Health Data - Eyes & Vision

Health data eyes textbook

ASSESSING EYES

For additional ancillary materials related to this chapter, please visit the point.

Learning Objectives

1 Describe the structures and functions of the eyes.

2 Discuss risk factors for the development of cataracts and ways to reduce risk factors.

3 Interview a client for an accurate eye and vision nursing history.

4 Assess a client’s distant and near visual acuity, visual fields, corneal light reflex, and eye movements.

5 Inspect the external eye structures and correctly use the ophthalmoscope to inspect internal eye structures.

6 Differentiate between normal and abnormal findings of the eye and vision.

7 Analyze interview and physical assessment data related to the eyes and vision to formulate valid clinical judgments.

NURSING CONCEPTS

Assessment

Safety

Sensory Perception

CASE STUDY

Susan Jones (S.J.), age 24, presents to the clinic after sustaining an injury to her right eye. She is holding her hand over her eye.

STRUCTURE AND FUNCTION

The eye transmits visual stimuli to the brain for interpretation and, in doing so, functions as the organ of vision. The eyeball is located in the eye orbit, a round, bony hollow formed by several different bones of the skull. In the orbit, a cushion of fat surrounds the eye. The bony orbit and fat cushion protect the eyeball.

To perform a thorough assessment of the eye, you need a good understanding of the external and internal structures of the eye, the visual fields and pathways, and the visual reflexes.

External Structures of the Eye

The eyelids (upper and lower) are two movable structures composed of skin and two types of muscle: striated and smooth. Their purpose is to protect the eye from foreign bodies and limit the amount of light entering the eye. In addition, they serve to distribute tears that lubricate the surface of the eye (Fig. 16-1). The upper eyelid is larger, more mobile, and contains tarsal plates made up of connective tissue. These plates contain the meibomian glands, which secrete an oily substance that lubricates the eyelid.

FIGURE 16-1 External structures of the eye.

The eyelids join at two points: the lateral (outer) canthus and medial (inner) canthus. The medial canthus contains the puncta, two small openings that allow drainage of tears into the lacrimal system, and the caruncle, a small, fleshy mass that contains sebaceous glands. The white space between open eyelids is called the palpebral fissure. When closed, the eyelids should touch. When open, the upper lid position should be between the upper margin of the iris and the upper margin of the pupil. The lower lid should rest on the lower border of the iris. No sclera should be seen above or below the limbus (the point where the sclera meets the cornea).

Eyelashes are projections of stiff hair curving outward along the margins of the eyelids that filter dust and dirt from air entering the eye.

The conjunctiva is a thin, transparent, continuous membrane that is divided into two portions: a palpebral and a bulbar portion. The palpebral conjunctiva lines the inside of the eyelids, and the bulbar conjunctiva covers most of the anterior eye, merging with the cornea at the limbus. The point at which the palpebral and bulbar conjunctivae meet creates a folded recess that allows movement of the eyeball. This transparent membrane allows for inspection of underlying tissue and protects the eye from foreign bodies.

The lacrimal apparatus consists of glands and ducts that lubricate the eye (Fig. 16-2). The lacrimal gland, located in the upper outer corner of the orbital cavity just above the eye, produces tears. As the lid blinks, tears wash across the eye and then drain into the puncta, which are visible on the upper and lower lids at the inner canthus. Tears empty into the lacrimal canals and are then channeled into the nasolacrimal sac through the nasolacrimal duct. They drain into the nasal meatus.

FIGURE 16-2 The lacrimal apparatus consists of tear (lacrimal) glands and ducts.

The extraocular muscles are the six muscles attached to the outer surface of each eyeball (Fig. 16-3). These muscles and

p. 303

p. 304

associated nerves control six different directions of eye movement. There are four rectus muscles (superior, inferior, lateral, and medial) and two oblique muscles (superior and inferior) that are responsible for moving the eye in the direction controlled by that muscle. Each muscle coordinates with a muscle in the opposite eye. This allows for parallel movement of the eyes and thus the binocular vision characteristic of humans. Innervation for these muscles is supplied by three cranial nerves: the oculomotor (III), trochlear (IV), and abducens (VI).

FIGURE 16-3 Extraocular muscles control the direction of eye movement.

Internal Structures of the Eye

The eyeball is composed of three separate coats or layers (Fig. 16-4). The external layer consists of the sclera and cornea. The sclera is a dense, protective, white covering that physically supports the internal structures of the eye. It is continuous anteriorly with the transparent cornea (the “window of the eye”). The cornea permits the entrance of light, which passes through the lens to the retina. It is well supplied with nerve endings, making it responsive to pain and touch.

FIGURE 16-4 Anatomy of the eye.

CLINICAL TIP

Because of this sensory property, contact with a wisp of cotton stimulates a blink in both eyes known as the corneal reflex. This reflex is supported by the trigeminal nerve, which carries the afferent sensation into the brain, and the facial nerve, which carries the efferent message that stimulates the blink.

The middle layer contains both an anterior portion, which includes the iris and the ciliary body, and a posterior layer, which includes the choroid. The ciliary body consists of muscle tissue that controls the thickness of the lens, which must be adapted to focus on objects near and far away.

The iris is a circular disc of muscle containing pigments that determine eye color. The central aperture of the iris is called the pupil. Muscles in the iris adjust to control the pupil’s size, which controls the amount of light entering the eye. The muscle fibers of the iris also decrease the size of the pupil to accommodate for near vision and dilate the pupil when far vision is needed.

The lens is a biconvex, transparent, avascular, encapsulated structure located immediately posterior to the iris. Suspensory ligaments attached to the ciliary body support the position of the lens. The lens functions to refract (bend) light rays onto the retina. Adjustments must be made in refraction depending on the distance of the object being viewed. Refractive ability of the lens can be changed by a change in shape of the lens (which is controlled by the ciliary body). The lens bulges to focus on close objects and flattens to focus on far objects.

The choroid layer contains the vascularity necessary to provide nourishment to the inner aspect of the eye and prevents light from reflecting internally. Anteriorly, it is continuous with the ciliary body and the iris.

The innermost layer, the retina, extends only to the ciliary body anteriorly. It receives visual stimuli and sends it to the brain. The retina consists of numerous layers of nerve cells, including the cells commonly called rods and cones. These specialized nerve cells are often referred to as “photoreceptors” because they are responsive to light. The rods are highly sensitive to light, regulate black-and-white vision, and function in dim light. The cones function in bright light and are sensitive to color.

The optic disc is a cream-colored, circular area located on the retina toward the medial or nasal side of the eye. It is where the optic nerve enters the eyeball. The optic disc can be seen with the use of an ophthalmoscope and is normally round or oval in shape, with distinct margins. A smaller circular area that appears slightly depressed is referred to as the physiologic cup. This area is approximately one-third the size of the entire optic disc and appears somewhat lighter/whiter than the disc borders.

p. 304

p. 305

The retinal vessels can be readily viewed with the aid of an ophthalmoscope. Four sets of arterioles and venules travel through the optic disc, bifurcate, and extend to the periphery of the fundus. Venules are dark red and grow progressively narrower as they extend out to the peripheral areas. Arterioles carry oxygenated blood and appear brighter red and narrower than the veins. The general background, or fundus (Fig. 16-5), varies in color, depending on skin color. A retinal depression known as the fovea centralis is located adjacent to the optic disc in the temporal section of the fundus. This area is surrounded by the macula, which appears darker than the rest of the fundus. The fovea centralis and macular area are highly concentrated with cones and form the area of highest visual resolution and color vision.

FIGURE 16-5 Normal ocular fundus.

The eyeball contains several chambers that maintain structure, protect against injury, and transmit light rays. The anterior chamber is located between the cornea and the iris; the posterior chamber is the area between the iris and the lens. These chambers are filled with aqueous humor, a clear liquid substance produced by the ciliary body. Aqueous humor helps cleanse and nourish the cornea and lens as well as maintain intraocular pressure (IOP). The aqueous humor filters out of the eye from the posterior to the anterior chamber and then into the canal of Schlemm through a filtering site called the trabecular meshwork. Another chamber, the vitreous chamber, is located in the area behind the lens to the retina. It is the largest of the chambers and is filled with a vitreous humor that is clear and gelatinous.

Vision

Visual Fields and Visual Pathways

A visual field refers to what a person sees with one eye. The visual field of each eye can be divided into four quadrants: upper temporal, lower temporal, upper nasal, and lower nasal (Fig. 16-6). The temporal quadrants of each visual field extend farther than the nasal quadrants. Thus, each eye sees a slightly different view, but their visual fields overlap quite a bit. As a result, humans have binocular vision (“two-eyed” vision) in which the visual cortex fuses the two slightly different images and provides depth perception, or three-dimensional vision.

FIGURE 16-6 Visual fields and visual pathways. Each eye has a slightly different view of the same field. However, the views overlap significantly, which accounts for binocular vision.

Visual perception occurs as light rays strike the retina, where they are transformed into nerve impulses, conducted to the

p. 305

Chapter 7 Eyes

The detailed anatomical drawing of a human figure is shown from the back and side, with one arm raised and bent. The illustration highlights the muscles of the shoulder, upper back, and arm using fine sket cetrah lines, focusing on muscle structure.

Anatomy

The eye is the sensory organ of vision. The eyelids protect the eye from injury, strong light, and dust ( Fig. 7.1 ). The palpebral fissure is the open space between the eyelids.

7.1 External eye structures.

Follow for extended description

The exposed part of the eye has a transparent protective covering, the conjunctiva . The palpebral conjunctiva lines the lids and is clear, with many small blood vessels. It forms a deep recess and then folds back over the eye. The bulbar conjunctiva overlays the eyeball, with the white sclera showing through. At the limbus the conjunctiva merges with the cornea. The cornea covers and protects the iris and pupil.

The eye is a sphere composed of 3 concentric coats: (1) the outer fibrous sclera, (2) the middle vascular choroid, and (3) the inner nervous retina ( Fig. 7.2 ). Inside the retina is the transparent vitreous body.

7.2 Internal eye structures.

Follow for extended description

The retina is the visual receptive layer of the eye in which light waves are changed into nerve impulses. The ocular fundus is the area of the retina visible through the ophthalmoscope ( Fig. 7.3 ).

7.3 Ocular fundus.

Follow for extended description

TABLE 7.3 Abnormalities in the Pupil

Follow for extended description

Unequal Pupil Size—Anisocoria

Although anisocoria exists normally in 5% of the population, a person with this condition may have central nervous system disease.

Follow for extended description

Monocular Blindness

When light is directed to the blind eye, there is no response. When light is directed to the normal eye, both pupils constrict (direct and consensual response to light) as long as the oculomotor nerve is intact.

Constricted and Fixed Pupils—Miosis

Miosis occurs with the use of pilocarpine drops for glaucoma treatment, with the use of opioids, with iritis, and with brain damage of the pons.

Dilated and Fixed Pupils—Mydriasis

Enlarged pupils occur with stimulation of the sympathetic nervous system, as a reaction of sympathomimetic drugs, with use of dilating drops, with acute glaucoma, and with past or recent trauma. Enlarged pupils may also indicate central nervous system injury, cardiac arrest, or deep anesthesia.

The optic disc is the area in which fibers from the retina converge to form the optic nerve. The macula is the area of sharpest vision.

Genetics and Environment

A cataract is a clouding of the crystalline lens due to continual growth of lens fibers with aging and photo-oxidative stress from ultraviolet light exposure, smoking, diabetes, obesity Page 70 (Broadhead et al., 2021). Then the lens is no longer completely transparent, resulting in blurry vision. This is curable with lens replacement surgery, which the person can consider when vision changes interfere with daily activities and quality of life. Cataract prevalence increases with age, affecting 24.4 million Americans by age 40 years and older and half of Americans by age 75 years ( American Academy of Ophthalmology, 2021 ).

Glaucoma is an optic nerve compression caused by increased intraocular pressure. Untreated vision loss gradually increases, first robbing peripheral visual fields and then encroaching on to central vision. Age is the primary risk factor, as well as African ethnicity and positive family Page 71 history (Broadhead et al., 2021; National Institutes of Health and National Eye Institute [NIH and NEI], 2021). More than 2.7 million adults older than 40 years of age have the disease; there are no symptoms, so millions more do not know that they have it. Because women have a longer life expectancy than men in the United States, women account for 61% of those with glaucoma (NIH and NEI, 2021).

Age-related macular degeneration (AMD) is a loss of central vision of unknown cause, possibly oxidative stress and inflammation. The degeneration is characterized by yellow deposits (drusen) and neovascularity in the macula. AMD prevalence rises sharply with age starting around 50 years; by age 80 years, 1 in 10 Americans suffer from late-stage AMD, more common in women ( American Academy of Ophthalmology, 2021 ). With AMD the person is unable to read books or papers, sew, or do fine work and has difficulty distinguishing faces. When the lifestyle is oriented around these activities, loss of central vision causes great distress. Peripheral vision is not affected; for a while the person can manage self-care and not become completely disabled.

Visual impairment (VI) is not being able to see letters on the eye chart at line 20/50 or below. In the United States, the number of people with VI and blindness is expected to double because of the aging population and shifting demographics (Varma et al., 2016).

TABLE 7.2 Abnormalities in the Eyelids

Exophthalmos (Protruding Eyes) Ptosis (Drooping Upper Lid)

Exophthalmos is a forward displacement associated with thyroid disease. Note “lid lag,” i.e., the upper lid rests well above the limbus, and white sclera is visible. Ptosis occurs from neuromuscular weakness (e.g., myasthenia gravis), oculomotor cranial nerve III damage, or sympathetic nerve damage (e.g., Horner syndrome).

Ectropion Entropion

The lower lid is loose and rolling out and does not approximate to the eyeball. Puncta cannot siphon tears effectively; therefore excess tearing results. Exposed palpebral conjunctiva increases risk for inflammation. The lower lid rolls in as a result of spasm of lids or contraction of scar tissue. Lashes may irritate cornea. Symptoms are foreign body sensation, tearing, and red eye.

Hordeolum (Stye) Chalazion

Hordeolum is a localized staphylococcal infection of the hair follicles at the lid margin. It is painful, red, and swollen and resembles a pustule at the lid margin. A beady nodule protruding on the lid, chalazion is an infection or retention cyst of a meibomian gland. It is a nontender, firm, discrete swelling with freely movable skin overlying the nodule. If it becomes inflamed, it points inside and not on the lid margin (in contrast with a stye).

Basal Cell Carcinoma Conjunctivitis

Carcinoma is rare, but it occurs most often on the lower lid. It looks like a papule with an ulcerated center. The edges are rolled out and pearly. Infection of the conjunctiva shows red, beefy-looking vessels at the periphery but looks clearer around the iris. This is common from bacterial or viral infection, allergy, or chemical irritant. It often accompanies an upper respiratory infection. Purulent discharge signals bacterial infection.

Source: Images © Pat Thomas, 2010.

Subjective Data

1 Vision difficulty (decreased acuity, blurring, blind spots)

2 Pain

3 Strabismus, diplopia

4 Redness, swelling

5 Watering, discharge

6 Past history of ocular problems

7 Glaucoma

8 Use of glasses or contact lenses

9 Patient-centered care (vision last tested, method of care for contacts or glasses, efforts to protect eyes)

Objective Data

Equipment Needed

Snellen eye chart

Handheld visual screener

Opaque card or occluder

Penlight

Ophthalmoscope

Normal Range of Findings Abnormal Findings

Test Central Visual Acuity

Snellen Eye Chart

Position the person on a mark exactly 20 feet from the chart. Leave glasses or

contact lenses in place. Shield one eye at a time during the test. Ask the person to read through the chart to the smallest line of letters possible. Hesitancy, squinting, leaning forward, misreading letters.

Record the result using the numeric fraction at the end of the last successful line read. Indicate whether any letters were missed and whether corrective lenses were worn (e.g., “Right eye 20/30—1, with glasses”).

Normal visual acuity is 20/20. The top number (numerator) indicates the distance the person is standing from the chart; the denominator gives the distance at which a normal eye can read a particular line. The larger the denominator, the poorer the vision. If vision is poorer than 20/30, refer to an eye specialist. Impaired vision occurs with refractive error, opacity in the media (cornea, lens, vitreous), or disorder in the retina or optic pathway.

Near Vision

For people older than 40 years of age or for those who report increasing difficulty reading, test near vision using a handheld vision screener with various sizes of print (e.g., a Jaeger card). Hold the card in good light about 35 cm (14 inches) from the eye. Test each eye separately with glasses on. A normal result is “14/14” in each eye read without hesitancy and without moving the card closer or farther away. Presbyopia, the decrease in power of accommodation with aging, is suggested when the person moves the card farther away.

Test Visual Fields

Confrontation Test

Position yourself at eye level with the patient and about 2 feet away. Direct them to cover one eye with an opaque card and look straight at you with the other eye. Hold your finger as a target midline between you and the patient and slowly advance it in from the periphery in several directions (upward, downward, temporally, nasally).

Ask the person to say “now” as the wiggling fingertip is first seen; this should be just as you also see it. If the person is unable to see as you do, the test suggests peripheral field loss. Refer to an eye specialist for more precise testing.

Inspect Extraocular Muscle Function

Diagnostic Positions Test

Leading the eyes through the 6 cardinal positions of gaze elicits any muscle weakness during movement. Ask the person to hold the head steady and follow the movement of your finger, only with the eyes. Hold your finger back about 12 inches so the person can focus on it comfortably; move it to each of the 6 positions, hold it momentarily, then move it back to center. Progress clockwise ( Fig. 7.4 ). A normal response is parallel tracking of the object with both eyes.

7.4

Eye movement is not parallel. Failure to follow in a certain direction indicates weakness of an extraocular muscle (EOM) or dysfunction of the cranial nerve that innervates it.

In addition to parallel movement, note any nystagmus, a fine oscillating movement best seen around the iris. Mild nystagmus at extreme lateral gaze is normal; nystagmus at any other position is not. Nystagmus occurs with disease of the semicircular canals in the ears, a paretic eye muscle, multiple sclerosis, or brain lesion.

Finally note that the upper eyelid continues to overlap the superior part of the iris, even during downward movement. A white rim of sclera between the lid and the iris, referred to as “lid lag,” occurs with hyperthyroidism.

Inspect External Ocular Structures

General

Note the person’s ability to move around the room with vision functioning well enough to avoid obstacles and respond to your directions. The facial expression is relaxed with adequate vision. Groping with hands.

Squinting or craning forward.

Eyebrows

Normally the eyebrows are present bilaterally, move symmetrically as the facial expression changes, and have no scaling or lesions. Unequal or absent movement with nerve damage.

Scaling with seborrhea.

Eyelids and Lashes

The upper lids normally overlap the superior part of the iris and approximate completely when closed. The skin is intact without redness, swelling, discharge, or lesions. Lid lag occurs with hyperthyroidism. Incomplete closure creates risk for corneal damage.

Ptosis—drooping of upper lid as with myasthenia gravis.

Periorbital edema, lesions.

The eyelashes are evenly distributed along the lid margins and curve outward. Ectropion and entropion ( Table 7.2 , p. 83).

Eyeballs

The eyeballs are aligned normally with no protrusion or sunken appearance. Black persons may normally have a slight protrusion of the eyeball beyond the supraorbital ridge. Exophthalmos—protruding eyes (see Table 7.2 ).

Enophthalmos—sunken eyes.

Conjunctiva and Sclera

Ask the person to look up. Using your thumbs, slide the lower lids down along the bony orbital rim. Take care not to push against the eyeball ( Fig. 7.5 ). Inspect the exposed area. The eyeball looks moist and glossy. Numerous small blood vessels normally show through the transparent conjunctiva. Otherwise the conjunctivae are clear and show the normal color of the structure below—pink over the lower lids and white over the sclera. Note any color change, swelling, or lesions.

7.5

General reddening (see Table 7.2 ).

Cyanosis of the lower lids.

Pallor near the outer canthus of the lower lid may indicate anemia (the inner canthus normally contains less pigment).

The sclera is china white, although occasionally it is gray-blue or “muddy” color in Black persons. Dark-skinned people may have small brown macules (like freckles) on the sclera; do not confuse these with foreign bodies or petechiae. Black persons may have yellowish fatty deposits beneath the lids away from the cornea. Do not confuse these yellow spots with the overall scleral yellowing that accompanies jaundice. Scleral icterus is a yellowing of the sclera extending up to the cornea, indicating jaundice.

Tenderness, foreign body, discharge, or lesions.

Inspect Anterior Eyeball Structures

Cornea and Lens

Shine a light from the side across the cornea and check for smoothness and clarity. There should be no opacities (cloudiness) in the cornea, the anterior chamber, or in the lens behind the pupil. Do not confuse arcus senilis with an opacity. This is a normal finding in older adults and is described on p. 80. A corneal abrasion causes irregular ridges in reflected light, usually visible only with fluorescein stain.

Iris and Pupils

The iris normally has a round, regular shape and an even coloration.

Normally the pupils appear round, regular, and of equal size. In adults resting size is from 3 to 5 mm. A small number of people (5%) have pupils of two different sizes, a condition called anisocoria. Irregular shape.

Pupils with unequal size occur with a central nervous system injury.

To test the pupillary light reflex, darken the room and ask the person to gaze into the distance. (This dilates the pupils.) Advance a light in from the side, a and note the response. Normally you will see (1) constriction of the pupil on the same side (a direct light reflex ), and (2) simultaneous constriction of the other pupil (a consensual light reflex ). Dilated pupils.

Dilated and fixed pupils.

Constricted pupils.

Unequal or no response to light ( Table 7.3 ).

Test for accommodation by asking the person to focus on a distant object. This process dilates the pupils. Then have the person shift the gaze to a near object such as your finger held about 7 to 8 cm (3 inches) from the nose.

A normal response includes (1) pupillary constriction and (2) convergence of the axes of the eyes. Absence of constriction or convergence.

Asymmetric response.

Record the normal response to these maneuvers as PERRLA, or Pupils Equal, Round, React to Light, and Accommodation.

Advanced Practice Techniques

Inspect the Ocular Fundus

Darken the room to help dilate the pupils. Remove eyeglasses from yourself or the other person; they obstruct close movement, and you can compensate for their correction by using the diopter setting. Contact lenses can be left in.

Select the large round aperture with the white light of the ophthalmoscope for routine examination. If the pupils are small, use the smaller white light.

Tell the person, “Please keep looking at that light switch [or mark] on the wall across the room, even though my head will get in the way.” Staring at a distant fixed object helps dilate the pupils and hold the retinal structures still.

Match sides with the person: that is, hold the ophthalmoscope in your right hand up to your right eye to view the person’s right eye ( Fig. 7.6 ). You must do this to avoid bumping noses during the procedure. Place your free hand on the person’s shoulder or forehead.

7.6

Systematically inspect the structures in the ocular fundus: (1) optic disc, (2) retinal vessels, (3) general background, and (4) macula (see Fig. 7.3 ). (Note that the illustration shows a large area of the fundus. Your actual view through the ophthalmoscope is much smaller, slightly larger than 1 disc diameter.)

Optic Disc

The most prominent landmark is the optic disc, located on the nasal side of the retina. Explore these characteristics:

1 Color—Creamy yellow-orange to pink

Pallor. Hyperemia.

2 Shape—Round or oval

Irregular.

3 Margins—Distinct, sharply demarcated, although the nasal edge may be slightly fuzzy

Blurred margins.

4 Cup-to-disc ratio—Distinctness varies. When visible, cup is a brighter yellow-white than the rest of the disc. Its width is not more than one-half of the disc diameter (DD).

Cup extending to the disc border (see Table 15.9 , p. 320, in Jarvis: Physical Examination and Health Assessment, 9th ed.).

Retinal Vessels

Follow a paired artery and vein out to the periphery in the four quadrants (see Fig. 7.3 ), noting these points:

1 Number—A paired artery and vein pass to each quadrant. Vessels look straighter at the nasal side.

Absence of major vessels.

2 Color—Arteries are brighter red than veins. They also have the arterial light reflex, a thin stripe of light down the middle.

3 A:V ratio—The ratio comparing the artery-to-vein width is 2:3 or 4:5.

Arteries too constricted.

Veins dilated.

4 Caliber—Arteries and veins show a regular decrease in caliber as they extend to periphery.

Focal constriction.

Neovascularization.

5 Arteriovenous (AV) crossing—An artery and vein may cross paths. This is not significant if within 2 DD of disc and if no sign of interruption in blood flow. There should be no indenting or displacing of vessel.

Crossings more than 2 DD away from disc.

Nicking or pinching of underlying vessel.

Vessel engorged peripheral to crossing.

6 Tortuosity—Mild vessel twisting when present in both eyes is usually congenital and not significant.

Extreme tortuosity or marked asymmetry in two eyes.

7 Pulsations—Present in veins near the disc as their drainage meets the intermittent pressure of arterial systole (often hard to see).

Absent pulsations (see Table 15.9 , p. 320, in Jarvis: Physical Examination and Health Assessment, 9th ed.).

General Background of the Fundus

The color normally varies from light red to dark brown–red, generally corresponding with the person’s skin color. There should be no lesions obstructing the retinal structures. Abnormal lesions—hemorrhages, exudates, microaneurysms.

Macula

The macula is 1 DD in size and is located 2 DD temporal to the disc. Inspect this area last in the funduscopic examination. A bright light on this area of central vision causes some watering, discomfort, and pupillary constriction. Note that the normal color of the macula is somewhat darker than the rest of the fundus, but it is even and homogeneous. Clumped pigment may occur with aging. Clumped pigment occurs with trauma or retinal detachment.

Hemorrhage or exudate in the macula occurs with macular degeneration.

A circular icon containing four diamond-shaped elements arranged symmetrically in a cross-like pattern at the center. Developmental Competence

Infants and Children

Test a newborn’s light perception using the blink reflex; neonates blink in response to bright light. The pupillary light reflex also shows that the pupils constrict in response to light. Absent blinking.

Absent pupillary light reflex, especially after 3 weeks, indicates blindness.

Testing for strabismus (squint, crossed eye) is an important screening measure during early childhood. Untreated strabismus can lead to permanent visual damage, called amblyopia ex anopsia . Early recognition and treatment are essential. Diagnosis after age 6 years has a poor prognosis.

Check the corneal light reflex by shining a light toward the child’s eyes. The light should be reflected at exactly the same spot in the two corneas. Some asymmetry (where one light falls off center) under age 6 months is normal. Asymmetry in the corneal light reflex after 6 months is abnormal, and the infant must be referred.

Many infants have an epicanthal fold, an excess skinfold extending over the inner corner of the eye, partly or totally overlapping the inner canthus. This occurs frequently in Asian children and in 20% of White children. Epicanthal folds give a false appearance of malalignment, called pseudostrabismus, but the corneal light reflex is normal.

Asian infants normally have an upward slant of the palpebral fissures. Entropion, a turning inward of the eyelid, is normally found in some Asian children. If the lashes do not abrade the cornea, it is not significant. An upward lateral slope together with epicanthal folds and hypertelorism (large spacing between the eyes) occurs with Down syndrome.

The Aging Adult

The eyebrows may show a loss of the outer one-third of hair. The brow hair is coarse. Because of atrophy of elastic tissue, the skin around the eyes may show wrinkles or crow’s feet. The upper lid may be so elongated as to rest on the lashes ( Table 7.1 on p. 80).

The eyes may appear sunken because of atrophy of the orbital fat. The orbital fat may also herniate, causing bulging at the lower lids and inner third of the upper lids.

Atrophy of the levator palpebrae muscle causes a partial ptosis. In contrast with the baggy lids previously described, ptosis is an actual drooping. The lower lid may drop away (i.e., ectropion ). Then tears cannot drain into the out-turned puncta. Alternately, entropion, or a turning inward, may irritate the eye from friction of lashes (see Table 7.2 on p. 83).

Tear production may decrease, causing the eyes to look dry and lusterless and the person to report a burning sensation. Pingueculae commonly show on the sclera (see Table 7.1 ). These yellowish elevated nodules are caused by a thickening of the bulbar conjunctiva from prolonged exposure to sun, wind, and dust. Pingueculae appear at the 3 o’clock and 9 o’clock positions, first on the nasal side and then on the temporal side. Distinguish pingueculae from the abnormal pterygium, an opacity also on the bulbar conjunctiva, but which grows over the cornea and may block vision.

The cornea may look cloudy with age. Arcus senilis is commonly seen around the cornea (see Table 7.1 ). This is a gray-white arc or circle around the

limbus caused by deposition of lipid material. As more lipid accumulates, the cornea may look thickened and raised, but the arcus has no effect on vision.

Xanthelasma are soft, raised yellow plaques occurring on the lids of the inner canthus (see Table 7.1 ). These commonly occur around age 50 and older, more frequently in women. Xanthelasma occur with both high and normal blood levels of cholesterol and have no pathologic significance.

Pupils are small, and the pupillary light reflex may be slowed. The lens loses transparency and appears opaque.

In the ocular fundus the blood vessels appear pale, narrow, and attenuated. Arterioles appear pale and straight, with a narrow light reflex. More AV crossing defects occur.

A normal development on the retinal surface is drusen, or benign degenerative hyaline deposits. They are small, round yellow dots that are scattered haphazardly on the retina. Although they do not occur in a pattern, drusen are usually symmetrically placed in the two eyes. They have no effect on vision. Drusen are easily confused with the abnormal finding of lipid (hard) exudates (see Table 15.10 , p. 321, in Jarvis: Physical Examination and Health Assessment, 9th ed.).

a Always advance the light in from the side to test the light reflex. If you advance from the front, the pupils will constrict to accommodate for near vision. Thus you do not know what the pure response to the light would have been.

TABLE 7.1 Aging Eye Changes

Follow for extended description

Health Promotion and Patient Teaching

(To all adults over 40 years ) I want to refer you to an eye specialist for screening for glaucoma. This is a progressive eye disease that affects 2.7 million Americans and robs them of peripheral (side) vision. Most people with glaucoma have no symptoms and do not know they have the disease, but it can be treated. An eye specialist can screen you with specific equipment that we do not have in the hospital or in the primary care office.

Glaucoma is a set of progressive eye neuropathies that can lead to severe visual field loss and blindness. Risk factors include older age, Black or Latino heritage, and a family history of glaucoma (NIH and NEI, 2021). Glaucoma can reduce peripheral vision without yet harming central vision. Those who have glaucoma who are not blind still may have limited function, e.g., decreased ability to drive a car or to read. Page 82

Summary Checklist: Eyes

1 Test visual acuity:

Snellen eye chart

Near vision (those ≥40 years or those having difficulty reading)

2 Test visual fields:

Confrontation test

3 Inspect EOM function:

Corneal light reflex

Diagnostic positions test

4 Inspect external eye structures:

General

Eyebrows

Eyelids and lashes

Eyeball alignment

Conjunctivae and sclerae

5 Inspect anterior eyeball structures:

Cornea and lens

Iris and pupil

Size, shape, and equality

Pupillary light reflex

Accommodation

6 Inspect the ocular fundus:

Optic disc (color, shape, margins, cup:disc ratio)

Retinal vessels (number, color, artery:vein [A:V] ratio, caliber, AV crossings, tortuosity, pulsations)

General background (color, integrity)

Macula

Documentation

Sample Charting

Subjective

Vision reported “good” with no recent change. No eye pain, no inflammation, no discharge, no lesions. Wears no corrective lenses, vision last tested 1 year PTA; test for glaucoma at that time was normal.

Objective

Snellen chart—Right 20/20, Left 20/20 −1. Fields normal by confrontation. Corneal light reflex symmetric bilaterally. Diagnostic positions test shows EOMs intact. Brows and lashes present. No ptosis. Conjunctiva clear. Sclera white. No lesions. PERRLA.

Fundi —Red reflex present bilaterally. Discs flat with sharp margins. Vessels present in all quadrants without crossing defects. Retinal background has even color with no hemorrhages or exudates. Macula has even color.

Assessment

Healthy vision function

Healthy eye structures

Abnormal Findings