What is glaucoma?
Glaucoma is one of the leading causes of avoidable sight loss. It’s most often caused by a gradual rise in pressure inside the eye which causes damage to the sensitive nerve fibres at the back of the eye. For most people, glaucoma develops slowly and painlessly with many people unaware they have the condition, and is usually only detected as part of a routine eye test.
Your optometrist will assess the pressure inside your eye, the appearance and health of the optic nerve, and your visual fields to pick up early signs of glaucoma. If you are diagnosed with glaucoma, you may be treated with eye drops, or laser surgery, depending on the severity.
What are cataracts?
Cataracts are another common eye condition, typically age related, that occur as the clear lens inside the eye becomes cloudy — like looking through a frosted window.
It is quite normal for the eye’s lens to become less transparent with age, but a cataract would generally be diagnosed if this loss of transparency develops at a faster than average rate, typically causing visual symptoms.
During the early stages of cataracts, vision becomes less clear and glare can affect you — a very common first sign of cataracts would be difficulties when driving at night, especially with seeing glare from oncoming car headlights.
As cataracts develop, your eyesight can become blurrier and seem faded, with colours becoming less vivid. Cataracts can also cause your glasses prescription to change rapidly, or more frequently.
As with glaucoma, the early stages of cataract can be picked up by an optometrist — and if you do have it, treatment options can involve UV protective eyewear to try and slow down the progression, but most cases will be treated with surgery.
Are glaucoma and cataracts connected?
Both glaucoma and cataracts can be a natural part of ageing, but are they connected at all? The answer for most people is generally no, and if you have both, it is likely to be because both become more common with age. However, in some situations, cataracts can make a certain less common type of glaucoma worse, as they can cause the eye pressure to rise. This happens because as a cataract develops it generally causes the lens inside the eye to become thicker. As the lens thickness increases, it can make it more difficult for the eye’s natural fluid (the aqueous humour) to circulate and drain from the eye.
What cataracts and glaucoma do have in common is that they are both serious eye conditions that can lead to sight loss. As both can be a part of the natural ageing process, some people aged over 60 may have both, but they are generally not linked, nor is there a sequence where one typically occurs after the other. Loss of vision due to cataracts is usually reversible with surgery, but while progression of sight loss from glaucoma can be slowed or halted with treatment, any nerve damage resulting in sight loss cannot yet be restored.
The majority of people with the most common types of glaucoma are not at a higher risk of cataracts. However, a minority of people who have less common types of glaucoma, perhaps due to eye trauma, eye inflammation or steroid use, may find they are at higher risk of cataracts. What’s more, people with rare developmental conditions such as congenital rubella (when the mother has rubella while the baby is in the womb) can be at higher risk of both cataracts and glaucoma.
Can treatment affect the conditions?
Cataracts are not treated using medication, but eye drops for glaucoma can occasionally cause issues if you have cataracts. Some glaucoma eye drops make the pupil larger and can give someone with cataracts increased problems with glare. Other eye drops can make the pupil smaller which allows less light into the eye: for someone who also has cataracts, this can cause a drop in the level of vision. If you notice problems with glare or level of vision after starting eye drops for glaucoma, it’s important to talk to your ophthalmologist.
If you have both conditions and need surgery, your ophthalmologist’s priority will be to control the glaucoma first, which may be with medication or surgery. If you need surgery for glaucoma and cataracts, your ophthalmologist will advise whether it’s best to do both at the same time or one followed by the other. Cataract surgery can be an effective method to reduce eye pressure in patients with primary angle-closure glaucoma, and this may be considered by your ophthalmologist if you have both conditions.
The bottom line
Being diagnosed with glaucoma or cataracts can feel stressful, but fortunately both conditions can be treated. One of the easiest ways to keep your eyes healthy is with a regular eye test. And if you ever have any concerns about your eyes or your vision, just call or pop in to your local store.
For more information on glaucoma causes, you can discover similar content in our dedicated glaucoma causes information hub.