SECTION 5 Problems Related to Altered Sensory Input
22
Assessment and Management:
Visual Problems
Mariann M. Harding
http://evolve.elsevier.com/Lewis/medsurg/
CONCEPTUAL FOCUS
Coping Infection
Functional Ability Sensory Perception
LEARNING OUTCOMES
1. Describe the structures and functions of the visual system. 7. Describe the purpose, significance of results, and nursing
2. Explain the physiologic processes involved in normal responsibilities related to diagnostic studies of the visual
vision. system.
3. Obtain significant subjective and objective assessment 8. Compare and contrast the types of refractive errors and
data related to the visual system. appropriate corrections.
4. Perform a physical assessment of the visual system using 9. Describe the common causes and assistive measures for
the appropriate techniques. visual impairment.
5. Distinguish normal from common abnormal findings of a 10. Discuss nursing measures that promote eye health.
physical assessment of the visual system. 11. Explain the pathophysiology, clinical manifestations, and
6. Link the age-related changes in the visual system to interprofessional and nursing management of the patient
differences in assessment findings. with an eye disorder.
12. Discuss the general nursing care of patients undergoing
eye surgery.
KEY TERMS
age-related macular degeneration (AMD) hyperopia
astigmatism keratitis
cataract myopia
conjunctivitis presbyopia
enucleation retinal detachment
glaucoma retinopathy
hordeolum strabismus
For people to be as independent as possible and take part vision-loss prevention, detection, and treatment measures
in fulfilling activities, it is important that the visual sys- important.
tem is as functional as possible. The impact of poor vision
or blindness can be devastating to activities of daily living STRUCTURES AND FUNCTIONS OF VISUAL
(ADLs) and independence. The psychosocial consequences
can include decreased quality of life, social isolation,
SYSTEM
depression, and loss of self-esteem. Vision loss also takes The visual system is part of the central nervous system (CNS).
a huge toll on caregivers. This makes our being involved in It consists of 2 main parts, the eyes, which contain the image
407
,408 SECTION 5 Problems Related to Altered Sensory Input
receptors, and the brain. The brain functions to process and the orbits contain the associated muscles, nerves, blood vessels,
interpret the information transmitted from the receptors into and fat.
images. Anatomically, the visual system is made up of the orbit, Within the orbit are 3 main orbital openings, or fissures: optic
the ocular adnexa (external tissues and structures surrounding canal, superior orbital fissure, and inferior orbital fissure. They
the eye), the eye, and the visual pathway (optic nerve, optic chi- are all important channels for arteries, veins, and nerves. The
asm, lateral geniculate nucleus, and visual cortex). optic canal is located at the top of the socket. It provides an entry
point for the optic nerve (cranial nerve [CN] II). The superior
Periocular Structures orbital fissure is a small slit in the posterior orbit. It is the main
Orbit entry point for several other cranial nerves to enter the orbit from
The orbits, or eye sockets, are the bony structures that house the the brain. These include the oculomotor nerve (CN III), trochlear
eyeballs. 7 bones form the orbit: frontal, zygoma, maxilla, eth- nerve (CN IV), trigeminal nerve (CN V), and abducens nerve
moid, sphenoid, lacrimal, and palatine (Fig. 22.1). The average (CN VI). The inferior orbital fissure is in the floor of the orbit. It
orbit is 35 mm high and 40 mm wide. In addition to the eye, holds the zygomatic branch of the maxillary nerve.
There are 6 extraocular muscles: (1) superior and inferior
Frontal Lacrimal Ethmoid
rectus muscles, (2) medial and lateral rectus muscles, and (3)
superior and inferior oblique muscles. They emerge from the
apex of the orbit and attach to the eye to stabilize and move it
Sphenoid
(Fig. 22.2). Neuromuscular coordination produces simultane-
(greater wing)
ous movement of the eyes in the same direction.
Ocular Adnexa
Palatine
The ocular adnexa include the eyebrows, eyelids, eyelashes, and
lacrimal system. Eyebrows, eyelids, and eyelashes are vital in
protecting the eye. They are a physical barrier to dust and for-
eign particles. Blinking protects the eye from injury, distributes
tears over the anterior surface of the eyeball, and supplies nec-
Zygoma essary nourishment to surface cells.
The upper and lower eyelids join at the medial and lateral
Maxilla
canthi. Eyelid skin is the thinnest skin in the body. It measures
less than 1 mm thick. The upper eyelids contain the levator
Medial Orbital surface of maxilla Lateral palpebrae superioris muscle. It is innervated by the superior
Fig. 22.1 Bones that form the orbit, or eye socket. (From Lampignano division of CN III. This muscle elevates and retracts the upper
J, Kendrick L: Bontrager’s textbook of radiographic positioning and eyelid. The eyelids close through the action of the orbicularis
related anatomy, ed 9, St Louis, 2018, Mosby.) muscle. It is innervated by CN VII.
Trochlea Levator palpebrae superioris
Superior oblique
Superior rectus
Medial
rectus
Superior oblique
Medial rectus
Superior rectus
Lateral rectus
Inferior oblique
Lateral rectus
Inferior rectus
Fig. 22.2 The 6 extraocular muscles. (From Drake R, Vogl AW, Mitchell AWM: Gray’s anatomy for students,
ed 3, Philadelphia, 2015, Churchill Livingstone.)
, CHAPTER 22 Assessment and Management: Visual Problems 409
Lacrimal System The cornea allows light to enter the eye. It is transparent and
The lacrimal system includes the structures for tear production avascular. Its curved shape refracts or bends incoming light rays
and drainage. The main lacrimal gland and accessory lacrimal to help focus them on the retina. The cornea has 6 layers: epithe-
glands make tears. The lacrimal glands, in the superotemporal lium, Bowman layer, stroma, Descemet membrane, Dua layer,
orbit, are exocrine glands. They make and secrete the aqueous and endothelium.
layer of tear film and are responsible for reflex tear production. The sclera, the white part of the eye, is a fibrous connective
The tear film moistens the eye and supplies oxygen to the cor- tissue layer. It protects the eye and helps the eye to maintain its
nea. The accessory lacrimal glands, the glands of Wolfring and shape and structure. The sclera extends from the cornea to the
glands of Krause, are found within the conjunctiva of the upper optic nerve. We call the junction of the sclera and cornea the
eyelid. They are responsible for baseline tear production. Tears limbus.
pass over the surface of the eye and then enter the nasolacrimal
system. The nasolacrimal drainage system includes the puncta,
canaliculi, lacrimal sac, and nasolacrimal duct (Fig. 22.3).
Eyeball Lacrimal caruncle
Lacrimal gland
The eyeball, or globe, is composed of 3 layers (Fig. 22.4). The
Lacrimal canals
tough outer layer is composed of the cornea, conjunctiva, and Lacrimal ducts
sclera. The middle layer consists of the uveal tract (iris, choroid
and ciliary body) and the innermost layer, the retina. The anterior
Puncta
cavity is divided into the anterior and posterior chambers. The Lacrimal sac
anterior chamber lies between the iris and posterior surface of the
cornea. The posterior chamber lies between the anterior surface Nasolacrimal duct
of the lens and posterior surface of the iris. The posterior cavity
lies in the large space behind the lens and in front of the retina.
External Ocular Structures
The conjunctiva is a transparent mucous membrane that cov-
ers the inner surfaces of the eyelids and extends over the sclera.
Fig. 22.3 External eye and lacrimal apparatus. Tears made in the lacri-
Glands in the conjunctiva secrete mucus and tears. Tenon cap-
mal gland pass over the surface of the eye and enter the lacrimal canal.
sule, also called the fascia bulbi, is a thin layer of fascia that From there the tears are carried through the nasolacrimal duct to the
encases the eyeball behind the conjunctiva. The capsule extends nasal cavity. (Modified from Patton KT, Thibodeau GA: Anatomy and
posteriorly, ultimately fusing with the optic nerve. physiology, ed 8, St Louis, 2013, Mosby.)
Sclera
Choroid
Retina
Canal of
Schlemm
Lens
Fovea centralis
Iris
Cornea Macula
(transparent)
Anterior
chamber
Pupil
Posterior Optic nerve
chamber
Optic disc
Suspensory
ligament
Ciliary body Posterior
cavity
Vitreous humor
Fig. 22.4 The human eye. (Modified from Patton KT, Thibodeau GA: Anatomy and physiology, ed 8, St Louis,
2013, Mosby.)
22
Assessment and Management:
Visual Problems
Mariann M. Harding
http://evolve.elsevier.com/Lewis/medsurg/
CONCEPTUAL FOCUS
Coping Infection
Functional Ability Sensory Perception
LEARNING OUTCOMES
1. Describe the structures and functions of the visual system. 7. Describe the purpose, significance of results, and nursing
2. Explain the physiologic processes involved in normal responsibilities related to diagnostic studies of the visual
vision. system.
3. Obtain significant subjective and objective assessment 8. Compare and contrast the types of refractive errors and
data related to the visual system. appropriate corrections.
4. Perform a physical assessment of the visual system using 9. Describe the common causes and assistive measures for
the appropriate techniques. visual impairment.
5. Distinguish normal from common abnormal findings of a 10. Discuss nursing measures that promote eye health.
physical assessment of the visual system. 11. Explain the pathophysiology, clinical manifestations, and
6. Link the age-related changes in the visual system to interprofessional and nursing management of the patient
differences in assessment findings. with an eye disorder.
12. Discuss the general nursing care of patients undergoing
eye surgery.
KEY TERMS
age-related macular degeneration (AMD) hyperopia
astigmatism keratitis
cataract myopia
conjunctivitis presbyopia
enucleation retinal detachment
glaucoma retinopathy
hordeolum strabismus
For people to be as independent as possible and take part vision-loss prevention, detection, and treatment measures
in fulfilling activities, it is important that the visual sys- important.
tem is as functional as possible. The impact of poor vision
or blindness can be devastating to activities of daily living STRUCTURES AND FUNCTIONS OF VISUAL
(ADLs) and independence. The psychosocial consequences
can include decreased quality of life, social isolation,
SYSTEM
depression, and loss of self-esteem. Vision loss also takes The visual system is part of the central nervous system (CNS).
a huge toll on caregivers. This makes our being involved in It consists of 2 main parts, the eyes, which contain the image
407
,408 SECTION 5 Problems Related to Altered Sensory Input
receptors, and the brain. The brain functions to process and the orbits contain the associated muscles, nerves, blood vessels,
interpret the information transmitted from the receptors into and fat.
images. Anatomically, the visual system is made up of the orbit, Within the orbit are 3 main orbital openings, or fissures: optic
the ocular adnexa (external tissues and structures surrounding canal, superior orbital fissure, and inferior orbital fissure. They
the eye), the eye, and the visual pathway (optic nerve, optic chi- are all important channels for arteries, veins, and nerves. The
asm, lateral geniculate nucleus, and visual cortex). optic canal is located at the top of the socket. It provides an entry
point for the optic nerve (cranial nerve [CN] II). The superior
Periocular Structures orbital fissure is a small slit in the posterior orbit. It is the main
Orbit entry point for several other cranial nerves to enter the orbit from
The orbits, or eye sockets, are the bony structures that house the the brain. These include the oculomotor nerve (CN III), trochlear
eyeballs. 7 bones form the orbit: frontal, zygoma, maxilla, eth- nerve (CN IV), trigeminal nerve (CN V), and abducens nerve
moid, sphenoid, lacrimal, and palatine (Fig. 22.1). The average (CN VI). The inferior orbital fissure is in the floor of the orbit. It
orbit is 35 mm high and 40 mm wide. In addition to the eye, holds the zygomatic branch of the maxillary nerve.
There are 6 extraocular muscles: (1) superior and inferior
Frontal Lacrimal Ethmoid
rectus muscles, (2) medial and lateral rectus muscles, and (3)
superior and inferior oblique muscles. They emerge from the
apex of the orbit and attach to the eye to stabilize and move it
Sphenoid
(Fig. 22.2). Neuromuscular coordination produces simultane-
(greater wing)
ous movement of the eyes in the same direction.
Ocular Adnexa
Palatine
The ocular adnexa include the eyebrows, eyelids, eyelashes, and
lacrimal system. Eyebrows, eyelids, and eyelashes are vital in
protecting the eye. They are a physical barrier to dust and for-
eign particles. Blinking protects the eye from injury, distributes
tears over the anterior surface of the eyeball, and supplies nec-
Zygoma essary nourishment to surface cells.
The upper and lower eyelids join at the medial and lateral
Maxilla
canthi. Eyelid skin is the thinnest skin in the body. It measures
less than 1 mm thick. The upper eyelids contain the levator
Medial Orbital surface of maxilla Lateral palpebrae superioris muscle. It is innervated by the superior
Fig. 22.1 Bones that form the orbit, or eye socket. (From Lampignano division of CN III. This muscle elevates and retracts the upper
J, Kendrick L: Bontrager’s textbook of radiographic positioning and eyelid. The eyelids close through the action of the orbicularis
related anatomy, ed 9, St Louis, 2018, Mosby.) muscle. It is innervated by CN VII.
Trochlea Levator palpebrae superioris
Superior oblique
Superior rectus
Medial
rectus
Superior oblique
Medial rectus
Superior rectus
Lateral rectus
Inferior oblique
Lateral rectus
Inferior rectus
Fig. 22.2 The 6 extraocular muscles. (From Drake R, Vogl AW, Mitchell AWM: Gray’s anatomy for students,
ed 3, Philadelphia, 2015, Churchill Livingstone.)
, CHAPTER 22 Assessment and Management: Visual Problems 409
Lacrimal System The cornea allows light to enter the eye. It is transparent and
The lacrimal system includes the structures for tear production avascular. Its curved shape refracts or bends incoming light rays
and drainage. The main lacrimal gland and accessory lacrimal to help focus them on the retina. The cornea has 6 layers: epithe-
glands make tears. The lacrimal glands, in the superotemporal lium, Bowman layer, stroma, Descemet membrane, Dua layer,
orbit, are exocrine glands. They make and secrete the aqueous and endothelium.
layer of tear film and are responsible for reflex tear production. The sclera, the white part of the eye, is a fibrous connective
The tear film moistens the eye and supplies oxygen to the cor- tissue layer. It protects the eye and helps the eye to maintain its
nea. The accessory lacrimal glands, the glands of Wolfring and shape and structure. The sclera extends from the cornea to the
glands of Krause, are found within the conjunctiva of the upper optic nerve. We call the junction of the sclera and cornea the
eyelid. They are responsible for baseline tear production. Tears limbus.
pass over the surface of the eye and then enter the nasolacrimal
system. The nasolacrimal drainage system includes the puncta,
canaliculi, lacrimal sac, and nasolacrimal duct (Fig. 22.3).
Eyeball Lacrimal caruncle
Lacrimal gland
The eyeball, or globe, is composed of 3 layers (Fig. 22.4). The
Lacrimal canals
tough outer layer is composed of the cornea, conjunctiva, and Lacrimal ducts
sclera. The middle layer consists of the uveal tract (iris, choroid
and ciliary body) and the innermost layer, the retina. The anterior
Puncta
cavity is divided into the anterior and posterior chambers. The Lacrimal sac
anterior chamber lies between the iris and posterior surface of the
cornea. The posterior chamber lies between the anterior surface Nasolacrimal duct
of the lens and posterior surface of the iris. The posterior cavity
lies in the large space behind the lens and in front of the retina.
External Ocular Structures
The conjunctiva is a transparent mucous membrane that cov-
ers the inner surfaces of the eyelids and extends over the sclera.
Fig. 22.3 External eye and lacrimal apparatus. Tears made in the lacri-
Glands in the conjunctiva secrete mucus and tears. Tenon cap-
mal gland pass over the surface of the eye and enter the lacrimal canal.
sule, also called the fascia bulbi, is a thin layer of fascia that From there the tears are carried through the nasolacrimal duct to the
encases the eyeball behind the conjunctiva. The capsule extends nasal cavity. (Modified from Patton KT, Thibodeau GA: Anatomy and
posteriorly, ultimately fusing with the optic nerve. physiology, ed 8, St Louis, 2013, Mosby.)
Sclera
Choroid
Retina
Canal of
Schlemm
Lens
Fovea centralis
Iris
Cornea Macula
(transparent)
Anterior
chamber
Pupil
Posterior Optic nerve
chamber
Optic disc
Suspensory
ligament
Ciliary body Posterior
cavity
Vitreous humor
Fig. 22.4 The human eye. (Modified from Patton KT, Thibodeau GA: Anatomy and physiology, ed 8, St Louis,
2013, Mosby.)
