Problems Related to Eye Contacts

Wearing contact lenses alters every component of your eyes, reports ophthalmologists Mark Ventocilla and Donna Wicker: the conjunctiva (the clear membrane covering your eye,) the endothelium (the lining of blood vessels in your eyes,) your eyelids and the stroma (the structural component of your eyes.)



The Mayo Clinic reports that all contact lenses limit the amount of oxygen your eyes would normally receive and this makes your eyes more susceptible to infections.



Although blurred vision, irritation and redness are often common problems with contact lenses and their causes are easily remedied, you should have these problems evaluated because they can be a sign of a much bigger problem, writes professors of ophthalmology Frank Weinstock and Dr. James Key II.



Luckily, Ventocilla and Wicker say most people use contact lenses without major problems. Most problems with eye contacts are due to poor fit, poor care, sensitivity to certain solutions or improper use.

Allergic Reactions

• Allergic reactions can cause redness, swelling and discharge.

  Allergic reactions to chemicals in contact lens solutions can occur. Ventocilla and Wicker explain that a change of solution or topical steroids can relieve the burning, redness and mucus discharge that can result from these contact allergies.

  In some cases, chemicals in eye contact solutions can lead to more severe immune reactions. Small grayish granules can develop across the cornea. Preservatives in contact lens solutions are the most common cause of such problems.

  Contact lens-induced superior limbic keratoconjunctivitis (CL-SLK) is an immune reaction in which the conjunctiva thickens and becomes stained. Immune cells invade the eye and burning, itching, tearing and vision loss can occur. Both preservatives and too much contact lens movement can cause CL-SLK.

  Giant papillary conjunctivitis occurs in 1 to 3 percent of contact lens wearers writes Ventocilla and Wicker. This problem is caused by deposits that build up on the lens and trigger immune responses. It most commonly occurs with soft contact lenses. Frequent cleaning and replacement of contact lenses, along with shorter wearing times can alleviate giant papillary conjunctivitis.

Abrasions

• Contact lenses can trap debris that scrapes the eye.

  Blinking is how our eyes clear foreign bodies away. Each blink presses contact lenses against the corneal epithelium and may result in stress that allows bacteria to enter the eye.

  Inserting and removing contacts can also result in abrasions of the eye. Debris trapped under contact lenses can scrape the eye and miniscule chips or tears along contact lenses can abrade the eye. Soft contact lenses often cause more of these problems than hard lenses.

Hypoxia

• Contact lenses reduce the amount of oxygen that gets to the eye.

  Hypoxia is the term for oxygen starvation. Because contact lenses prevent more oxygen from reaching the eye than normally would, the lack of oxygen can produce swelling and blurred vision. Severe cases result in cell death. Hypoxia is more likely when contact lenses are worn to bed and the eyelid is closed.

  Thinner eye contacts or those with better permeability to oxygen can help reduce the risk of hypoxia. Slight vision problems, however, may be the only problem that a person experiences. Over time, wearing contact lenses reduces sensitivity in the cornea. This can lead to thinning of the epithelium and an increase in bacterial infections.

Bacterial Infections

• Some bacterial infections have been traced to contaminated solutions.

  A serious problem that can affect contact lens wearers is infectious keratitis. The eye has a number of defense mechanisms to combat bacterial infections: contacts lenses affect all of them.

  Contact lenses prevent the lid from wiping the surface of the eye clear; tears are unable to wash the eye area under eye contacts effectively; the epithelial cells are unable to shed and regenerate as they normally would and reduced sensitivity in the cornea prevents wearers from realizing that an infection might be present.

  1 in 2,500 daily contact lens wearers and 1 in 500 overnight users develop infectious keratitis every year in the U.S., according to Ventocilla and Wicker. The bacteria that cause the infections are usually P aeruginosa, Staphylococcus aureus and Staphylococcus epidermis.

  In some cases, contact lens solutions may be infected with bacteria.

  Another serious infection is known as Acanthamoeba keratitis. Acanthamoeba is a protozoan found in air, soil and water. Using tap water to clean contact lenses is the most common source of this infection.

Other Problems

• Long-term use of contacts can change the shape of the cornea.

  Rarely, hard contact lenses can become embedded in the eyelids. Years of wearing eye contacts can stretch the eyelid during insertion and removal. The rubbing of the contact lens edge may create swelling in the eyelid that contributes to the embedding.

  Other problems that can occur because of contact lens use include tight lens syndrome or corneal warpage. Tight lens syndrome is also known as acute red eye. The contact lens can adhere very tightly to the eye and cause inflammation, pain and tearing. Corneal warpage refers to the gradual changes that can occur in the shape of the cornea from eye contact wear. It is more often seen with hard contacts than soft.