What is Blepharitis?
Blepharitis is a chronic inflammatory condition of the eyelids, eyelid margins and ocular surface. There are currently no approved treatments for the condition, which is one of the most common reasons for a patient to consult an ophthalmologist. Blepharitis affects more than 10 million people visiting an ophthalmology clinic in the United States and a similar number is estimated for Europe.
Blepharitis often results in an unsightly redness and crusting of the eyelid margins, which troubles patients. It is also uncomfortable, with a broad spectrum of ocular symptoms ranging from mild transient irritation to persistent burning, itching, pain, contact lens intolerance, photophobia, ocular fatigue and visual disturbance. Symptoms are usually worse in the mornings and patients often have multiple exacerbations.
In the most severe cases, ulceration and perforation of the cornea may occur. Though not normally sight-threatening, blepharitis represents a considerable healthcare burden, both to patients and the practitioners charged with their management.
The high prevalence is a significant factor – it is one of the most common presentations in a general ophthalmology clinic. In two surveys, conducted in 2009 and 2019, ophthalmologists reported that 37%1 and 31%2 of their patients respectively, suffered with blepharitis.
The disease is also problematic because there are currently no approved pharmacological treatments, neither in Europe nor the US. In the absence of a recognised standard of care, ‘off-label’ topical antibiotics and topical corticosteroids are the most widely prescribed options.
‘Off-label’ topical antibiotics are most commonly prescribed. However, the role of bacteria in the aetiology of the disease is poorly understood and the clinical evidence supporting this approach is underwhelming.
Excessive use of topical antibiotics is known to be a key driver of antimicrobial resistance (AMR) and there is evidence that the topical use of ocular antibiotics can induce bacterial resistance at extraocular sites3. The threat posed to public health by the growing emergence of AMR is well publicised and has resulted in the widespread adoption of antimicrobial stewardship programmes. In the absence of a clearly defined clinical benefit, the widespread use of prolonged courses of topical antibiotics to treat blepharitis contradicts these principles and may be contributing to the problem of increasing antimicrobial resistance.
Although the use of topical ocular corticosteroids in such a chronic condition is a concern to many ophthalmologists, after topical antibiotics, this is the most commonly employed treatment modality. Only short courses are permissible, since prolonged dosing exposes patients to well-documented and sight-threatening sides effects, namely, raised intra-ocular pressure, cataracts and opportunistic infections. Surprisingly, there is little published evidence to definitively demonstrate the clinical benefit of topical corticosteroids, even in the acute management of signs and symptoms, and they are contra-indicated for long-term treatment. However, it is very likely that some patients are being exposed to the risk of potentially serious side-effects, through inappropriately prolonged use, without compelling evidence of clinical benefit.
Surprisingly, and in stark contrast to dry eye, blepharitis continues to be largely overlooked by the pharmaceutical industry and there continues to be little ongoing, late-stage clinical research.