Article Date: 8/1/2009

Treating the Underlying Disease

Treating the Underlying Disease

Ocular surface disease can greatly affect the comfort of contact lens wear. Studies have shown that dry eye affects up to 15% of the general population.1-3 Additionally, allergies have been shown to affect from 10% to 30% of the population, with ocular symptoms affecting 90.5% of those who experience allergies.4 Surely this is a reason for concern, because of the sheer number of patients this may affect.

Unfortunately, these disease states slowly erode our patients' contact lens-wearing abilities and often silently lead to dropout. Patients have access to a plethora of over-the-counter agents to minimize symptoms, so many don't consult their eyecare providers to ask about the proper use of these agents. This is unfortunate because some of the agents may have a counterproductive effect on the underlying disease state that manifests as contact lens discomfort.

We believe it's necessary to identify patients with discomfort issues, so we can guide their treatment regimens. First, we'll discuss some of the strategies we use to identify patients with underlying dry eye disease, then we'll offer current thoughts regarding treatment for these patients. Later, we'll turn our attention to allergic eye disease, emphasizing treatment protocols that tend to be most successful in a primary eyecare setting.

IDENTIFYING DRY EYE

The chief complaint may help us identify some dry eye patients, but patients who don't voice their complaints are more likely to self-treat without an eyecare practitioner's guidance. Unfortunately, these are often the same patients who are silently dropping out of lens wear.

There are various questionnaires that may help identify dry eye patients. Simply type "dry eye questionnaire" into an online search engine and numerous options will appear. One of the most often used resources is the ocular surface disease index (OSDI).5

Remember that it's also important to obtain a comprehensive history, and pay particular attention to conditions for which the patient may be taking medications that contribute to ocular dryness. Conditions to watch for include blepharitis, rheumatoid arthritis, Sjögren's syndrome, lupus and Stevens Johnson syndrome. Classes of medications that may cause dry eye include systemic antihistamines, antihypertensives, diuretics and antidepressants.

Although history forms and questionnaires may help identify patients with risk factors for dry eye, there may be more effective ways of communicating with your patients to discover underlying surface disease. Specific examples of these are listed in Figure 1 and have given us greater insights into a patient's true contact lens-wearing experience. Basically, instead of asking "How are your contact lenses?" which leads patients to say "fine" or "good," think about asking open-ended questions that will force a more informative response.

Just as important as a thorough history are exam findings that may relate to ocular dryness. Two of the most effective, yet underutilized, tools are fluorescein and lissamine green dyes. When applied to the eye, these dyes give us valuable insights into the health of the anterior segment and, in particular, the ocular surface.

Fluorescein is best viewed with a cobalt blue light and a wratten filter. Practitioners can view lissamine green with the regular white light on a slit lamp. They can check the integrity of the tear film by measuring tear film break-up time with fluorescein (Figure 2). We consider anything less than an 8-second tear film break-up time to be significant.6

Figure 2. This patient has a history of radial keratectomy with a significantly reduced tear film break-up time. Here, we see the patients' tear film 3 seconds after a complete blink.

Corneal staining may be associated with ocular dryness, in addition to contact lens-solution interactions (See contact lens care section, beginning on 'The Science of Contact Lens Care'). Additionally, the lid wiper area, which is the area just posterior to the meibomian gland orifices on the superior lid, often will stain with either fluorescein or lissamine green in patients who complain of discomfort (Figure 3).7,8

Figure 3. Lid wiper epitheliopathy is evident as fluorescein staining present just posterior to the meibomian glands on the upper eye lid.

Lid margin assessment is important, because it may contribute significantly to the quality of the lipids produced to support the tear film. Collarettes located at the base of the lashes are likely to lead to comfort issues. Additionally, inflammation of the meibomian glands may lead to altered quality lipids being secreted from these sebaceous glands, which might lead to additional inflammatory mediators invading the tear film, exacerbating existing dry eye issues.9

TREATING DRY EYE

One of the best tools practitioners have to guide their treatment decisions for dry eye patients is the Delphi panel consensus for dry eye management. This review10 was published in 2006. The guidelines continue to provide the framework for a logical flow of treatment for patients. Figure 4 highlights the findings of the panel and shows a logical progression of advancing treatment with advancing disease.

Figure 4. A summary of the Delphi approach to dry eye diagnosis and treatment.

We usually start patients at the initial level of treatment, making sure proper environmental modifications have been made. Additionally, we have them use artificial tears on a regular basis. We also specify the type of artificial tear to use, so when we follow up with the patient, we can measure success in terms of compliance and effectiveness of the selected product. In contact lens wearers, we've found significant success using an ocular lubricant that contains the active demulcents polyethylene glycol and propylene glycol with the gelling agent HP-guar (SYSTANE® ULTRA Lubricant Eye Drops) before lens instillation and after lens removal.11 When indicated, we also tell contact lens wearers to instill this drop over their contact lenses, because we've seen significant improvements in comfort when they follow a regular dosing regimen. Although this is an off-label use, it's been shown to be safe.12

When warranted, we may add anti-inflammatory agents. We typically prescribe loteprednol 0.5% with qid dosing and ask the patient to return in 1 month for followup.13 Usually this will be enough time for the agent to sequester the inflammatory response. If the inflammatory response isn't sequestered, we'll continue with this medication until the dry eye is under control. For those patients who would benefit from long-term immunomodulatory therapy, we usually prescribe 0.05% cyclosporine bid.14

Additionally, the eyelids should be treated if underlying disease exists. Lid scrubs work very well if the treatment regimen is followed. Heat applied to the lids will improve the quality of the oils being secreted from the meibomian glands. Oral doxycycline also works well in returning the meibum to normal and usually is dosed bid, between 20 mg and 100 mg per day. Recent reports of the off-label use of azithromycin (Azasite, Inspire Pharmaceuticals) bid have also indicated improvements in both signs and symptoms of blepharitis as well.

Treating the underlying disease will help create a more robust tear film that will lead to a more successful wearing experience for the contact lens patient. Uncovering and treating underlying disease issues will help prevent contact lens dropouts secondary to dry eye.

IDENTIFYING ALLERGIES

Allergens can pose a significant threat to comfortable contact lens wear. Ocular symptoms account for the second most common allergy presentation (Figure 5).15 The allergic cascade (Figure 6) begins when an antigen cross-links to IgE that's bound to a mast cell. The conjunctiva is saturated with nearly 50 million mast cells.16 This causes degranulation and the release of various mediators, including prostaglandin, tryptase, heparin and histamine into the ocular environment. Of greatest concern is the release of histamine, which causes conjunctival nerve stimulation (itching) within 3 to 5 minutes of its release and vasodilation (redness and swelling) within 10 minutes of its release.

Figure 5. Ocular symptoms account for the second most common allergy presentation.

Figure 6. The allergic cascade begins when an antigen cross-links to IgE that's bound to a mast cell.

In mild cases, patients may have little-to-no slit lamp findings. In more severe states, the patient may present with bilateral redness, chemosis, lid swelling and epiphora. The most common presentation is a patient with nose and throat symptoms. But many times, allergy symptoms go unnoticed by eyecare practitioners, so it's very important that we ask the right questions of our patients, because many patients don't think to mention their allergic eye issues during their exam. They may attempt to self-treat. In fact, in 2000, 46 million bottles of eye medications were sold to consumers seeking to alleviate their ocular allergies.17 Of the 46 million sold, 41 million were over-the-counter allergy eye drops; only 5 million were prescription allergy medications.17 It's important to identify allergy patients to prevent them from self-treating with suboptimal over-the-counter options.

Contact lens wearers who have allergy symptoms may not realize the etiology of their discomfort. For many patients, the symptoms of allergies mimic those of dry eye: discomfort, dryness, itching, burning, stinging, watering and redness. Without proper questioning and evaluation, these patients may treat their symptoms with less than ideal artificial tears or over-the-counter allergy medications, including those containing vasoconstrictors.

It's important to inquire about all of the prescription and nonprescription medications patients may have used since their last visit.

TREATING ALLERGIC EYE DISEASE

The best way to handle allergies is to avoid the offending allergen. Unfortunately, this is rarely a feasible approach, but patients should attempt to limit their exposure.

Closing windows and doors and removing shoes and outer garments before entering living spaces will help to reduce allergens. Frequent vacuuming and the addition of air purifiers in bedrooms and living spaces will help to reduce airborne allergens. Patients with long hair should wash their hair in the evening to remove accumulated allergens. The use of artificial tears can provide mild temporary relief of allergic symptoms by helping to flush allergens out of the eyes.

Mast cell stabilizers, as their name implies, stabilize mast cells to prevent the release of histamine. Antihistamines are histamine antagonists, which counteract the effects of histamine at the receptor sites on ocular tissues. The unfortunate reality is that each of these medications, although they play a valuable role, are relatively short-lasting, so they require frequent dosing, often tid or qid, which presents a significant inconvenience for most contact lens wearers.

Due to dosing frequencies, the use of these medications have been replaced by antihistamine-mast cell stabilizers, such as ketotifen (Zaditor*), azelastine (Optivar*), epinastine (Elestat*), olopatadine 0.1% (PATANOL®) and olopatadine 0.2% (PATADAY™). These medications are excellent treatment choices, because of their reduced dosing schedules and high level of effectiveness. All aforementioned agents are approved for bid dosing, except PATADAY™, which is approved for once-daily dosing. All topical anti-allergy drops require a 10-minute wait before inserting contact lenses.

IDENTIFY AND TREAT

It's evident that we're empowered with a variety of agents to help patients with allergies continue to wear their contact lenses more comfortably when they're experiencing ocular symptoms. The most important factor in treating allergy patients continues to be identifying them and guiding their therapies as opposed to having them attempt to self-treat. By identifying allergy patients and treating them appropriately, we'll be able to significantly reduce the number of contact lens dropouts. CLS

REFERENCES

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  10. Behrens A, Doyle JJ, Stern L, et al. (Dysfunctional Tear Film Study Group.) Dysfunctional tear syndrome: a Delphi approach to treatment recommendations. Cornea. 2006;25:900-907.
  11. Christensen M, Cohen S, Tudor M. Confirmation of efficacy by cessation of therapy with SYSTANE® lubricant eye drops. Poster presented during the 2005 annual meeting of the American Academy of Optometry.
  12. Kading D. Safety evaluation of Systane Ultra® in contact lens wearers. Poster abstract accepted for the 2009 annual meeting of the American Optometric Association.
  13. Pavesio CE, Decory HH. Treatment of ocular inflammatory conditions with loteprednol etabonate. Br J Ophthalmol. 2008;92:455-459.
  14. Bowling E. Contact lens-related dry eye. Review of Optometry. September 2007.
  15. Brodsky M. Allergic conjunctivitis and contact lenses: experience with olopatadine hydrochloride 0.1% therapy. Acta Ophthalmol Scand Suppl. 2000;(230)56-59.
  16. Adelman DC, Casale TB, Corren J. Manual of allergy and immunology. 4th edition. Philadelphia: Lippincott Williams & Wilkins; 2002:80.
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Contact Lens Spectrum, Issue: August 2009