When Is Early Diagnosis Too Early?
- When working up a glaucoma suspect, check the pressures at
different times from visit to visit, or even check the IOP
every two hours over the course of a single day. Always note
the time of day when taking tonometric measurements. Use Goldmann
applanation tonometry and pachymetry when evaluating and following
glaucoma suspects and glaucoma patients.
- General guidelines for setting a target IOP: Reduce IOP by
the percentage of the pretreatment baseline. For example, if
the initial IOP is 30mm Hg, try to reduce IOP by 30%, aiming
for a target of about 20mm Hg. Modify the target IOP according
to the stage and severity of the disease.
- To maximize ocular absorption, enhance efficacy and minimize
systemic absorption of adrenergic drugs, such as beta-blockers
or alpha agonists, instruct patients to gently close their
eyes for a full three minutes after instillation. Lid closure
is not necessary with the prostaglandins or CAIs. If more than
one medication is being used, wait at least 20 minutes between
instillations.
- Avoid adding new medications until efficacy and compliance
with the initial therapy are established. Remember, there is
a 10% non-response rate with most all topical ophthalmic drugs.
Efficacy is best determined via a monocular therapeutic trial.
While such a maneuver is not an exact science, it can be enormously
helpful in most patients most of the time. Have the patient
try to return near the same time of the day for their follow-up
visit for the monocular trial so as to attempt to minimize
any deviation in the diurnal physiological IOP variation. The
validity of the monocular trial is time-honored in clinical
practice and should be done in virtually all circumstances.
- Perform at least two visual fields during the first three
to six months of evaluation and/or therapy, and repeat testing
annually for most patients.
- When unilateral glaucoma is present, carefully evaluate for
traumatic angle recession, pigmentary glaucoma and pseudo-exfoliative
glaucoma.
- When you inherit a patient on three or four different glaucoma
drugs, he or she is most likely overmedicated. Try doing a
reverse-therapeutic-discontinuation monocular trial. First
stop the drug deemed least effective and recheck the patient
in a month, preferably at the same time of day. If the pressure
remains essentially the same, discontinue the drop in both
eyes and recheck in a month or two. If IOP remains stable,
try a monocular discontinuation of what you deem to be the
next least clinically effective eye drop, etc.
- Always pre-appoint glaucoma and glaucoma suspect patients
so that “no-shows” can be identified and contacted. This is
good, sound patient care, and is also a wise medicolegal practice.
- When treating a patient with concurrent glaucoma and asthma,
consider one of the prostaglandins, unoprostone isopropyl,
brimonidine, a topical CAI, or even Pilopine HS gel. Since
the prostaglandins appear to most effectively reduce IOP, they
would be drugs of choice in treating low tension glaucoma.
- Iridocorneal angles can narrow over the years to the point
of intermittent angle closure and complete angle closure. If
a patient has grade I or grade II angles at baseline, and after
years of follow up, the IOP in one eye becomes elevated by
several millimeters of mercury, perform gonioscopy again. Such
increases can occur in patients being treated for glaucoma,
as well as in non-glaucomatous patients. The scenario may be
hastened by the development and progression of nuclear sclerosis,
as the thickening cataract pushes the iris diaphragm anteriorly.
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