What are the benefits of early cataract surgery for glaucoma patients?

Glaucoma and cataracts often occur together, especially as we get older. Both are common, both affect vision, and both can be treated. What many patients do not realise is that cataract surgery in someone with glaucoma is not just about clearing the vision. It can also have a direct, positive effect on the underlying glaucoma.

Why cataracts matter in glaucoma

A cataract clouds the natural lens inside the eye. In a patient with glaucoma, this clouding does two things: it reduces vision, and it makes monitoring the optic nerve and retina much harder. The ophthalmologist needs a clear view of the back of the eye to check whether the glaucoma is stable or progressing. A dense cataract can hide important details, making it difficult to judge whether treatment changes are needed.

Cataract surgery can lower eye pressure

One of the most important benefits of early cataract surgery in glaucoma patients is a potential drop in intraocular pressure. Removing the cataract and replacing it with a thinner intraocular lens increases the space inside the eye and can improve the flow of fluid through the drainage system. For some patients, this means needing fewer glaucoma drops or delaying more invasive glaucoma surgery.

The effect varies from person to person. It is generally more pronounced in eyes with narrow angles or in patients who have some degree of angle-closure glaucoma, but it can help in open-angle glaucoma too.

Better glaucoma monitoring after surgery

After the cataract is removed, the view of the optic nerve and retinal nerve fibre layer becomes much clearer. This means OCT scans, visual field tests and optic disc examinations are more reliable. Detecting small changes early is the key to protecting sight in glaucoma, because by the time vision loss is noticeable, the damage is usually advanced.

Combining cataract and glaucoma procedures

In some cases, cataract surgery can be combined with a glaucoma procedure such as selective laser trabeculoplasty, iStent, Hydrus, or minimally invasive glaucoma surgery (MIGS). These combined approaches can reduce the number of drops a patient needs and improve pressure control, while only adding a small amount of time to the operation. Whether this is appropriate depends on the type and severity of glaucoma and the structure of the eye.

Reducing the burden of medication

Glaucoma drops are effective, but they can cause irritation, redness, dry eye and eyelid changes. They also need to be used every day for life. If cataract surgery lowers the eye pressure enough, some patients are able to reduce the number of drops they use. This is not guaranteed, but it is a meaningful benefit for many people.

Is early cataract surgery right for every glaucoma patient?

Not always. The decision depends on the type of glaucoma, how well controlled the pressure is, whether the cataract is affecting vision or daily life, and the overall health of the eye. In some advanced glaucomas, surgery needs to be planned very carefully to avoid any pressure spike during recovery.

That is why the assessment is so important. We measure the cornea, anterior chamber depth, optic nerve, visual field and OCT, and we discuss the risks and benefits in detail before recommending surgery.

Next steps

If you have glaucoma and have been told you also have cataracts, ask whether early cataract surgery could help both your vision and your pressure control. A consultant-led assessment will give you a clear answer and a plan that protects your sight for the long term.