Examination by an ophthalmologist is always required if a patient with contact lenses has prolonged eye symptoms.
If there is a suspicion of keratitis Corneal Ulcers the patient should be referred to an ophthalmologist as an emergency.
Contact lenses should not be worn in situations that involve eye irritation (e.g. allergic eye symptoms, common cold, dry eyes, dusty or very dry air, swimming in unclean water).
Contact lens use after cataract surgery or refractive corneal surgery (e.g. by PRK or LASIK) requires consideration and regular follow-up by an ophthalmologist.
In keratoconus, the use of contact lenses is challenging, since many patients are atopic.
Use of scleral contact lenses to correct substantial irregularity of the cornea or after trauma should be followed-up in a unit with adequate expertise of the condition.
Good hygiene must be kept in mind, either by using single-use contact lenses or with other lens types by following the instructions concerning replacement frequency and disinfection measures.
Eye drops that are used in association with wearing of contact lenses should not contain preservatives.
A general practitioner should not prescribe glucocorticoid-containing eye drops for a contact lens user.
Types of contact lenses
Soft contact lenses
Most commonly used contact lens type
The usage time of disposable contact lenses varies, depending on the lens type, from one day to a month or more.
Also astigmatism and presbyopia can be corrected with contact lenses (it is also possible to use multifocal contact lenses).
Hard (rigid) contact lenses
May be considered if refractive error cannot be sufficiently corrected with regular lenses.
Hard, oxygen-permeable contact lenses are used, for example, to correct high degree of astigmatism.
Also used in the treatment of keratoconus.
Hard contact lenses are durable.
Problems associated with contact lens use
Common symptoms include dry-feeling eyes as well as eye redness and irritation.
Impurities deriving from the eye or the environment may accumulate in the contact lenses and cause an inflammatory reaction.
Inflammation of the surface of the eye often appears as conjunctival redness and as irritation on the inner eyelid surface.
The earliest signs of problems in tolerating contact lenses can be seen on the conjunctiva of the upper eyelid as increased redness and as surface roughness (follicles and papillae). When examining problems with contact lenses, the upper eyelid should always be everted.
The corneal limbus reacts easily: limbal vasculature increases and, especially in the upper part, conjunctival thickening may appear (inflammatory infiltrate).
When using long-lasting contact lenses, the role of hygiene becomes even more important and also the possiblity of a more serious infection must be taken into account (for example Acanthamoeba if concurrent exposure to contaminated water).
Hard contact lenses may inflict more friction on the corneal surface, but complications caused by them are seen less often than complications caused by soft contact lenses. Unsuitable or damaged contact lens may cause damage to the cornea.
Many ophthalmic preparations and their preservatives (e.g. benzalkonium chloride) are absorbed by contact lenses, resulting in toxic or allergic reactions. Furthermore, contact lenses, being a foreign body, delay healing.
Users who are allergic to pollen should avoid using contact lenses when they have eye symptoms.
The use of contact lenses should also be avoided during other allergic ocular manifestations.
Dry eyes are a relative contraindication to the use of contact lenses when the condition is mild; in severe cases dry eyes are an absolute contraindication.
Contact lenses should not be used in a very dusty environment, or when the air is particularly dry or hot. Intensive computer work is also a relative contraindication.
When swimming or diving in unclean water (e.g. swimming pool) contact lenses should not be worn (if single-use lenses are used, they should be removed immediately after swimming and replaced with a new fresh pair).
Contact lenses should not be used during coughs and colds.
All people using contact lenses should see an ophthalmologist regularly: young (< 20 years) patients and/or patients with allergies once or twice a year, other atopic patients with symptoms, as well as atopic patients with keratoconus, once a year or more often if needed.
An ophthalmologist should individually ensure the suitability of continuously worn contact lenses and the regular controls during the use.
Daily-wear contact lenses (interval for replacement 1-3 months) are worn for e.g. 5-6 days a week. As for continuous wear contact lenses, it is safest to wear them only for a limited number of hours per day, and they should be replaced at one-month intervals. If they are worn for longer times uninterrupted, follow-up should take place at an ophthalmologist.
Regular ophthalmologic control is needed once a year in persons using continuous wear lenses.
Regular use of contact lenses after refractive surgery is not recommended except in special cases, and it requires regular follow-up by an ophthalmologist.
Contact lenses are still a good and safe alternative to refractive (laser or other) surgery (if needed, a contact lens may always be removed from the eye).
Use of special contact lenses in the treatment of substantial corneal irregularity, corneal ulcer or other disease or trauma requires assessment and follow-up by a physician or hospital with expertise in such treatment.
Proper hand hygiene and cleaning of the contact lenses
Examination and treatment of problems in a contact lens user's eye
The lenses should be removed and their use should be avoided as long as the symptoms persist.
Examine the eye with a magnifying lens using blue light and a fluorescein stain. If a corneal lesion is detected (a fluorescein-absorbing area in the cornea), consult an ophthalmologist.
An eyelid eversion should always be performed and the situation before and after contact lens use reviewed in all examinations of the eye.
If the patient has clear conjunctivitis (picture 1), prescribe antimicrobial drops or ointment, or both. Before the treatment is recommenced take a specimen for bacterial culture from the conjunctiva for an antibiotic sensitivity test. Also take a sample for bacterial culture from the contact lens solution and from the lens itself.
An ophthalmologist should always verify the suitability of contact lenses after laser or other surgical procedures for refractive errors, after other surgical procedures of the cornea (removal of pterygium, corneal transplantation) and after trauma.
If the symptoms and visual acuity do not improve after a few days, repeat the examination with a fluorescein stain and consult an ophthalmologist (iritis, keratitis, acute attack of glaucoma must be ruled out).
A chronic inflammation or other continuing symptoms in the eye always require an examination by an ophthalmologist. In connection to this, it is advisable to take a bacteriological sample and a brush biopsy from the conjunctiva (both lower and upper lid).
A follicular/papillary inflammation in the inner surface of the upper eyelid is referred to as giant papillary conjunctivitis (GPC). It is a strong, allergic-type inflammation and prevents further use of contact lenses.
Another difficult complication is an inflammation in the upper margin of the limbus (it may also cover a larger area), referred to as superior limbic keratoconjunctivitis (SLK). It resembles the limbal form of vernal keratoconjunctivitis (VKC) and prevents subsequent use of contact lenses.
If, in addition to the other symptoms, an eosinophilic/allergic-type inflammation is established, the use of contact lenses is discontinued and medication to alleviate the inflammation is started for a sufficiently long period (e.g. 1 month); see Allergic Conjunctivitis. The situation is controlled by an ophthalmologist with whom potential limited subsequent use of contact lenses can be, as required, discussed.
If there is strong discharge, the eye is painful and the visual acuity is impaired, always refer the patient immediately to an ophthalmologic unit.
In primary care, glucocorticoid drops should not be prescribed for a contact lens user to treat an inflamed eye.
Persistent problems (however small) in the eyes of a contact lens user warrant a referral to an ophthalmologist.
Allergic conjunctivitis is often associated with itchy and dry eyes which may continue after the contact lenses have been removed. Contact lenses should not be worn whilst the eyes remain itchy or painful.
Severe all-year eye allergy (e.g. atopic blepharoconjunctivitis) is a contraindication to using contact lenses.
A variety of eye drops not containing glucocorticoids or preservatives may be used to treat allergic conjunctivitis.
Mast cell stabilizers (e.g. preservative-free sodium cromoglycate) may also be used when wearing contact lenses. Lodoxamide is an alternative; it should not be used concurrently with contact lenses.
Antihistamine drops should not be used together with contact lenses.
Troublesome chronic blepharitis is, when not treated, a contraindication to contact lens use.
Do not use vasoconstrictive drops for the treatment of a red eye.
When using moisturizing or other drops with contact lenses, use always preservative free ones.
Replacing contact lenses and the solution
The contact lenses should be replaced as instructed by the manufacturer. The containers should be replaced at least every 6 months.
Oxygen-permeable rigid contact lenses are replaced at 2 year intervals.
People with allergies or those with sensitive eyes for other reasons should preferably use one-day or short-term (one-month) lenses.
Allergic patients with keratoconus (keratoconus is often associated with atopy) may use rigid oxygen-permeable contact lenses under supervision of an ophthalmologist.
Solutions that are based on hydrogen peroxide (H2O2) are used for disinfection.
The contact lens solution may cause toxic reactions if, for example, the hydrogen peroxide in the solution has not neutralized sufficiently.
Contact lens solutions, as well as protein-absorbing tablets, may cause allergic reactions.
If the contact lenses have been in a container for some time after disinfection with hydrogen peroxide they should be rinsed well before being placed in the eyes.
References
Chalmers RL, Hickson-Curran SB, Keay L et al. Rates of adverse events with hydrogel and silicone hydrogel daily disposable lenses in a large postmarket surveillance registry: the TEMPO Registry. Invest Ophthalmol Vis Sci 2015;56(1):654-63. [PubMed]
Chalmers RL, Wagner H, Mitchell GL et al. Age and other risk factors for corneal infiltrative and inflammatory events in young soft contact lens wearers from the Contact Lens Assessment in Youth (CLAY) study. Invest Ophthalmol Vis Sci 2011;52(9):6690-6. [PubMed]
Kari O, Haahtela T. Is atopy a risk factor for the use of contact lenses? Allergy 1992;47(4 Pt 1):295-8. [PubMed]
Kari O, Teir H, Huuskonen R ym. Tolerance to different kinds of contact lenses in young atopic and non-atopic wearers. CLAO J 2001;27(3):151-4. [PubMed]