Glaucoma — Frequently asked questions (FAQ)
1) What does this algorithm cover?
This algorithm guides the clinical approach to glaucoma, from the identification of emergency situations, such as suspected acute angle closure, to the non-urgent assessment pathway. It integrates risk factors, referral criteria, essential ophthalmological tests such as tonometry, optic nerve assessment, visual field testing and OCT, as well as principles of treatment and follow-up, including the definition of target intraocular pressure and monitoring of progression.
2) What is glaucoma and why is early detection important?
Glaucoma is a progressive optic neuropathy, usually associated with elevated intraocular pressure and/or susceptibility of the optic nerve, which may cause irreversible visual loss, particularly affecting peripheral vision. In the early stages it may be asymptomatic, so early detection in people at increased risk allows treatment to be started and helps reduce the risk of progression.
3) Which main types of glaucoma are covered?
The algorithm distinguishes acute angle-closure glaucoma, an emergency with severe symptoms, from the more common pathway of chronic glaucoma, typically primary open-angle glaucoma, which progresses slowly and may be detected through screening findings or targeted assessment. It also includes the concepts of glaucoma suspect and ocular hypertension, situations that may require intensive surveillance.
4) What red flags suggest acute angle-closure glaucoma?
Acute glaucoma should be suspected in the presence of severe ocular pain, often with supraciliary pain or headache, blurred vision and halos around lights, associated with nausea/vomiting. Examination may show a red eye, cloudy cornea and fixed mydriasis, sometimes oval-shaped. This situation requires immediate treatment and urgent referral.
5) What should be done when acute glaucoma is strongly suspected before referral?
If suspicion is high and it is clinically safe, immediate reduction of intraocular pressure should be started, for example with acetazolamide and pressure-lowering eye drops such as a beta-blocker and/or alpha-agonist, together with analgesia and an antiemetic. Mydriatic agents should be avoided. Urgent ophthalmological assessment is essential, and laser iridotomy/iridectomy is often the definitive treatment.
6) What are the main risk factors for chronic glaucoma?
The most relevant risk factors include age, especially > 60 years, first-degree family history, elevated intraocular pressure, thin cornea when known, African ancestry and high myopia. Chronic corticosteroid therapy, either ocular topical or systemic, also increases risk. The presence of these factors justifies structured screening or targeted assessment.
7) Which tests are essential in ophthalmological assessment for glaucoma?
Assessment includes tonometry to measure intraocular pressure and examination of the optic nerve, including optic disc cupping and disc haemorrhages. To confirm damage and monitor progression, automated visual field testing and, when available, OCT of the retinal nerve fibre layer/structure are essential. Gonioscopy is important to classify the angle as open, narrow or closed, and to guide management.
8) What do “ocular hypertension” and “glaucoma suspect” mean?
Ocular hypertension refers to elevated intraocular pressure without evidence of optic nerve damage or visual field abnormalities. Glaucoma suspect refers to borderline or discordant findings, for example a suspicious structural abnormality without a clear functional defect, or vice versa. In both situations, risk stratification and surveillance are important because progression to glaucoma may occur.
9) When should treatment be started in ocular hypertension or glaucoma suspect?
Ocular pressure-lowering treatment should be considered when there is persistently elevated intraocular pressure, high risk, for example multiple risk factors, or evidence of structural or functional progression. The decision is individualised and should balance risk of progression, tolerability, patient preference and ability to maintain follow-up.
10) What is the most common initial treatment for chronic glaucoma?
Initial treatment is usually based on pressure-lowering eye drops, with prostaglandin analogues being the first-line option in most patients. Depending on the context, selective laser trabeculoplasty (SLT) may be considered as an alternative or add-on treatment. If control is insufficient or progression occurs, combination therapy may be required and, in selected cases, surgery.
11) What is “target intraocular pressure” and why is it important?
Target pressure is an individualised intraocular pressure value defined to reduce the likelihood of progression, taking into account disease severity, whether early, moderate or advanced, age, risk of progression and life expectancy. The target pressure may need to be adjusted over time, especially if there is progression despite apparently controlled intraocular pressure.
12) How often should follow-up be performed and what signs indicate progression?
Follow-up frequency depends on risk and disease stage. In higher-risk glaucoma suspect/ocular hypertension, reassessment every 6–12 months is common. In confirmed glaucoma, follow-up includes intraocular pressure, optic nerve examination and periodic repetition of visual field testing and/or OCT. Progression is suggested by consistent worsening of the visual field, structural loss on OCT or deterioration of the optic nerve, and should prompt revision of the target pressure and treatment escalation.
13) Why is adherence so important and how can it be improved?
Treatment adherence is crucial because glaucoma requires continuous treatment to prevent visual loss. The instillation technique should be checked, barriers such as forgetfulness, cost and adverse effects should be identified, and the regimen simplified whenever possible. Strategies such as reminders, routines linked to daily habits and education about the disease may improve persistence with treatment.
14) What are common precautions and contraindications of eye drops?
It is important to review comorbidities and potential contraindications. For example, topical beta-blockers may worsen asthma/COPD and bradycardia or AV block; prostaglandin analogues may cause hyperaemia and cosmetic changes; some drugs may have systemic effects in vulnerable patients. Tolerability monitoring and periodic treatment review are essential for safety.
