Many thanks for your interest in our article. Our aim in producing a ‘10-Minute Consultation’ piece was to provide the generalist with a broad overview of a common and troublesome condition. By definition, the ‘10-Minute Consultation’ should be brief, so we did not set out to provide a comprehensive review of the subject complete with ongoing controversies regarding pathophysiology and treatment. Rather than simply stating that blepharitis is a chronic condition, as you suggest, we gave tips for making the diagnosis, highlighted pitfalls in terms of the differential diagnosis and suggested a treatment regime.
As you correctly point out, the hospital eye service is increasingly oversubscribed and it would be unsustainable for all blepharitis patients to be referred. Consequently, we explained that most patients with blepharitis can be managed conservatively in the community, but in cases of poor response or doubts in the diagnosis, a secondary referral is appropriate.
With regards to Demodex folliculorum, there is debate as to its role in blepharitis. Demodex is an extremely common commensal, which ordinarily does not elicit any pathological response. A recent meta-analysis demonstrated a significant association between Demodex and blepharitis (1), but it should also be pointed out that similar, high prevalences of Demodex infestation have been found in both patients with blepharitis (28.8%) and normal control subjects (26.7%) (2). The general consensus is that in cases of blepharitis where robust attempts at conventional treatment fail, investigation for demodecosis may be appropriate. These patients fall into the category which is appropriate for secondary ophthalmic referral. We would not advocate that human patients should consult a vet.
Clearly, we realise there are controversies and questions which have not yet been answered. Many comprehensive papers exist in the scientific literature to address these issues, including an excellent Cochrane review published earlier this year (3). Further work will hopefully elucidate ways in which blepharitis can be cured instead of just controlled.
Dr Andrew Turnbull
Dr Martin Mayfield
1) Zhao YE, Wu LP, Hu L, Xu JR. Association of blepharitis with Demodex: a meta-analysis. Ophthalmic Epidemiol. 2012 Apr;19(2):95-102. Epub 2012 Feb 24.
2) Kemal M, Sümer Z, Toker MI, et al. The prevalence of Demodex folliculorum in blepharitis patients and the normal population. Ophthalmic Epidemiol. 2005 Aug;12(4):287-90.
3) Lindsley K, Matsumura S, Hatef E, Akpek EK. Interventions for chronic blepharitis. Cochrane Database Syst Rev. 2012 May 16;5:CD005556
Competing interests: No competing interests