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Ocular surface inflammation impacts
on glaucoma treatment outcomes
Dermot McGrath
in Paris
Inflammatory infiltrates in the conjunctiva
Courtesy of Christophe Baudouin MD, PhD
INFLAMMATION of the
ocular surface should not
be underestimated in the
management of glaucoma,
as it may have a direct
impact on the success or
otherwise of the
therapeutic regimen being
Christophe Baudouin administered to treat the
disease, according to
Christophe Baudouin MD, PhD.
“Patients with glaucoma and concomitant ocular
surface disorders may have incomplete responses to
anti-glaucoma medications which may be partly due
to disease or inflammation of the ocular surface.We
should also bear in mind that some glaucoma
treatments may in turn have toxic effects on the
ocular surface, and treatment may exacerbate ocular
surface disease,” he said.
Dr Baudouin, professor and chair of
ophthalmology at Quinze-Vingts National
Ophthalmology Hospital, Paris, said that the
complex interrelationship between the ocular
surface and glaucoma has not always been fully
appreciated by clinicians.
He noted that part of this perception stems from
the results of randomised clinical trials of antiglaucoma medications, which tended to mask the
real impact of inflammation on the management of
glaucoma.
“Looking at the clinical trials of the principal antiglaucoma drugs, it would appear that there is not
really any serious issue or problem associated with
their use. However, we see on average about three
per cent to five per cent of patients experiencing
allergies, while 10 per cent to 12 per cent of
patients reported redness or significant irritation,”
he said.
However, as Dr Baudouin emphasised, there is a
world of difference between the simulated
environment of clinical trials and real-life
experience.
“The fact is that real life is not about one drug
being administered for one year to a selected
patient. Real life entails treatment over 10 or 20
years, and usually involves the association of
different drugs. An estimated 70 per cent of
glaucoma patients will use a combination of different
drugs. And we also know that ocular surface
diseases are very frequent over the age of 60,
affecting about 20 per cent to 30 per cent of the
population. So mathematically we will have about 20
per cent of patients with glaucoma treatment also
having concomitant ocular surface disease,” he said.
For most clinicians dealing with glaucoma patients
on a daily basis, the real challenge is to deliver a safe
and effective therapeutic regimen that takes on
board all facets of a patient’s ocular health.
“This is why we have to appreciate the
Toxic keratoconjunctivitis in a multitreated patient
importance of dealing with inflammation at the
ocular surface level. For instance, we know that
allergic reactions are comparatively easy to deal
with and will usually resolve if we stop the antiglaucoma medication. However, how do we choose
between stopping the allergic inflammation and
EuroTimes,Vol 13, Issue 3, March 2008 – Not for reprinting
taking the risk of allowing the glaucoma to progress
and resulting in visual field loss? And if we allow the
inflammation to develop, we may end up with
chronic inflammation of the ocular surface that is
very severe and almost impossible to treat in the
context of management of the glaucoma,” he said.
Chronic conjunctivitis
While allergic reactions occur in a small number of
glaucoma patients, Dr Baudouin said that a more
common and serious occurrence in such cases is
the presence of non-specific chronic conjunctivitis.
He noted that treatment for glaucoma using one
or more topical preserved eyedrops might increase
subclinical inflammation or aggravate ocular surface
disease that may already be present.
Benzalkonium chloride (BAK), the preservative
most often used in anti-glaucoma drugs, has been
associated with allergic reactions and other ocular
disorders, said Dr Baudouin. For glaucoma patients,
the presence of BAK on the ocular surface may lead
to a decrease in corneal epithelial integrity,
secondary increase in corneal and conjunctival
inflammatory cells, loss of goblet cells and reduction
in tear function.
Dr Baudouin advised measuring tear break-up
time as a quick and reliable means of monitoring the
health of the ocular surface, as an estimated 70 per
cent of glaucoma patients may show a decrease in
tear break-up time, indicating the presence of
inflammation.
Furthermore, Dr Baudouin noted that long-term
topical combination therapy using preserved eye
drops is a significant risk factor for the failure of
subsequent glaucoma surgery.
“We know from different studies in the past that
inflammation is frequently present and is related to
anti-glaucoma drugs that can influence the outcome
of glaucoma surgery.This is due to fibrotic tissue
response in the bleb after glaucoma surgery, where
collagen deposition may encapsulate the bleb or
block aqueous outflow resulting in a flat, inefficient
bleb,” he said.
With this in mind, reducing the amount and
number of topical treatments decreases the amount
of preservative-associated toxicity and may improve
outcomes related to glaucoma surgery, he said.
This is also true for ocular surface inflammation,
even at the subclinical level, added Dr Baudouin,
“Several studies have shown that the level of
inflammation present in glaucoma patients is directly
related to the number and duration of treatments,
and that the inflammation is decreased if we use
non-preserved glaucoma medication,” he said.
Dr Baudouin said that clinicians should bear in
mind the interrelationship between the ocular
surface and glaucoma in order to deliver treatments
that take account of overall ocular health and help
to maximise patient outcomes.
[email protected]
EuroTimes,Vol 13, Issue 3, March 2008 – Not for reprinting