Sep 2015

SPECIAL FEATURE: DRY EYE
Driving dry eye developments
Dry eye is a hot topic in ocular circles
these days. Where once there was a
dearth of diagnostic and treatment
options, there now appears to be a
plethora of new tools, drops, and recipes all aimed
at helping patients with dry eye.
Jennifer Craig, an associate professor with
the University of Auckland’s Ophthalmology
Department and vice-chair of the internationally
renowned Tear Film & Ocular Society’s (TFOS’s)
second dry eye Workshop (DEWSII), says the
problem has always been there, but these days
professionals are able to diagnose it properly and
thus respond better.
“Until recently the profession relied very heavily
on artificial tear drops for affected patients
irrespective of the cause of the dry eye and clearly
that doesn’t work for everybody. Recognition of
the importance of evaporative dry eye, ongoing
research and industry’s increasing support
through research and development in this area is
now providing us with better knowledge, better
diagnostic techniques and tools, and better
therapies for dry eye.”
Greater definition
BY LESLEY SPRINGALL
TFOS’s first dry eye workshop (DEWS), published
eight years ago, was instrumental in bringing
the problem to the fore by developing a common
and accepted starting platform from which
organisations could develop products.
Out went the old definitions, deemed
inadequate, and in came a new consensus
definition:
Dry eye is a multifactorial disease of the tears
and ocular surface that results in symptoms
of discomfort, visual disturbance and tear film
instability with potential damage to the ocular
surface. It is accompanied by increased osmolarity
of the tear film and inflammation of the ocular
surface.
The chronic lack of lubrication and moisture
on the surface of the eye resulting from dry eye
can result in symptoms ranging from subtle but
constant irritation to inflammation of the front
tissues of the eye. Persistent dryness, red eyes, a
feeling of scratchiness or that something’s in your
eye or a burning sensation are common symptoms,
as are watery eyes caused by an over-stimulation
of the watery component of tears as the eye
struggles to protect itself.
Causes and prevalence
According to the experts, there are two main forms
of dry eye: aqueous-deficient dry eye, where the
lacrimal gland fails to produce enough tears; and
evaporative dry eye, where the tear film evaporates
too quickly. The most common cause of the latter
is meibomian gland dysfunction (see separate
story), which is believed to be involved in about 80
per cent of all dry eye cases.
Nailing down the causes of either, however, is
tricky because, researchers say, there are many
possibilities.
Age is a factor. It is estimated that more than 70
per cent of women and 60 per cent of men aged
over 60 have dry eye. Women are more prone due
to hormonal changes, such as menopause.
But dry eye is also increasing in younger people,
even children, with many studies citing our
addiction to screens as an exacerbating factor.
“It seems to be becoming more prevalent, likely
influenced by the lifestyles we lead,” says Dr
Craig. “We know when people are concentrating
on smartphones or tablets they tend to blink less
frequently and less well than they should, often
not closing their eyes fully with each blink.”
Our lack of blinking is considered such a problem
that TFOS commissioned a song, Blink Around the
World, for its international campaign to get people
to blink more.
“Blink Around the World is a fun and catchy
way to remind people to blink their eyes, which
both exercises and protects this preciously vital
organ,” said Amy Gallant Sullivan, executive
director of TFOS, when the campaign launched in
2013. “The simple act of blinking reduces dry eye
symptoms by flushing fresh tears over the eye,
re-moisturising and keeping foreign matter and
irritants out.”
Dry eye can be a side effect of medications,
including antihistamines, antidepressants, some
blood pressure drugs, Parkinson’s medications,
and birth control pills. Environmental factors are
also connected to dry eye. Studies have shown
Some of the imagery used to launch the TFOS DEWS II
higher incidence rates in densely populated (ie.
heavily polluted) cities, dusty or high-altitude
climates, and among those living with constant air
conditioning or dry heating systems.
Other factors cited include contact lens wear;
eyelid diseases such as blepharitis; systemic
diseases such as lupus and Sjögren’s (pronounced
“show-grins”—see separate story); allergens; as an
after effect of eye surgery; as well as poor diet and
dehydration (see separate story).
Treating dry eye
The list of potential treatments and treatment
regimes mirrors the list of causes. Dry eye is
considered to be a chronic and typically progressive
condition that may not be completely curable,
though most agree it can and should be managed
well to relieve symptoms as not treating dry eye
can lead to damage to the ocular surface.
A recent study co-authored by Professor Reza
Dana, professor of ophthalmology at Harvard
Medical School, also found that not treating dry
eye could lead to a significant decrease in corneal
endothelial cell density, lending support to those
who favour treating the underlying inflammation
often associated with dry eye to reduce the
chances of dry eye progression.
In its mildest form dry eye can be managed with
eye drops and other lubricants, with some artificial
tear products addressing specific tear deficiencies,
such as a lack of sufficient lipids. There are also
prescription eye drops; warm compresses to help
melt the thickened oil in the meibomian glands;
and blepharitis treatments to cleanse the lid
margins and keep the controversial, microscopic
and ever-so-common Demodex mite (see separate
story) under control.
Diet can also make a difference with a lack
of vitamin A and essential fatty acids and
dehydration often cited as a cause or exacerbation
of dry eye (see separate story).
For the aqueous deficient form of dry eye, some
practitioners advocate punctal occlusion, where
a small plug, either temporary or permanent, is
inserted into one or more puncta in the eyes to
slow tear drainage. Punctal plugs are preferred
over intracanalicular plugs by some, due to
the lower risk of infection and—in those with
confirmed benefits from punctal occlusion—
punctal cautery can be a superior long term option
(see separate story).
The future
Our knowledge, diagnostic tools and treatment
practices are getting better, says Dr Craig, but
there’s still a long way to go. “We’re learning all the
time. We have to remain open to understanding
the different ways that dry eye can be caused and
other complicating factors.” But the industry’s
increased focus on meibomian gland dysfunction
and its role in evaporative dry eye is certainly
helping far more people with dry eye than ever
before, as is improved understanding of lid hygiene
and the importance of blinking.
We will undoubtedly also learn more following
publication of the DEWS II outcomes, but given
that the workshop was only officially launched in
March 2015, it’s still very early days, she says.
DEWSII’s sub-committees have been set up and
are currently compiling the outlines of what they
propose to include in their reports, which are due
to have their preliminary readings at the next TFOS
conference in Montpellier, France in September
next year. O
Dry Eye & Allergy
Centre of Excellence
123 Remuera Rd, Remuera
0800 393 527
info@eyeinstitute.co.nz
Dry eye research at New Zealand’s Ocular
Surface Laboratory
Located within the Department of
Ophthalmology at the University of
Auckland, the Ocular Surface Laboratory
(OSL), led by Associate Professor Jennifer
Craig, provides an environment for
clinical and basic science researchers to
collaborate to improve understanding of the
mechanisms underlying the development
and propagation of ocular surface disease,
particularly dry eye disease, and to develop
and test new therapies for managing this
prevalent and debilitating condition.
We asked Dr Craig to outline some of the
research projects underway at the OSL at
present.
BY JENNIFER CRAIG
At the OSL, we continue to explore the efficacy of
a number of therapies for both aqueous deficient
dry eye and evaporative dry eye. Current projects
include:
• Recent BOptom honours and summer student
projects confirmed that a microwavable
seed-filled warm compress (MGDRx EyeBag)
has greater predictability and heat transfer
capabilities than a portable heating mask
(Eyegiene). Published earlier this year, the
results show that despite these differences,
both devices demonstrated clinical benefits for
individuals with mild MGD.
• Native Manuka honey, with its intrinsic
antibacterial and anti-inflammatory
properties, has also been under scrutiny
for its potential as a therapeutic agent for
patients with lid disease. From an idea first
proposed by optometrist Grant Watters,
the OSL has worked in collaboration with
senior lecturer and BOTU Director Dr Ilva
Rupenthal; microbiologist Dr Simon Swift; and
Manuka Health NZ to create a Manuka honey
formulation designed for daily overnight
topical application to the eyelids. Development
and preclinical testing began several years ago
and the clinical tolerability trial has recently
been completed in healthy individuals, with
the assistance of Auckland optometrist Chee
Loh and trainee ophthalmologist Dr Leah Te
Weehi.
The next stage of the process involves testing
the efficacy of the product in clinically
significant blepharitis. A call will be made
to clinicians in the Auckland area in coming
months for patients who may wish to
participate in this three month trial. This work
will be coordinated by postdoctoral research
fellow Dr Isabella Cheung, while evaluation of
inflammatory markers is being undertaken by
Auckland optometrist Varny Ganesalingam,
currently working towards a MHSc on the topic
of ocular surface inflammation.
• Successful publication of Amy Chen’s NZAOsponsored
summer studentship conducting a
pilot study on the efficacy of IPL has led to a
new international industry collaboration. The
future project forms the basis of Ally Xue’s PhD
studies, where she is delving deeper into the
mechanisms of action of IPL (see associated
story)
• The group at the OSL has also been working
in collaboration with Oculeve, a US company
recently acquired by Allergan. Participation
as one of the sites in Oculeve’s international
multicentre trial last year created the
opportunity for further collaboration with the
team in the area of nasal neurostimulation,
using a device which has been designed to
help address aqueous deficiency.
• Learning more about ocular demodecosis
and seeking better tolerated and efficacious
treatments for Demodex infestation has been
CONTINUED ON P12
8 NEW ZEALAND OPTICS September 2015