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Describe ocular hypertension and the assessment of a glaucoma suspect.

Ophthalmology · 3rd Professional

Ocular hypertension is an intraocular pressure consistently above 21 mmHg with a normal optic disc, normal visual field and an open angle, and no secondary cause.
A glaucoma suspect is a wider category: anyone with a suspicious disc, a suspicious field, or a raised pressure, in whom the diagnosis is not yet established.
The clinical problem is one of probability, not of diagnosis: most people with ocular hypertension will never develop glaucoma, and treating them all would mean treating many people for decades for no benefit — while failing to treat those who will convert means avoidable blindness

Risk factor for conversion	Comment
Higher intraocular pressure	Risk rises continuously; a pressure above 30 is treated
Thinner central cornea	A powerful independent predictor identified by OHTS, over and above its effect on the measured pressure. Pachymetry is therefore essential in every suspect
Larger cup-disc ratio	And particularly asymmetry between the eyes
Greater pattern standard deviation	Even within the normal range, suggesting early localised loss
Older age	A consistent predictor
Family history and african ancestry	Both raise the risk substantially
Disc haemorrhage	Its presence largely settles the question; it indicates that damage is occurring
Pseudoexfoliation	Converts at a much higher rate, and should be treated

Before labelling anyone — repeat the pressure on a separate occasion; measure pachymetry, since a thick cornea may explain the reading entirely; perform gonioscopy to confirm an open angle and exclude secondary causes; and exclude steroid use by every route
Establish a baseline — disc photographs or OCT, and two or three visual fields, because a single field is unreliable and progression can only be judged against a record
Whom TO treat — a pressure above 30 mmHg, at which the risk is high and the eye is also at risk of vein occlusion; multiple risk factors, particularly a thin cornea with a large cup; a disc haemorrhage; pseudoexfoliation; a strong family history; being the only seeing eye; and documented progression of any kind

Repeat the pressure before labelling anyone; a single raised reading is frequently an artefact of technique, posture or a tight collar
Measure the corneal thickness in every suspect; it may explain the reading away entirely, or identify a patient at genuine risk
Record a proper baseline of disc image and two or three fields; without it the next ten years of follow-up cannot be interpreted

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