Dry eye pathology is divided into two fundamental groups:
- Acuodeficient, in which the cause is an alteration in tear production with a decrease in tear volume or “quantity”. Age, menopause, use of contact lenses, Sjögren’s syndrome, certain medications such as anxiolytics, antidepressants, antihistamines, treatments for arterial hypertension, etc. are the most common causes.
- The second type is evaporative dry eye. It is caused by a rapid evaporation of tears, which leads to a lack of protection of the ocular surface, instability of the tear film with alteration in the quality of vision and potential damage to the ocular surface, with chronic inflammation and progressive symptoms of discomfort.
The fundamental cause is blepharitis or dysfunction of the meibomian glands, which are responsible for the production of a fatty or lipid layer that covers the tear film and protects it from evaporation.
This poor tear quality, together with a series of changes in lifestyle habits, such as the use of mobile screens, very dry environments due to heating, air conditioning, etc., has led to a worrying increase in the number of patients with dry eye symptoms. In fact, in recent years it has become the most frequent cause of dry eye in ophthalmology consultations. In most cases, both types are present to a greater or lesser degree.
Consequences of dry eye
The tear film is essential because it “protects” the ocular surface from potential damage from environmental stress and is, in a healthy eye, what gives us “visual quality”, as, for example, water on a windshield.
Therefore, alterations in the quantity and quality of tears will produce symptoms of discomfort that may be mild, such as itching and occasional stinging, sensation of sand or dryness, tearing and visual instability….
If they are not identified and treated preventively, they can progressively worsen with constant symptoms, such as ocular pain (neuropathic pain), which alters and conditions the patient’s life, his work performance, or makes him unable to carry out activities such as reading, handicrafts, watching television, driving and a long etcetera, in many cases affecting the patient’s emotional stability.
Treatment of dry eye
The most important thing is the diagnosis of this pathology. Many patients do not give importance to the symptoms, they “rub” their eyes when they itch or see blurred vision, they go to the pharmacy to get something to relieve the discomfort or redness, they confuse them with allergies and delay going to the ophthalmologist.
On the other hand, ophthalmologists should not rely only on the patient’s symptoms, which can be misleading, but look for the “signs” in the examination that make us detect an initial damage on the surface, which sometimes “does not show its face” in a routine examination and can manifest itself after a situation of change such as refractive surgery (laser, lens surgery with multifocal lenses…), disappointing the expectations of a patient who was not previously warned of his dryness problem.
The examination of eyelids, state of the Meibomian glands or the presence of blepharitis, the use of stains to assess the evaporation time of the tear and the presence of positive staining, make us detect a dry eye disease in its early stages that with proper advice, can prevent or control its progression.
The treatment will be staggered, with substitutive therapy with artificial tears of different composition according to the type of dry eye, heat foments and eyelid hygiene with wipes or foams and gels, food supplements with omega 3, anti-inflammatories, punctal plugs, solutions such as autologous serum or Platelet Rich Plasma (PRP).
If there is a case of more severe damage to the ocular surface, the treatment will be based on therapeutic contact lenses…
Treatment should be personalized according to the type and severity of dry eye and whether or not there is chronic inflammation and, for that, specific diagnostic tests are needed (LIpiview, Keratograph…), osmolarity test, Schirmer, staining, surveys such as OSDI or Speed.
Nowadays, new physical therapies are available for mebomian gland dysfunction such as Lipiflow or pulsed light treatments (IPL).
Can dry eye lead to more serious pathologies?
Yes, the lack of assessment, diagnosis and treatment can lead the patient to enter a “vicious circle” where the decrease of tears together with excessive tear evaporation, associated with environmental and occupational factors.
This leads to a loss of tear equilibrium or “homeostasis”, with a sequence of events: increased tear osmolarity, damage to the surface cells with dry keratoconjunctivitis, from which the patient cannot escape without the help of the ocular surface specialist.
It is also essential to know the patient’s diseases (diabetes, hypothyroidism, rheumatism, atopic dermatitis…) and their associated symptoms, such as dry mouth, swelling and/or joint pain, fibromyalgia…. These make it necessary to send the patient to Internal Medicine or Rheumatology to rule out an immunological pathology.
Sjögren’s Syndrome, which is diagnosed late and wrongly and can jeopardize the patient’s general health if it is not diagnosed.
Can dry eyes be avoided?
Knowing which patients are more at risk, such as a history of blepharitis and styes in childhood, seborrheic dermatitis or atopic dermatitis, the continued use of contact lenses, diseases such as diabetes, hypothyroidism, depression, multi-medicated patients, fibromyalgia, use of CPAP for sleep apnea, menopause…. Also environmental factors such as continuous work with screens, air-cooled environments… and patients with an increased frequency of blinking and tics, should put us on the track to make a correct education of preventive measures to be performed by the patient to avoid going from a dry eye to what we call “dry eye disease”.
Since there is no cure for this pathology, it is important to teach the patient how to control it so that it does not become something that conditions their quality of life and work performance.