Leprosy Mailing List – March 29th, 2007
Ref.: Ocular deformities in
leprosy; a simplified grading system (see
attachment)
From: Ebenezer D., Baltimore,
USA
Dear Dr Noto,
Despite its importance in ocular leprosy,
investigating corneal sensation has not been a primary interest
in most studies. A few
studies have looked at corneal sensation but much more needs to be
done if we are to arrive at a consensus as to the best methodology to
be employed in estimating it.
Dr Kawuma has a good question (LML
March 21st, 2007).
Does loss of corneal sensation correlate with an abnormal blink
reflex? The primary
difficulty here is defining what is corneal sensory impairment
and in defining an abnormal blink reflex. We obviously do not have a
good definition for impaired corneal sensation as we do not have a
definitive methodology to estimate it without too much variability and
our discussions thus far has only strengthened our case for evolving a
good method to evaluate corneal sensation.
We meet with the same difficulty in blink
reflex. A normal blink
reflex is one which occurs several times in a minute (this again needs
to be standardized in different populations) and one in which both the
upper lid and the lower lid touch each other momentarily without
apparent consciousness. Timing
a blink reflex is difficult unless we arbitrarily set a time (e.g. no
blink in 15 seconds). So
what time interval do we set? Is
blinking spaced out regularly? To
get a reasonably good average figure how long do we need to take to
estimate blink reflex. Since
we are talking leprosy, any lagophthalmos or orbicularis oculi
weakness will preclude a normal blink reflex and estimating corneal
sensation in these patients (who need it most) using the blink reflex
would be (as you can see) very difficult. So, there are many things to
think through.
I had written an article a year ago but never got around to publishing
it because it did not contain data that I wanted to obtain. I am attaching it so that it
can be circulated. If we
could do something about it I'll be very happy.
Dr Ebenezer Daniel
Division of Ocular Immunology
The Wilmer Eye Institute
School of Medicine
The Johns Hopkins University
(See attached file: EYE DEFORMITY GRADING PAPER Ebenezer Daniel.doc)
