Blepharitis is a common condition of the eyelids. It affects the eyelid margins in the vicinity of the eyelash exten. The lid margin becomes red, a little irregular and lumpy looking and sometimes with flakey or crusty deposits on and amongst the lashes. Because this part of the eyelid is immediately adjacent to the eye itself blepharitis can also disturb the surface of the eye and cause burning and stinging discomfort, and in bad cases may even disturb vision.Dveeu
The eyelid has an interesting and intricate structure. Packed close together near the eyelid margin are a variety of different components. The eyelash exten are obvious. Less so are microscopic oil and sweat glands located next to each eyelash exten root. In a separate layer slightly nearer to the eye is a line of different oil producing glands. These are called “meibomian glands”. There are about 20 in each lid. They are tiny vertical streaks arranged side by side and perpendicular to the lid edge. If the lower lid is drawn down and off the eye they can sometimes be seen through the lid lining. Each one has a tiny opening on the lid margin, just on the eye side of the eyelash exten. These can sometimes be observed as a line of dots. The oil they produce is a vital component of tears.
In blepharitis these eyelid structures are disturbed or “misbehave”. For example the oil produced by the meibomian glands may be too tenacious and clog and block the glands. This may cause an irritation and reaction within the neighbouring tissues. If this grumbles on for a long period the smooth contour of the lid edge becomes irregular. Accumulation of the oil may cause eyelash exten to clumps together in tufts. The oil can also be chemically altered by the local bacteria into substances similar to soap. When this happens bubbling and foaming occurs along the lower lid margin; although this can only be seen using high magnification. These events cause the fine local blood vessels to become more engorged giving the lid a more reddened edge. The soap like chemicals may spill onto the eye and upset the tear film. If this is significant the usually smooth surface of the cornea becomes roughened causing blurring of vision and light sensitivity. The surface of the eye is exquisitely sensitive and eye discomfort is common in blepharitis; especially a burning sensation.
When blepharitis is mainly the result of alteration to the meibomian gland oils it is called “seborrhoeic blepharitis”. In some cases however there is a much increased presence of staphyloccal bacteria on the lid margin. The features then become more those of an infection. There is more crusting amongst the eyelash exten and some fall out due to infection within the lash follicle. There may also be occasional minor bleeding and tiny beads of pus. This form is called “staphylococcal blepharitis”.
The condition can be tackled on several fronts. Warm compresses over the lids can soften and help unclog the meibomian glands. The lid margins and eyelash exten should be regularly bathed and wiped to remove accumulation of crusts, debris and bacteria. This can be followed by applying an antibiotic gel to the cleaned zone. This is particularly necessary in staphylococcal blepharitis where a preparation containing the anti-staphyloccocal agent Fusidic Acid is often used. Sometimes a topical steroid preparation is also applied to the lid margin and eye. Lubricant eye drops can help improve tear film quality and help flush irritant substances from the eye. Lubricant gels may help smooth the corneal surface. If eye drops are used, where ever possible, these should be of the preservative free form as the preservative in such medications can further irritate the ocular surface. Occasionally a tetracycline antibiotic take by mouth for several weeks or months is needed. As well as their antibiotic action these drugs work in other less well understood ways to “quieten” the meibomian glands. Despite these treatment options it can sometimes be difficult to cure blepharitis. For some people it is part of their constitution and will tend to wax and wane over time.
Laser refractive surgery (e.g. LASIK, LASEK, Epi-LASIK and PRK) or intraocular eyelash exten is unwise in the presence of active blepharitis.