A glaucoma suspect with a disc haemorrhage and no family doctor
Mr. K, 61, attends for a routine examination; his mother has open-angle glaucoma. Best-corrected acuity is 6/6 OU. Goldmann applanation (mean of two readings each, taken at 9:40 am) is 25 mmHg OD and 23 mmHg OS; central corneal thickness is 487 µm OD and 492 µm OS. Gonioscopy shows open angles to the ciliary body band for 360° with heavy uniform trabecular pigmentation; there are no synechiae and the iris is flat. Discs show cup–disc 0.70 OD with inferior rim thinning and a splinter haemorrhage at 6 o'clock, and 0.60 OS with an intact rim. Humphrey 24-2 fields are reliable (fixation losses 1/12, false positives 4%) and show a repeatable inferior arcuate defect with a pattern-deviation cluster in the right eye; the left field is normal. He has no family doctor and asks whether he 'needs to worry'.
1. Rank the findings that matter here and state what else you would do or measure before committing to a diagnosis and a referral urgency. Include the effect of corneal thickness and the significance of the pigmentation.
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The package, not any one number, drives the decision. Ranked by weight: (1) the splinter haemorrhage on a thinned inferior rim - a disc haemorrhage in a suspect substantially raises the probability of conversion and progression; (2) the field defect, which is reproducible, reliable and topographically concordant with the disc; (3) IOP; (4) family history; (5) thin corneas.
Corneal thickness: at roughly 490 µm his true IOP is underestimated by Goldmann applanation - roughly 0.3–0.5 mmHg per 10 µm below 545 µm, so add about 2 mmHg. More importantly, thin CCT is itself an independent risk factor.
Pigmentation: heavy uniform trabecular pigment at 61 should prompt a search for pigment dispersion - Krukenberg spindle, iris transillumination defects, deep anterior chamber, myopia, a Sampaolesi line - and for pseudoexfoliation, which is patchy and usually shows material at the pupil margin and anterior lens capsule. The two carry different risk profiles.
Still to do: a repeat field to confirm the defect; baseline disc photography or OCT retinal nerve fibre layer; IOP at a different time of day or a diurnal curve, since a single 9:40 am reading cannot exclude glaucoma; and a check that the disc appearance explains the field and that the defect respects the midline.
2. What is your referral urgency, and how do you manage the practical problem that he has no family doctor?
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Urgency: this is urgent but not an emergency. There are no acute angle-closure symptoms (and gonioscopy shows open angles), no sudden visual loss and no pain. The combination of a disc haemorrhage, rim thinning, a concordant field defect and elevated corrected IOP justifies referral within a few weeks to an ophthalmologist, with a note flagging the haemorrhage so he is not simply placed in a routine suspect queue.
The missing family doctor is a systems problem, not a clinical one:
- Send a full report - IOPs with time of measurement, CCT, gonioscopy findings including the pigmentation, disc description, and the field printouts.
- Give Mr. K copies of everything and tell him to take them to the appointment.
- Ask the ophthalmologist's office to confirm receipt and give him the appointment date before he leaves the building.
- Ask about blood pressure, diabetes, sleep apnoea and vasospastic history, since these modify risk, and suggest he register with a primary care provider.
What I would not do: start treatment myself, or file him as a 12-month recall. Both are the common failure modes in this scenario.
3. He mentions that his mother went blind from glaucoma, that he is frightened of drops and surgery, and that he would rather 'wait and see'. How do you counsel him?
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Acknowledge the fear before giving information - his mother's outcome is the frame through which everything you say will be heard.
'What happened to your mother is exactly what worries me too, and it's the reason I'm sending you rather than watching. Glaucoma can't be cured, but it can be managed, and most people who are monitored and treated keep useful sight for life. Her outcome may have had a lot to do with when she was found and whether she could stay on treatment - that is not automatically your story.'
Then be concrete and honest:
- Treatment slows progression; it does not restore lost vision. Nobody can promise him he will not progress.
- Modern options include drops, laser (SLT) and surgery, and the ophthalmologist will discuss them; drops are usually first, with side effects, cost and adherence discussed openly.
- Emphasise that the field loss he has now is peripheral and he will not notice new loss himself - which is why testing matters more than symptoms.
- Offer written material - Glaucoma Canada or provincial association resources - and a follow-up appointment after the ophthalmology visit to answer questions.
- Ask whether he wants anyone involved in these discussions.
Record that the natural history and the rationale for referral were explained, and that he expressed anxiety about treatment.