Allergic Conjunctivitis
There are four major eye problems commonly seen by allergists:
- 1Seasonal allergic conjunctivitis
- 2Vernal keratoconjunctivitis
- 3Giant papillary conjunctivitis
- 4Atopic conjunctivitis
Seasonal Allergic Conjunctivitis
Seasonal allergic conjunctivitis is the most common eye allergy. Symptoms of this condition can last from six months to several years. Intermittent episodes can evolve into constant symptoms. The clinical findings of seasonal allergic conjunctivitis are:
- Itchy, watery and slightly red eyes with the whites of the eyes showing mild or moderate swelling and redness.
- Nasal Symptoms typical of allergic rhinitis.
- “Allergic shiners” (swollen, pigmented eyelids)
Vernal Conjunctivitis
- Vernal conjunctivitis occurs mainly in teenagers.
- Males are affected more often than females by a ratio of two to one.
- Most patients have symptoms from early May to December in temperate climates. This condition is more common in warmer climates.
- Vernal conjunctivitis has the following clinical symptoms: extreme itching, stringy or rope-like mucous discharge (patients often rub their eyes vigorously). Giant bumps, greater than 1 mm wide each, called papillae, are found on the inside of the upper eyelid.
- Treatment is often with topical steroids (check with your eye doctor to guard against onset of glaucoma, due to overuse), antihistamines, cromolyn and vasoconstrictors.
Giant Papillary Conjunctivitis (GPC)
- Giant Papillary Conjunctivitis is a condition that occurs in people who wear contact lenses or eye prostheses. It can appear after eye surgery.
- The clinical findings in GPC are: itching; decreased tolerance of contact lenses and blurred vision; also giant bumps, greater than 1 mm. wide, on the inner surface of the upper eyelid.
- The condition differs from vernal conjunctivitis in that histamine levels in tears are not elevated.
- It is similar to vernal conjunctivitis in that eosinophil or allergy cell infiltration is usually observed in both conditions.
Atopic Conjunctivitis
- Atopic conjunctivitis is commonly present in persons with atopic dermatitis or eczema. The skin around the eyes can have eczematous features i.e. oozing, roughened skin.
- This condition usually involves the lower lid and shows redness and fine bumps or papillae in the conjunctiva.
- If severe, the cornea can become involved and scarring can lead to blindness.
The Role of Mast Cells in Eye Allergy
The tissues around the human eye contain an estimated 50 million mast cells. Mast cells contain histamine and other mediators that produce the allergic reaction. They serve as sentinel cells to protect or react against invasion from the external environment. Mast cells and circulating basophils are the only cells in the body that contain histamine, which is the major cause of the itching that occurs in all types of allergic conjunctivitis. Choroid body (one of the parts of the eye) has one of the highest densities of mast cells of any tissue of the body. Each mast cell can release chemical substances such as prostaglandins, thromboxanes and leukotrienes which all contribute to the allergic response. Mast cells are also located in the nose, bronchial tubes, gastrointestinal tract, skin, and around blood vessels.
The Role of Eosinophils in Eye Allergy
- Eosinophils are white blood cells that play an important role in allergy.
- Tissue damage associated with allergic disease may be the result of eosinophilic mediators or chemical substances released by eosinophils.
Treatment for Eye Allergy
There are many options for treatment, we will find the best one suited for you.