DRY EYE CLINIC

Dry Eye Investigation & Treatment

Dry Eye Disease is caused by deficiency of one or more of the the three layers of the tears, which are:

• The oily (lipid) layer produced by the Meibomian Glands in the eye lids  

  
  

• The watery (aqueous)  layer 
  

• The mucus layer

TearLab® Osmolarity System:

• The TearLab® Osmolarity System is intended to measure the osmolarity of human tears to aid in the diagnosis of ocular surface health disease in patients, such as Dry Eye Disease.

• Ocular Surface Disease (OSD) may affect the clarity and stability of vision and reduce the accuracy of refractive diagnostic tests. OSD can also negatively impact the results of surgical procedures, including cataract surgery, leading to refractive surprises and dissatisfaction.

• The Osmolarity System is an objective, precise and quantitative diagnostic test, done in conjunction with other methods of clinical evaluation, including the use of Inflammadry and Lipiview equipment. These tests guide Optometrists in gaining immediate insights into Ocular Surface Disease.

For more information about the TearLab® Osmolarity System, click here.

Meibomian Gland Dysfunction (MGD):

Evaporative Dry Eye  

Most patients with Dry Eye Disease do not have reduced aqueous tear production but rather faulty tear function, in which the tear film is unstable and prone to rapid evaporation.

In the majority of cases the evaporative dry eye is typically the result of Meibomian Gland Dysfunction (MGD) alone or combined with  aqueous deficiency (Lemp, Crews et al. 2012). Researchers found that; 86% of patients who were diagnosed as having a Dry Eye Disease (DED) showed MGD. They concluded that evaporative dry eye from MGD was far more common than purey Aqueous Deficient Dry Eyes (ADDE)''. (Lemp, Crews et al. 2012).

It has been estimated that MGD occurs in over 19 %  of Caucasian individuals over 40 years of age (Nichols, Foulks et al. 2011).

The Problem

Although MGD is a very common and significant condition in terms of its prevalence, morbidity and negative effect on the quality of life of individuals, research into treatment modalities has proceeded slowly.

Until recently, the treatment for this condition was the use of artificial tears, poorly controlled home treatments; warm compresses and lid scrubs, as well as the use of topical and systemic antibiotics.

Beyond discomfort, it has been clearly established that MGD significantly degrades the quality of vision (Mijianovic et al 2007). Dry eye conditions, including MGD, do not resolve on their own but are chronic and progressive (Rao, 2010). 

The Solution: Modern Diagnosis and Treatment

Initial treatment of anterior blepharitis and lid margin disease may still include drug therapy, but in addition, your optometrist at Barnard Levit may advise an in-practice cleaning of your lid margins using Blephex.

The diagnosis and treatment of MGD has been transformed by the TearScience system, which consists of the LipiView Ocular Surface Interferometer and the LipiFlow Thermal Pulsation system. For the first time we have an opportunity to treat MGD in a holistic way, which has the potential to offer patients relief from this chronic disorder.

Barnard Levit Optometrists is one of a few practices with the TearScience LipiView which provides diagnostic information on the Meibomian glands, and LipFlow, an advanced system that delivers a highly effective method of cleansing the Meibomian glands. 

Aqueous Deficiency

The watery layer has the function of keeping the cornea wet and forming a "tear lens".

Deficiency of this layer will produce dry eye. Deficiency of the watery layer can be caused by many conditions, an example of which is Sjogren syndrome. One way of keeping the tears that are present from draining away is for punctum or intracanalicular plugs to be fitted. Barnard Levit Optometrists stock and are able to fit a range of temporary and permant punctum and intracanalicular plugs.

Mucus Deficiency

The function of the mucus layer is to coat the surface of the cornea and conjunctiva to allow the watery layer to spread smoothly. Deficiencies in the mucus layer can sometimes be helped with nutritional supplements. 

Dry Eye and Tears

"Dry Eye" due to tear dysfunction occurs in between 15 to 33% of the population and is more common in females. There are many causes of "dry eye". To learn more, watch the video below or take the SPEED questionnaire and book an examination with us.

If you would still like to know more about Lipiflow, or to make an appointment please call us on 020 8458 0599. We would be very happy to help.

Your Amazing Tears 

The tears are not simply water but are actually a complex structure which, in simple terms, is made up of three layers. Every time we blink, this three layer structure concertinas down as the eye closes and then stretches back out again as the eye lids open.

The tears have a number of functions: (1) a refractive surface, focusing light onwards through the eye  (2). a lubricant reducing friction during blinking (3) supports corneal transparency (4). contains anti-bacterial enzymes (5). contains nutrients for the corneal epithelium.  

The healthy tear film is therefore critical to the wellbeing and comfort of the eye and to vision as well, enabling the cornea to act as a lens refracting light onwards through the eye, lubricating and helping to clear debris from the surface and providing both nutrients and enzymes to feed and keep the surface of the eye healthy.

Dry Eye

There are many causes of “dry eye” because the human tear film itself is not simply a layer of water but a wonderful complex structure. In a healthy eye with a normal tear film there is a thin layer of mucin adjacent to and coating the surface (conjunctiva & cornea) of the eye, the function of which is to enable the middle, watery (aqueous) layer to spread smoothly across the surface.

On top of the aqueous layer there is a thin layer of lipid (oil) the function of which is to reduce the amount of evaporation of tears,

So, the tears are made of three components and, if one or more of them is abnormal or deficient then “dry eye” will result.

If you are suffering from “dry eye” symptoms your optometrist will want to diagnose the likely cause of the dryness because the treatment and management will depend upon which part of your tears is deficient.

Mucin Abnormalities

There are a number of types of mucin found in the tears. Some are produced by goblet cells in the conjunctiva and others by the lacrimal gland. A severe deficiency in mucins can be caused by Stevens-Johnson syndrome, Sjögren syndrome and other non-Sjögren dry eye diseases.

Research is ongoing with the aim of developing medication that will treat mucin abnormalities. There is some evidence that Vitamin-A may improve goblet cell production of mucin and eye ointment with Vitamin A is available.

Aqueous Deficiency

There are many causes of aqueous layer deficiency. Treatment usually consists of the instillation of tear supplement eye drops.

Another management strategy is to insert tiny “plugs” in the puncta of the eye lids. Each eye lid has a punctum  which is a tiny drainage hole leading to a fine pipe called the caniliculus. The canaliculae drain into the nose which is why, if you produce normal tears, your nose runs when you cry. The tiny plugs stop the drainage of tears and allow a greater volume of tears to remain on the surface of the eye.

At Barnard Levit the optometrists usually fit temporary plugs first, to allow the patient to assess the effect. The plugs dissolve over a finite period of time. If the plugs worked well and the patient perceived an improvement in comfort, then more “permanent” plugs can be fitted. These either sit in the punctum themselves or are fitted into the canaliculus so that they are completely hidden (Herrick Lacrimal Plugs). The plugs can be removed if required.

Diagram showing position of "permanent" Herrick plug (blue) and temporary dissolvable plug (purple) in the canaliculi.

Lipid Deficiency

The oily layer of the tear film is produced by the Meibomian glands which are little oil wells lying within the eye lid margins immediately behind the eye lashes. They are similar to the Sebaceous glands of the skin.

The Sebaceous glands produce sebum whilst the Meibomian glands produce meibum. If a Sebaceous gland becomes blocked the content becomes thick and solid and this is often called in layman’s  terms, a “whitehead”. Similar blockages occur in the Meibomian glands often because of a bacteria called staphylococcus. The condition is termed posterior blepharitis and this leads to Meibomian gland dysfunction and dry eye.

The photograph above shows thick meibum being expressed from a dysfunctional Meibomian gland.

Treatment usually consists of heat compresses to the eye lids with manipulation and gentle cleaning of the lid margins. Topical antibiotics are often used and in chronic cases may require a course of oral antibiotics.

Contact Lenses For Dry Eye

Special contact lenses may also be fitted to protect the eye.

How Do I Book an Appointment?

If you would like to know more about Lipiflow, or to make an appointment please call us on 020 8458 0599. We would be very happy to help.