Abstract
Purpose :
Eyelash base collarettes are the pathognomonic sign of Demodex Blepharitis (DB). However, mites may still be present deeper in the eyelash follicles out of sight, leading to failure to diagnose DB. Demodex mites living on the face may provide a clue as to the presence of Demodex in the eyelids of symptomatic blepharitis patients, even in the absence of eyelash collarettes.
Dermal collarettes are rapidly and easily visualized through the slit lamp oculars with the side arm at a 45 degree angle--highlighting the elevated projections of the nasal bridge skin such as fine vellus hairs and the courser, thicker dermal collarettes (figure 1), giving an alpenglow effect. A retrospective chart review was performed to determine if the Alpenglow Sign is predictive of the presence of Demodex mites on microscopic examination of epilated eyelashes.
Methods :
A single-center, single-physician retrospective chart review was performed by searching the electronic medical record (EMR) database for the procedure code 87177, microscopic examination of eyelashes. A total of 119 charts were identified and analyzed for the period 1/1/23 to 8/1/23. Data collected included: eyelid hygiene, examination findings of collarettes, telangiectasias, severity of meibomian gland dysfunction (MGD), presence or absence of the Alpenglow Sign and the presence or absence of Demodex mites on microscopic examination were entered into a Microsoft Excel spreadsheet for statistical analysis.
Results :
Of the 119 charts identified, the Alpenglow Sign was positive in 69 (58%), negative in 13 (10.9%) non-recorded for 37 (31.1%) patients. Microscopic examination for Demodex mites was positive for 81 patients (68.1%), negative for 24 (20.2%) and incomplete data for 14 (11.7%) of patients.
The overall positive predictive value (PPV) of a positive Alpenglow Sign to the microscopic presence of demodex mites on epilated eyelashes was 78% with a sensitivity of 87%.
Conclusions :
The presence of collarettes on the eyelashes are the pathognomonic sign for DB. However, the absence of collarettes does not mean that Demodex is not present in symptomatic patients.
While prospective studies are needed, the Alpenglow Sign is a novel, rapid, clinical point of care examination finding that can assist clinicians in the accurate identification and treatment of DB patients.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.