Infancy

Newborns keep their eyes closed except during brief awake periods. If you attempt to separate their eyelids, they will tighten them even more. Bright light causes infants to blink, so use subdued lighting. If you awaken the baby gently, turn down the lights, and support the baby in a sitting position, you will often find that the eyes open. The eyes of many newborns are edema-tous from the birth process.

Newborns may look at your face and follow a bright light if you catch them during an alert period. You can even get some newborns to follow your face and turn their heads 90° to each side, much to the delight of new parents.

If a newborn fails to gaze at you and follow your face during alert periods, pay particular attention to the rest of the ocular examination. This may still be a normal child, but may indicate visual impairment.

The photo below shows one way to examine young infants for eye movements. Hold the baby upright, supporting the head. Rotate yourself with the baby slowly in one direction. This usually causes the baby's eyes to open, allowing you to examine the sclerae, pupils, irides, and extraocular movements. The baby's eyes gaze in the direction you are turning. When the rotation stops, the eyes look in the opposite direction, after a few nystag-moid movements.

Nystagmus (wandering or shaking eye movements) persisting after a few days or persisting after the maneuver described on the left may indicate poor vision or central nervous system disease.

During the first 10 days of life, the eyes may be fixed, staring in one direction if just the head is turned without moving the body (doll's eye reflex). During the first few months of life, some infants have intermittent crossed eyes ( intermittent alternating convergent strabismus, or esotropia) or intermittent laterally deviated eyes (intermittent alternating divergent strabismus, or exotropia).

Alternating convergent or divergent strabismus persisting beyond 3 months, or persistent strabismus of any type, may indicate ocular motor weakness or another abnormality in the visual system.

Look for abnormalities or congenital problems in the sclerae and pupils. Sub-conjunctival hemorrhages are common in newborns.

Colobomas (p. 188) may be seen with the naked eye, and represent defects in the iris.

Pupillary reactions can be observed either by response to light or by covering each eye with your hand and then uncovering it. Although there may be some initial asymmetry in the size of the pupils, over time they should be equal in size and reaction to light.

Inspect the irides carefully for abnormalities.

Examine the conjunctiva for swelling or redness. Chemical conjunctivitis is common following application of silver nitrate at birth as prophylaxis against gonorrheal conjunctivitis (ophthalmia neonatorum). Most newborn nurseries have switched to using erythromycin ointment because it produces less irritation.

You will not be able to measure the visual acuity of newborns or infants. You can use visual reflexes to indirectly assess vision: direct and consensual pupillary constriction in response to light, blinking in response to bright light (optic blink reflex), and blinking in response to quick movement of an object toward the eyes. During the first year of life, visual acuity sharpens as the ability to focus improves. Infants achieve the following visual milestones:

Birth 1 month 1^2-2 months 3 months 12 months

Blinks, may regard face Fixes on objects Coordinated eye movements Eyes converge, baby reaches Acuity around 20/50

For the ophthalmoscopic examination, with the newborn awake and eyes open, examine the red retinal (fundus) reflex by setting the ophthalmoscope at 0 diopters and viewing the pupil from about 10 inches. Normally, a red or orange color is reflected from the fundus through the pupil.

A thorough ophthalmoscopic examination is difficult in young infants, but may be needed if ocular or neurologic abnormalities are noted. Occasionally, a mydriatic solution may be required to examine the fundus successfully (e.g., using one drop of 2.5% phenylephrine with 0.5% cyclopentolate in each eye); this is usually done with the help of a neurologist or ophthalmologist. The cornea can ordinarily be seen at +20 diopters, the lens at +15 diopters, and the fundus at 0 diopters.

Examine the optic disc area as you would for an adult. In infants, the optic disk is lighter in color. There may be less macular pigmentation, and the foveal light reflection may not be visible. Look carefully for retinal hemorrhages. Papilledema is rare in infants because the fontanelles and open sutures accommodate any increased intracranial pressure, sparing the optic discs.

Brushfield spots are a ring of white specks in the iris (see Table 17-14, p. 771). While sometimes present in normal children, these strongly suggest Down syndrome.

Persistent ocular discharge and tearing since birth may be due to dacryocystitis or nasolacrimal duct obstruction.

Failure to progress along these visual developmental milestones may indicate delayed visual maturation.

Cloudiness of the cornea may be caused by congenital glaucoma. A dark light reflex can be caused by cataracts, retinopathy of prematurity, or other disorders. A white retinal reflex (leukokoria) is abnormal and cataract, retinal detachment, chorioretinitis, or retinoblastoma should be suspected.

Small retinal hemorrhages may occur in normal newborns. Extensive hemorrhages may suggest severe anoxia, subdural hematoma, subarachnoid hemorrhage, or severe trauma.

Pigment changes in the retina can occur in newborns with congenital toxoplasmosis, cytomegalovirus, or rubella.

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