CARTA AL DIRECTOR

Diagnostic criteria in dry eye

Criterios diagnósticos en ojo seco

Dear Director:

I have read with interest Doctor Tomlinson's article about the diagnostic criteria in dry eye, and its difficulties (1), which are so similar to those in my daily practice. The dry eye syndrome with its multiple aetiology, pathophysiology factors, symptoms and signs guiding to several classifications, reminds me of the combinations in maths classes which can express the large number of results that we can get from the combination of so many variables.

Since the 70's the studies about dry eye have improved the knowledge around this issue, such as the pathogenic and aetiopathogenic factors that are involved. This new knowledge has required newer diagnostic methods, many of which have been published. However, the sensitivity and specificity vary with the characteristics and biases of the study population. Not all of them are commonly used in the practical clinic maybe because of the uncertainty caused in the definition of the presence of dry eye. As was well shown by Dr. Tomlinson the prevalence of dry eye is not well known due to the uncertainty of the diagnosis.

The interest of the diagnostic criteria is different but complementary to the interest of the clinical classifications. Some recent clinical classifications try to establish an order based on specific pre-established characteristics such as evaporative factors, or the presence or not of blepharitis. But the clinicians who face a patient must determine the causes of each dry eye (plurifactorial in most cases), the affectation of the various dacryoglands, the severity of the case, etc. in order to face and establish a therapeutical program. Therefore, Dr. Tomlinson's article about the difficult problem of the diagnostic criteria serves as a good base for the difficult problem of the clinical classification.

In order to determine a clear, specific and useful diagnostic classification in the daily clinical practice, a triple classification was proposed in Madrid 2003, at the XIV congress of the European Society of Ophthalmology. It was called the «Madrid Triple Classification of Dry Eye», and was based on ten aetiology families of tear insufficiency, the severity in five grades, and an anatomo-pathologic classification (2). It was soon used in many parts of the world, due to its practical applicability in the daily clinic to establish the treatment to follow. In order to adapt it to the clinical practice new meeting will be held by the International Society of Dacryology & Dry Eye, on 1 to 3 April of 2005 in Madrid for new discussion of these points.

All the discussions about this issue are so exciting, because of the rising interest and knowledge of this condition, many times related to older people. Now the world population is getting older, it will be more and more studied looking for new and more specific diagnostic methods, which can lead to new, successful treatment.

M. Newmann
Brasilia. Brazil

REFERENCES

1. Tomlinson A. Diagnostic Criteria in Dry Eye. Arch Soc Esp Oftalmol 2004; 79: 257-258.

2. Murube J, Benítez del Castillo JM, ChenZhuo L, Berta A, Rolando M. The Madrid Triple Classification of Dry Eye. Arch Soc Esp Oftalmol 2003; 78: 587-594.