Page 10 - JOP2020_FINAL2.pf

eyelid skin, facial skin, bone, and paranasal
sinuses. Figure 1 and Figure 2 show some Reflex near pupil is often sharpest
of the structures the ocularist and other Shadows/reflections Lid shadow on iris
members of the reconstructive team must of eyelashes
consider solely around the eye.

Relationships Between the
Normal Eye and Orbit: A Review
Understanding the basic anatomy of the
human eye is a requirement for all health
care providers, and even more significant
to eye care practitioners, including ocu-
larists. Although the companion eye in
monocular patients is usually within the
normal range of aesthetics and function,
the affected side is always distorted after Lights on larger Tearfilm reflex is Light passing
exenteration. In many respects, knowing vessels often linear through cornea
8
and understanding the anatomy of the hu-
man eye is of paramount importance when Figure 1. Key anatomy around the eye includes the proportions of the
creating orbital prostheses. This is due to palpebral fissure. This figure also shows the typical interplay of reflect-
the fact that almost all the orbital anatomy ed light and shadow on the eye, which is essential for the ocularist to
is removed before the prosthetic specialist know in order to create the most realistic facsimile of the fellow eye.
begins work. The ocularist is more involved
in reconstruction in cases of exenteration
than in the more common cases of enucle-
ation, in which they work with and around
the remaining palpebral fissures.
While prosthetic specialists rarely work
on actual eyeballs (except to cover micro-
phthalmic and blind, phthisical eyes using
scleral cover shells), this knowledge can as-
sist in creating a natural-appearing orbital
prosthesis, which will be of benefit to the
patient. Cooperation and dialogue among
ocularists, facial prosthetic specialists,
surgeons, and patients are enhanced by
the ocularist’s strong background knowl-
edge of orbital anatomy. A skilled ocularist
should be familiar with the relationships Figure 2. The palpebral fissure exposes the area of the eye that is
between features of the healthy, normal normally visible. The size and shape of this area varies from person to
eye in order to understand the elements person. The diameter of the iris also affects how much of the rest of
to be crafted for a realistic prosthesis. the eye is visible. These proportions are essential to know in order to
Of course, all “normal” features will be create natural-looking ocular (and orbital) prostheses.
considered in light of the patient’s unique
appearance in order to create the most natural-appearing reconstruction possible.
The opening of the lids in primary (forward) gaze is normally somewhat asymmetrical. When the eyelids are
open, the apex or highest point of the upper lid is typically slightly nasal to the center of the eye, while the lowest
point of the lower lid is slightly temporal to it. The medial canthus is slightly lower than the lateral canthus. This
knowledge is helpful for patients who have experienced trauma, for whom their prosthesis may become the
“normal” appearing eye.

8 | MICHAEL HUGHES / NEIL HUGHES / BARRON JOURNAL OF OPHTHALMIC PROSTHETICS