Ocular Allergies

Eye allergies are very common. They also present in many forms and stem from many causes. The American College of Allergy, Asthma and Immunology estimates that 50 million people in the United States have seasonal allergies, which is just one form of allergy that can affect the eyes, causing them to itch, appear red, swell, and water.

But seasonal allergens, like pollen, aren’t the only form of allergies that can affect the eyes. Perennial allergens such as pet dander and mold can cause identical symptoms.

Beyond seasonal allergic conjunctivitis (SAC) and perennial allergic conjunctivitis (PAC), less common, yet more severe, forms of ocular allergies include atopic keratoconjunctivitis (AKC), giant papillary conjunctivitis (GPC), and vernal keratoconjunctivitis (VKC). AKC occurs when the immune system produces higher than normal antibodies in response to an allergen. GPC isn’t an allergy in the truest sense since it is primarily an inflammatory condition caused by repetitive mechanical irritation versus a strictly conventional allergen. GPC is also unique because it typically is characterized by large bumps that form under the eyelid. VKC appears much like a cross between SAC and GPC because it is caused by seasonal allergens, but the effects are more severe and it also presents with lumps on the underside of the eyelid.

What Causes Allergies?

Like all allergies, those that affect the eye are the manifestation of an immune system overreaction to a foreign substance. What causes a reaction in one person may have no effect whatsoever on another. If you are fortunate enough to not suffer from any allergies, contact with pollen and other allergens will produce virtually no symptoms. However, if you do have allergies, your body will produce histamine and other chemical mediators that set into motion an allergic cascade that produces symptoms like itching, redness and discomfort.

Common culprits are airborne allergens like pollen, mold, dust and pet dander, but chemicals like those found in eye makeup and some eye drops can also cause eye allergies. Mechanical interaction with the eyelid can cause GPC, which is also influenced by proteins and lipids that get attached to contact lenses that aren’t properly cleaned.

How Are Ocular Allergies Diagnosed?

Optometrists and ophthalmologists see eye allergies every day. Telltale signs include redness, itching, swelling, tearing, and foreign body sensation. In some cases, and more commonly with GPC, mucus discharge may be increased.1,2

A careful clinical exam and history will help your doctor uncover the cause.

Ocular Allergy Treatments

There is a long list of ways to approach ocular allergies. While, perhaps, the most unrealistic method, the most basic yet effective way to manage allergies is to avoid exposure in the first place. If you’re allergic to cats, stay out of the pet store. But, of course, not all allergens can be so easily dodged. Dust and pollen are all around us. Still, it is helpful to clean the air filters in HVAC units and and close the windows on high pollen count days.

Prescription and over-the counter eye drops can also be used to treat ocular allergy symptoms. Many of these can help relieve itchiness, redness and other responses to allergies. Steroid and NSAID eye drops can also help control inflammatory responses to allergies, offering more rapid relief than can typically be achieved using an over-the-counter eye drop.

Oral medications can also help patients overcome the effects of allergies. For example, a decongestant can help shrink swollen vessels, while mast cell stabilizers can help prevent histamine release.

Finally, if your allergies are severe or significantly impact your daily life, an allergist may recommend immunotherapy, which involves injections with small amounts of allergens to help patients gradually build up immunity.

Allergies and Contact Lens Wear

Wearing soft and small diameter rigid contact lenses when you’re suffering from ocular allergies can be especially uncomfortable. In some cases, if your prescription or corneal shape doesn’t limit your lens selection, a daily disposable contact lens may be worn. Since you throw these lenses away each night, you’ll likely have reduced lens deposits.

Another option that offers outstanding optics and are available in even the most complex designs are gas permeable (GP) lenses, which are typically more resistant to deposits.3 Additionally, because soft contact lens-associated GPC is more common than GPC stemming from GP lens wear, changing to a GP material can help eliminate GPC.4

Scleral Lenses for Ocular Allergies

Scleral lenses, in particular, can be very helpful in managing ocular allergies because they can create a barrier against pollen, allergens and the lids.

A scleral lens is a type of GP lens featuring a large-diameter that allows the lens to rest on the white part of the eye, known as the sclera. Unlike traditional, small diameter GP lenses that rest on the highly innervated and sensitive cornea, the scleral lens vaults over the cornea and is much more comfortable than its smaller diameter counterpart.  

For patients who have allergy sensitivities, a scleral lens can shield much of the cornea from allergens. Also, if a patient has papillae under the eyelids, scleral lenses may help protect the cornea. Another feature that adds to comfort with a scleral lens is the liquid buffer that exists between the back of the lens and the front of the eye. Liquid fills this space and can help protect your corneal tissue.

Indeed, scleral lenses have been shown to improve vision and help to maintain the health of the ocular surface even in patients with VKC.5 They also have been shown to be useful and safe to use in the management of the ocular surface and in the visual rehabilitation of eyes with medically controlled advanced AKC.6

If you suffer from allergies, contact your doctor for information about new treatments that can help you see and feel your best.

 


[1] Forister JF, Forister EF, Yeung KK, et al. Prevalence of contact lens-related complications: UCLA contact lens study. Eye Contact Lens. Jul 2009;35(4):176-80. 

[2] Abelson MB, Torkildsen G, Plumer A, et al. Giant Papillary Conjunctivitis; The dangers and treatment measures involved with “GPC.” RCCL. 2005;Nov;141(8):7. 

[3] Bielory BP, O’Brien TP, Bielory L. Management of seasonal allergic conjunctivitis: guide to therapy. Acta Ophthalmol.

[4] Donshik PC. Giant papillary conjunctivitis. Trans Am Ophthalmol Soc. 1994;92:687-744.  

[5] Rathi VM, et al. Fluid-filled scleral contact lenses in vernal keratoconjunctivitis. Eye Contact Lens. 2012 May;38(3):203-6.

[6] Margolis R, Thakrar V, Perez VL. Role of rigid gas-permeable scleral contact lenses in the management of advanced atopic keratoconjunctivitis. Cornea. 2007 Oct;26(9):1032-4.