Contact Lens Problems
The following information is provided as a guide only. Careful assessment and treatment by an eye specialist (ophthalmologist) who has the expert training and experience to accurately determine your diagnosis and best treatment approach is important.
Contact lenses are worn by more than 3 million people in the UK. They are generally safe, and give few problems with proper use.
3 GOLDEN RULES FOR CONTACT LENS WEARERS:
- Never, ever swim or shower whilst wearing contact lenses!! This can cause serious infection (acanthamoeba) leading to blindness. No tap water or pool water should ever come in contact with an eye wearing a contact lens.
- If your eye ever looks red, feels uncomfortable or vision is blurry whilst wearing a contact lens, remove it and wait until the eye is white and comfortable before trying to wear a lens again.
- Never go to bed with a painful red eye, always try to see an eye doctor immediately. Bring the contact lens, solution and case when you see the eye doctor.
Common reasons for difficulty tolerating contact lenses
- Infection secondary to the contact lens– this must always be ruled out first
- Dry eye, Meibomian gland dysfunction and Blepharitis
- Allergic eye disease
- Problems with the contact lens itself
Infection related to contact lens wear (microbial keratitis)
Infection due to contact lens wear is the most severe, and most common complication of contact lens wear. It can cause permanent sight loss due to corneal scarring.
- Overnight soft contact lens wear carries the highest risk of severe infection.
- Of the soft contact lenses, daily disposable contact lenses are the safest. Fortnightly and monthly contact lenses can be associated with severe infection (Pseudomonas, Fusarium) due to bacteria and fungi growing in the contact lens case or solution.
- Rigid gas permeable (RGP) contact lenses are the safest of all contact lenses, in terms of infection risk.
- Acanthamoeba is a serious and difficult to treat infection which occurs in people who swim or shower whilst wearing contact lenses.
- Any contact lens wearer with a red eye that does not resolve 24 hours after removing the lens should be treated with intensive quinolone antibiotic (e.g. Levofloxacin, Moxifloxacin, Ofloxacin) for at least 3 to 5 days, and must be closely followed up.
- Herpes corneal infection can occur during contact lens wear, but no association has been found between the two. Always suspect Acanthamoeba infection in a contact lens wearer who appears to have a dendritic-type ulcer.
- Adenoviral corneal infection can occur during contact lens wear. Discard the contact lens and wait until the infection has fully resolved before resuming contact lens wear.
Dry eye and Meibomian gland dysfunction and Blepharitis
There are several reasons for dry eye being associated with contact lens wear:
- The physical presence of a contact lens divides the tear film into a pre- and post lens tear film. This is associated with decreased stability of the tear film, increased tear evaporation.
- Soft contact lenses which have a high water content can absorb moisture from the surface of the eye, leading to dryness.
- Long term contact lens wear leads to a reduction in corneal sensitivity, and this can lead to a form of dry eye due to reduced tear production.
- Contact lens wear is associated with a reduced blink rate, which can result in drying of the lens
- Contact lens wear is associated with reduced Meibomian gland function.
Treating dry eye associated with contact lens wear involves
- Identifying any other underlying causes of dry eye e.g. oral medications
- Optimising the type of contact lens to be most suitable for dry eyes
- Correcting, where possible, any environmental factors adverse to dry eye (e.g. air conditioning, excessive heating)
- Treating any Meibomian gland dysfunction and Blepharitis (see Dry Eye and Blepharitis)
- Treating aqueous (watery) tear deficiency with lubricants and the step-ladder approach (see Dry Eye)
- Remember to Blink when looking at computer screens or reading.
Allergic Eye Disease
- Contact lens wearers may be allergic to common allergens including dust mite, pollens, and experience both seasonal or perennial allergic conjunctivitis. See Allergic Eye Disease.
- Contact lens wearers can also develop a form of allergy due to the contact lens itself. This is called Giant Papillary Conjunctivitis. It is due to chronic irritation from the contact lens, mediated by both mechanical and immune mechanisms.
Treatment consists of:
- removing the contact lens until the condition has improved/resolved, b. improving the care (regular enzymatic protein cleaning) and
- improving the fit of the contact lens, and
- using topical mast cell stabilisers (e.g. sodium cromoglycate).
- Allergy to the preservative in contact lens solutions (e.g. thiomersal allergy) can also occur. Using an alternative solution should correct this.
Problems with the Contact Lens itself
Poor Lens Care:
- Failure to clean the contact lenses properly can lead to protein and lipid deposits on the lens, which cause irritation of the cornea and impaired vision. Bacteria, fungi and other microbes can form a film over the contact lens and lead to infection.
- Hair spray, hand cream and smoke can come into contact with contact lenses and cause damage to the cornea.
- Using lenses beyond the recommended time can lead to lack of oxygenation of the cornea. Chronic lack of oxygen to the cornea leads to blood vessel growth on the cornea which is permanent.
Lens Damage: Tears, cracks, chips or warping of the lens can cause local irritation or trauma to the cornea, and increases the risk of infection.
Poor Lens Fit: Both tight and loose lens fitting can cause damage. Tight lenses can lead to corneal swelling. Loose lenses result in lens decentration, with increased awareness of the lens and varying vision with each blink.
These problems are rectified by better education about lens care, and by having contact lenses fitted corrected by an optometrist. Using contact lenses which have been ordered online and not checked for fitting by an optometrist, is associated with an increased risk of contact lens-related eye infection.