Neovascular glaucoma
An ischaemic retina makes new vessels grow on the iris and close the drainage angle. The pressure rises sharply; the cause must be treated fast.
What it is
A severe secondary glaucoma caused by new blood vessels growing on the iris and over the drainage angle, driven by VEGF released from an ischaemic retina. The fibrovascular membrane first blocks and then closes the angle, causing very high pressure and pain. Proliferative diabetic retinopathy, ischaemic central retinal vein occlusion and ocular ischaemic syndrome cause most cases.
See it in 3D
Who gets it
Mostly in people with advanced diabetic retinopathy or after ischaemic central retinal vein occlusion.
Causes
- Proliferative diabetic retinopathy
- Ischaemic central retinal vein occlusion
- Ocular ischaemic syndrome (carotid disease)
- Central retinal artery occlusion
- Chronic retinal detachment, tumours and radiation
Risk factors
- Poorly controlled diabetes
- Ischaemic vein occlusion
- Severe carotid stenosis
- Missed follow-up after a retinal vascular event
Pathophysiology
Ischaemic retina releases VEGF, which diffuses forward and stimulates new vessels at the pupil margin and in the angle. A fibrovascular membrane grows over the trabecular meshwork and then contracts, closing the angle permanently.
Classification
- Rubeosis iridis (new vessels on the iris, normal pressure)
- Open-angle stage (vessels over the angle, raised pressure)
- Closed-angle stage (synechial closure, very high pressure)
Symptoms and signs
- Painful red eye
- Blurred or very poor vision
- Headache, nausea with very high pressure
Diagnosis
- Clinical
- New vessels at the pupil margin and on the iris, raised pressure and an ischaemic retina on fundoscopy.
- Tests
- Gonioscopy to see angle vessels; glucose, blood pressure and carotid assessment to find the cause.
- Imaging
- Fluorescein angiography shows retinal non-perfusion; carotid Doppler if ocular ischaemic syndrome is suspected.
Differential diagnosis
- Acute angle closure
- Uveitic glaucoma
- Iris vessels from inflammation
Goal of treatment
Remove the ischaemic drive, lower the pressure and relieve pain.
Treatment
- Procedure
- Panretinal laser photocoagulation of the ischaemic retina.
- Medical
- Intravitreal anti-VEGF injections to make the new vessels regress quickly; pressure-lowering drops and topical steroids and cycloplegics for comfort.
- Surgical
- Glaucoma drainage device or cyclodestruction for uncontrolled pressure.
Complications
- Blindness
- Chronic pain
- Hyphema
Prognosis
Poor once the angle closes; much better when iris vessels are treated early.
Prevention
- Diabetic retinal screening and timely laser
- Close follow-up in the months after an ischaemic vein occlusion
Test yourself
Think of the answer, then tap the question to see it.
What drives the new vessels in neovascular glaucoma?
VEGF released by an ischaemic retina.
Which conditions most often cause it?
Proliferative diabetic retinopathy, ischaemic central retinal vein occlusion and ocular ischaemic syndrome.
What treats the cause?
Panretinal laser photocoagulation, with anti-VEGF injections for rapid regression.
In ophthalmology
- Glaucoma lasers and surgery: from iridotomy to tube shunts
- Gonioscopy: looking into the drainage angle
Connections
Educational information, not medical advice. For any symptom, see a health professional.
Sources: Neovascular Glaucoma (StatPearls Publishing (NCBI Bookshelf), 2022).
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Representative model, for educational purposes only.