sion appears clear to mildly opaque, few particles, low viscosity. The cornea was clear in both eyes. There was mild bulbar conjunctival injection and a diffuse amount of CD present in both eyes. The lids appeared to be mildly greasy, with a mild amount of distention at the base of the lashes. Epilation of two lashes from each upper lid reveals Demodex present. On one follicle, the microscope at 10× showed D. brevis (Fig. 4).
Patient 2 Discussion
Of the two species in humans, D. brevis is not commonly seen in the general population. Demodex brevis normally resides singly in the sebaceous and meibomian glands.14 Because the mite is not usually found on the lash follicles, detection after epilation is rare.3 Gao et al.24 reported that five of 422 epilated specimens were D. brevis. According to Tseng, the prevalence of D. brevis is 9.1%.14 From an eye care practitioner’s point of view, D. brevis may be rarely seen and may require more lashes to be epilated.19 But, in the big picture outside the lids, D. brevis does inhabit a larger area of the human body compared with D. folliculorum.26
In 1963, Akbulatova first identified D. brevis.3,22 Demodex brevis is typically smaller than D. folliculorum and has a spindle shape and stubby legs.3 Demodex brevis presence is much higher in patients who developed corneal lesions, such as peripheral and nodular scarring, vascularization, and central opacities.3,14 Because D. brevis primarily resides in meibomian glands, the inflammation has greater proximity and might more easily reach the conjunctiva and the cornea.19 In this case, the patient did not have any corneal abnormalities.
A 40-year-old white woman presented with a history of allergies and dry eyes. There was MGD present (opaque or many particles with medium viscosity) in both eyes and inferior nasal and temporal lissamine green staining in the right eye. The right eye also had grade 1 corneal infiltration in the peripheral cornea. Closer examination of the lids revealed CD (diffuse amount; greater than 10 pieces per eye) in both eyes and the appearance of D. folliculorum tails (Fig. 5).
Patient 3 Discussion
Demodex avoids light, and it is unusual to see the mites under a biomicroscope.11 Demodex mites position themselves with their heads upside down in the deeper parts of the follicle. The elongated bodies protrude with their tails (opisthosoma) from the follicle in groups of three to five mites.34,35 Infrequently, the tails can be seen under the bright illumination of a biomicroscope. The tails have been described as cream-colored tails protruding from the lid margin like fine bristles.11,22 Because of their photosensitivity, most of the mating and movement of the mite are believed to occur at night. Mating plays an important role in perpetuating Demodex infestation because of the limited life span of 1 to 2 weeks for the adults.1,12 Females are territorial; they remain in their respective follicles and wait for the nomadic males that travel over the surface of the skin from one follicle to another in search of females. After copulation, the female burrows back into the follicle near the opening of the pilosebaceous gland and lays her eggs.35 Larva and protonymph develop in the sebaceous gland. They are brought to the opening of follicle and mature into deutonymph. Deutonymph crawls onto skin surface and reenters a hair follicle to become an adult.3 All of this movement likely happens in the dark.
A 60-year-old white woman with a history of rosacea came in with complaints of eyelid swelling, redness, and loss of lashes. She is currently using oral antihistamines for a history of allergy. In the past 3 years, she was prescribed topical antihistamines and a combination of steroid and antibiotic for eyelid inflammation, with no success. Meibomian gland dysfunction was grade 2+ OU and conjunctival redness grade 1+ OU. Mites were present on epilated lashes under the microscope.
Patient 4 Discussion
In 1930, Ayers called attention to D. folliculorum as a causative agent of Pityriasis folliculorum and one type of acne rosacea.11 Sinc