It is an important fact that upto 35% of all dry eye patients suffer from dry eyes. We have known since the mid-1980s that contact lens wear can aggravate, or even produce, dry eye. This maybe related to 2 causes:
- The contact lens itself may increase tear evaporation, rendering the tear film unable to provide adequate lubrication during blink.
- Wearing contact lenses decreases corneal sensation. We know that the cornea becomes desensitised with contact lens wear. This allows you to wear contact lenses. The downside is the stimulus to create tears is reduced and produces relative water deficiency on the eye surface.
In many cases, dryness of the eyes is caused by our environment. Air conditioning in the summer and central heating in the winter can both lead to ocular discomfort. Allergies and air pollution are also culprits.
There are several reasons why contact lenses cause discomfort.
People who wear contact lenses find comfort particularly poor in the afternoon and evenings. This is due to the continuous evaporation of the tear film throughout the day. Additionally, a reduction in the production of water due to dry eye disease. renders the eye unable to fully replenish the evaporating tear film. A diminished tear volume increases discomfort as lubrication is fundamentally reduced. The combination of increased evaporation and diminished aqueous production also increases the tear film osmolarity, further irritating the eye.
In dry eye disease, loss of water from the lens matrix combined with the osmolarity of the tear film may affect contact lens' configuration, leading to an altered fit and potentially adding to the patient's discomfort and blurred vision.
Contact Lenses and Dry Eye
Contact lenses can produce or aggravate dry eyes
- Increased tear Film Evapouration
- Decreased corneal sensation and decreased tear production
- Irritation by increased osmolarity
Relieve with artificial tears
Diagnose MGD using
- Meibomian Gland Evaluator
Treat MGD with:
Lipiflow/Warm compresses Antibiotics
When aqueous deficiency present
- Try plugs
Assess contact lens material and fit
Often preservative free lubricants can ease discomfort by restoring stability to the tear film and rehydrating the contact lens. The difficulty is to select a drop that is compatible with the patient's contact lens.
Hard contact lenses, such as rigid gas permeable lenses, can accommodate most drops, even viscous polymers. Using thick polymer drops with soft contact lenses, however, can interfere with clarity of vision. Additionally, lipid containing drops may leave deposits on soft contact lenses, especially silicone hydrogel lenses. Because of these potential interactions, aqueous electrolyte solutions or simple rewetting drops may be the best choice for soft lens wearers.
Keeping Patients in Contact Lenses
Meibomian gland disease (MGD) is the most common cause of contact lens intolerance.
Wearing contact lenses can aggravate MGD in patients who previous suffer MGD. This exacerbates dry eye symptoms by combining two factors that are known to produce tear evaporation (underlying lid disease and contact lens wear). Treating MGD is the best way to restore overall eye health and, hopefully, return the patient to comfortable contact lens wear.
The first line recommendation is warm compresses and mechanical massage of the glands in the lid. Oral or topical antibiotics can help if there is significant inflammation present, oral doxycycline or topical azithromycin are good options.
Punctal plugs will sometimes solve the problem. However, if the patient has true dry eye disease, using punctal plugs can exacerbate symptoms by retaining high concentrations of inflammatory mediators on the eye. Cyclosporin eyedrops in these patients can be helpful.
Visiting your optometrist to check contact lens fitting would also be of benefit. Necessary adjustments to fit and tear exchange may maximise the chance of contact lens tolerance.
Finally, look for surface damage to the eye. Patients without surface damage have a better chance of returning to contact lens wear. But if dry eye is severe and damage is present, therapeutic scleral contact lenses may be needed.
If you have been affected by any of the symptoms mentioned above, please don't hesitate to give us a call.
We have a team of experts on stand-by who are ready to take your call at our Manchester (0161 907 2685) Clinic or our Blackpool (01253 308 031) Clinic.