DEWS II report published

September 1, 2017 Staff reporters

After almost two and a half years of work, the near 400-page TFOS DEWS II report has been published by the Tear Film & Ocular Surface Society (TFOS). This massive undertaking involved 150 researchers from 23 countries who analysed, crunched and compared thousands of evidence-based articles into reports covering all factors relating to dry eye.

 

Building on the work begun in 1995 by the US-based National Eye Institute and the completely ground-breaking TFOS DEWS report in 2007, the DEWS II report aimed to:

 

• Update the definition, classification and diagnosis of dry eye disease (DED);
• Critically assess the etiology, mechanism, distribution and impact of the disorder; and
• Address its management and therapy

 

This mammoth task was led by a 25-member steering committee, chaired by Dr Dan Nelson, associate medical director for specialty care for HealthPartners Medical Group and Clinics in Minnesota; the vice-chair was New Zealand’s own Jennifer Craig, associate professor in the Department of Ophthalmology at the University of Auckland; and the organiser was Dr David Sullivan, associate professor at Harvard Medical School. Ten sub-committees were created to develop reports to cover definition and classification; sex, gender, and hormones; epidemiology; tear film; pain and sensation; pathophysiology; iatrogenic dry eye; diagnostic methodology; management and therapy; and clinical trial design. There were two additional subcommittees that focused on public awareness and education; and industry liaison.

 

Definition

 

The report highlights a number of areas that require further study to better clarify the extent and precise nature of some of the causes and prevalence (especially south of the equator and in younger people) of DED, and to better diagnose dry eye. But the new definition, and clear diagnostic criteria, will help standardise studies so they can be better compared, combined and understood, says A/Prof Craig.

 

The newly developed TFOS DEWS II definition states:

 

Dry eye is a multifactorial disease of the ocular surface characterised 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 neurosensory abnormalities play etiological roles.

Key findings

 

Other key findings include:

 

1. Meibomian gland dysfunction (MGD) and Sjögren and non-Sjögren lacrimal disease remain leading causes of evaporative and aqueous-deficient DED, respectively, but many hybrid forms of DED exist

 

1. Evidence supports the more contemporary two-phase model of the tear film, with a lipid layer overlying a mucoaqueous phase. While the whole tear film (lipids, mucins, proteins and salts) may prevent tear film evaporation and collapse, additional studies are needed to confirm this

 

1. It’s now understood that sex, gender, and hormones play a major role in the regulation of the ocular surface and adnexal tissues, however further studies are needed to clarify the exact nature, extent and mechanisms of their effects

 

1. Inflammation of the ocular surface can cause inhibition of lacrimal secretion and loss of epithelial barrier function at the ocular surface, thus the role of increased friction in DED needs further investigation

 

1. The most prominent nerve disturbance is with cold thermoreceptors, suggesting that dryness-induced nerve damage dominates over inflammation

 

1. Topical and systemic medications, contact lenses, ophthalmic surgeries and non-surgical procedures can cause DED. Work is needed to better define specific risk factors, create less toxic medications and preservatives, devise less invasive ophthalmic procedures and identify early DED prior to surgery

 

1. Currently the best way to diagnose DED involves triaging questions, risk factor analysis and symptoms analysis, combined with a detailed anterior eye exam for further evaluation should DED be suspected. New approaches and better-validated instrumentation and techniques are needed to more critically assess DED and to link underlying causes in an individual to the most suitable therapies to manage their DED

 

1. Restoration of tear film homeostasis is the ultimate goal in the management of DED, therefore determining whether the major cause of a person’s DED pertains predominantly to aqueous tear deficiency or evaporative causes, or both, is critical in helping select the most appropriate management strategy

 

“The TFOS DEWS II report is available for download at no cost, and I encourage my colleagues to read it,” said Bill Townsend, president of the US Ocular Surface Society of Optometry, in Optometry Times. “It sheds important light and offers new evidence about on one of the conditions that (optometrists) commonly encounter. Kudos to this distinguished group for their work leading to this publication.”

 

In the same Optometry Times article, US-based Dr Milton Hom called the TFOS DEWS II report “groundbreaking”.

 

“What have I learned? Dry eye is the new multi disease: multi-factorial, multi-coloured, multi-cultural, multi-flavored… I’m absolutely certain TFOS DEWS II will be the new standard to follow. Hats off to TFOS for a great accomplishment.”