What causes cornea swelling after cataract surgery?
Cornea swelling after cataract surgery occurs in about five per cent of patients. The cornea is the clear front covering of the eye. Fluid that normally keeps the eye lubricated can build up beneath the cornea after cataract surgery, causing swelling of the cornea (corneal oedema) to occur.
Symptoms can be quite similar to the symptoms of cataracts. These symptoms can include pain in the eye, light sensitivity (photophobia), the feeling of having a foreign object in the eye, seeing halos around sources of light, and poor vision---especially after waking.
During or after surgery, bacteria can cause infection to develop within the eye. Infection does not necessarily mean that surgery was conducted in unhygienic surroundings: Patients may be naturally susceptible to infection through low immunity. Exposing the eye to water from the faucet while showering or washing your face can also cause infection. Because of this, every care should be taken to ensure water does not get into the eye when washing. Your doctor may give you an eye shield to prevent rubbing the eye when asleep. The sutures used in cataract surgery may also cause infection of the cornea.
Mechanical injury occurs when something physically hurts the cornea. This may happen when the patient accidentally injures the eye in some way---being hit with a ball while playing sports, for example, or scratching the eye with a nail. Irritation may occur, causing the cornea to swell.
Exposing the eye to chemicals can cause irritation and swelling. Patients should avoid using make up, such as mascara, eye liner and eyeshadow, while recovering from cataract surgery and should be careful not to get soap or shampoo in the eye while bathing. Substances such as the medication amantadine, commonly used to treat Parkinson's disease, or chlorhexidine, which is used in many mouthwashes and skin cleansers, can cause corneal oedema.
Certain eye diseases that are present at the same time as cataract surgery can cause the cornea to swell. Fuch's endothelial dystrophy is the most common of these and is known to cause corneal oedema. With Fuch's dystrophy, fluid does not drain from the eye as it should. The fluid builds up, causing the cornea to swell.
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Treatment for cornea swelling after cataract surgery varies depending on the severity of the swelling. A doctor may prescribe eye drops, which will encourage any fluid trapped behind the cornea into tears. If the oedema is more severe or if blisters are present (common with Fuch's endothelial dystrophy), a corneal transplant may be necessary.