Occasionally an article or "expert perspective" is
published which really causes the reader to contemplate its
gravity. Dr. Lichter is the Chief of the Glaucoma Service
at the University of Michigan School of Medicine, Department
of Opthalmology and truly challenges our approach to glaucoma
therapy. You will find the following selected quotations from
this masterful work very thought provoking.
Key Excerpts From
Glaucoma Clinical Trials and What They Mean for Our Patients
Paul R Lichter, MD, AJO, July 2003
“Extrapolating the results of clinical trials to everyday
practice is a challenge not only for the average clinician
reading the literature, but also for experts in clinical research.”
“Clinical trials typically ask and answer a single question,
and not the myriad questions a clinician needs to consider
when talking to a patient. Under tightly controlled parameters,
a clinical trial assesses one treatment or one aspect of therapy
to give physicians information to add to the mix that already
informs their clinical judgment.”
“xthere is no way for the trial results to indicate whether
that treatment will be effective in a particular patient.”
“In particular, I want to emphasize that despite the recent
publicity given to detection and management of ocular hypertension,
as few as half of the people with undiagnosed glaucoma will
be detected because they have increased IOP. The other half
will have their glaucoma discovered only by careful optic disk
examination and visual field assessment. “
“Before getting to the trials themselves, I would like to
frame six questions about open-angle glaucoma that describe
what we deal with regularly in our clinical practices in terms
of a patient with ocular hypertension or early glaucoma. We
may not all ask ourselves these questions in exactly the same
way, but they get to the essence of the dilemma we and our
patients face in dealing with this potentially blinding chronic
disease. First, what are the risks to our patients’ visual
function and activities of daily living (the nuts and bolts
of health-related quality of life) if their ocular hypertension
or glaucoma goes untreated? Second, if we accept that the natural
history of open-angle glaucoma has a likely outcome that our
patients and we are not willing to risk, then how early and
how aggressively must we treat our patients to alter the natural
history and preserve quality of life? Third, what are the downsides
to the treatment? Fourth, which treatment is best? Fifth, how
are the results of the treatment best measured? And, sixth,
what risk factors help most in making the best management decisions
for our patients?”
“Is an untreated patient who converts earlier greatly disadvantaged
in terms of long-term preservation of useful vision compared
with the treated patient who may convert many years later,
or never? In other words, once very minimal glaucoma damage
occurs, has this irreversible loss greatly compromised the
patient? Or is it better to watch an ocular hypertensive patient
without treatment and only begin treatment when the patient
converts to definite glaucoma? Or even continue to watch until
the frank glaucoma reaches a particular level of visual field
loss? What is the trade-off of allowing ocular hypertension
or early glaucoma patients to be followed without treatment
(therefore avoiding the nuisance, the side effects, and the
cost of eyedrops) compared with treating them early?”
“While the OHTS is a landmark study, it was not designed to
answer any of the questions posed above. But knowing that treatment
can reduce the conversion from ocular hypertension to glaucoma,
these become the critical questions, the ones that are of greatest
importance to us and to our patients as we manage them one
by one.”
“The mere fact that treating ocular hypertension patients
can reduce the incidence of POAG does not fulfill the requirements
of an evidence-based clinical decision to treat any given patient.
Instead, ophthalmologists need to frame the decision around
what the goals of treatment really are. Are they to slow or
prevent conversion from ocular hypertension to glaucoma, or
are they to prevent visual loss that would impair a patient’s
activities of daily living and quality of life? It makes sense
that the latter is the goal of this treatment decision.”
“Having the technical ability to find visual field loss at
the earliest possible moment does not necessarily mean we have
to act. For my part, early detection of minimal visual field
loss helps me in knowing who to watch more closely for further
change, not in telling me whom to treat.”
“In contemplating decisions on whether to treat ocular hypertensive
patients, we should recognize that letting the patients progress
(under careful observation) to frank glaucoma before treating
them still will allow for control of the disease in the vast
majority of patients. In addition, we know that this control
can occur well before there is a threat to interference with
activities of daily living.”
“But if the patients most at risk of blindness - namely those
with advanced glaucoma - are not likely to go blind while under
appropriate treatment, what does that tell us about the need
to treat a patient with ocular hypertension?”
“The problems I see in my practice with patients who have
lost significant vision from glaucoma are not the ones who
presented to me with ocular hypertension. The patients I recall
who have suffered most are those who, when I first saw them,
had advanced disease.”
“It may be very reasonable to watch for documented progression
of mild visual field loss detected at the initial examination
before beginning treatment. This way, our patients could avoid
the unnecessary burden of nuisance, side effects, and cost
associated with a questionable need for treatment. Conversely,
if the field loss is moderate or worse to begin with or if
the patient had high risk for progression, treatment could
be undertaken immediately.”
“In the case of ocular hypertension or even newly diagnosed
glaucoma, it is important to assess the risks of treatment
against the risks of simply watchful waiting. To repeat, a
critical question to ask is, ‘What is the significance of the
end point that treatment would be trying to prevent?’ “
“So we can ask ourselves how easy it would be, if we allowed
visual field loss to occur, to then institute successful treatment
without having caused meaningful, irreversible harm to the
patient.”
“Common sense would tell us that, given a choice, a person
would prefer not to be burdened even slightly by having to
use eyedrops unless they were important to vision preservation.”
M&T Commentary:
WOW! Maybe we should all take a valium and relax. If our society
were not so litigious, then perhaps such a laissez-faire
approach to therapeutic intervention could indeed be practical.
His observation; "Having the technical ability to find
visual field loss at the earliest possible moment does not
necessarily mean we have to act." is an excellent point
and one worthy of deep introspection. This observation probably
applies even moreso to optic nerve fiber layer scanning devices.
While we believe Dr. Lichter is a bit extreme in his watchful
waiting approach, we also believe many doctors are too quick
on the trigger. We might want to consider moving - at least
slightly - towards Dr. Lichter's perspective so that we do
not participate in an epidemic of haste and premature treatment.
Alas, we need to carefully and thoughtfully consider what is
the absolute best care for each individual patient.
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