Introduction  

Despite being safe and easy to use, contact lenses can present certain risks. One is the risk of getting an infection in the eye. The most common infection is keratitis (an infection of the cornea). Keratitis can give rise to a scar on the cornea thus affecting vision. Beside keratitis, there is the contact lens-induced acute red eye (CLARE). 
CLARE refers to an inflammation on the cornea and conjunctiva. The inflammation arises from sleeping in contact lenses. Contact lens papillary conjunctivitis (CLPC) is an inflammation of the upper eyelid. It is prevalent with people who extend their contact lens use. 
Corneal ulcers and eye infections may develop rapidly. Infections can lead to the growth of blood vessels in the cornea. Scratches can cause bacteria and fungus to enter the eye. These infections are serious and can sometimes cause blindness in rare cases.

Causes and Risk Factors

Infections related to wearing contact lenses may be caused by the following:

  • Bacteria, fungi and parasites 
  • Herpes virus
  • Use of extended-wear contact lenses
  • Poor hygiene, for example, dirty cases or lenses
  • Re-using or topping off contact lens solution
  • Failure to remove the contact lenses when sleeping
  • The building up of microbes under the lens
  • Reduced tear exchange under the lens
  • Old contacts or ill-fitting lenses that can scratch the surface of the cornea
     

Signs & Symptoms

The following symptoms may be observed:

  • Eyes that turn red
  • Eye pain 
  • Blurry vision
  • Foreign object sensation in the eye
  • Discharge or watery eye
  • Being more sensitive to light
  • Swelling
  • Itching or burning
     

Diagnosis

It is important for contact lens wearers who experience the above symptoms to contact the eye professional as soon as possible. The professional will conduct an examination to determine the infection. He/she may do the following:

  • A slit lamp examination - A special dye will be used to help with the diagnosis
  • Send a culture from the infected eye to the laboratory for further testing
     

Treatment 

Treatment of contact lens-related infections is directed toward clearing the infection.

Medical Treatment

In some cases like CLARE, no treatment is needed. The patient is required to discontinue the use of contact lenses which resolves the issue. However, he/she should watch out for symptoms such as pain, decreased vision and sensitivity to light. 

The eye doctor will prescribe antibiotic drops according to the severity of the infection. He/she will also prescribe additional medications for complications such as formation of blood vessels. Pharmaceutical antihistamines are prescribed for people with CLPC.

Surgical Treatment

If a scar severely affects the cornea, a corneal transplant will be required. A corneal transplant involves replacing the scarred cornea with a healthy donor cornea

Home Care

The patient is required to stop wearing the contact lenses until the infection has cleared.

Prognosis/Long-term outlook

Infections from improper use of contact lenses can lead to blindness if not treated. Eye irritations, corneal abrasions and conjunctivitis may result from improper use of contact lenses. 

The doctor will advise when to re-start using the contact lenses after an infection.

Prevention/Follow Up

The following can help keep infection away:

  • Practising hygiene which should include:
  1. Washing hands before cleaning the contact lenses
  2. Rubbing lenses when cleaning to rid them of the protein and bacteria that builds up 
  3. Rinsing the lenses in the prescribed solution. The lenses should be cleaned and stored in solutions bought at the store. Homemade solutions should be avoided since they contain dangerous germs that can cause blindness
  4. Avoid topping off or reusing contact lens solution
  5. The contact lens case should be cleaned and air-dried daily. The case should be washed and boiled weekly. The lens case should also be replaced frequently
  • Replacing contact lenses at least thrice per year
  • Resting the eyes by not wearing contact lenses from time to time
  • Never sleeping in contact lenses
  • Shunning the habit of extending the recommended time when the lenses should be won. For instance, some lenses should be won only for three months then discarded
  • Regularly visiting the doctor for an eye check. Once a year is good enough
  • Wearing contact lenses in the hot tub, bath, shower, swimming pool, ocean and so on is prohibited
  • Following the healthcare provider’s instructions exactly as directed
  • Avoiding storing contact lenses in non-sterile liquids such as tap water or distilled water
  • Avoiding application of eye drops without consulting the doctor. Some drops may interact with all types of contact lenses