Although cataract surgery is usually very successful, some people may experience complications which need further treatment. You may also need to wear glasses afterwards.
Cloudy vision
The most common risk associated with cataract surgery is developing a condition called posterior capsule opacification (PCO). This is where part of the lens capsule (the "pocket" that the lens sits inside) thickens and causes cloudy vision. This is not the cataract returning, but is due to cells growing over the back of the artificial lens.
PCO used to be very common, but there's much less risk of it now due to changes in modern intraocular lens design. PCO usually develops between six months and five years after the operation has been carried out.
If this happens, you may need to have another operation to correct it. This will be done with laser eye surgery (when energy beams are used to cut through part of the eye). During laser eye surgery, the cloudy part of the lens capsule will be removed, with enough left to continue holding the artificial lens in place.
This procedure should only take around 15 minutes, and your vision should be improved immediately or within a few days. As no surgical incisions (cuts) or stitches are necessary, you can usually return to your normal activities straight away. It is common to see floaters in your eyes after this procedure.
Other complications
Other possible complications of cataract surgery are much rarer but can include:
- infection in the eye
- bleeding in the eye
- inflammation (swelling and redness) in the eye
- tearing of the lens capsule
- a bit of the cataract dropping into the back of the eye
- damage to other parts of the eye, such as the cornea (the transparent outer layer of the eye)
The College of Optometrists has estimated that, in most cases, the risk of complications occurring during cataract surgery is less than 1%. The most common complication is tearing of the lens capsule, which may occur more frequently than this.
It is usually possible to treat any complications that arise from cataract surgery successfully. Occasionally, your vision may be worse than it was before surgery or there may be permanent damage to your eye, causing a loss of sight. However, this is very rare.
Cystoid macular oedema
One possible complication that can cause loss of vision is cystoid macular oedema. This is where fluid builds up between layers of the retina (the layer of nerve cells that lines the inside of the back of the eye).
There are two different types of cystoid macular oedema:
- angiographic cystoid macular oedema
- clinical cystoid macular oedema
Angiographic cystoid macular oedema is a very common condition, but it doesn't affect vision. Clinical cystoid macular oedema can cause vision loss and is thought to make up between 0.1% and 12% of cases.
Cystoid macular oedema may sometimes be treated with non-steroidal anti-inflammatory drugs (NSAIDs). However, research is still being carried out in this area.
Wearing glasses
The natural lens in your eye can change shape. This is how it enables your eyes to focus on objects that are both near to you and further away.
Fixed-strength (monofocal) and multifocal replacement plastic lenses cannot do this. Therefore, after cataract surgery you may also need reading glasses or glasses for distance vision.
A review of some studies found that 95% of people with a monofocal lens and 68% of people with a multifocal lens needed to wear glasses after having cataract surgery.
Another type of artificial lens, called an accommodating lens, aims to allow the eye to focus on both near and distant objects.
The National Institute of Health and Clinical Excellence (NICE) has reported that there is some evidence that this type of lens improves clearness of vision. However, more evidence is needed to confirm that this lens improves "accommodation" (how the lens adapts to focus images). NICE also noted that this area of technology is changing rapidly, and it is not yet fully understood how these lenses work.
Read the NICE guidance on the use of accommodating replacement plastic lenses and multifocal lenses.
