Dry eye treatment

Classically, the treatment used to be based on a classification of the type of dry eye and the severity of signs and symptoms showed on different diagnostic test and protocols that unfortunately haven’t shown the desired efficiency. We believe that the failure of these protocols is mainly because they do not consider the most innovative aspects of dry eye as well as data obtained from tests that have become obsolete and erroneous in many cases regardless of the information provided by new technologies.

Currently we prefer to establish a specific treatment plan based on disease status in each case and in each developmental stage. To achieve this objective we consider fundamental to analysis the causative factors, the degree of subjective discomforts and the level of anxiety of the patient, and to take into account the results obtained in the eight diagnostic factors mentioned and described above. According to this new perspective, this is how we approach the treatment:

Towards a new approach in the treatment of dry eye

 

It is necessary to abandon obsolete protocols and lead the way to new concepts about dry eye and, in the same line, use new technologies, which offer much more accurate and useful data to establish a meticulous diagnosis and to set a more effective and safe strategy for the treatment.

  • Prioritize in treating subjective discomfort felt by patients and educate people about the coming problems and limitations of this disease.
  • Improve environmental conditions to eliminate the factors that represent an assault tot he ocular surface.
  • Give priority to the diet to improve the level of antioxidants and rich in unsaturated omega 3 fatty acids.
  • Explore blinking,to be effective, especially after blepharoplasty and botox injections in the periorbital area.
  • Relevance of the role of meibomian glands and the free edge of the eyelids. Importance of meibography and opening and probing the glands.
  • Exfoliation of the eyelids free edge when hyperkeratinization on this area.
  • Consider tear hyperosmolarity and inflammatory response of the ocular surface as key factors in the development of the disease.
  • Reduce the number of eye drops and artificial tear drops prioritizing autologous serum and plasmaderived.

Rule of thumb: Dry eye can be controlled and discomfort and incapacitation can be prevented, but it is necessary to follow the instructions by an ophthalmologist specialised in dry eye.

1.-. Subjective discomfort. General therapeutic measures:

1.1.-  With the OSDI test we can see how the patients “feel” their discomfort, and put us on the track of the priorities in treatment. It is essential to reduce the anxiety of these patients, explaining the treatment, different options to solve the problem with real expectative about their future. It is fundamental that the patients understand that dry eye has solutions to improve the disease. It´s also necessary to explain to the family and close environment the problems of this disease and how they could help with their understanding and tolerance of the patient.

1.2.- Secondly, we have to balance the diet and eating habits of these patients. After many years of practice, I have seen some food imbalance but an improvement of it would always result in symptomatic improvement of dry eye. It is necessary to reduce the levels of omega-6 and increase foodstuffs that provide omega 3 and antioxidants. On many occasions, it will be necessary to address to a dietitian for better advice.

omega 3

Figure 8.- Food rich in omega-3 and low in omega-6 fatty acids.

 

1.3.- In the third place, it is necessary to establish a pattern of ocular hygiene and environmental health, such as the protection of the eye against the sun, dry conditions, very windy environments and close helmet if we drive motorcycles. Well ventilated homes and avoiding toxic and chemical products at home, basically smoke and certain cleaning products are also a priority. Avoid creams and astringents makeup or eye drops. If you need to be using the computer during a long time and very often, it must be placed lower than the line of sight and taking breaks every 30 minutes, as a basic rule.

Contact lenses are also important; we see many patients with contact lenses problems and dry eye, meaning they have little or poor quality tears and, since contact lenses are like a foreign body, they damage the ocular surface and impair even more the dry eye.

Within these general measures, we may include glasses that create a more humid environment over the eyes. They use a liquid reservoir that moistens the eyes from the saddle. They are not very popular for their appearance or their complexity of porting, but there are patients who report improvement in symptoms. Along the same lines, humidifiers to increase humidity in the room where we spend more hours, can help improving the symptoms of these patients.

There are special contact lenses PROSE (Prosthetic Replacement of the Ocular Surface Ecosystem), with a reservoir of balance salt solution or artificial tears in permanent contact with the ocular surface and improve this ecosystem improving at the same time vision and comfort.

2 .- Palpebral Dynamics.

The study of blink is often overlooked and in many cases we can find that it is incomplete or it is not done as often as needed, which makes it not fully effective in producing a good tear film at the time of the opening of the eyelids. We see this frequently in contact lens wearers, patients undergoing frequent botox injections in the periorbital area or because their blink was not perfect but asymptomatic and at a given moment start the the problem or symptoms.

3 .- State of the meibomian glands and the eyelids margin.

We know that the most frequent factor that appears altered in dry eye is the meibomian gland failure, usually due to the obstruction of the external orifices in the eyelid margin. First of all, we have to check the appearance of these glands by meibography and secondly, the appearance of the eyelid margin with the slit lamp, the presence of keratinized epithelium at this level. If this happens, we recommend opening and probing the meibomian glands to restore the lipid secretion and tear film structure. At the same time, we recommend the exfoliation of the eyelid margin, to eliminate the keratinization that can occlude the meibomian glands orifices again.

Probing meibomian glands and exfoliation the eyelid margin, are two of the newest treatments and offer best results to control dry eye. Unfortunately, they are still not very popular and not all ophthalmologists would use them, but we are confident that gradually incorporated into the therapeutic arsenal of dry eye.

We consider that heat and massage of the eyelids wouldn’t be beneficial when meibomian glands orifices are clogged; they induce mechanical trauma that still generates more inflammation, instead. In most cases altered meibomian gland is not perfectly evident and  it is difficult to recognize the occlusion of the gland orifices, a fact that is clear only when probing is done. The majority of times, a thin membrane lines the gland orifice and when is punctured and opened with the probe, we can see again how the glands release the lipids accumulated inside.

sondaje de glandulas de meibomio

Figure 9 .- (A) Probing meibomian glands and (B) probing with transillumination, appreciating the probe inside the glandular duct, (C) a patient Meibography before probing and (D) after treatment of opening and probing the glands. Improvement with less sinusoidal and longer appearance of the glands.

After performing the opening and probing of the meibomian glands and the exfoliation of the keratinized epithelium on the eyelid margin, we recommend patients to clean that area with mild soaps or wipes that are sold for this purpose, without pressing or intensely massaging the eyelids.

Another important point related to the meibomian gland treatment is the administration of drugs and hormones for improving its functionalism. As we said at menopause, declining sex hormones can produce changes in the tissues and the meibomian glands are very sensitive to these changes. Moreover, atrophy is induced, a fact that is exacerbated by the clogging of the gland orifices. For a time, the administration of hormones, especially estrogen or androgens, is proposed to alleviate this situation but the experience has shown limited effectiveness and also an increase of the risk of cancers (breast or prostate), so we don’t recommend it.

We now know the benefit and the improvement in meibomian gland with diets low in omega 6 and rich in omega 3. Unsaturated fats are critical for improving lipid metabolism within these glands and also a protective action against involution and atrophy of these glands that comes with ageorhormonal changes.

To improve the metabolism of lipids in meibomian gland, drugs such as Doxycycline have been proposed as well and, we agree that they are effective in cases where skin disorders such as acne rosacea or if there is an associated blepharitis coexisting.

exfoliacion parpados para ojo seco

Figure 10 .- Eyelid margin exfoliation. (A) Preparation with pulsed heat and massage to improve lymphatic drainage of the eyelids. (B) Exfoliation of the eyelid margin. (C) Appearance of the eyelid margin in a patient with keratosis prior the exfoliation, (D) same patient after treatment, with a clear improvement in the mucosa and les inflammation.

 

4 .- Stability of the tear film.

The stability of the tear film depends on the blink and it must be effective to generate a correct three-layer. We have discussed before the importance of blinking and also the importance of the treatment being correct. The structure of the tear film consists of three layers with a first inner layer of mucus, which fixes the tear film to the ocular surface, a second intermediate aqueous layer, with water and nutrients, which humidifies the ocular surface, and a third outer lipid layer, which protects the two other layers and helps avoiding rapid evaporation and premature breakage of the tear film.

4.1 .- Handling the mucus layer. A deficit of mucus is seen in the advanced stages of dry eye, especially in cases associated with rheumatic diseases, Sjögren, etc, destruction of conjunctival goblet cells, which are responsible for mucus secretion. The main factor that triggers the involvement of goblet cells is tear hyperosmolarity, which appears in most cases of dry eye, as we said. In some cases we can see the opposite phenomenon, excess of mucus, especially in the early stages of dry eye, and can also destabilize the tear film.

Mucus deficiency is treated with eye drops that provide similar molecules to mucus and try to emulate their role. A second option is hypoosmolar drops, trying to avoid the toxic effect of hyperosmolarity. In cases of excess of mucus, oral drugs or drops having a mucolytic effect are given, but its efficiency is questionable.

4.2 .- Restoration of the aqueous layer. The aqueous layer is reduced in the case of dry eye and it is due to lachrymal gland failure, usually by physiological action of age, hormonal changes after menopause or direct attack in patients suffering from other diseases, such as arthritis, Sjogren’s and other autoimmune related diseases. In these cases, the common denominator is the inflammatory reaction against the lachrymal gland and other tissues, hence the need to administer anti-inflammatory drugs or cyclosporine A, which is particularly effective improving the functionalism of these glands.

Another drug that has shown good results is Doxycycline; even if it is an antibiotic, there are some evidences to improve the functionalism of the lachrymal gland. To complete the treatment, as a supplement, we have eye drops, also called artificial tears, that provide ion water content attempting components resembling the aqueous part of the tears.

In cases where the deficit of the aqueous layer predominates, the result usually is a reduction in tear volume, there is a shortfall in the amount of tear in these patients therefore recommend “hold” the tear by placing what is called, lachrymal implants or “tears plugs”. A device is placed in the lachrymal canaliculus, which partially obstructs the drainage of tears, staying longer in contact with the ocular surface. There are several types of punctual plugs. The choice used to depend on the severity of signs and symptoms, a value obtained through the Schirmmer test but, as we said, this test offers little reliable values, so we prefer to value what we know as “tear river” or “tear meniscus” and the secretion-dynamics of the tear drainage through new technologies like videography.

Figura 11.- Aspecto de un tapón lagrimal tras su colocación en el conducto lagrimal (flecha).

Figure 11 .- Appearance of a punctual plug after insertion into the lacrimal orifice (arrow).

4.3 .- Restoration of the lipid layer. The lipid layer is the one that has been more relevant in a case of dry eye. We know that in most cases the lipids are of poor quality and deficient, so they cannot perform their function, lubricate the ocular surface or slow the evaporation rate of the tear film. The meibomian glands are clogged and atrophied, which reduces the secretion of lipids and alters its quality. They are “stale” lipids, which are not distributed well enough to generate the outer layer of the tear film. Also, they have a low pH, acid, which irritates the eye surface even more.

To improve the lipid layer, we must act on the meibomian glands and the eyelid margin, as we noticed in the previous section, and if we want to supplement the treatment, we can add some eyedrops new generation, that attempts to emulate the lipid layer.

As we see, the stability of the tear film is a key point being confusing when planning treatment at the same time. Faced with the simple administration of drops, artificial tears, which try to emulate and tear supply deficits and restore stability of the tear film, we propose to treat the causes of instability, especially with regard to the lipid layer, opening the orifice of the meibomian gland and probing the internal duct, restoring lipid secretion and leaving the artificial tears only as an aid to treat dry eye. We also know that artificial tears are not free of secondary effects, even now that most of them are hasve no preservatives. The excessive use of artificial tears can have a toxic effect on the ocular surface.

The improvement of the lipid layer also depends on the level and quality of lipids, on the metabolism in the meibomian glands, something related to diet, (to be precise, to the balance of saturated and unsaturated fats), as stated above in paragraph 3 on therapeutic measures to improve meibomian gland and eyelid margin.

5 .- State of the tissues of the ocular surface. Osmolarity and inflammation.

The direct action of the air on the ocular surface is responsible of cells damage in the cornea and conjunctiva, a phenomenon that will be aggravated by tear hyperosmolarity and an inflammatory response to this aggression.

So far, not much importance has been given to this fact; when the tissue damage was evident with vital dyes, which is basically known as keratitis, a treatment that consists of the prescription of more drops, more viscous artificial tears or contact lenses to protect the cornea. Today the situation has totally changed, both in approach and treatment.

As the tissue damage is the final result of the instability of the tear film, this damaged tissue is responsible for the discomfort felt by the patient and it`s essential to focus the treatment correctly to solve the problem as soon as possible. We must focus our attention on: (1) cell damage, especially in the corneal epithelium, (2) osmolarity of the tear and (3) the presence of inflammatory mediators in tears.

We have pointed out previously the growing importance of hyperosmolarity and especially inflammation, anf that is why the treatment should be focused on the administration of drops that reduce osmolarity, hypoosmolar tears and antiinflammatory drugs. We are aware that this is a controversial issue; there are still many ophthalmologists who occur to be reluctant to the administration of anti-inflammatory drugs. However, we know that in the active phase of dry eye, especially when associated with other diseases with a clear inflammatory component, we must administer these drugs. The good news is that we have a test that measures inflammation so we can adjust the type, intensity of anti-inflammatory and time management, to be able to monitor changes in the concentration of inflammatory mediators, such as metalloproteinase 9 (InflammaDry Detector RPS ®).

It is suitable to administer anti-inflammatory indiscriminately, especially steroidal derivatives, but we know that in the phases of inflammatory activity the cells aggression on the ocular surface is improved and, as a result, the disease progresses rapidly and patient feel more subjective discomfort. For this reason we need the administration of anti-inflammatory drugs to be controlled. In other wordws, we have to choose the most appropriate in each case, adjusting the dose and time of administration.

To help and improve the damaged cells of the ocular surface, we manage substances that have a high regenerative power, as serum and blood plasma derivate. This is not new in medicine: in other specialties, such substance contributes as mediator of cell growth and natural anti-inflammatory effect and, in our case, it helps to soften dry eye. In more advanced cases, when there are corneal ulcers with low response to conventional treatments, new drugs like Cacicol ® (heparan sulfate) have been proven to be effective, reducing the inflammatory reaction of the ulcerated area and helping to regenerate the corneal matrix.

Along with these measures, we could include other drugs such as derivatives of vitamin A, which try to help tissue regeneration even though their benefits are not entirely proven. Recently, many other drugs with molecules that also look  for this regenerative effect have been discovered. However, time is needed to verify its effectiveness as a positive alternative to autologous serum and plasma derivatives, more difficult to obtain and manage.

In severe cases, when there is a significant loss of cells in the corneal epithelium and keratitis or corneal ulcers, it is necessary to protect this area and this is why we have special contact lenses acting as a patch, so there is no need to occlude the eye or tarsorrhaphy. Silicone hydrogel with high Dk can enhance the strong subjective complaints that these patients suffer.