Douglas K. Devries, OD, outlines the common risk factors associated with Demodex blepharitis.
Douglas K. Devries, OD: The risk factors are interesting. Hygiene isn’t a part of it. That’s the most difficult part, when you tell a patient that they have these mites and it isn’t a hygiene issue. It’s their physiology. The risk factors are those fair-skinned individuals who have an increase in biofilm. We’re starting to clean that biofilm off. They have an increase in biofilm, which gives the food source. The patients with rosacea are No. 1. If they have facial rosacea or telangiectasias on the eyelid, then it’s worth further investigating to find out if they have Demodex and at what point it proliferates to the point of becoming symptomatic.
The prevalence increases with age, but Demodex blepharitis needs to be screened at all ages. We need to take a look because that physiologic environment can be set up in anyone that will allow the proliferation of Demodex blepharitis. The screening technique is just a simple modification of what we do in our slit lamp examination. You want to look at the base of the lashes. You want to look for collarettes, that volcano sign on the lashes. Because you’ll sometimes miss that when you’re looking directly on, the easiest way to do that is to have the patient look down and then to look at the base of the lashes. We’re looking for collarettes, which are debris from the Demodex. Rarely will you see a Demodex itself, but you’ll see the remnants. You’ll see these collarettes. You’ll see this volcano form around the base of the lashes.
The limitations are just not doing it. It’s quite easy to screen patients. Do you need to epilay the lash? Do you need to use a microscope? No. The studies have been very conclusive that when there are collarettes, there’s the presence of Demodex, so you don’t need to take that next step. We have all the equipment we need in our examination rooms right now. The limitation is just not executing and taking that extra few seconds in the slit lamp examination to identify if that patient has the presence or proliferation of Demodex.
Transcript edited for clarity.