Advanced Trauma Life Support ATLS Student Course Manual 2018

Appendix A
OCULAR TRAUMA
OBJECTIVES
1. Understand basic orbital and ocular anatomy.
2. Describe a focused history for ocular trauma.
3. Describe a systematic examination of the orbit and
its contents.
4. Explain how to assess intraocular pressure.
5. Understand the characteristics of lid lacerations
that require referral to a specialist.
6. Describe the fluorescein dye test and its utility.
7. Identify signs of retrobulbar hemorrhage and
explain the necessity for immediate treatment
and referral.
8. Describe the treatment of eye injuries that result
from chemical exposure.
9. Identify signs of a ruptured-globe injury and
describe its initial management before referral to
an ophthalmologist.
10. Understand the characteristics of eye injuries that
require referral to an ophthalmologist.
In military medicine, doctors and support personnel
have long cited the mantra “life, limb, or eyesight” to
describe what constitutes a true medical emergency.
Although emergent medical care has changed with
time, this concept still holds true. The eye is important
indeed, but it is typically not evaluated until after the
patient is deemed medically stable.
Minor abrasions and lacerations to the eye and
eyelids are common in polytrauma patients. This
appendix focuses on the few ocular injuries that can
blind a patient if not treated within the first few hours
after onset. Understanding the fundamentals of the
eye exam after injury, begins with a review of basic
eye anatomy.
Anatomy review
The cornea is the transparent layer that forms the anterior
boundary of the space known as the anterior chamber,
and it is contiguous with the sclera. The interior of the
globe is divided into anterior and posterior segments
by the lens. The anterior segment includes the cornea,
sclera, conjunctiva, iris, and lens. The space between
the cornea and iris is called the anterior chamber and
is filled with aqueous humor—a solution of sodium,
chloride, and other ions. The posterior segment of the
globe is between the lens and the retina, and it is filled
with vitreous humor—a clear, jelly-like substance. The
optic nerve is at the back of the eye; it travels through
the muscle cone, through the orbit, and then into the
brain. n FIGURE A-1 provides a review a anatomy of
the eye.
The globe includes the attachments of the extraocular
muscles to the sclera. The sclera and muscles are
covered by an epithelium called the conjunctiva,
which extends from the cornea-sclera junction over
the sclera and then turns to cover the inside of the
eyelids. The extraocular muscles join together to
make a “cone,” which is covered in a fascia-like sheath
called Tenon’s capsule. This minimally distensible
fascial covering limits the ability of these muscles to
expand; thus, hemorrhage in this area may produce a
compartment syndrome.
The globe–muscle cone complex sits in the orbit
of the eye, which is a pear-shaped cavity formed
by bones that separate the orbital compartment
from the sinus and brain tissue. The eyelids have
tendinous attachments (canthal tendons) medially
and temporally on the bony orbit, which keep the
globe from moving forward. This arrangement
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