Snippets on... Ophthalmology
Dr Amar Alwitry outlines the presentation and
GP management of blepharitis
What's going on?
There is a problem with the lid margin, usually caused by a collection of dandruff-like skin flakes around the bases of the lashes. This is often associated with some inflammation and low-grade infective colonisation with bacterial organisms (usually staphylococci). This inflammation results in irritation of the ocular surface with consequent dryness, burning and foreign-body sensation.
Bacteria may release exotoxins, which can cause an immune-mediated peripheral corneal ulcer.
There is another form of blepharitis,
often called posterior blepharitis, where
the meibomian glands are dysfunctional. About 20 lipid-secreting glands line the upper and lower lids. These secrete fat on to the ocular surface to coat the tear film and prevent evaporation. These fatty secretions can stagnate and block the meibomian gland orifices.
They are seen as a line of small domes of yellowish material overlying each meibomian gland pore. This form of blepharitis (meibomian gland dysfunction) is often associated with cutaneous rosacea.
If I examine the patient, what will I find?
The lid margins will be red, with some flaky material around the bases of the lashes. The orifices of the meibomian glands may have an overlying cap of fat.
What if I have diagnosed it?
The mainstay of therapy is lubricant drops, to minimise ocular irritation, and lid hygiene. The lid margins should be cleaned daily.
• First the lids should be warmed with a hot flannel to loosen any flakes and liquefy the meibomian gland secretions.
• An eggcup of water should be boiled and allowed to cool, and a drop of specialised non-irritant baby shampoo (to avoid stinging) should be added.
• The upper and lower lid margins at the lash bases should be cleaned with a cotton bud moistened with the water.
What will the hospital do?
The patient should be given a leaflet on lid hygiene. If they show any evidence of rosacea or have eyes with significant meibomian gland dysfunction, they may benefit from a course of oral oxytetracycline or doxycycline.
These drugs work by their anticollagenase activity rather than their antibiotic properties, and thus a minimum of a six-week course is usually required.
What do I need to do?
Patients should have been advised about the importance of regular lid hygiene, and the need for compliance should be emphasised.
What to tell the patient
This is likely to be a chronic condition. Topical lubricant drops will alleviate symptoms to some degree, but the pathology will only be resolved by regular lid hygiene.
What problems may arise, and how do I deal with them?
Blepharitis can cause an ulcer on the cornea through the release of exotoxins. This will present as a red eye with a fluorescein staining area on the peripheral cornea, typically at the five o'clock or seven o'clock positions.
Amar Alwitry is a specialist registrar in ophthalmology in Nottingham – he is vice-chair of the ophthalmic trainees group with a seat on the Royal College of Ophthalmologists training committee
This is an extract from Ophthalmology in Primary Care by Dr Alwitry, published by the RCGP,
priced £24.95 – to order a copy, go to www.rcgp.org.uk/acatalog