Ocular Demodicosis - Risk Factors, Symptoms, Diagnosis, and Treatment

Introduction

Demodex species are small and can travel through the skin's surface and infect the eyes. It causes the disease to the eyes, hair, and skin. Demodex species are the most common parasites in humans. Demodex folliculorum is found in hair and eyelash follicles and is more common than Demodex brevis. A single hair follicle can have nearly 25 Demodex folliculorum organisms. Demodex brevis is located in the body's sebaceous glands and in the meibomian gland (the sebaceous gland that secretes lipids and helps produce tear film) and the gland of Zeis (sebaceous gland found on the margin of the eyelid). Demodicosis is age-dependent. It is seen with increasing age. It is characterized by the pathognomonic presence of cylindrical dandruff at the base of the eyelashes.

What Are the Risk Factors Associated With Ocular Demodicosis?

• Rosacea (a condition that causes flushing and blushing of blood vessels in your face) is considered a potential risk factor for occurrence.

• Skin phototype (depends on the melanin pigmentation of the skin). Darker skin is at greater risk.

• Exposure to sunlight may cause the condition because it produces abnormal changes in melanocytes and thus causes ocular demodicosis.

• Intake of excess alcohol can lead to ocular demodicosis.

• Smoking can cause demodicosis.

• Stress can lead to this condition.

• Intake of hot beverages and spicy food should be avoided.

• Abrupt temperature changes can cause this disorder.

• When the immune system is compromised in HIV (human immunodeficiency virus) patients, it is observed when the CD4 count is below 150 per mm cube.

• Increasing age with compromised immunity can lead to ocular demodicosis, and the individuals who care for the elderly are associated with this condition.

What Is the Pathophysiology of Ocular Demodicosis?

Demodex mites can transfer skin-to-skin contact and cause problems through different mechanisms.

1. Mites act on the lining of follicles and lay eggs, resulting in the enlargement of the follicle and misdirection of the lashes.

2. There is irritation in the margin of the eyelids because of mechanical blockage of sebaceous ducts.

3. The chitin is formed and can initiate an inflammatory response and a foreign body-like granulomatous reaction.

What Are the Symptoms Associated With Ocular Demodicosis?

• It causes irritation in the eyes.

• The presence of dandruff at the base of eyelashes is seen.

• It creates discomfort in the eyes.

• Burning sensation in the eyes.

• Excessive tearing from the eyes.

• The sensation of itching in the eyes.

• Scaling of eyelids.

• In some cases, the thickening of lids is seen.

• Loss of eyelashes or eyebrows is called madarosis and gives an aesthetic look to the patient.

• Inflammation of the conjunctiva.

• Meibomian gland dysfunction (sebaceous glands in eyelids) can lead to altered tear composition and eye discomfort.

• Rosacea can result in blushing or flushing of blood vessels on the face.

• Vision loss is there.

• The feeling of the presence of any foreign substances in the eyes.

• Drying of eyes.

What About the Diagnosis of Ocular Demodicosis?

• Diagnosis is based on clinical findings and symptoms. Ophthalmologic examination is carried out with the help of ophthalmologists.

• Nasal skin scrapings can also be used to diagnose and rule out acne rosacea.

• Metazoan parasites can be observed in high-power magnification.

• Epilated lash can be observed under low power magnification and may also help detect the organism.

• Adding fluorescein dye can also help in detecting and counting mites.

• An electron microscope can also help in visualizing the organism.

• In certain conditions, a biopsy of the skin surface is done.

What Is the Differential Diagnosis of Ocular Demodicosis?

• Conjunctivitis - Inflammation of the conjunctiva.

• Keratitis - Inflammation of the cornea.

• Adult Blepharitis - It is the inflammation of eyelids.

• Chalazion - It is the formation of a red bump on the eyelids.

• Trichiasis - Eyelashes are misdirected from the ocular surface.

• Dry Eye Disease - Also called keratoconjunctivitis sicca, conjunctiva, and cornea become dry.

• Hordeolum - Disorder of the eyelids, and there is a formation of red bumps on the edge of the eyelid.

What Is the Treatment of Ocular Demodicosis?

• Scrubbing of eyelids should be done twice daily with diluted baby shampoo and water.

• Applying an antibiotic ointment at night until the resolution of symptoms.

• The mechanical rotating handpiece is also used with a microsponge tip combined with Polyaminopropyl biguanide foam solution to remove oil, scurf, and debris; exfoliates the eyelids; and claims to decrease Demodex infestation. The ointment is applied at the base of the eyelashes, especially at night, to trap mites as they emerge from their burrow or when they move from one follicle to another. A tea tree oil product named Cliradex can also be used. The most active component of tea tree oil is Terpinen-4-ol.

• Topical application is made with the help of yellow mercury ointment or sulphuric ointment.

• Camphor oil, Crotamiton, cholinesterase inhibitors, and Sulfacetamide have also proved to achieve good outcomes and the management of the condition.

• Steroids, antibiotics, and antifungal drugs can also be used to treat the condition.

• Oral Ivermectin and Permethrin cream can also treat the condition.

• Overall good results are seen when treatment is done with Metronidazole.

• Weekly follow-up is essential to monitor the condition and effectiveness of the treatment.

What Are the Precautions Taken to Prevent Ocular Demodicosis?

• Ask the patient to follow specific instructions.

• Patients should maintain hygiene and wash sheets and pillowcases with the help of hot water and dry it with the dryer.

• Avoid using makeup for at least one week.

• Use tea tree soap and tea tree hair shampoo.

• As a maintenance regimen, the patient should indefinitely continue lid scrubs at least twice a week. A six-month follow-up appointment should be scheduled to see the patient's condition.

Conclusion:

Demodex infestation is a common but overlooked condition in corneal and ocular diseases. Mites are a normal part of skin fauna and have high host specificity. Demodex is an eight-legged ectoparasite that lives in hair follicles and sebaceous glands. The mites are first acquired through breastfeeding from mother to infant as they are present on the nipples. To prevent this condition, it is advised to maintain hygiene with soaks, and scrubbing can also be helpful.