- Cataract and glaucoma are both common with age, so many people have both.
- Cataract surgery can be done on its own or combined with a glaucoma procedure in the same operation.
- In some eyes, especially those with a narrow drainage angle, removing the natural lens lowers eye pressure.
- Lens choice needs more care once glaucoma has affected the optic nerve.
- Keep using your glaucoma drops unless your surgeon tells you to stop.
Why the two conditions often go together
A cataract is clouding of the eye’s natural lens. Glaucoma is damage to the optic nerve, the cable that carries information from the eye to the brain, and it is usually linked to pressure inside the eye. They are separate conditions, but both become more common as we get older, so it is normal to be diagnosed with one while already living with the other.
Sometimes the link is more direct. Long courses of steroid medication can cause both cataract and raised eye pressure, and a previous glaucoma operation such as a trabeculectomy can make a cataract develop sooner.
Does cataract surgery change eye pressure?
It can. After cataract surgery, eye pressure often falls a little and stays lower. The effect is usually larger in eyes with a narrow drainage angle, where a thick natural lens crowds the space that fluid needs to drain through. Replacing it with a much thinner artificial lens opens that space up.
In the first hours and days after surgery, pressure can also rise for a short time. For people with glaucoma this matters more, because the optic nerve is already sensitive to pressure. That is why your pressure is usually checked soon after the operation.
Cataract surgery alone, or combined?
The right plan depends on how advanced your glaucoma is, how well your pressure is controlled, and how many drops you use. The three broad options are:
| Option | What it involves | Often considered when |
|---|---|---|
| Cataract surgery alone | The cloudy lens is replaced. Glaucoma treatment continues as before. | Glaucoma is mild and well controlled on drops. |
| Cataract surgery with MIGS | A minimally invasive glaucoma procedure, such as iStent inject or GATT, is added during the same operation. | Glaucoma is mild to moderate, and the aim is lower pressure or fewer drops. |
| Cataract surgery with a trabeculectomy or tube | A more powerful glaucoma operation, done at the same time or as a separate procedure. | Glaucoma is advanced or pressure is not controlled. |
Combining procedures means one trip to theatre and one recovery period. It is not always the best choice, though. When glaucoma is advanced, some surgeons prefer to control the pressure first and treat the cataract later, so the plan is made for each eye.
Choosing a lens when you have glaucoma
Every cataract operation puts in an artificial lens, called an intraocular lens or IOL. Some lenses focus at one distance, others spread focus across several. With healthy eyes the choice is mainly about lifestyle. With glaucoma, it also has to account for the optic nerve.
Monofocal lenses
These give sharp vision at one distance, usually far, with reading glasses for near. They keep contrast as high as possible, which makes them a safe choice when glaucoma has already caused damage.
Toric lenses
A toric lens corrects astigmatism. It can be a monofocal or extended-range lens, and astigmatism correction does not usually conflict with glaucoma.
EDOF lenses
Extended depth of focus lenses stretch the range of clear vision from distance into the middle range, such as a computer screen. They lose a little contrast compared with a monofocal, but less than a multifocal, so they may suit some people with early, stable glaucoma.
Multifocal lenses
Multifocal lenses split light between distance, middle and near. This reduces contrast sensitivity, which glaucoma also reduces. For that reason they are usually not advised once glaucoma has affected the field of vision, or when it is likely to progress.
Because glaucoma can progress, the lens is chosen for how the eye is likely to see in the future as well as now.
Before and after surgery
- Keep using your glaucoma drops before surgery unless you are told otherwise.
- Tell the team about every medicine you take, including tablets for the prostate, which can affect the iris during surgery.
- You will be given anti-inflammatory and antibiotic drops for a few weeks after the operation.
- Your pressure will be checked soon after surgery and again at follow-up.
- Some people can reduce their glaucoma drops afterwards, but only on the advice of their eye doctor.
Questions to ask at your consultation
- How advanced is my glaucoma, and how stable has my pressure been?
- Would you combine my cataract surgery with a glaucoma procedure? Why or why not?
- Which lens types are suitable for my eyes, and which would you avoid?
- How will my pressure be checked in the days after surgery?
- Could I need fewer glaucoma drops afterwards?
- What vision can I realistically expect, with and without glasses?
Dr Sherif Ekram
Dr Ekram is a UK-based eye surgeon with subspecialty training in glaucoma and refractive surgery and more than 18 years in ophthalmology. He holds the Royal College of Ophthalmologists’ Certificate in Laser and Refractive Surgery and is registered with the General Medical Council. Read his full biography.
Written and reviewed by Dr Sherif Ekram. This article is general information and is not a substitute for a consultation about your own eyes.
