Biomedical Engineering Reference
In-Depth Information
that the animal being examined and the animal for which the data is
being entered correspond.
Depending on the compound being evaluated and the SOP,
the ophthalmologist will be expected to wear shoe covers, a lab
coat, or surgical scrubs and gloves at a minimum and may be
required to wear a Tyvek
®
suit, surgical cap, mask, and occasionally
a respirator. When working with nonhuman primates (NHPs),
annual testing for tuberculosis (TB) using a TB intradermal PPD
skin test or the new QuantiFERON
®
-TB blood test will generally
be required of all personnel including the ophthalmologist.
The ophthalmologist must be familiar with what is normal for
the species being examined and what are the common, spontaneous
abnormalities for that species, age of animal, and breed/strain.
Albino vs. pigmented eye may be a factor as is the type of retinal
vasculature, ranging from anangiotic to merangiotic to holangiotic.
The presence or the absence of a tapetum and whether the animal
has a fovea should be considered. In addition, the examination
techniques to be used, type of biomicroscope and indirect ophthal-
moscope, size and diopter of the indirect lens, and number of
animals that can be examined in an hour must be understood. The
role of the veterinary ophthalmologist is to perform a pretest exami-
nation designed to eliminate those animals not suited to the study
and to establish a baseline database to compare interim and end-of-
study findings. Animals are then subsequently examined one or
more times during the study, at the conclusion of the study, and
possibly in a recovery phase depending on the study duration and
design. Typically studies are divided into acute, subacute, subchro-
nic, and chronic depending on the duration. The ophthalmologist
must then interpret findings in light of the species examined, pretest
data, compound evaluated, additional study procedures performed
(anesthesia, orbital blood collection), and dose group outcome.
Since most laboratory studies involve a significant number of
animals, organization and efficiency are essential. In general, most
canine, primate, swine, feline, and rabbit studies involve 40-60
animals while rats and mice may involve 250-1,500 animals in a
single study. A single ophthalmologist generally requires 2-3 ani-
mal handlers, a data entry individual, and in studies over 250
animals 1-2 individuals to go ahead of the animal handlers to dilate
the pupils. For efficiency, an animal should be in front of the
ophthalmologist at all times. The ophthalmologist's findings are
reported verbally to the data entry individual who then either enters
it into a computer program or records on a paper record for later
entry into a computer database. This data is then verified at the end
of the examination and both the ophthalmologist and data entry
individual date and initial the accuracy of the report.
When an ophthalmic abnormality is observed, it must be char-
acterized with respect to diagnosis, location, and severity. Depend-
ing on the laboratory, some will utilize a standardized scheme for
recording of clinical observations such as Provantis
®
that has a set of
