Dry eye disease(DED) is a prevalent age-related ophthalmic condition. Depending on the
population studied and the diagnostic criteria used, dry eye disease is estimated to have
a high prevalence in most populations , with a female preponderance. In the latest 2017
Tear Film and Ocular Surface Society Dry Eye Workshop II (TFOS DEWS II) Epidemiology
Report, which compiled dry eye prevalence data from studies worldwide, the reported the
prevalence of DED ranged from 5 to 50%. The risk of dry eye disease increases with age,
where with every increase in 10 years of age, the self-reported symptoms of DED increased
by 2%. In one study in Asia, up to 70% of elderly patients greater than 60 years of age
suffering from symptomatic dry eye disease. Dry eye disease causes gritty and painful
eyes, with associated blurred vision. For sufferers, it poses a significant burden on
quality of life and limitations activities on activities of daily living, resulting in
considerable economic costs to society. A 2006 health-economics study in the United
Kingdom estimated that the annual healthcare costs to the public sector for every 1000
dry eye patients was USD 1.1 million.
The causes of dry eye can be broadly classified into those with aqueous tear deficiency,
excessive tear evaporation or a combination of both. The most common cause of excessive
tear evaporation is meibomian gland dysfunction (MGD). This is a common condition of the
eyelids where there is a significant change in both the consistency and quantity of
meibum, resulting in chronic inflammation of the eyelids and subsequent ocular surface
dysfunction. MGD has a prevalence from 46.2% to 69.3% in several studies targeting Asian
populations, with a trend of higher prevalence in the elderly. Insufficient lipid
secretion from meibomian gland undermines tear film stability, producing dry eye symptoms
despite normal tear secretion. In a recent study, up to 70.3% of dry eye patients were
found to have concurrent MGD. Refractory MGD is defined by the failure to respond to more
than at least three types of conventional therapy, including lubricating eyedrops, gels
and ointments and topical or systemic anti-inflammatory treatment, in the past two years.
Currently heat-based therapies are the mainstay and most effective strategies against
MGD. Eyelid warming, thermal pulsation and intense light therapy are three prevailing
heat-based treatments for MGD- related dry eye disease. Eyelid warming usually involves
the application of warm towels, commercialized eye masks (EyeGiene® or Blephasteam®) or
eye bags (MGDRx Eye Bag) at least twice a day. Thermal pulsation (Lipiflow®) refers to
the delivery of controlled heat together with gentle massage to the eyelids by the
machine for 10-17 minutes. Intense pulsed light (IPL) therapy, which uses light energy on
the skin surface, is widely used in dermatology to treat a variety of conditions
including dermal vascular lesions, such as port wine stains and hemangiomas, facial
rosacea, and acne. Each treatment strategy however carries significant limitations.
Self-applied eyelid warm compress is cheap and easily available, but when used alone has
limited efficacy. Furthermore, sustained patient adherence to treatment is difficult long
term. A single treatment of thermal pulsation therapy has been shown to have sustained
therapeutic effects up to 12 months after treatment. However, thermal pulsation is not
effective in moderate to severe cases of MGD. From existing studies, IPL has greater
clinical efficacy than thermal pulsation, but its therapeutic effects are maintained for
a significantly shorter period. As such, monthly repeated treatments for up to 8 months
may be required for sustained effects. It is also important to note that none of the
existing treatments allow the eyelids to evacuate inspissated meibum effectively, with
meibum expression by an ophthalmologist an important step in the treatment process. Thus,
MGD is likely to recur long-term.
The Thermage FLX System (WA, USA) is a non-ablative radiofrequency (RF) energy-based
device, which has been widely adopted in the cosmetic industry for radiofrequency tissue
tightening. RF transfers high energy fluences through the skin to deep dermal layers
uniformly while protecting the epidermis. It is postulated that RF stimulates subdermal
collagen production for tissue tightening effect. There are several advantages of using
non-invasive RF treatment over other currently available energy-based devices. Firstly,
the Thermage FLX has a much more precise applicator directly targeting the meibomian
glands. Thermage FLX addresses both the upper and lower eyelids as close as possible to
the lid margin, which is directly where the meibomian glands are situated, it also
addresses the tragus area as well, hence a more precise and direct treatment area can be
achieved. Secondly, compared to other energy-based devices, Thermage FLX provides a
higher accumulative heat transfer effect around the periocular region, due to its
repeated application of at least 4-5 cycles around the periorbital region. With higher
accumulative heat energy, we anticipate a better and more effective melting of the
meibum, which aids in more effective meibum expression. Thirdly, as Thermage FLX has been
widely adopted for radiofrequency tissue tightening due to its collagen resynthesis
effect, there has been proven improvement of the elasticity of orbicularis and periocular
skin tissue, this can promote better blinking effort and better apposition of lid
margins. This may enhance the pumping effect of the orbicularis oculi in the long-term.
RF treatment is potentially a safe and effective multimodal treatment for MGD-related dry
eye disease.