Risks and complications
Approximately 2 or 3 in every hundred eyes undergoing cataract surgery will have some complication during or after the procedure that has a permanent effect on vision. This may not necessarily leave the eye worse off (depending on the degree of cataract), but will mean that after everything has settled down the sight is not as good as had been hoped.
Approximately 1 eye in every 1000 operations will end up with a severe complication, leaving it with little or no sight.
Complications of removing the human lens
Cataract surgery, like all other procedures carries a risk of complications.
There are a variety of risks associated with cataract surgery. The headline levels of risk are that approximately 2-3 eyes in every hundred will end up with a less than normal (or expected) level of vision and approximately one in a thousand will have a very serious complication and end up with little or no vision. The major risks of this surgery include:
- Mild discomfort in the first day or so after surgery is quite common. Severe pain is rare, if you have this you must contact me urgently.
- Rupture of the posterior capsule – the thin membrane used to support the IOL Intraocular lens.
- Disturbing the vitreous gel behind the posterior capsule, which increases the risk of other complications such as detachment of the retina, cystoid macular oedema, serious intraocular infection or endophthalmitis.
- Corneal abrasion, or scratching of the cornea.
- Retained pieces of the lens may drop into the back of the eye. This may need further surgery to retrieve the lens material.
- Haemorrhage or bleeding inside the eye.
- Clouding due to swelling of the cornea clear window on the front of the eye known as corneal oedema, this is more common when there is pre-existing disease of the cornea. This may require a corneal transplant to correct the problem.
- Raised pressure in the eye (Glaucoma), which may be short-term or may be a long-term problem, this is more likely if the eye already had glaucoma.
- Detachment of the retina – particularly a risk in very myopic short-sighted or nearsighted where things close up are seen without glasses, but not things in the distance eyes, which will need a further operation to rectify it, this further surgery is usually successful, but if not may result in severe loss of vision.
- Swelling of the central part of the retina the film at the back of the eye, which receives, focussed light and converts it to a signal for the brain, this is known as cystoid macular oedema. This usually improves spontaneously, but treatment can speed up recovery. When the central part of the retina is swollen the sharp central vision is blurred.
- Drooping of the eyelid or ptosis.
- Increased astigmatism when the eye is rugby ball shaped rather than football shaped, this can be corrected with glasses but things at all distances will be out of focus without glasses.
- Double vision, which may be correctable with glasses or further surgery.
Additional surgery may be required to treat these complications. The cost for this additional surgery is not included in the price you pay for the cataract surgery.
Complications associated with inserting an Intraocular lens (IOL)
There are a number of optical aberrations, which occur in all intraocular lenses. These include glare (especially at night), halos, ghosting or double images, glinting or reflection of light from the edge of the IOL within the eye. These problems are more common with multifocal IOLs. Rarely these problems could be severe enough to warrant surgery to change the IOL.
Dislocation of the IOL may occur during or after surgery, this is likely to be correctable with further surgery.
Refractive error, extremely accurate measurements and using a number of different carefully designed formulae help me to choose the best IOL to give you the focussing result you decide will be best for you. Even with the very best measurements and latest technology, there are variations in the way individuals heal up which affect the final focus of the eye after cataract surgery. Whilst the methods of measuring your eye to work out which strength of IOL to use are very accurate, it is more difficult to accurately predict the lens to give the best focus in eyes which needed very strong glasses before the cataract developed. Eyes which have had any form of laser or other refractive surgery are especially difficult to obtain accurate measurements from and are therefore particularly prone to ending up needing stronger than planned glasses following cataract surgery.
Since only one eye will undergo surgery at a time, you may experience a period of imbalance between the two eyes (anisometropia). There are a variety of ways of dealing with this, including asking your optician to make up some temporary glasses, not wearing glasses and relying on the good vision in the operated eye or removing the lens from your old glasses in front of the eye that has been operated on. Where there is a large difference between the two eyes, wearing a contact lens in the eye that has not yet had surgery will restore balance. Some people will continue to feel a little unbalanced until the second eye has had surgery too.
To optimise the results of your surgery I prefer to wait until the focus has stabilised in the first eye and until the risk of late complications has largely passed, if you want surgery on your second eye I will usually operate six weeks after the first eye, having seen you for review at five weeks. It is possible to operate sooner; some surgeons routinely operate on the second eye two weeks after the first. But I want to know the outcome of the first eye and use that information to fine-tune what I do to the second eye to obtain the best possible results for you.
Complications associated with Limbal Relaxing Incisions
These include an increased level of minor discomfort following surgery compared with straightforward cataract surgery, rarely infection may occur. Vision may fluctuate as the wounds heal.
Whilst cataract surgery is a very successful procedure, there is no guarantee that it will improve your vision. As a result of the surgery and/or anaesthesia, it is possible that your vision could be made worse. In some cases, complications may occur weeks, months or even years later. These and other complications may result in poor vision, total loss of vision, or even loss of the eye in very rare situations. You may need additional treatment or surgery to treat these complications. Any additional treatment would not be included in the fee for this procedure.