US Pharm. 2010;35(4):42-46.
With pharmacists increasingly becoming the first port of call for many patients, it is useful to have basic knowledge of common eye disorders. This article will discuss distinctive signs and symptoms for common eye conditions and provide a rationale for their management. TABLE 1 lists possible questions pharmacists may ask during a consultation with a patient presenting with an eye problem.1
Red Eye
Red eye is commonly presented to pharmacists, and its causes vary from a minor subconjunctival hemorrhage to a more severe chemical burn; most often it is indicative of conjunctivitis, commonly referred to as pink eye.1 Other common causes include blepharitis, corneal abrasion, foreign body, keratitis, iritis, glaucoma, and scleritis. In addition to the redness, patients may experience eye discharge, pain, photophobia, itching, and visual changes. There are certain distinctive signs that assist in identifying the cause of red eye, such as watering and itching.
Apart from red eye, pharmacists may come across a number of eye disorders in everyday practice. It is important to distinguish when to recommend nonprescription therapies and when a referral may be necessary.
Allergic Conjunctivitis
Allergic conjunctivitis is usually a bilateral condition caused by pollen or other allergens. In cases where only one eye comes into contact with the allergen, the response may be unilateral. Typical symptoms are red, itchy eyes associated with tearing and burning that gradually disappear when the patient is no longer in proximity to the inciting allergen. The condition is often associated with runny nose, itching of the soft palate of the mouth, and sneezing. Approximately 70% of patients with allergic conjunctivitis also have asthma and/or atopic dermatitis.2
Cold compresses and tear substitutes are useful in relieving burning and dry eyes in patients with a mild allergy. However, many patients require more aggressive therapy with selective histamine-1 (H1)-receptor antihistamines (e.g., levocabastine) that relieve itching and watery eyes. Ketotifen (available OTC as Alaway, Zaditor, Zyrtec Itchy-Eye Drops, and Claritin Eye) is a multiple-action H1-receptor antihistamine that prevents the activation of inflammatory mediators.3 While first- and second-generation oral antihistamines are effective in treating allergic conjunctivitis, topical ophthalmic products are superior in treating this condition.3
For rapid but short-lived relief of redness, patients may choose a topical decongestant such as naphazoline, tetrahydrozoline, or oxymetazoline. These are available as single-ingredient OTC preparations, including All Clear, Murine, and Visine, respectively.4 Preparations such as Naphcon-A, Opcon-A, and Visine-A are combinations of a topical decongestant and an antihistamine.4 When recommending topical decongestants, it is important to note that these products can cause further complications such as conjunctivitis medicamentosa and irritation if used over long periods of time.
If OTC medications do not provide effective relief within 7 days or the condition worsens, patients should be referred to their physician for further investigation. Prescription medications for allergic conjunctivitis include mast-cell stabilizing agents such as sodium cromolyn and nedocromil, as well as anti-inflammatory agents and topical nonsteroidal anti-inflammatory drugs (NSAIDs), namely ketorolac.5
Bacterial Conjunctivitis
Acute bacterial conjunctivitis is characterized by a copious, purulent discharge, mild-to-moderate pain with a tingling sensation, and diminished vision. Other symptoms include red eye with a foreign body sensation. The best diagnostic indicator is glued eye(s) upon waking.5 Bacterial conjunctivitis can only be treated using prescription medications; therefore, patients should be referred to their physician.
Blepharitis
Chronic inflammation of the eyelids causes a condition known as blepharitis. Patients commonly complain of an itchy, gritty, uncomfortable red eye that is worse upon waking. It is not uncommon to see dandrufflike scaling on eyelashes, missing or misdirected eyelashes, and swollen eyelids.5,6 Patients should be advised that they should wash the eyelids with diluted baby shampoo or eye scrub solution. Gentle lid massages and warm compresses will also provide some relief. While patients should experience relief within one month, this treatment should be continued indefinitely. If this fails, however, a prescription ophthalmic antibiotic may be required.5,6 Oral antibiotics and topical steroids may be required in severe cases.
Episcleritis
The episclera is the layer found under the conjunctiva, covering the white of the eye. Inflammation of this layer presents as redness as a result of dilation of the blood vessels that are found in this layer. This maybe sectoral whereby only one part is affected, or diffuse, in which case most of the episclera is inflamed. Episcleritis is commonly self-limiting and resolves itself within 3 weeks. In rare cases, episcleritis has been associated with rheumatoid arthritis. Patients with recurring episodes should be referred to an ophthalmologist. Topical NSAIDs and topical steroids may be prescribed for severe cases.5,6
Herpes Simplex
Herpes simplex is a viral infection that first appears between the age of 6 months and 5 years.7 The herpes simplex virus-1 strain affects the eyelids, conjunctiva, and cornea. Typically, the patient presents with an uncomfortable eye, pain, redness, tearing, photophobia, and blurred vision. It is not uncommon to see herpetic vesicles on the eyelids or skin around the eye that rupture, crust, and heal without scarring after about 7 days.7 All patients presenting with a herpes simplex eye infection should be referred to their physician or ophthalmologist.6
Antiviral treatment using topical or oral agents is the mainstay of therapy. Topical trifluridine 1% solution (administered 5-8 times per day) and 200 to 400 mg of oral acyclovir administered 5 times daily are available by prescription. Other options include acyclovir ophthalmic ointment, oral valacyclovir (500 mg 2-3 times daily), and oral famciclovir (250 mg twice daily). Since topical antivirals can cause toxicity if used for more than 2 weeks, they are generally avoided. Similarly, topical steroids are not recommended since they can worsen the infection.8
Marginal Keratitis
Marginal keratitis is an inflammation of the cornea characterized by reduced vision, a painful red eye, sensitivity to light, foreign body sensation, and a mucopurulent discharge. It is a common, transient, usually unilateral condition that may be associated with chronic staphylococcal blepharitis.7 Patients presenting with the above listed symptoms should be referred to an ophthalmologist for a diagnosis. Marginal keratitis can be successfully treated using topical steroids.1
Subconjunctival Hemorrhage
A subconjunctival hemorrhage is characterized by red, flat discoloration due to bleeding from the small blood vessels that run through the conjunctiva. The most common cause for spontaneous subconjunctival hemorrhage is idiopathic in nature; the condition is painless, clearing itself within 7 to 14 days. In a few cases, the redness may be associated with bleeding disorders, the use of anticoagulants, conjunctivitis, scleritis, or trauma to the eye. Warm compresses may be useful in symptomatic relief. Treatment involves the identification and appropriate management of the underlying cause.1,5,7
Uveitis
Uveitis or iritis is an inflammation of the iris, the ciliary body, or the choroid. Iritis may result in pain that radiates to the brow and temple; it develops with time along with redness in the eye. Other symptoms of iritis include watering, red eye, blurred vision, and photophobia. Iritis should be referred for further investigation. Patients are commonly treated with steroid eye drops to alleviate the pain and inflammation.6
Arcus Senilis
Arcus senilis (corneal arcus) is a bilateral condition manifesting as a white ring in the periphery of the cornea.7 It is a lipid-rich corneal deposit that does not affect the patient’s vision. It begins at the top and bottom of the cornea and spreads to form a complete ring. It is most commonly seen in elderly patients. Therefore, arcus senilis in patients below 50 years of age should be referred for a lipid profile, since it may indicate hyperlipidemia, hypercholesterolemia, or hyperlipoproteinemia.8 However, the relationship between arcus senilis and cardiovascular disease is yet to be established.9
Dry Eye Syndrome
Dry eye syndrome, due to decreased production of tears or excessive tear evaporation, causes discomfort and soreness. Patients may also complain about a foreign body sensation in the eye(s). Underlying causes of dry eye include Sjögren’s syndrome, aging, staring at a computer screen for too long, blinking problems, and environmental factors. Additionally, patients taking such medications as oral contraceptives, antihistamines, and beta-blockers may experience dry eyes. Pharmacists are in an ideal position to discover this adverse reaction.
Dry eye syndrome can be managed using nonprescription artificial tear products (e.g., Murine Tears Dry Eyes, Visine Tears Dry Eye Relief).10 Many OTC products are available, and preservative-free formulations are recommended if the patient experiences itching and irritation with the drops (e.g., Bion Tears, Refresh Celluvisc).10 Dryness can also be prevented by the use of humidifiers. Cyclosporine eye drops that increase tear production are available by prescription (e.g., Restasis).5
Floaters
Patients describe floaters as dark specks or cobwebs that are seen in the field of vision. They are shadows of the fibers that clump together in the vitreous gel. While floaters are a normal part of the aging process and occur as some point or another in most patients, individuals suddenly experiencing new floaters, with or without flashing lights, should be referred to an ophthalmologist immediately.6
Meibomian Cysts (Chalazia)
A chalazion, or meibomian cyst, is a benign lipogranulomatous inflammation of the meibomian glands lining the tarsal plate of the eyelid.11 It is caused by lipid blockage of the gland duct, causing a pea-like swelling. Patients usually present when the lump becomes symptomatic, either because of cosmetic reasons or, if the chalazion is of a considerable size, because it is causing ptosis, astigmatism, and/or vision loss. If left untreated, chalazia may resolve over many months. A warm compress can be applied over the cyst to allow the oils to liquefy and flow properly. The cyst should be massaged daily for about 1 minute following the warm compress. If this does not work or the cyst is too large, surgery on the everted eyelid may be required.6,11
Nevi
A pigmented or nonpigmented mole on the conjunctiva of the eye is known as a nevus. The nevus may be flat or slightly raised.1 Since nevi are normally harmless, no treatment is necessary, unless they become malignant. Patients should be referred for further investigation if the nevus is growing. The presence of nevi on the iris is an indication of neurofibromatosis type 1, an autoimmune disease.
Pingueculae and Pterygia
Pingueculae are yellow-white, flat or slightly raised, usually bilateral lesions on the conjunctiva found adjacent to the nasal or temporal limbus.1,7 Pterygia are similar asymmetrical lesions that encroach on the cornea.7 Pterygia can either grow as separate entities or start out as pingueculae.12 Pingueculae do not normally require treatment except mild steroid drops to reduce any inflammation. However, pterygia can stretch the cornea, resulting in astigmatism and blurred or low vision. It is essential that these be surgically removed.12 Any patients presenting with such a growth should therefore be referred for further investigation.
Styes
A bacterial infection of the eyelash follicle causes a painful swelling at the margin of the eyelid known as a stye. The causative organism is usually Staphylococcus species. Warm compresses are typically recommended to provide symptomatic relief and quicken recovery. In most cases the stye will heal itself within 1 to 2 weeks. Referral and a prescription for oral antibiotics may be necessary if no relief is seen in approximately 14 days.7
Trichiasis
Trichiasis is a condition whereby the eyelashes grow inwards, causing corneal abrasion and thus affecting the eyesight. The eyelash needs to be regularly pulled out with a tweezer by a qualified health care professional, and sometimes electrolysis or cryotherapy of the hair follicles may be considered.
Watery Eyes
Watery eyes are caused by excessive tear production, a natural process that keeps the eye lubricated and clean. Allergies are a common cause of watery eyes, in addition to blepharitis and infection. The choice of treatment will be based upon the cause. Nonprescription antihistamines may be useful in preventing watery eyes related to allergies.
Xanthelasma
Xanthelasma is a frequently bilateral condition that is usually found in elderly individuals and those with hypercholesterolemia. It presents as a yellow subcutaneous plaque on the eyelids. Since it can be an indication of hypercholesterolemia, patients should be referred for a cholesterol test.7
Foreign Body in the Eye
The symptoms of a foreign body include sharp pain, burning, irritation, tearing, and redness. The patient may feel something in the eye when moving the eye around while it is closed and a scratching sensation upon blinking. Bleeding may be seen in the white part of the eye, and in more severe cases the vision may be affected or there may be a complete loss of vision. In less serious situations, whereby there is no corneal abrasion or loss of vision, a simple eye wash can be used to remove the foreign body.
Preservatives in Eye Care Products
Additives, such as preservatives, need to be taken into consideration when selecting an appropriate medication. Preservatives in eye drops can cause stinging and itching as well as keratitis.13 Furthermore, preservatives decrease the stability of the precorneal tear film and have a detergent effect on the lipid layer, worsening a dry eye.14 Preservatives, such as benzalkonium chloride, are taken up by contact lenses, particularly soft contact lenses. The accumulation of such preservatives eventually reaches toxic levels, causing further irritation to the eye. Patients should be advised not to wear any lenses for an hour after instilling eye drops containing preservatives.15
Role of the Pharmacist
Pharmacists should demonstrate the proper use of ophthalmic drops to patients so that the medication is applied correctly. Leaflets that instruct patients on how to instill eye drops are readily available and should be used to reinforce the explanation. TABLE 2 lists the symptoms that require immediate referral. As a rule of thumb, any patients presenting with pain in the eye should be referred for further investigation immediately. Many symptoms, particularly dryness, watery eyes, and redness, are common to a number of ocular conditions. While pharmacists are not experts in treating eye conditions, they are in a position to give patients advice based upon the symptoms presented and explain the correct use of the medications.
REFERENCES
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