Blepharitis is chronic inflammation of the eyelid.
It's more common that you think it is - affecting 5% of those who visit their primary practitioner, and 40% of those who visit their eye doctor.
But what actually causes this condition?
That's the million dollar question doctors and researchers have been investigating for decades.
The short answer is that infections, inflammatory condition of the skin, or gland dysfunction might be to blame.
And what makes Blepharitis complex, is that many of these causes tend to overlap!
Let's take a deeper look at what each of these causes mean:
When infection comes to mind, you might be visualising big, oozing, yellow and swollen wounds.
Interestingly, when an eye is infected in the case of Blepharitis, it can be quite subtle.
Infections around the eye can be caused by bacterial, viral or parasitic.
Bacteria such as staphylococcus aureus, can begin to accumulate along the margins of the eylid over time. As it accumulates, it causes an inflammatory response, as your body is trying to fight the infection.
Unfortunately this type of bacteria can be very stubborn and can be difficult to shrug. Remember when you hear of infections in hospitals that are antibiotic resistant? The Staph bacteria is usually the culprit.
A healthy eye is self-regulating and doesn't require much cleaning. A healthy eye is able to produce tears at a normal rate and also has unblocked glands to help flush out any foreign matter. Yet in a bacterial infection, the eye's natural cleaning mechanisms become disrupted.
Bacteria, like all living things, leave behind waste (exotoxins). These exotoxins further disrupt the eye's natural cleaning mechanisms. The bacteria produces a biofilm, or shield which can make it more resistant to treatment. This biofilm can form along the tear film which can cause the eyelid (Meibomian) glands to become blocked.
These adorable little things are called Demodex mites.
They inhabit the base of the eyelashes and glands.
Demodex mites feed on the cells and often plug up the glands which make fighting them so difficult.
Like a bacterial infection, these mites also lay waste around the eyelid.
In case that wasn't horrifying enough - Demodex mites are relatives of ticks, spiders and scorpions.
2) Inflammatory Conditions Of The Skin
Seborrheic Dermatitis (Dandruff), Rosacea (Acne) and Psoarsis (Rashes) are chronic skin conditions that can cause blepharitis.
Seborrheic Dermatitis - As a result of this skin condition, the eyelid margins can shed dandruff-like flakes. This causes inflammation which can further block the glands and disrupt the tear film.
Rosacea - This inflammatory condition causes eyelid margins to become red and inflammed. Over a long period of time, abnormal blood vessels may start to grow into the cornea (clear part of the eye). (https://www.eyemackay.com.au/blepharitis-and-rosacea.html)
Psoarsis - As with other skin conditions, psoarsis impacts the body's normal functioning and immune response. This can cause the eye to produce too much or too little oil, causing the eye to be itchy and irritated.
3) Gland Dysfunction
The Meibonian Glands are located on the inner eyelid, they are essential for a healthy eye.
Each eyelid contains a row of these glands. They have a very important role in forming tears. The Meibonian Gland is responsible for producing the oily part of the tear film.
When these glands become blocked, or if the secretions become thick, they are not able to lubricate or moisturise the eye well. This can cause dry eyes, blurriness and inflammation.
With all these causes, it's easy to see the complexity of Blepharitis. The fact is, it's common for many of these causes to overlap - sometimes an inflammtory skin condition can lead to a bacterial infection and vice/versa.
Regardless of your cause of Blepharitis, the one consistent theme is to ensure you are maintaining proper lid hygiene.