Do your eyes itch?

Ask this question of your patients, and the others listed here, to help you differentiate from other ocular surface disorders and to plan treatment.

By Lorenzo J. Cervantes, MD

You can be assured that patients will visit your office with signs and symptoms of ocular allergies — even if they present for another reason. An estimated 15% to 20% of the world population has some form of allergic disease, and an estimated 40% to 60% of allergic patients have ocular symptoms.¹ Presentations can vary widely in severity — from mild occasional itching to a severe blepharokeratoconjunctivitis.

Asking these eight questions can alert patients to their signs and symptoms and help you differentiate ocular allergies from other ocular surface issues, like blepharitis and dry eyes, and to help manage it appropriately.

1. Do they itch?

Itching is the pathognomonic symptom of ocular allergies.^2,3 Patients consider ocular itching the most disruptive symptom, and can be accompanied by tearing, burning, hyperemia and chemosis.⁴ Conjunctival papillae (Figure 1) are a typical finding, but can be accompanied by follicles in situations of topical medication-related allergy.

Figure 1. Moderate palpebral conjunctival papillary reaction.

2. Do you have other symptoms?

Ocular allergies are not always isolated problems. Blepharitis and dry eye syndrome, for example, have many symptoms that overlap with ocular allergies. Due to their high prevalence, it is common to have a comorbidity scenario. As alluded to above, the presence of itching includes allergies in the differential diagnosis. Lacking it as a symptom might focus attention to another etiology.

Ask the patient if he or she frequently gets hordeolum or chalazia. Also, determine whether the meibomian glands appear congested with thick secretions. If so, treatment for blepharitis might be more appropriate. In addition, ask whether the symptoms become worse during activities like reading, driving, watching television or using a computer. These scenarios can aggravate the ocular surface in a dry eye patient.

To make matters worse, allergies, blepharitis and dry eyes can be interrelated due to their treatments. Oral antihistamines, for example, can induce dry eyes, and topical treatments for ocular surface disease can be triggers for allergies.

3. How long have you had the symptom/s, and when are they worst?

The timing of symptom onset can help to determine the offending allergen and the underlying pathophysiology. The ocular allergy spectrum includes seasonal allergic conjunctivitis (SAC), perennial allergic conjunctivitis (PAC), contact blepharoconjunctivitis (CBC), vernal keratoconjunctivitis (VKC) and atopic keratoconjunctivitis (AKC).

SAC and PAC are the most common forms of ocular allergy, estimated to affect 15% to 25% of the U.S. population.⁵ Symptoms from SAC fluctuate with seasonal levels of antigens, like tree pollens and grasses. Symptoms from PAC tend to be more persistent due to chronic exposure to indoor allergens like animal dander, molds and dust mites. CBC is an allergic reaction to a substance applied to the eyelid skin or conjunctiva. VKC classically presents in children and adolescents, predominantly in boys, and disappears after puberty. AKC usually appears primarily in adults 30-50 years of age.

Other ocular allergy entities to be aware of are acute allergic conjunctivitis, occupational allergic conjunctivitis and drug-induced conjunctivitis or medicamentosa.^6,7

4. Are there any other problems aside from your eyes?

Ocular complaints can be accompanied by systemic symptoms, including rhinitis and other atopic conditions, like asthma or eczema. These conditions should not be ignored as they can make a severe negative impact on the patient’s quality of life.

5. Are you allergic to anything?

The patient might already know the identity of the offending allergen, and you can take appropriate action. Frequently, however, patients will deny any history of allergies or allergen sensitivity, especially in the setting of a routine eye exam or a mixed-etiology ocular surface inflammatory picture.

Although many treatments can block the inflammatory cascade, prevention is an important strategy in ocular allergy management. In chronic cases, or in cases recalcitrant to medical therapy, removing the offending agent from the patient’s environment might be the only solution.

If the source is not known, and the level of concern warrants further investigation, then a test identifying the particular allergen can be performed by an allergist, or at the time of presentation at the ophthalmologist’s office with the Doctor’s Allergy Formula diagnostic test (Bausch + Lomb). This skin test utilizes a panel of 60 allergens that are specific to each region of the country and provides results within 10 to 15 minutes.

6. Do you rub your eyes?

The results of eye rubbing are not benign. While providing minimal short-lived relief, it perpetuates the duration of conjunctival itching, chemosis and hyperemia. It further exacerbates periocular swelling and redness presenting as allergic shiners and aggravates eyelid eczema (Figure 2).

Figure 2. Allergic shiners and eyelid eczema.

Eye rubbing has also been implicated in the pathogenesis of keratoconus⁸ and glaucoma.⁹

7. What therapies have you tried before?

When selecting and initiating treatments, the physician should provide targeted therapy for the various conditions affecting the ocular surface. Use of topical antihistamines alone, for example, might not address comorbid blepharitis. This can lead to frustration to both the physician and the patient that progress is not being made.

Similarly, even when treating ocular allergies, different medication classes exist that target various points along the inflammation cascade. A recent poll showed that current trends for the treatment of ocular allergies have little concordance with current recommendations. For example, of 2,687 polled subjects, 43% used over-the-counter decongestants, 41% used corticosteroids, 29% used topical antihistamines, 27% used systemic antihistamines and 15% used mast-cell stabilizers. Interestingly, 40% of patients used a combination of decongestants and corticosteroids for ocular allergy — a combination that does nothing to inhibit histamine release or the associated, early-phase reaction inflammatory mediators that are released from activated mast cells.¹⁰

Topical decongestants, like naphazoline, reduce hyperemia but do little to relieve itching.¹¹ Also, they carry a risk of tachyphylaxis or rebound hyperemia, making it necessary to remain on the drops for white-appearing eyes.

At one point systemic antihistamines were historically popular for the treatment of ocular conditions, as they were comprehensive therapy for rhinitis, sinusitis and other forms of non-site-specific allergy. First-generation antihistamines were known for their sedating and anticholinergic effects, while second-generation antihistamines, including loratadine and fexofenadine, had a greater specificity for H1-receptors. The problem: They have little or no effect on dopaminergic, adrenergic, or serotonergic receptors, and their bioavailability is impaired by some fruit juices and their usage can be associated with dry-eye symptoms.

Mast cell stabilizers, like cromolyn sodium, reduce degranulation and/or biosynthesis of inflammatory mediators. Their onset of action is slow, and requires a preloading period of up to two weeks. Because of this, they are not effective against existing symptoms, but work well to control chronic cases.

Topical nonsteroidal anti-inflammatory drugs (NSAIDs) inhibit prostaglandin and leukotriene production. Topical ketorolac is indicated for the temporary relief of ocular itching due to seasonal allergic conjunctivitis, but requires frequent dosing and can be associated with significant corneal epitheliopathy.

Topical steroids do not effectively treat the early phase of allergic reaction, but suppress the late-phase reaction by inhibiting the production or the release of inflammatory mediators. They are best used in patients with refractory symptoms like those in VKC and AKC in which the inflammation is chronic, allergen-independent, and T-cell-mediated. Prednisolone phosphate solution traditionally has been used for cases such as these, as well as for GPC. Dual-action agents combine the rapid actions of antihistamine-receptor antagonists and long-term benefit of mast cell stabilizers, and can be viewed as first-line therapy for ocular allergies. Examples include olopatadine (Pataday, Pazeo, Alcon), ketotifen (Zaditor, Alcon), azelastine (Optivar, Meda Pharmaceuticals), epinastine (Elestat, Allergan), bepotastine (Bepreve, Bausch + Lomb) and alcaftadine (Lastacaft, Allergan).

8. How do you feel about seeing an allergist?

When the symptoms become chronic and recalcitrant to simple medical care, or when an underlying causative allergen has not been identified, consider consultation with an allergist. They perform a wide variety of allergy testing that otherwise would not be available in the ophthalmologist’s office. Once an allergen has been identified, immunotherapy, be it subcutaneous injections, sublingual drops or tablets, can help desensitize a patient’s immune response. OM

REFERENCES

About the Author
	Lorenzo Cervantes, MD, is a cornea and refractive specialist in practice at OptiCare in Waterbury, Conn. He may be reached at lorenzo.cervantes.md@gmail.com. Dr. Cervantes has no financial interest in the products or companies mentioned.