DRY eye disease (DED) has a significant impact on Australian society. The prevalence of DED in Australians is likely to be severely underestimated.
According to the 2016 Australian Bureau of Statistics Census, 34.1% of our population is aged 50 years or older. Bearing in mind the Australian and global ageing population, and the international consensus that DED is underdiagnosed, in 2020 the prevalence of DED in older Australians is likely to be much higher than the prevalence quoted in a 2003 Blue Mountains Eye Study, which found at least one DED symptom in 57.5% of people over the age of 50 years.
With dry eye becoming increasingly more common in younger populations due to a surge in digital screen time (here and here), DED is in fact likely to affect much more than 7.4% of the Australian population quoted in a 1998 Melbourne study.
Even with this underestimation, DED in Australia already constitutes a major health issue. The annual economic burden of dry eye in Australia is estimated to be about $330.5 million per year, when both direct costs such as visits to doctors and indirect costs such as lost work productivity are taken into account. Patients with DED have significantly reduced quality of life, as DED affects multiple aspects of daily living. DED has been shown to affect reading, computer work, driving and sleep (here, here and here). Quality of life metrics show respondents with severe dry eye have reduced quality of life indices similar to patients with severe angina or receiving renal dialysis. Dry eye has been linked to depression and this may add further costs to the individual, society and the health care system.
There are no Australian guidelines on the management of DED. Currently, DED is treated on an ad hoc basis by four main health practitioners: pharmacists, GPs, optometrists and ophthalmologists. Self-treatment with over-the-counter artificial tears is likely to be common but there are no statistics available to verify this. This is out of line with the recommendations of the Dry Eye Workshop 2 (DEWS 2), an updated set of international guidelines for the treatment of DED – a document that took 2.5 years to develop, is comprised of the collaborative efforts of 150 clinical and basic research experts and is about 400 pages long (here, here, here and here). One of the key points of DEWS 2 is the need for application of standardised diagnostic criteria for DED and step-by-step treatment according to the severity of DED. Recommended diagnostic criteria involve standardised disease index questionnaires, Schirmer testing, tear film break-up time and corneal staining as measured by fluorescein and slit lamp evaluation and tear osmolarity. These diagnostic tools are not typically in the scope of practice of a pharmacist or GP.
This is especially relevant in patients with moderate to severe disease who, in my experience, find that their symptoms and complaints are often underappreciated and dismissed as unimportant. After all, with a few notable exceptions, DED does not blind patients. However, patients’ functional impairment should not be underestimated. Therefore, awareness of the risk factors for dry eye and more severe DED is crucial in appropriate triage to optometrists or ophthalmologists.
For example, 40% of patients with glaucoma and 40% of patients with diabetes may have dry eye (here, here and here). The risk of having DED and the severity of the DED increases with the number of preservative-containing glaucoma medications. Likewise, diabetic epitheliopathy due to glycosylation of corneal nerve endings would be expected to increase with duration and poorer control of diabetes. Females are also more at risk of DED than males (here, here and here) and certain subgroups are more at risk of moderate to severe DED. These include women being treated with aromatase inhibitors, postmenopausal women and women with autoimmune diseases such as Sjögren syndrome and rheumatoid arthritis. One study found that the majority of women (78%) taking aromatase inhibitors have dry eye symptoms. Another study found that more than one in three (35%) of postmenopausal women have dry eye. Androgen deficiency appears to play a role in meibomian gland dysfunction. Conventional hormone replacement therapy generally has been found to increase dry eye symptoms and signs (here and here).
Clinicians should be aware of what symptoms may indicate patients with more severe DED. Use of artificial tears more than four times a day is one indicator. Relief with use of drops may be only partial or not at all. Visual blurring and fluctuation can be another flag of more severe DED. Disturbed sleep due to night-time pain and corneal erosions during REM sleep may also indicate more severe disease.
DEWS 2 also outlined the need for prescription medicines when artificial tears are non-effective and DED is more severe. Some of these can be prescribed by GPs and optometrists and some only by ophthalmologists. For example, topical steroids are often a first-line treatment if artificial tear drops are not effective. Topical steroids can result in a rise in intraocular pressure and glaucoma and so unless the health practitioner has access to an instrument to measure intraocular pressure, then generally it is not recommended to prescribe even weak topical steroids such as fluorometholone for more than 1–2 weeks.
It is not known how commonly GPs prescribe topical steroids for dry eye, but in my experience, it is very uncommon. More data exist for optometrists. A survey of Australian optometrists found that 14% prescribed topical steroids for moderate DED and 52% for more severe DED. Second-line options include topical immunomodulators such as cyclosporine and lifitegrast. These second-line options offer a potentially safer and more effective treatment for patients with chronic and more severe DED. However, all these second-line options, while approved by the Therapeutic Drugs Administration, are not listed in the Pharmaceutical Benefits Scheme. These medications may be prescribed through Special Access Scheme application and compassionate programs or private script. Serum autologous tears can also be effective and is a service currently provided by the Red Cross and the Royal Prince Alfred’s Haematology Department in Sydney.
In summary, there are many areas for improvement in the management of patients with dry eye in Australia. Awareness of the significant functional impact DED can have on patients is vital. Appropriate triage and referral of patients with symptoms of and risk factors for more severe DED is important. Topical steroids and topical immunomodulators can be effective treatments for moderate to severe DED.
Associate Professor Colin Chan is an ophthalmologist at the Vision Eye Institute. He is also an Adjunct Associate Professor at the University of Canberra (Faculty of Health), a Senior Clinical Lecturer and Director of the Refractive Surgery Degree at the University of Sydney.
Disclaimer: Associate Professor Colin Chan is the Chairman of the Advisory Board for Cequa (Sun Pharmaceuticals). He has donated his honorarium to Red Cross Australia.
The statements or opinions expressed in this article reflect the views of the authors and do not represent the official policy of the AMA, the MJA or InSight+ unless so stated.