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As ocular allergies increase on a global scale, treatment options abound
Allergies are up and so is the availability of drugs. This means finding the optimal treatment is every day both more complex and more interesting.
Ocular allergies appear to be on the rise worldwide. Particularly in industrialized nations, environmental pollution is widely considered a major contributor to the heightened sensitivity of allergic individuals. In addition to worsening emissions pollution, studies have also pointed to a global increase in airborne allergens.
"Worldwide epidemiology shows an increasing prevalence of seasonal allergic conjunctivitis over the last few decades, and this increase is evident in studies from a number of countries," said Dominique Bremond-Gignac, MD, PhD, a pediatric ocular allergy specialist in Paris.
England, Wales, Sweden and Australia, for example, have virtually doubled their incidence of seasonal allergic disorders over the past two decades, according to a recent report cited by Dr. Bremond-Gignac.
Specialists agree that different allergens are problematic in different countries. Also, treatment options vary depending on what drugs are available in each market.
Finding common ground
Despite geographic peculiarities, physicians from around the world find common ground in their criteria for choosing an appropriate treatment course. These include efficacy, safety, convenience of dosing and comfort of administration for the patient, according to specialists from several countries.
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Photos courtesy of Osmo Kari, MD, PhD. | |
Universally, the most common types of ocular allergies are seasonal allergic conjunctivitis (SAC) and its chronic, year-round variant, perennial allergic conjunctivitis (PAC). The most commonly heard complaint stemming from these diseases is itchiness, a symptom often accompanied by redness, swollen eyelids and watery or mild mucous discharge.
Doctors agree that, whenever possible, the first course of action is to identify the offending allergen or allergens and then try to diminish the patient’s exposure. When allergen avoidance measures have been exhausted, the next step is to prescribe therapeutic medications based on a careful diagnostic classification of the allergy.
Abhay R. Vasavada, MBBS, AMS, FRCS, who practices at the Raghudeep Eye Clinic in Ahmedabad, India, places special emphasis on educating his patients before prescribing any medication for mild conjunctivitis.
"I put a lot of effort into counseling the patient as well as the relatives to inform them of the harmless persistence of the symptoms and the innocent course of the disease," Dr. Vasavada said.
"Otherwise, the disease could be complicated by injudicious use of the inappropriate eye drops, and thus it would be advisable for them to tolerate the mild discomfort. Most of the patients accept the disease and they do not need treatment," he said.
Experts agree that many symptoms can be alleviated with such steps as applying cold compresses, wearing sunglasses, closing windows during allergy season and using an air conditioner, as well as basic hygienic practices including frequent hand washing and avoiding eye rubbing.
Beyond these prophylactic measures, treating seasonal or perennial conjunctivitis presents a unique global challenge because of the sustained nature of the symptoms. Furthermore, it is important to differentiate allergies from dry eye syndrome. Both pathologies present symptoms such as mild conjunctival irritation and burning.
Another reason allergies and dry eye are often confused is because patients with dry eye are more prone to suffer from ocular allergies. This is because the tear film is an important barrier in preventing allergens from coming into contact with mast cells.
Juan Murube, MD, PhD, who practices in Spain, stressed that doctors must not ignore the possible interrelation between allergic conjunctivitis and dry eye.
"Dry eye frequently produces a sand sensation, while allergic conjunctivitis produces itching. When both coexist, the clinician must think of the possibility either of an interrelation or a coexistence of both conditions," Dr. Murube said.
"In the same way, when an anti-allergic topical treatment, such as Livostin (levocabastine, Novartis Ophthalmics) or Acular (ketorolac tromethamine, Allergan) improves the itching but not the sand sensation, and when very frequent artificial tears application improves both symptoms, it suggests that the allergic conjunctivitis is secondary to the low flow of dry eye," he said.
The latest in treatment options
With an increasing number of patients complaining of a range of allergic symptoms, physicians must be aware of the latest trends in treatment and pharmaceutical applications.
"In chronic ocular allergies, long-term treatment with alternating drug modalities is important in order to avoid conjunctival scarring and loss of normal function," said Osmo Kari, MD, PhD, of the Skin and Allergy Hospital in Helsinki, Finland.
Most doctors interviewed for this article said they prefer to use an agent with mast-cell-stabilizing activity for long-term therapy. Adding an agent with antihistaminic properties will help particularly in reducing itching.
Dr. Kari noted that patients in northern Finland are particularly prone to dry eye syndrome as well, which becomes exacerbated during the winter months when people are mostly indoors. In these cases, when dry eye complicates the situation, Kari said he avoids prescribing antihistamines because they have anticholinergic properties.
"The combination of chronic allergic conjunctivitis and dry eye is quite common in Finland. The increasing dry eye problem is due to common artificial climatization, indoor and outdoor pollutants and to other, unknown reasons," Dr. Kari said.
In recent years, multimodality drugs have surfaced as the newest answer to the growing worldwide need for better and safer allergy therapeutics. Two popular topical products are Zaditor (ketotifen fumarate, Novartis) and Opatanol (olopatadine hydrochloride, Alcon). Both products combine antihistamine action plus mast-cell-stabilizing agents in one prescription eye drop.
In general there is no shortage of pharmaceutical options, as the ocular allergy market continues to grow rapidly.
In Japan, practitioners follow a similar treatment course as in other countries. They are able to choose from six types of mast-cell stabilizers in conjunction with two types of H1-blocker eye drops.
Yet Etsuko Takamura, MD, of the Tokyo Women’s Medical University, believes the country has special characteristics that could make it the object of the drug industry’s attention.
"SAC patients suffer from Japanese cedar pollinosis, and severe atopic keratoconjunctivitis patients increase in Japan year after year. Therefore many pharmaceutical companies and doctors — and of course patients — are interested in seeing new medications developed," Dr. Takamura said.
According to Dr. Takamura, there are approximately 1,200,000 patients suffering from cedar pollinosis in Japan. Out of roughly 50 varieties of pollinosis that affect allergic people in Japan, cedar pollinosis is considered the most pervasive.
Specialists agree that immunotherapy, or allergy shots, is typically reserved for cases that do not respond to allergen avoidance combined with systemic and topical treatments.
A rare form of ocular allergy, vernal keratoconjunctivitis (VKC), is most frequently seen in young males living in the warm climates of the Middle East, the Mediterranean basin, South America and South Africa. Relatively infrequent cases are reported in Europe and the United Kingdom. It is only rarely seen in the United States.
According to a recent survey of doctors from around the word conducted by Dr. Bremond-Gignac, VKC appears to be uncommon in France, but is seen with more frequency in southern Spain and Italy. Apart from Europe, VKC was found to be infrequent in Australia, while in South America, Argentinean doctors report a relatively high incidence of the disease.
Almost every doctor surveyed recommended to save the use of topical steroids for chronic severe cases that are not controlled with other therapies. In Argentina, doctors cited Patanolas an effective drug. Patanol is still not available throughout most of Europe. However, olopatadine has been recently approved in Europe and will become available soon.
Most doctors from countries where VKC is a problem mentioned the benefits of cyclosporine, an immunosuppressive agent proven to be beneficial in the treatment of many inflammatory disorders.
Alejandro Climent, MD, of the Santa Fe Hospital in Mexico City, said VKC is particularly common in the spring and summer months. However, he noted that Mexico City and other large, highly polluted Latin American cities have a high incidence of chronic perennial conjunctivitis as well.
"Symptoms such as itching, red eye, tearing, foreign body sensation and dry eye are very common," Dr. Climent said.
Lourdes Arellanes, MD, director of the Inflammatory Eye Disease Clinic in Mexico City, concurs that ocular allergies there have become so commonplace that they have lost their seasonal quality.
"In Mexico City ocular allergy is not seasonal anymore, maybe because of the severe pollution in our environment," Dr. Arellanes said.
No easy answers
While pollution is considered a critical factor in allergic reactions, so is humidity. Humid tropical countries in the developing world, even those with poor air quality, may actually see less ocular allergy than would be expected because the humidity helps maintain the eye’s natural moisture barrier, thereby protecting it against allergens.
According to Mark Abelson, MD, an ocular allergy specialist, clinical associate professor at Harvard Medical School and senior clinical scientist at Schepens Eye Research Institute, these aspects have yet to be examined in a comprehensive study. Still another consideration is that residents of poorer countries are less likely to even seek treatment for ocular allergies, a factor which may keep the reported incidence of the disease artificially low in these countries.
"In underdeveloped countries, the fact that people’s eyes are itchy or swollen has less significance for their quality of life," Dr. Abelson said.
"In contrast, in more developed countries people are more aware than ever of red, swollen, itchy eyes because of the different ways we use our eyes. All the stresses of modern life are a major component in helping us recognize that we may have allergies, and we are much less tolerant," he said.
For Your Information:
- Dominique Bremond-Gignac, MD, PhD, can be reached at the Hôpital Robert Debre, 48 Bd Serurier, 75019 Paris, France; +(33) 1-40-03-57-63; fax: +(33) 1-40-03-24-32; e-mail: dominique.bremond@rdb.ap-hop-paris.fr. Dr. Bremond-Gignac has no direct financial interest in the products mentioned in this article, nor is she a paid consultant for any company mentioned.
- Abhay R. Vasavada, MBBS, AMS, FRCS, can be reached at the Raghudeep Eye Clinic, Gurukul Road, Near Shreeji Complex, Memnager, Ahmedabad 380052 India; +(91) 79-749-2303; fax: +(91) 79-741-1200; e-mail: shailad1@sancharnet.in. Dr. Vasavada has no direct financial interest in any product mentioned in this article, nor is he a paid consultant for any company mentioned.
- Juan Murube, MD, PhD, can be reached at University of Alcala, Moralzarzal 43 E-28034, Madrid, Spain; +(34) 917-290-055; fax: +(34) 917-340-956; e-mail: murubejuan@terra.es. Dr. Murube has no direct financial interest in any product mentioned in this article, nor is he a paid consultant for any company mentioned.
- Osmo Kari, MD, PhD, can be reached at Nyyrikntie 20 FIN 02100 Espoo, Finland; +(358) 9-467-467; fax: +(358) 9-467-782; e-mail: osmo.kari@optokari.fi. Dr. Kari has no direct financial interest in any product mentioned in this article, nor is he a paid consultant for any company mentioned.
- Etsuko Takamura, MD, can be reached at the department of ophthalmology at Tokyo Women’s Medical University, School of Medicine, 8-1 Kawada-cho, Shinjuku-ku, Tokyo, 162-8666, Japan; e-mail: e-takamura@nifty.com. Ocular Surgery News could not confirm whether Dr. Takamura has a direct financial interest in any of the products mentioned in this article of if she is a paid consultant for any company mentioned.
- Alejandro Climent, MD, can be reached at the Hospital Santa Fe, Torre de Consultorios, Calle de San Luis Potosi 143, Entre Tonala y Japala, Colonia Roma, Codigo Postal 06700, Mexico; +(52) 55-52646303; fax: +(55) 55745108; e-mail: skandara@att.net.mx. Ocular Surgery News could not confirm whether Dr. Climent has a direct financial interest in any of the products mentioned in this article of if he is a paid consultant for any company mentioned.
- Lourdes Arellanes, MD, can be reached at the Inflammatory Eye Disease Clinic, Dr. Luis Sànchez Bulnes Hospital, Asociaciòn Para Evitar la Ceguera en Mèxico, Vicente Garcìa Torres 46, Coyoacàn, Mèxico 04030; +(52) 55-56-58-52-41; fax: +(52) 55-56-59-33-08; e-mail: agml@servidor.unam.mx. Ocular Surgery News could not confirm whether Dr. Arellanes has a direct financial interest in any of the products mentioned in this article of if she is a paid consultant for any company mentioned.
- Mark B. Abelson, MD, can be reached at 138 Haverhill St., North Andover, MA 01845 U.S.A.; +(1) 978-685-8900; fax: +(1) 978-475-0008: e-mail: mbabelson@oraclinical.com. Dr. Abelson consults for the pharmaceutical industry.