Ocular hypertension, suspects and juvenile glaucoma
Key Takeaways
OHT has raised pressure without demonstrated glaucomatous damage; a suspect may be defined by nerve or field uncertainty.
Interpret pressure, corneal thickness, optic nerve, fields and lifetime risk together.
The NICE 24 mmHg treatment pathway is a national recommendation, not a universal safe-pressure boundary.
Young patients with high pressure and damage need prompt evaluation for juvenile and secondary glaucoma.
Pressure is a risk factor, not the diagnosis
Ocular hypertension (OHT) means raised intraocular pressure (IOP) without demonstrated glaucomatous disc or field damage after appropriate assessment. A glaucoma suspect may instead have suspicious nerve appearance, a questionable field, strong family history or a relevant secondary mechanism. Juvenile open-angle glaucoma presents at a young age with an open angle and potentially severe pressure elevation. These categories require different decisions; treating every large cup as established glaucoma creates unnecessary lifelong medication, while dismissing high pressure in a young person risks decades of avoidable damage.
Confirm repeated Goldmann-type measurements, examine the angle, assess corneal thickness and inspect both optic nerves. Record acuity, refraction, pupils, stereoscopic disc appearance and baseline photographs or optical coherence tomography (OCT). Obtain reliable automated fields and repeat an unexpected defect. Review corticosteroid exposure, trauma, uveitis, pigment dispersion and pseudoexfoliation. A normal central field does not eliminate early structural disease, and an isolated red OCT sector does not prove glaucoma.
Estimating lifetime risk
The decision involves the probability of conversion, the likely speed of subsequent loss and the patient's remaining lifetime. Older age, higher pressure, thinner central cornea, larger vertical cup-to-disc ratio and worse field pattern standard deviation are recognized predictors in adult OHT cohorts. The Ocular Hypertension Treatment Study risk model concerns a defined adult population: it is not automatically calibrated for a child, a secondary glaucoma or an unusually high myopic disc. Family history and access to dependable surveillance also influence clinical judgement.
Corneal thickness is both a measurement-related consideration and an associated risk marker. Do not convert it into a universal number of mmHg to subtract. For example, a patient with pressures of 27 mmHg, a thin cornea and reproducible rim loss is not simply a low-risk OHT patient whose pressure can be mathematically corrected downward. Conversely, a thick cornea with an otherwise healthy nerve does not guarantee protection.
| Assessment | What changes the decision | Common error |
|---|---|---|
| Pressure | Repeated level, fluctuations, treatment exposure | Diagnosing from one air-puff result |
| Nerve | Rim loss, haemorrhage, longitudinal change | Using cup size without disc size |
| Field | Reproducible anatomically consistent deficit | Treating one unreliable test as progression |
| Lifetime | Age, comorbidity, expected rate, follow-up | Applying the same target to every patient |
| Angle | Open angle versus closure or secondary signs | Omitting gonioscopy in a pressure referral |
Observation and preventive treatment
Observation is active care: agree when pressure, disc imaging and fields will be repeated and what findings would trigger treatment. Explain that the patient may feel well despite developing glaucoma. Arrange earlier review for uncertainty, high pressure or unreliable access, rather than issuing an indefinite discharge based on one normal field.
The UK National Institute for Health and Care Excellence (NICE) recommends offering 360-degree selective laser trabeculoplasty to newly diagnosed OHT with IOP of at least 24 mmHg when there is a lifetime risk of visual impairment, excluding pigment-dispersion-associated cases from that recommendation. A prostaglandin analogue is an alternative when laser is declined, unsuitable, awaited or insufficient. This is a specific national pathway, not a definition that every European pressure below 24 mmHg is safe. European Glaucoma Society principles emphasize individualized risk and reassessment.
Treatment discussions include expected benefit, adverse effects, surface disease, adherence, costs and future options. Demonstrate drop instillation and check the patient can use the bottle. Document the untreated baseline before assigning a percentage reduction target. A medication-associated fall in pressure is not proof that the optic nerve will remain stable; longitudinal nerve and field assessment remains necessary.
Juvenile disease and family assessment
A teenager or young adult with markedly raised pressure, open angles and progressive cupping needs prompt specialist assessment. Distinguish juvenile open-angle disease from congenital glaucoma, anterior-segment dysgenesis, steroid response and trauma. Absence of infantile buphthalmos does not make severe juvenile disease benign. Ask about affected relatives and consider genetic counselling and appropriate testing, including MYOC in a compatible phenotype. A genetic result informs family evaluation; it does not replace examination or establish the severity in each relative.
Children may need adapted perimetry, imaging and sometimes examination under anaesthesia. Interpret pressure in the context of the anaesthetic and measurement conditions. Treatment must protect optic nerve function while supporting visual development. Drops require age-specific safety review, and refractory high pressure may need incisional surgery. Give the family a clear explanation of surveillance and the risk to the fellow eye.
Case reasoning
A 24-year-old has pressures of 36 and 34 mmHg, open angles, superior rim loss and repeatable inferior arcuate defects. Calling this OHT because the patient has no symptoms misses established damage. Identify juvenile open-angle glaucoma after excluding secondary causes, initiate pressure-lowering care, assess family history and plan a target appropriate to existing loss and long remaining lifetime. A different patient with healthy nerves, dependable normal fields and modest repeated elevation may reasonably be monitored after discussing individualized risk.
Sources: NICE NG81 recommendations and European Glaucoma Society guidelines.
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