Glaucoma and Retinal Vein Occlusion: A Two-Way Risk

Glaucoma and retinal vein occlusion are linked in both directions.

Glaucoma raises the risk of vein occlusion, and occlusion can cause glaucoma.

Therefore, every patient with one condition needs a check for the other.

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Why the Two Diseases Overlap

Both involve damage to the optic nerve head and its vessels.

The central retinal vein runs through the lamina cribrosa next to the artery.

Also, raised pressure can compress the vein at this point.

As a result, the same anatomy explains the link.

Glaucoma and Retinal Vein Occlusion in Population Studies

The Beaver Dam Eye Study and the Blue Mountains Eye Study found associations between glaucoma and vein occlusion.

Pooled data in Ophthalmology confirmed that vein occlusion is common worldwide.

Also, the risk rises with age.

Therefore, large cohorts support the link.

Meta-Analysis Evidence

Yin and colleagues pooled studies and found that glaucoma raised the risk of vein occlusion.

The effect was clearer for central occlusion.

Also, open-angle glaucoma was the main type studied.

As a result, the association is well supported.

Mechanisms of Higher Risk

Raised pressure compresses the vein and slows flow.

Glaucomatous damage may alter the vessels at the disc.

Also, shared vascular risks such as hypertension add to both.

In addition, nocturnal hypotension may reduce perfusion.

Ocular Hypertension

Eyes with high pressure but no damage also face a higher risk.

Pressure lowering may reduce the risk of occlusion.

Also, the evidence is observational.

Therefore, treat high pressure in patients with vein occlusion in the other eye.

Intraocular Pressure at Presentation

Check pressure at the first visit in every patient with vein occlusion.

Pressure may be high in the affected eye or in both.

Also, a difference between eyes may point to underlying glaucoma.

As a result, document pressure and optic discs.

Examination of the Angle

Perform gonioscopy in all patients with central vein occlusion.

Look for new vessels in the angle and for narrow angles.

Also, repeat it at each early visit.

Therefore, early neovascular glaucoma is not missed.

Neovascular Glaucoma After Occlusion

Ischemic central vein occlusion can cause new vessels on the iris and angle.

The pressure may rise within weeks to months, often by about three months.

Also, this complication is severe and hard to treat (see neovascular glaucoma).

Therefore, close follow-up in the first six months is needed.

Pressure Rise After Treatment

Intravitreal injections can raise pressure briefly or over time.

Steroid implants and injections raise pressure in a share of eyes.

Also, patients with glaucoma are at higher risk.

As a result, check pressure after each injection round.

Choosing Drugs in Glaucomatous Eyes

Anti-VEGF drugs are the first choice for macular edema in eyes with glaucoma.

Steroids carry a higher risk of pressure rise.

Also, avoid them in eyes with poorly controlled glaucoma.

Therefore, weigh benefit and risk for each eye.

Treating Glaucoma in Vein Occlusion

Lower pressure with drops as in other glaucoma.

Avoid drugs that lower perfusion pressure at night when possible.

Also, prostaglandin analogs are acceptable but may add to macular edema in rare cases.

In addition, treat both eyes.

Role of Blood Pressure

Systemic hypertension is the main shared risk.

Treat it, but avoid excessive lowering at night.

Also, check the balance between perfusion pressure and intraocular pressure.

Therefore, coordinate with the physician.

Optic Disc Assessment

Examine the disc for cupping and rim loss.

OCT of the nerve fiber layer helps after the edema settles.

Also, visual fields detect glaucomatous loss.

As a result, a baseline helps long-term care.

Long-Term Glaucoma Follow-Up

Examine both eyes every few months in the first year.

Check pressure, discs and angles.

Also, repeat fields yearly.

Therefore, late glaucoma is detected.

Counseling Patients

Explain that vein occlusion may signal glaucoma risk.

Tell them to attend all pressure checks.

Also, advise on blood pressure control and not smoking.

In addition, explain symptoms of high pressure.

Pitfalls to Avoid

• Do not forget gonioscopy in central vein occlusion
• Never ignore a pressure difference between the eyes
• Do not give steroids freely to eyes with glaucoma
• Never stop pressure checks after the edema resolves

Steroid Response and Glaucoma

Patients with glaucoma have a higher steroid response.

Pressure can rise within weeks of a steroid injection or implant.

Also, a family history of glaucoma raises the risk.

Therefore, check pressure often after steroid therapy.

For the latest studies, see the PubMed results for glaucoma.

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References

1. Yin X, Li J, Zhang B, Lu P. Association of glaucoma with risk of retinal vein occlusion: a meta-analysis. Acta Ophthalmol. 2019;97:652-659.
2. Rogers S, McIntosh RL, Cheung N, et al. The prevalence of retinal vein occlusion: pooled data from population studies from the United States, Europe, Asia, and Australia. Ophthalmology. 2010;117:313-319.
3. Mitchell P, Smith W, Chang A. Prevalence and associations of retinal vein occlusion in Australia: the Blue Mountains Eye Study. Arch Ophthalmol. 1996;114:1243-1247.
4. Klein R, Klein BEK, Moss SE, Meuer SM. The epidemiology of retinal vein occlusion: the Beaver Dam Eye Study. Trans Am Ophthalmol Soc. 2000;98:133-141.