Rohto Dry Aid – a dry eye drop developed and manufactured in Japan – has been launched to the Australian and New Zealand markets.

The Australian launch event, which occurred during the 2025 Optometry Clinical Conference in Melbourne, featured the first public presentation of findings from the Tear Film and Ocular Surface Society Dry Eye Workshop III (TFOS DEWS III), delivered by Scientia Professor Fiona Stapleton (University of New South Wales, Sydney), alongside practical implementation insights from Dr Margaret Lam (Sydney).

DEWS III: A SIGNIFICANT EVOLUTION

The DEWS III project involved extensive international collaboration with multiple subcommittees and more than 80 contributors working under Chair, Professor Victor Perez and organiser, Professor David Sullivan.1

Prof Stapleton, who chaired the workshop’s digest group, said the new report represented a significant evolution from DEWS II, published in 2017, and outlined sweeping updates to the international consensus recommendations that will reshape clinical practice globally.

The updated definition recognises dry eye as a multifactorial symptomatic disease characterised by “loss of homeostasis” of the tear film and ocular surface, acknowledging that etiological factors including tear instability, hyperosmolarity, inflammation, and neurosensory abnormalities may not all be present in every patient.2

Simplified Diagnostic Tools

DEWS III introduces the (Ocular Surface Disease Index) OSDI-6 questionnaire to replace the sometimes conflicting results between existing screening tools. The six-item questionnaire uses simple scoring, asking patients questions about “symptoms that they can understand” with a diagnostic cutoff of four, requiring no normalisation calculations.

For objective diagnosis, practitioners need only one of three markers: non-invasive tear break-up time, osmolarity, or ocular surface staining. And Prof Stapleton said practitioners without expensive osmolarity instruments need not worry, as “breakup time is equally as good as a diagnostic test”.

Beyond Binary Classification

The guidelines move away from the traditional binary classification of aqueous deficient versus evaporative dry eye. Instead, DEWS III recognises four main subclassification areas: tear film deficiencies, eyelid anomalies, ocular surface abnormalities, and systemic diseases leading to dry eye. This shift reflects growing understanding that most patients present with mixed presentations rather than fitting neatly into single categories.

Younger Patients at Risk

Perhaps most surprisingly, DEWS III reveals high rates of dry eye disease in patients under 40 – an age group previously overlooked. Analysis of 96 different diagnostic criteria showed “quite high rates of disease, particularly symptoms being reported in the under 40s”, according to Prof Stapleton.

The findings also confirm sex-related differences, with women showing higher rates for most criteria except meibomian gland dysfunction, where men demonstrate higher prevalence in adulthood.3

Pathophysiology Breakthroughs

The workshop revealed new understanding of disease mechanisms, including previously unknown communication between meibomian glands and corneal epithelial cells. Researchers have also gained deeper insights into lipid layer interactions, with lipid ordering and saturation playing crucial roles in tear spreading and evaporation resistance.

Inflammatory pathways, once considered central to all dry eye forms, are now recognised as absent in certain disease subtypes, explaining why anti-inflammatory treatments sometimes fail.

Evidence-Based Treatment Algorithms

DEWS III provides 10 treatment categories, with evidence-based prescribing algorithms that map specific diagnostic findings to appropriate therapies. These colour-coded algorithms allow clinicians to target treatments based on individual patient presentations rather than applying broad-brush approaches. Treatment categories span from universal lifestyle advice to sophisticated ocular surface promoters and regenerators, including emerging biologics and platelet-derived preparations.

Clinical Implementation

The guidelines recommend moving from “less to more invasive” diagnostic approaches, beginning with symptom screening using OSDI-6, followed by non-invasive tear break-up time assessment, then osmolarity (if available), fluorescein tear break-up time (if non-invasive is not available), and finally ocular surface staining.

Each subtype driver requires different testing series to determine positive outcomes, with the framework designed to identify relevant treatment types for specific subcategories.

The full DEWS III report is published in the American Journal of Ophthalmology at sciencedirect.com/special-issue/10PHL822N4T.

ROHTO DRY AID: MULTI-MECHANISM APPROACH

Dr Lam, Head of Optometry and Professional Services at 1001 Optometry, detailed how Rohto Dry Aid aligns with the new DEWS III paradigm. DEWS III encourages more targeted therapy, she explained, and can be recommended for patients with mild through to severe disease. In a workshop the following day, she presented a case where Rohto was used in conjunction with other eye drops for maximal effect in a patient with chronic dry eye.

Dr Lam said drops or treatments that have multiple mechanisms are going to be more effective than drops or treatments that can only serve one purpose. Rohto Dry Aid contains several active ingredients, working synergistically across all three tear film layers. The formulation includes sesame oil, which aggregates with and complements the non-polar layer and has very effective anti-inflammatory properties and antioxidant properties. Castor oil increases lipid layer thickness and tear break-up time, while also providing antimicrobial and anti-inflammatory benefits.

THE MENTHOL ADVANTAGE

A unique feature of Rohto Dry Aid is its menthol component, which addresses neurosensory symptoms increasingly recognised in DEWS III. Explaining the mechanism of action, Dr Lam said the menthol inside Rohto eye drops works on TRPM8 ion channels (which act as the main sensor for cold temperatures in mammals) by accentuating a cooling sensation and increasing basal tear secretion, producing a soothing effect and relieving dry eye symptoms.

This cooling sensation occurs because, as the tear film evaporates, the ocular surface temperature decreases; the cold receptors monitor the rate of tear film evaporation, providing real-time biofeedback about tear film status.

Dr Lam presented comparative studies showing Rohto Dry Aid’s efficacy against existing treatments. She cited a 2023 study demonstrating superior performance compared to sodium hyaluronate 0.15%, with longer tear break-up time, lower OSDI score, and less staining with fluorescein.4

Global Presence, Local Launch

While new to the Australian and New Zealand markets, Rohto was established in Japan in 1899 and has established a global market for several eye drop products.

Three Japanese representatives from Rohto attended the Melbourne launch, asserting the company’s commitment to the Australian local market.

References available at mivision.com.au.