Dry eye affects hundreds of millions of people globally. In some populations, as many as 75% of people suffer from the disease to some degree. Despite its prevalence, the complex nature of its causation, the vicious cycle of its symptomology, and uncertainty in the previous diagnostic criteria mean that many dry eye patients have gone without adequate or effective treatment, while others have never even been diagnosed.
The TFOS DEWS II report, which was published earlier this year, has refined the definition of dry eye disease (DED), set out a number of diagnostic criteria for primary care providers and specialists, and proposed a staged approach to treatment and management bringing more clarity for practitioners.
In November this year, five of the UK and Ireland’s leading optometrists and ophthalmologists met in Dublin for The Annual International OSD Review. Hosted by Scope, the professionals discussed the report in detail; covering its implications for the future of DED diagnosis and treatment and strategies for greater awareness among optometrists, ophthalmologists, GPs, pharmacists and the general public.
“The new definition matches with the patients we see,” said Samer Hamada, consultant ophthalmologist. “It’s reflective of reality and a very good guide for us as practitioners.”
Defining DED and early diagnosis
Importantly, the new definition of DED emphasises that it is a multifactorial condition, not caused or characterised by any singular process. The distinguishing feature is a loss of homeostasis of the tear film, accompanied by ocular symptoms, including tear film instability and hyperosmolarity, inflammation and damage, and neurosensory abnormalities that all play etiological roles.
The panel unanimously praised the inclusion of osmolarity in the new definition.
“Osmolarity is key, and yet it’s not used by clinicians as much as it should be,” said optometrist and DED specialist Nick Dash. “It’s a biomarker which is the most accurate that we have available to us. It’s fundamental,” he added.
Catching DED before it develops, or in its early stages, is absolutely crucial to ensure that it does not cause the patient long-term problems and impact their quality of life. However, with overall awareness of the condition and its effective treatment low, this is a difficult issue.
"It all comes back to compliance. We have to make it easy as possible for patients"
Lifestyle driving DED prevalence in young and old
DED mostly affects older patients, but will often present in those who live and work in dry environments, take certain medications, or have underlying medical conditions. Contact lens wear also plays a role, but the most important – and increasingly widespread – is screen usage.
“In history, there’s hardly ever been anything evolutionary that’s happened so quickly,” said consultant eye surgeon, Arthur Cummings. “We went from looking at things in the distance and looking at things up close to suddenly staring at screens at intermediate distance the whole day, and never taking a break from it,” he added.
When we do take a break from the PC, it’s to look at another screen: our smartphones.
When we look at a screen for a prolonged period of time, we blink less and often not completely. By not blinking properly, our tear film, which maintains homeostasis of the ocular surface, is not replenished as frequently and the meibomian glands do not inject their protective oils onto the tear film surface, thereby increasing evaporative stress. This can lead to corneal damage.
Flagging and managing DED
To raise awareness of the severity of DED among primary care providers and the general public, Dr Aoife Lloyd McKernan, optometry lecturer at the Dublin Institute of Technology, suggested incorporating a DED screening procedure into digital screen equipment risk assessments, which British and Irish companies are required to carry out by law.
A simple questionnaire, included as part of the assessment, would ask the employee about their screen use and whether they are experiencing any signs or symptoms concurrent with DED.
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“Educating and making people aware of [dry eye] so we address it earlier is important,” said Mr Cummings. “When people are complaining about their eyes, most of THE time, especially young people sitting in front of screens, it’s dry eyes.”
In clinic, the DEWS II diagnosis model suggests the DEQ or OSDI questionnaires to screen for dry eye, with non-invasive tear break-up time, osmolarity testing and ocular surface staining are required to confirm the diagnosis.
While awareness of the prevalence and symptoms of DED is a crucial step in tackling the disease, deeper collaboration between primary care providers and ophthalmologists is necessary to ensure patients receive timely and appropriate care.
An element of ‘work sharing’ is therefore crucial. On the front line of eye health, optometrists should screen for dry eye within a routine eye test, but a separate appointment in a specialist clinic is required to allow the time for a proper diagnosis, sub-classification and management of the condition.
It’s important for a clinician to delay corrective procedures, such as contact lens fitting, or cataract or refractive surgery, in patients with symptoms and/or signs of DED.
Ultimately, a full investigation and step-by-step plan will help to reduce costly repeat appointments and improve patient satisfaction. “It's imperative that we do not delay,” said Mr Dash. “By dealing with [dry eye] issues before we implement vision correction, we're going to have happy patients,” he added.
DED management is long-term and it should be holistic. The panel agreed that the DEWS II report’s staged approach to dry eye management is solid. They restated that patients must continue their treatment regimen at home to keep their symptoms under control.
“We need to focus more on education, and give patients resources where they can read about dry eye or show them where they are on the dry eye scale,” said Mr Hamada. “Once you involve patients in the management [of their condition]... they'll take responsibility and it will improve compliance,” he added.
Panel chair Professor James Wolffsohn suggested that the eye care community needed to make greater use of digital tools, like apps, as well as videos and animations, to increase awareness and compliance among patients – the panel agreed.
A smartphone app, for example, could be particularly effective in guiding the patient through their diagnosis and prescribed treatment, and reminding them to take their medication or apply a treatment, like a moist heat mask, Omega-3 supplement or drops.
Panellist Dr McKernan emphasised: “It all comes back to compliance. We have to make it easy as possible for patients. To improve compliance, she suggested optometrists and ophthalmologists advise their patients to incorporate certain treatments, like heat masks, into their mindfulness and meditation regimes.
Dry eye is a common but complex, multifaceted disease that varies widely from patient to patient. DEWS II provides primary care providers and eye care specialists with an invaluable toolset to diagnose and treat it. However, with screen usage increasing, and DED alongside it, this alone is not enough: awareness campaigns, closer collaboration between healthcare practitioners, and more tools for patient compliance must be developed as a matter of urgency.
The roundtable was chaired by Professor James Wolffsohn, associate pro-vice chancellor at Aston University, academic chair of the British Contact Lens Association, and chair of the TFOS DEWS II diagnostic and methodology sub-committee.