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3. Schirmer test The Schirmer test is the oldest of the diagnostic tools used in diagnosing dry eye. It predomi- n a n t l y m e a s u r e s t h e s e c r e t i o n o f t h e a q u e o u s s e g m e n t o f t h e t e a r f i l m , m a k i n g i t a n i m p o r -

tant tool in diagnosing hyposecretory dry eye. It is performed by placing the folded end of a standardized filter paper strip into the lower conjunctival sac, and, after five minutes, measu- ring the length of the paper that is wetted. Values are expressed in millimeters. In no way can the Schirmer test substitute for the TBUT or other tests as the only test used in diagnosing dry eye, since it measures only one segment of tear film function. The Schirmer test is even more

variable in interpretation, since it also is performed with many different modifications (eyes open, closed, with or without anaesthetic), yielding very different results. The values listed below are again those most widely accepted in the literature.

Figure 4 – Schirmer test

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    10 mm normal secretion of aqueous segment of

tear film 5 – 10 mm marginal finding, inconclusive in ruling out aqueous-deficient dry eye < 5 mm highly probable aqueous-deficient dry eye < 3 mm aqueous deficient dry eye

4. Meibomian Gland Expression Meibomian Gland Expression is a diagnostic tool that has been introduced into ophthalmic practice fairly recently. It may be very useful in assessing the function of the meibomian glands in the lids, responsible for secretion of the lipid layer of the tear film. Meibomian gland dys- function (MGD) may be the cause of hyperevaporative dry eye. The test is performed with the slit lamp, by gently squeezing upwards the middle portion of both lower eyelids, and noting any secretion thus expressed from the meibomian gland orifices. [19]

1. Clear fluid is expressed from 75 % of orifices 2. Clear or milky fluid is expressed from 50 % of orifices 3. Less than 50 % of orifices yield any secretion

normal mild MGD

secretion is creamy 4. Less than 25 % of orifices yield any secretion

moderate MGD

secretion purulent

severe MGD

Other tests used in dry eye diagnosis There are many other tests in use for establishing the diagnosis of dry eye. Their use depends on the experience and the skill of the ophthalmologist and on the equipment available. The most commonly used tests are listed below:

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    Bengal red staining

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    Lissamine green staining

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    NIBUT (Non-invasive tear break-up test)

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    LIPCOF (lid parallel conjunctival folds)

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    Tear film detritus assessment

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    Lipid Layer Thickness measurement (LLT)



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    Tear osmometry

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    Tear meniscus measurement

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    Tear ferning test


Dry eye cannot be cured.

It is a condition that will stay with the patient for the rest of his/her life. This is an additional reason why this diagnosis should not be made lightly. Once this diagnosis is established and confirmed, the patient should be carefully informed about the goals of dry eye therapy, to avoid disappointment and loss of the patient's confidence.

There are two goals of dry eye therapy: 1. To alleviate symptoms, and thus enhance the patient's quality of life.

2 . T o p r e v e n t d e v e l o p m e n t o f p o s s i b l e c o m p l i c a t i o n s o f d r y e y e , s u c h a s b a c t e r i a l o r v i r a l i n f e c -

tions or more severe corneal and conjunctival complications like perforation or scarring.

GENERAL RECOMMENDATIONS Several simple and inexpensive recommendations may help the patient alleviate his/her dry eye-related symptoms:

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    Avoid situations that are known to worsen dry eye-related symptoms (smoking, dust, strong wind, cold air, dry air).

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    Place the computer screen 10 – 20° below eye level, to reduce the eye aperture and the- refore reduce tear evaporation.

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    Use wide-rimmed eyeglasses that wrap around the face to reduce eye exposure to wind.

The importance in differentiating between hyposecretory and hyperevaporative dry eye resides in the fact that therapy choices are different for each condition. However, it must not be for- gotten that these conditions may coexist and are not mutually exclusive, and therefore the patient’s condition may require combined therapy.

HYPOSECRETORY DRY EYE Artificial tears Artificial tears in their many varieties still form the backbone of dry eye therapy. It is particu- larly true for hyposecretory dry eye. However, artificial tears have their limitations, and patients should be instructed on how to use them properly.

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    Artificial tears do not cure the disease. They are substituting what is lacking, i.e. tears, and will not make decreased tear secretion come back to the normal level. In order to avoid unreasonable expectations and loss of confidence in the practitioner by the patient, he/she should be clearly informed about this.



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