Although the overwhelming majority of surgeries carried out to treat cataracts are successful, there are a few minor problems that can be caused by surgery and treated easily. There are also a relatively few major problems that can follow cataract surgery that may require a second surgical procedure to be fully corrected.
Cataract surgery is required when the natural lens inside the eye becomes cloudy and non-surgical treatment of the cataract fails. Cataracts have a number of causes including eye injuries, disease, side effects to medication and the natural ageing of the eye.
Surgery is the most common and successful form of cataract treatment, proving a success in around 98% of cases. During surgery the affected natural lens of the eye is removed and is replaced by an artificial lens called an intraocular lens (IOC), which is usually made of plastic, silicone or acrylic.
Common minor problems following cataract surgery include swelling of the cornea or retina, an increase in pressure within the eye and a droopy eyelid known as ptosis. These minor problems are usually solved with sufficient healing time and, in some cases, medication.
Posterior Capsule Opacity
Posterior capsule opacity (PCO) is a complication of surgery resulting in cloudy or blurred vision. During cataract surgery the IOC is placed within the capsular bag that contains the cloudy natural lens which is removed during the surgical procedure. A hazy membrane within the capsular bag can sometimes be trapped behind the IOC, resulting in PCO.
Around 20% of patients experience blurred, hazy vision following surgery, caused by PCO. PCO is usually treated with a second surgical procedure to remove the membrane.
Dislocated Intraocular Lenses
Following surgery a patient may be able to see the edge of the IOC or develop double vision; this is the result of an incorrectly positioned or dislocated IOC. The capsular bag into which the IOC is placed is approximately the thickness of a single red blood cell and is easily ruptured or broken, resulting in the misplacement of the IOC. This surgical complication is known as dislocated intraocular lense.
The capsular bag can also break due to a weakness of the fibres that hold the bag in place; this condition is known as zonular dialysis and places the patient at a greater risk of dislocated intraocular lense. A second surgical procedure is usually required to reposition the artificial lens and correct the vision problems.