Glaucoma is a progressive optic neuropathy — a condition causing gradual, irreversible damage to the optic nerve — most commonly associated with elevated intraocular pressure (IOP). It is the leading cause of irreversible blindness globally and the leading cause of preventable blindness in South Africa. The critical feature is that significant vision loss can occur without any symptoms; by the time patients notice vision impairment, up to 40% of nerve fibres may already be permanently lost. As a CDL condition, medical aids must fund ongoing treatment — and the primary goal of all treatment is to prevent blindness, not to restore vision that has already been lost.
Types of Glaucoma
Primary open-angle glaucoma (POAG): The most common form. IOP is elevated due to reduced aqueous humour outflow through the trabecular meshwork. No pain; no symptoms in early-to-moderate disease. Diagnosed through routine eye examination. Progressive peripheral visual field loss, eventually threatening central vision. Lifelong management required.
Normal-tension glaucoma (NTG): Optic nerve damage occurs despite IOP within the statistical normal range. Same treatment goals and principles as POAG. Requires particular vigilance in monitoring.
Angle-closure glaucoma: Obstruction of aqueous humour drainage at the angle of the anterior chamber. Acute angle-closure is an ophthalmic emergency with severe eye pain, headache, nausea, blurred vision, and rapid IOP elevation. Requires immediate intervention.
Secondary glaucomas: Arise from other causes — steroid-induced, pseudoexfoliative, pigmentary, post-traumatic, and others.
CDL Coverage
Glaucoma is a CDL condition. Ongoing prescribed eye drops for IOP reduction and glaucoma monitoring must be funded from the CDL benefit once registered. The CDL benefit covers the pharmacological management layer — which is also the least expensive layer. Procedural interventions (laser trabeculoplasty, trabeculectomy, drainage devices) carry different cost profiles and are covered under the in-hospital/surgical benefit rather than CDL.
Treatment Pathway
Eye drops — first-line medical management: All pharmacological glaucoma treatment involves IOP-reducing eye drops used daily (or twice daily for some agents). Treatment is lifelong; adherence is the single most important determinant of outcome. Most patients require one or two drop types; advanced cases may require three.
Standard classes: - Prostaglandin analogues (first-line): Latanoprost, bimatoprost, travoprost. Once daily. Monthly cost: R300–R450 per preparation. Excellent IOP reduction. On most CDL formularies. - Beta-blockers: Timolol 0.5% (twice daily). Inexpensive; R150–R200/month. Requires caution in asthma, COPD, and bradycardia. On virtually all CDL formularies. - Carbonic anhydrase inhibitors: Dorzolamide (drops; twice daily). Systemic acetazolamide for acute IOP control. Monthly cost for drops: R250–R350. - Alpha-agonists: Brimonidine. Monthly cost: R250–R350. - Combination preparations: Fixed-dose combinations (e.g., latanoprost/timolol; dorzolamide/timolol) improve adherence and reduce instillation burden. Monthly cost: R400–R600.
Monitoring — the most important ongoing cost:
Glaucoma is managed through lifelong monitoring, not just medication. Key monitoring tests: - Visual field testing (automated perimetry): Tests the peripheral visual field for progressive damage. Typically every 6–12 months in stable disease; more frequently when disease is progressing. Cost: R400–R900 per test. - OCT (optical coherence tomography) of optic nerve and retinal nerve fibre layer: Structural imaging for optic nerve damage. Typically annually or semi-annually. Cost: R800–R1,500 per scan.
Coverage for these monitoring investigations varies significantly by plan. Some plans include them as specialist consultations; others have separate diagnostic imaging or ophthalmological benefit limits that are readily exhausted in a condition requiring annual monitoring for life.
Selective Laser Trabeculoplasty (SLT): Laser procedure to improve trabecular meshwork outflow. Now recommended as a first-line or adjunct treatment — evidence shows it is as effective as eye drops in many patients and may reduce the number of medications required. Typically performed as an outpatient procedure. Cost: R5,000–R15,000 per session. Can be repeated if IOP rises again.
Trabeculectomy: Surgical creation of a drainage channel from the anterior chamber under a conjunctival flap. Gold-standard surgical intervention for IOP reduction. Reserved for moderate-to-advanced glaucoma not controlled on maximum medical therapy. Done under general anaesthesia; hospital admission. Total surgical cost (facility, surgeon, anaesthetist): R40,000–R80,000.
Drainage implants (tube shunts): Devices (Ahmed, Baerveldt) implanted to create a drainage pathway. Used in failed trabeculectomy, complex cases, or when trabeculectomy is not feasible. Cost similar to or higher than trabeculectomy.
Annual Cost Estimates
| Scenario | Estimated Annual Cost |
|---|---|
| Early glaucoma on 1–2 eye drops, stable | R5,000 – R15,000 |
| Moderate glaucoma — drops + monitoring (OCT, VF tests) | R15,000 – R35,000 |
| Advanced — drops + SLT procedure year | R25,000 – R55,000 |
| Surgical year (trabeculectomy or tube shunt) | R50,000 – R100,000 |
Gap Cover Relevance
Glaucoma's routine annual cost is low — primarily inexpensive eye drops and monitoring. Gap cover exposure arises in surgical years (trabeculectomy, tube shunt implantation) where ophthalmologist and anaesthetist shortfalls can reach R20,000–R50,000. The gap OPL (~R220,000/year) is more than adequate for glaucoma-specific events.
The Monitoring Coverage Gap
The most underfunded aspect of glaucoma management is monitoring — not medication. Annual OCT and visual field testing can cost R3,000–R5,000/year. On plans where these are charged against the specialist benefit or diagnostic imaging benefit, costs accumulate quickly against benefit limits. Confirm with your plan how these investigations are funded and whether a separate ophthalmological benefit exists.
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This page is general information about medical schemes. It is not medical advice: speak to a healthcare professional about your own treatment. Medical aid and gap cover advice is given by Eldon de Waal, a Supervised Representative of Approach Administration (FSP 23579).