What is dry eye?
Dry eye disease is now recognized to be a complex multifactorial disorder. Our tear film ages as we do and becomes less efficient at providing comfort and good vision. As well as good tear production, healthy wetting of the eye also relies on good lid positioning and a healthy tear composition. Treatment strategies may therefore address a number of potential problems.
What are the symptoms?
Patients with dry eye syndrome typically complain of "gritty eyes" or a feeling of sand. This may be associated with watering which is technically called "paradoxical epiphora". The paradox is that dry eyes often water! The reason for this is that dry eye disease is due to tears not functioning, i.e. lubricating adequately and this can be due to poor quality tears even is the quantity is OK. In such circumstances, the failure to lubricate stimulates more tears to be produced and eventually there is over-flow and watering.
What is the treatment?
Good treatment is a complex matter but includes lubricating drops, gels and ointments; specific dry eye drugs; punctal plugs and surgery. Sometimes changing the drugs you already take or adding a new tablet can resolve the issue. Exactly what is right for you can only be ascertained at a consultation and it is helpful if you can bring a list of anything you have tried previously even if it was ineffective. As with all medical treatments, the aim is to reduce or abolish the symptoms with the minimum number of drugs and maximum safety. Sometimes, underlying conditions (such as poor lid positioning or excessive skin “conjunctivochalasis” can contribute to a dry eye state and investigations and treatment can often help.
The first line of treatment is to make sure that the environment of the tear film is optimal. This may include treatment of blepharitis or correction of any lid or lash abnormality.
The second line is address the tear film. Commonly there is a combination of "evaporative dry eye" due to lid margin disease or blepharitis and "aqueous deficiency dry eye" due to a reduction tear production. The health of the lid margin and its meibomian (oil) glands needs to be assessed at a consultation, and if necessary treated (already described in the “blepharitis” section). One then looks at tear film substitutes or artificial tears. If they contain preservatives, they should be stopped and replaced with preservative-free drops. If evaporative dry eye predominates then a lipid-containing drop may be helpful but the main problem with lubricant eye drops is their short duration of action, often not more than 2 hours. Since repeated administration is bothersome, the use of an eye gels may be better or punctal plugs which reduce drainage of tears from the eye and allow the lubricants to be retained for longer. Punctal plugs can be fitted in the clinic and is a very low-risk procedure although occasionally eyes water after they are fitted.
If symptoms are particularly bad on waking, this can be due to nocturnal exposure and the fact that we make few tears when we are asleep. This can be relieved by the use of a lubricating ointment used just before sleep. Unfortunately a true ointment does blur vision to some extent and is often poorly tolerated during the day.
Patients with severe dry eye syndrome may benefit from drugs to stimulate secretion of tears or a short course of anti-inflammatory eye drops.
Although having dry eye disease can be troublesome, there is good treatment available which if individualised, can make a very big difference to symptoms.