Preservatives were popular in the 1950s as an addition to ophthalmic products to prevent bacterial contamination.
Decades later, reports showed the damage the preservatives can cause to the cornea, the conjunctiva and tear film.
Single dose units seemed to be the most effective answer in the short term to avoid irritation and inflammation. The expense and environmental impact made them less from ideal. Since then, a company named THEA has developed a special system for a first multi- dose bottle dispensing preservative-free eye drops, now available.
What are preservatives?
Preservatives, or antimicrobial agents, are used to prevent or reduce bacterial contamination after a product has been opened. The chemicals used are made from various formulations, the most common being benzalkonium chloride(BAK)
Why are preservatives bad for my eyes?
Studies show preservatives in eye care products can be harmful to the surface of the eye, especially when used over a long period of time. It can damage the tear film layer, superficial structures and deeper parts of the eye.
Symptoms can range from mild discomfort to severe dry eye syndrome. So they can actually exacerbate the condition they are trying to treat and relieve.
Possible causes of dry eyes
Environmental – centrally heated, air conditioned offices and planes: long periods on a computer or driving, as you blink less often: general health – arthritis sufferers are more prone to dry eye. Blepharitis is an inflammation of eyelids: hormonal imbalances, especially menopausal women: medication, including treatment for acne, oral contraceptives, antihistamines, diuretics, decongestants, alcohol, anti-depressants.
NOTE: do not alter your prescribed dose without consulting your doctor.
For some, it’s simply part of the ageing process and a change in the tear chemistry.
Various products are aimed to help dry eye sufferers, but many have preservatives in them. The key is to ensure the product you use is preservative free. Most independent opticians will stock suitable preservative free products.
In all cases, the cause must be carefully determined to find the best way to manage the problem by consulting with your optician.