigley HA, Broman AT, The number of people with glaucoma worldwide in 2010 and 2020, British Journal of Ophthalmology, 2006. https://doi.org/10.1136/bjo.2005.081224
Kass MA et al., The Ocular Hypertension Treatment Study, a randomised trial determines that topical ocular hypotensive medication delays or prevents the onset of primary open-angle glaucoma, Archives of Ophthalmology, 2002. https://doi.org/10.1001/archopht.120.6.701
Heijl A et al., Early Manifest Glaucoma Trial, reduction of intraocular pressure and glaucoma progression, Archives of Ophthalmology, 2002. https://doi.org/10.1001/archopht.120.10.1268
Teo ZL et al., Global prevalence of diabetic retinopathy and projection of burden through 2045, Ophthalmology, 2021. https://doi.org/10.1016/j.ophtha.2021.04.027
Liew G, Michaelides M, Bunce C, A comparison of the causes of blindness certifications in England and Wales in working age adults, BMJ Open, 2014. https://doi.org/10.1136/bmjopen-2014-004015
Abràmoff MD, Lavin PT, Birch M, Shah N, Folk JC, Pivotal trial of an autonomous AI-based diagnostic system for detection of diabetic retinopathy in primary care offices, npj Digital Medicine, 2018. https://doi.org/10.1038/s41746-018-0040-6
US Food and Drug Administration, De Novo classification request DEN180001, autonomous artificial intelligence diabetic retinopathy detection device. https://www.accessdata.fda.gov/
Wong WL et al., Global prevalence of age-related macular degeneration and disease burden projection for 2020 and 2040, The Lancet Global Health, 2014. https://doi.org/10.1016/S2214-109X(13)70145-1
Tseng VL et al., Risk of fractures following cataract surgery in Medicare beneficiaries, JAMA, 2012. https://doi.org/10.1001/jama.2012.13011
Harwood RH et al., Falls and health status in elderly women following first eye cataract surgery, randomised controlled trial, British Journal of Ophthalmology, 2005. https://doi.org/10.1136/bjo.2004.049478
Kerrigan-Baumrind LA et al., Number of ganglion cells in glaucoma eyes compared with threshold visual field tests in the same persons, Investigative Ophthalmology and Visual Science, 2000.
Direction de la recherche, des études, de l’évaluation et des statistiques, Enquête sur les délais d’attente pour un rendez-vous chez un médecin spécialiste, France. https://drees.solidarites-sante.gouv.fr/
NHS England, Referral to Treatment Waiting Times. https://www.england.nhs.uk/statistics/statistical-work-areas/rtt-waiting-times/
American Academy of Ophthalmology, Primary Open-Angle Glaucoma Preferred Practice Pattern, 2025. https://www.aao.org/education/preferred-practice-pattern/primary-open-angle-glaucoma-ppp