Allergic reactions on the conjunctiva of the eyes can make the eyes red and uncomfortable. The hallmark of allergic conjunctivitis is ITCH. There are different types of allergic conjunctivitis: Seasonal Allergic Conjunctivitis (SAC) is a heightened sensitivity to pollens and occurs during the summer months. Perennial Allergic Conjunctivitis (PAC) is an identical reaction but the triggers, such as dust, are present all year round. More serious allergies, associated with asthma and eczema, also occur and are much more problematic(see facing page). Chronic irritation due to suture, artificial eyes and some contact lenses can also induce inflammatory responses identical to allergic reactions. If possible, these should be removed by trying to remove the trigger, but if not possible, anti-allergy medications can also be used. Sometimes these can also cause mechanical or toxic damage in which case the primary symptom would be grittiness rather than itch.
Histamine, a chemical promoting inflammation, is released by mast cells as a response to an irritation or injury. Mast cells are situated throughout the body but the conjunctiva of the eyes is extremely rich in them. A side effect of histamine can be to make the eyes itch. Management of allergies can be to simply block histamine already released, or try to stop mast cells releasing the chemical at all. As ‘Medical’ Optometrists we can treat with ‘prescription only medicines’ for more severe conditions
Prolonged irritation make the eyes look red and inflamed as well as feeling irritable or itchy, typically experienced after too much swimming, sunbathing or computer use. Decongestants (eye whiteners) and pure anti-histamines can be beneficial in these circumstances. However these are meant for occasional use only. Symptoms of more serious problems such as foreign bodies, abrasion or dry eye, can be masked by these cosmetic treatments. Also, overuse can result in rebound redness, (the eyes become redder than previously), so the drops are not for prolonged use and must never be instilled more than 3 times per day. Ortivine Antistin is an over the counter decongestant/anti-histamine. These drops give prompt relief of the symptoms so are good for occasional use.
As Medical Optometrists we tend to prefer other medications. Otrivine Antistin carries slightly higher risk when used by people with high blood pressure, history of stroke, heart disorders or hyperthyroidism. Other measures, when the symptoms are mild, including simple cold compresses and astringent eye baths (Vizulize), can help make the eyes more comfortable during peak episodes of discomfort.
Rather than simply blocking the action of histamine, mast cell stabilisers actually prevent mast cells from degranulating in the first place and so are far more effective in controlling long term chronic inflammation due to hay fever and allergies. These medications do not give immediate relief however, since they do not block the action of histamine already in the system. Ideally, medication should start prior to the onset of symptoms and be used throughout the susceptible period, summer months for SAC, but all year round for PAC.
The main stay of treatment for many years has been Sodium Cromoglycate as used in Opticrom. Newer products, Alomide, containing Lodoximide and Rapitilare also available.
Newer combination drops are now available and give both prompt symptomatic relief and long term control of allergic conjunctivitis. Optilast (Azelastine), Zaditen (Ketotifen) and Opatanol (Olopatadine) are all combination medications.
The drug of choice for us is Opatanol. Unfortunately this is a prescription only drug so can not be bought over the counter. However, as INDEPENDENTPRESCRIBING Optometrists, we can prescribe this medication and always have it available in our Dispensary. Unfortunately there is still no NHS funding stream for Medical Optometrists so we are forced to charge the standard private prescription fee but we can also prescribe via your GP.
For very severe inflammatory responses, or if very prompt treatment is necessary, mild steroids as well as other prescription only drugs can be prescribed. This is only possible because we are Medical Optometrists with the advanced training to treat, rather than simply refer, more significant allergic and inflammatory responses. Again the drugs, while never on display, can be supplied immediately from our dispensary or we can prescribe via your GP if necessary.
