Glaucoma Suspect: Treat or Monitor?
Mr. D is a 68-year-old retired engineer referred because of IOPs of 25 mmHg right and 23 mmHg left. Central corneal thickness is 534 µm right and 539 µm left. Optic discs show cup-to-disc ratios of 0.65 right and 0.55 left, with no hemorrhage or notching. Gonioscopy is open to the ciliary body band in both eyes. A 24-2 visual field is reliable and shows a borderline inferior arcuate defect in the right eye; the left field is normal. OCT retinal nerve fiber layer shows superior thinning in the right eye at the 5% level but no definite progression compared with a scan from 18 months ago. He has hypertension, a mother with glaucoma, and no diabetes. He is asymptomatic and asks whether he needs drops.
1. Stratify his risk of converting to glaucoma and recommend initial management.
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He has several risk factors: age 68, IOP 25/23 mmHg, thin central corneal thickness, cup-to-disc ratio 0.65 in the right eye, family history, and borderline structural and functional change in the right eye. Using OHTS-style risk factors, his 5-year risk is likely moderate to high, probably in the range of 15% to 20% or more. The right eye already has a borderline field defect and superior RNFL thinning, so he is more than a simple ocular hypertensive; he is a glaucoma suspect with early structural and functional suspicion. I would recommend treatment, especially for the right eye, with a prostaglandin analog at night, after discussing adherence, cost, and side effects. A shared decision to observe with close follow-up is defensible, but the combination of thin cornea, higher IOP, and disc appearance makes treatment reasonable.
2. If he elects observation, what monitoring interval and triggers would you use?
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If he elects observation, I would check IOP, optic disc, and visual field every 4 to 6 months, with OCT every 6 to 12 months. I would compare fields and OCT scans carefully for progression rather than relying on a single borderline result. Triggers to start treatment would include confirmed visual field progression, new disc hemorrhage, progressive RNFL thinning, IOP persistently above 30 mmHg, or a change in the disc that the patient and I agree is concerning. I would set a target IOP reduction of at least 20% if treatment begins. I would also document that observation is an active choice with a defined review schedule, not a decision to do nothing.
3. How would you discuss treatment burden and adherence with him?
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I would explain that glaucoma is asymptomatic until late, so drops are used to prevent progression rather than to improve current vision. I would describe the common side effects of prostaglandin analogs, including iris darkening, eyelash growth, and periorbital fat atrophy, and discuss cost and dosing. I would ask about his routine and any barriers to using drops nightly. I would explain that adherence is critical and that missed doses reduce protection. I would also explain that treatment does not guarantee no progression, which is why follow-up continues. If he prefers observation, I would respect that choice and schedule the next review. The discussion should be documented so that the decision is shared and transparent.