Dry eye diagnosis and treatment have undergone many changes in recent years

Issue: July 2012

ByBéatrice Cochener, MD, PhD

Ophthalmologists no longer have to view dry eye contemptuously and be embarrassed by the absence of an explanation and specific treatment for the frequent patient complaint of itching, burning or annoying eye pain. Ophthalmologists once prescribed artificial tears, asserting that nothing serious was behind dry eye symptoms, even if sometimes the symptoms were the source of a true handicap.

The advent of refractive surgery, the changes in environmental conditions including longer exposure to computer screens and the lengthening of age expectancy have increased the incidence of this symptomatology. But an entity called ocular surface disease (OSD) was popularized in 2007 by an international workshop organized by the Tear Film and Ocular Surface Society. OSD can be defined as a multifactorial disorder involving a key factor: inflammation. Since then, an organization tree for causes according to the pathogenesis (aqueous deficient, evaporative dry eye) has been proposed. It has been demonstrated that when it comes to ocular dryness, the involved process can commonly become a vicious circle, leading to a worsening of each phenomenon that drives the chronic nature of the disease.

OSD outcomes

Béatrice Cochener

Thanks to this better understanding of the responsible mechanisms, a revolution has occurred in the therapeutic field of dry eye treatment. Anti-inflammatory treatment (steroid and cyclosporine 0.05%) features more efficient lubricant solutions that aim to substitute tear film in not only quantity but also in quality. Nowadays, depending on the etiology of the disease, a strategy for the management of dry eye has been designed, aiming to propose preservative-free topical drugs, to develop effective anti-inflammatory steroids with no side effects and to evaluate the optimal concentration for cyclosporine. In terms of cyclosporine treatment, some European countries still require a specific agreement or a magisterial preparation to use it.

Other concerns

Particular interest today is focused on meibomian gland dysfunction (MGD), which has motivated a new international workshop and illustrates the importance of its incidence, severity and consequences. This workshop has looked to offer a new approach to the diagnosis and protocol of treatment, classically based on lid hygiene care. In modern strategies, we must also mention the role of heating masks and glasses that reinforce the efficacy of care.

In cases of major alterations of the ocular surface, a promising option is represented by scleral contact lenses. They provide a fluid-field reservoir that acts as a shield for the cornea, protecting it from the mediators of inflammation.

At the level of experimental research, agents with targeted actions are being tested in different ways. Nutraceuticals such as omega-3 may have a role in the regulation of interleukins and cells apoptosis. Studies on innovative anti-inflammatory molecules such as glucocorticoid receptor agonist or integrin agonist are also under way.

In short, in the current search for comfort and quality of life for patients with dry eye disease, in addition to visual improvement, the main consideration has been important innovations in ocular surface treatment. In addition, the development of tools for diagnosis needs to be considered, adding a new quantitative dimension to the evaluation based on purely subjective tests that were often poorly correlated to the clinic. However, the validity of conventional diagnostic means, such as Schirmer’s test, vital stains and life questionnaires such as the Ocular Surface Disease Index, should continue to be considered.

Instruments

Thorough analysis of the many dry eye syndromes has led to the creation of instruments to measure precise parameters. These include measuring the stability of volume and tears with the Tearscope (Keeler). In terms of analyzable parameters to date, measuring osmolarity was a crucial innovation, as we know that osmolarity increases in cases of inflammation. For a long time, its measurement was limited to laboratory settings, until the advent of the TearLab Osmolarity Test (TearLab), which is possible to use in the office. This device could be especially useful for the detection of subclinical ocular dryness (eg, at the stage of patient selection for refractive surgery) and for the evaluation and comparison of OSD treatments. In the same category, evaluation of matrix metalloproteinase-9 as an important inflammatory mediator has been made possible with the InflammaDry Detector (RPS).

Probably in the near future, competitive new tests will be made available. Their survival will depend on not only the value that they will provide, but also on their cost and ease of use.

Considering the central role of MGD (especially rosacea) in the etiology of OSD, it is easy to understand the enthusiasm aroused by the advent of the LipiView and LipiFlow devices (TearScience), which can provide quantification of the lipid layer of the tear film and identification and grading of meibomian glands, as well as combine diagnosis and therapy, based on heating and pneumatic eye cupping.

In this issue of Ocular Surgery News Europe Edition, readers will find state-of-the-art information on the cascade of events involved in OSD at the molecular reaction level. A review of the latest innovations in diagnosis and treatment will then be provided based on the modern definition of dry eye syndrome. The story should hold the attention of readers who are concerned with the everyday treatment of dry eye in their practices.

For more information:

Béatrice Cochener, MD, PhD, is OSN Europe Edition Chairperson of the Editorial Board. She can be reached at University Hospital of Brest CHRU MORVAN, LaTIM (Laboratory of Medical Informations Treatment), Batiment IV, 5 Ave, FOCH, 29609 Brest, Cedex, France; +33-2-98-22-34-40; email: beatrice.cochener-lamard@chu-brest.fr.
Disclosure: Dr. Cochener has no relevant financial disclosures.