Dry Eye Disease

The tear film consists of three distinct layers:

1. The mucous layer, which is produced by the conjunctiva and aims to adhere the tear to the surface of the eye.
2. The aqueous layer, produced by the lacrimal gland, which aims to hydrate the ocular surface.
3. The lipid layer, produced by glands in the eyelids, which aims to reduce the evaporation of tears.

Dry eye syndrome is one of the most common problems affecting the general population and can cause mild eye irritation to severe ocular issues. This syndrome is a general term that describes either reduced tear production or increased evaporation of tears. When the tear film is not healthy, it leads to a range of symptoms:

1. Burning sensation
2. Itching
3. Tearing
4. Foreign body sensation
5. Increased blink frequency
6. Ocular redness
7. Vision fluctuations
8. Photophobia
9. Ocular pain
10. Eye fatigue
11. Heavy eyelid sensation

Although there is a wide range of ophthalmological symptoms in patients with dry eye syndrome, the most common is tearing. This symptom is often seen as paradoxical by many patients, as excessive tear production may not seem related to dry eye disease. However, tearing is a result of the pathological tear film and the irritation it causes, which triggers the brain to produce tears in an attempt to compensate for this condition.

The most common causes of dry eye syndrome are:

1. Allergies
2. Reduced hormone production related to aging
3. Hormonal changes associated with pregnancy
4. Thyroid disorders
5. Inflammation of the eyelids
6. Medications (antihistamines, analgesics, diuretics, psychiatric drugs, and contraceptives)
7. Sjogren’s syndrome
8. Autoimmune diseases (rheumatoid arthritis)
9. Chemical burns to the eyes
10. Ocular surgeries
11. Reduced blinking, associated with computer screens (link with other article)
12. Environmental factors (wind, hot and dry climates)
13. Contact lens use
14. Neurological conditions (Parkinson’s disease, facial nerve paralysis)
15. Exposure keratopathy (when eyelids do not fully close during sleep)
16. After refractive surgeries (LASIK or PRK)
17. Ocular inflammations
18. Diabetes
19. Corneal infections
20. Vitamin A deficiency

The ophthalmologist, based on the patient’s history and clinical examination, must identify the cause of dry eye syndrome and administer the appropriate treatment. The main goal is to reduce the symptoms that disturb the patients as much as possible, in order to improve both their quality of life and their vision. It is not always possible to completely cure dry eye syndrome, and the doctor, together with the patient, must set a realistic goal, which is the long-term management of the syndrome.

Regarding treatment, the following therapeutic suggestions are recommended:

1. Use of artificial tears
2. Use of tear gels
3. Warm compresses
4. Eyelid hygiene (with washes)
5. Insertion of punctal plugs
6. Use of pharmaceutical eye drops (cyclosporine eye drops)
7. Use of corticosteroid eye drops
8. Use of autologous serum eye drops
9. Special treatments for the eyelids and the skin around the eyes

Most patients with dry eye syndrome who follow the therapeutic guidelines experience improvement in their symptoms, thereby improving their vision and quality of life. Because the nature of dry eye syndrome does not allow for a complete cure, patients should visit their ophthalmologist regularly, and whenever necessary, their treatment should be adjusted.