‘Dry eye is a multifactorial disease of the ocular surface characterized by a loss of homeostasis of the tear film, and accompanied by ocular symptoms, in which tear film instability and hyperosmolarity, ocular surface inflammation and damage, and neuro-sensory abnormalities play etiologocal roles’. – Tear Film and Ocular Surface Dry Eye Workshop (DEWS II)
WHAT IS DRY EYE?
WHAT DOES THIS MEAN FOR YOU?
Changes in the amount and/or quality of a persons tears can lead to an unstable tear film, inflammation and increased salt in the tears any of these can in turn can cause symptoms and damage to the front surface of the eye.
Your tears are made up of three layers;
Mucin Layer – the layer closest to the surface of the eye is secreted by goblet cells in the conjunctiva. Its keep the tears on the eye, and provides lubrication.
Aqueous Layer – the ‘middle’ and largest portion of the tears is secreted by the Lacrimal and accessory lacrimal gland. Its supplies oxygen to the cornea, washes away debris and has anti-bacterial action.
Lipid Layer – the outer most layer, is secreted by Meibomian glands that are located in the eye lids. This ‘oily layer’ helps reduce evaporation of the tears, and allows the eyelids to glide over the eye.
CAUSES OF "DRY EYE"
Dry eye disease is due to either a lack of the watery layer (Aqueous deficiency) or issues with the meibomian glands (Evaporative) but most commonly is ‘Mixed’. This means there is an element of aqueous and evaporative dysfunction.
Systemic health conditions and the treatment used to manage them can also lead to dry eye and dry eye symptoms.
Sjogren Syndrome is an auto-immune disease that causes not only dry eye, but dryness of the mouth, nose and other mucous-lined membranes.
Treatments for hayfever (anti-histamines), acne, the contraceptive pill/injection, HRT, and anti-depressants contribute to dry eye. Even other drops (such as glaucoma medication), can cause dry eye.*
Inaccurate or inappropriate spectacles or contact lens prescriptions, as well as issues with your binocular vision system, can manifest as dry eye symptoms.
*You should always consult your managing practitioner before changing any prescribed medications.
WHY IS DRY EYE PAINFUL?
The cornea has more nerve endings per mm than anywhere else in the body.
Adverse environments can irritate the these nerves leading to increased discomfort. Prolonged irritation will actually cause long term changes to the sensitivity of these nerves.
AIM OF TREATMENT FOR DRY EYE
The goal of treatment, simply, is to restore homeostasis of the tears.
To ensure a healthy environment for the ‘front of the eye’, leading to a happier, less irritated eye.
WHAT HAPPENS AT A DRY EYE ASSESSMENT?
To give us a subjective score on how you feel. We use an extremely well known and validated test referred to as the OSDI (Ocular Surface Disease Index)
This assesses the osmolarity of your years (how salty they are). A score over 308 or a difference between the eyes of 8 is considering significant.
This very specific test looks for a specific protein that identifies inflammatory markers within the tears.
This index tells us how long your tears sit on your eye. Studies have shown ‘normal’ break up time is greater than 10 secs.
Infra-red imaging of the eye lids can show us structural changes and the number of meibomian glands that are present.
TREATMENT AND MANAGEMENT OF DRY EYE
As per DEWSII we use a structured treatment protocol. No one is identical and therefore treatments are customised to you. After your initial assessment, a specific plan will be designed for you. The aim is to improve the quality and/or quantity of your own tears, so that you are less reliant on tear substitutes through the day and/or night.
How can you help yourself?
Hydration – you need to keep water intake up. Coffee, Tea and alcohol will dehydrate you.
Nutrition – a balanced diet, is as important in dry eye as it is every other aspect of general health. It has been shown that the preferred ratio of Omega 3 (anti-inflammatory) to Omega 6 (pro-inflammatory) should be approximately 4:1. Unfortunately modern diets have a bias to Omega 6. That balance needs to be addressed. Omega 3 rich foods are; Oily Fish (Tuna, Salmon), Caviar, Seeds (Flax, Chia, Sunflower), Nuts (Walnuts).
Environment – Dry eyes (and skin) are more comfortable in high humidity. So raise the humidity. Humidifiers are now very easily accessible and can be compact enough to sit on a desk.
Blink – Blinking spreads the tears over the eye. Incomplete blinks will leave exposed areas, which will dry out. When people do concentrated tasks, it has been shown that their blink rates decreases.
Lid hygiene – it is very important to keep your eye lids clear of bacterial build up. Colonies can accumulate along your eye lid margins, they can then release toxins and debris which cause irritation and de-stabilise the tear film. You will need to maintain cleansing at home once or twice a day.
Why don’t we advise diluted baby-shampoo?
Baby shampoo with strip the skin and eye lashes of the natural oils needed to maintain healthy function. This will exacerbate dry eye and irritate the skin around the eye. Johnson and Johnson do not advise using diluted baby shampoo for lid hygiene.
Warm compresses – the majority of dry eye patients have an element of evaporative dry eye, due to poor secretion from the meibomian glands.
To treat this, you need to soften the meibum so that it expresses more easily. Imagine olive oil and butter. To soften the meibum, we recommend warming the gland (>40’C) for 8-10 minutes, twice a day for 2 –3 weeks, then once a day every day/every other day. Warm compresses can be achieved by a variety of devices such as an EyeBag © or Blephasteam Goggles ©.
Why don’t we advise using a warm face flannel?
Warm/Hot face flannels have been shown not to get to the required temperature or stay at that temperature long enough be effective. It will just leave you with a damp face.
Artifical Tears – Lubrication. Although we aim to reduce the amount of drops/ointment you may need, it is often difficult to totally stop the need for artificial tears. If your eyes are dry, they will get irritated. This will lead to inflammation and osmolarity changes, which will cause your eyes to get drier. These elements are the basics, key and need to be on going. Try to get them into your routine, like brushing your teeth.
BEYOND THE BASICS OF DRY EYE
If there is blepharitis, one of our team will clean the lids. The cleaning products recommended will be dependent on the type of blepharitis present. Demodex blepharitis is commonly associated with dry eye (and rosacea), with the only available treatment being Terpinen-4-ol, which is found in Tea Tree oil. More recently IPL treatment has been shown to be effectice against demodex mites. Demodex mites have a life cycle of 4 week.
Anterior Blepharitis – this can be managed with regular lid hygiene modalities, such as wipes, foams or gels. Once or twice a day cleansing will be required.
Posterior Blepharitis – this is a deeper infection/inflammation and will require oral antibiotics.
Is there Inflammation? Were you Inflammadry positive?
We are proud to be one of the first practices in the country to use natural anti-inflammatory drops in our first line of treatment for dry eye.
*These medications can be prescribed in-house or via your GP.
Do you have Meibomian Gland Dysfunction?
This is a two-part question. Do they secrete and what is the secretion like? In a perfect world, all 30ish glands should meibum with olive oil-type consistency when expressed (squeezed). A common reason for them not expressing is a change in the consistency of the meibum, from olive oil (best) to toothpaste (worse). This can cause the glands to stop functioning, and then ultimately lead to gland atrophy (loss). In practice, we will make sure that the gland openings are clear.
Do you have Aqueous Deficiency?
Are you producing enough tears? Your eyes have 4 drainage points. 2 in each eye. If we need to keep the tears on the eye longer, we can plug them. Initially, we would use a temporary, 3-month dissolving plug (non-bovine/porcine). If this is beneficial, then we can install permanent plugs. We recommend that you have replacement plugs annually.
Neuropathic Dry Eye
Neuropathic dry eye, is where the eyes feel dry, but do not look dry, despite all interventions. This can be caused by long-standing dry eye, depression, post-traumatic stress disorder, and post-corneal surgery. In these cases, sometimes a referral is needed to a pain management clinic. Reports have suggested, that acupuncture, exercise and cognitive behaviour therapy can be helpful
INTENSE PULSE LIGHT (IPL)
We are proud to have been one of the first providers of IPL treatment in the country. A treatment that has entered optometry from dermatology where is was used to treat rosacea patients. Intense Pulse Light uses a Xenon Flash Lamp with a filter of approximately 500nm. The exact mechanism is unknown, but simply, it is believed to
- Decrease inflammatory markers at the lid margin
- Improve nerve function around the meibomian glands
- Flash heat the meibum increasing expressibility
IPL can not replace glands which are lost but can help them function better and there is increasing evidence to show it is a useful treatment in the management of Demodex. Our system involves a two-stage process and the appointment. Firstly a course of intense pulse light, followed by a 15min lower intensity mask. An initial course of 3 treatments is recommended, followed by a top-up once a year.
Speciality Contact Lenses
Believe it or not, contact lenses are a very useful tool for very dry eyes. Modern soft contact lenses can be used as a shield to protect the cornea, and hydrate the surface. Scleral contact lenses will shield the cornea as well creating a fluid reservoir for the cornea to sit in.
Long Term Immuno-modulating drops
If you are doing all of the above and you are still suffering from significant symptoms, you may benefit from immuno-modulating medication. These drops are used once a day and have a safer long–term profile than steroid drops. These drops are available privately, as well as via the GP.
Blephex © or NuLids ©
Using the state-of-the-art instruments, we are able to polish the eyelids and lashes to remove debris and dirt that has built up. The process is non-invasive, takes about 10mins to complete and tickles. You will be amazed at the pre-and post-treatment images. Once the in-practice procedure is completed, you will then be advised on the products you require at home to maintain clean and clear lids and lashes.
Zocular is the latest product available for the cleaning and comfort of eyelids and lashes. Derived from Okra (Lady Fingers), the gel is applied to the lids, and the lashes are manually cleaned. The process is non-invasive, takes about 10mins to complete and tickles. You will be amazed at the pre and post-treatment images. Once the in-practice procedure is completed, you will then be advised on the products you require at home to maintain clean and clear lids and lashes.