Intended for healthcare professionals

Practice Practice Pointer

How to assess eyes and vision in infants and preschool children

BMJ 2015; 350 doi: https://doi.org/10.1136/bmj.h1716 (Published 07 May 2015) Cite this as: BMJ 2015;350:h1716
  1. Andrew J Blaikie, consultant ophthalmologist, lead of paediatric services1,
  2. Gordon N Dutton, paediatric ophthalmologist, emeritus professor of visual science2
  1. 1Department of Ophthalmology, Fife Acute Hospitals Trust, Queen Margaret Hospital, Dunfermline KY12 0SU, UK
  2. 2Glasgow Caledonian University, Glasgow G4 0BA, UK
  1. Correspondence to: G N Dutton dutton{at}duttonhome.com

The bottom line

  • Appropriately positioning the child on the parent’s lap and using recognisable auditory distraction (whistling, humming, or singing) just before and during eye examination make assessment much easier

  • Observation from the moment of arrival may reveal conditions such as watery or red eyes, blepharitis, a swollen lacrimal sac, ptosis, squint, or lack of eye contact

  • Estimate visual acuity by checking the distance at which the child maintains eye contact

  • Identify a squint by shining a light at the child’s eyes and checking the symmetry of the “corneal reflexes”

Children for whom concerns exist about eyes or vision need competent assessment and management. For a young child, however, the general clinician in the community may find mastery of the requisite skills daunting. This article gives practical tips to guide eye assessment in infants and preschool children.

Consider the child’s comfort

Waiting and consultation areas should be welcoming and uncluttered. A feed, a recent sleep, and a short wait enhance comfort, cooperation, and the “window of opportunity.”

Beginning the consultation

Watch the child enter the room

Read any available salient information before seeing the child. Be friendly, calm, and confident and avoid appearing anxious. Smile as the child and parent(s) enter the room. Look to see if eye contact is returned and, if so, from how far away (table 1). Look at what the child looks at and consider its detail to get an idea of what the child is probably seeing.

Table 1

Approximate maximum distances at which eye contact with a young child can be maintained and “rule of thumb” equivalent visual acuities

View this table:

Taking the history

Take a brief initial open history of the presenting complaint and then seek salient additional information to help in planning the examination (tables 2 and 3). Next, examine the child while he or she is still engaged, using this to guide subsequent diagnostic history taking.

Table 2

Conditions commonly managed in the community without referral

View this table:
Table 3

Conditions requiring referral

View this table:

Examination approach

Have available a few clean, attractive toys. Ask for the child to sit on a parent’s lap while the parent leans slightly back, the infant’s head supported by the chest and the body cradled by the arms, to minimise imbalance and discomfort (fig 1). A pacifier or bottle can help to soothe a restless child. We recommend attracting and maintaining the child’s auditory attention by quietly whistling, humming, or singing a well known nursery song for several seconds before (to engage attention) and throughout the examination. Successful examination can usually be accomplished while the child is enjoying the song, oblivious to your examination.

Figure1

Fig 1 This child is being cradled in a comforting and secure way to assist in performance of an effective examination

Start by inspection, then assess visual function and test eye movements. Conditions such as sticky, watering, or red eyes, blepharitis, a swollen lacrimal sac, ptosis, squint, nystagmus, and lack of eye contact may be obvious from the start. Turn the main light off, maintaining dim background lighting. Look for red reflexes at a distance with the direct ophthalmoscope, then gently approach the child to examine the eyes as outlined in the following scenarios.1

Red reflex

Does my child have poor vision?

“Eye to eye” contact between mother and baby typically becomes consistent from 4-5 weeks.2 A history of lack of eye contact and poor visual attentiveness can be caused by delayed visual maturation (diagnosed retrospectively), ocular or anterior visual pathway disorders, or cerebral visual impairment related to visual pathway or occipital dysfunction.3

Estimating visual acuity—Identify the maximum distance at which the child maintains interest in his or her own face in a mirror or looks at your eyes while you smile and gradually move back. This helps in estimating visual acuity (table 1).4

Estimating visual acuity in babies

Pupil reactions—Dim the lights and use a bright pen torch to seek slow or limited pupil constriction due to dysfunction of retina or optic nerve but not the visual brain. The bright light often makes infants squeeze their eyes shut, but not if vision is poor.

Estimating pupil reaction

Look for nystagmus—and check whether it beats with the same pattern in each position of gaze when following a toy. If it does not, or if the nystagmus is irregular or unilateral or has a late onset, central nervous system neoplasia is a rare but possible cause.5

Visual acuity and nystagmus

Visual attention, visual fields, and eye movements—Parents may say that their toddler does not seem to see with “one eye.” Cover each eye in turn. Active avoidance by head movement away from the cover on one side suggests poorer vision in that eye. Alternatively, there may be lack of visual attention in one hemi-field obeying the vertical meridian or in the lower visual field, which is sometimes seen in ex-premature neonates with evolving cerebral palsy.6 Bring a toy into view in each quadrant in turn, seeking a head or eye turn. Quickly introduce a second toy in another quadrant. Look for a fast eye movement (saccade). Move the first toy out of sight as the attention switches. This is normal behaviour in children aged over 3 months. Lack of eye movement to switch attention to the left or right suggests a hemianopic visual field or a hemi-attentional deficit.

Checking visual fields

Hold the child vertically and rotate round in one direction then the other—Look for absence of the normal reflex horizontal flicking eye movements, with instead tonic deviation of the eyes to one side and then the other when rotating to left then right. This indicates saccadic initiation failure, which can resemble blindness because of lack of the typical fast eye movements that normally show that infants are seeing.1

Corroboration of the parents’ suspicion of any type of impaired vision from an early age requires immediate ophthalmic referral for investigation, spectacle testing, treatment, and early habilitation.

“Something wrong with how the eyes look”

Watery or sticky eyes in the infant

Red, swollen, sticky eyes with discharge soon after birth are swabbed for microscopy and culture seeking the organisms outlined in table 2. Watering eyes due to nasolacrimal duct obstruction is common. Extrusion of mucus by gently pressing a clean little finger on the duct, behind the palpable ridge close to the inner canthus—the anterior lacrimal crest—supports the diagnosis, as does the dye disappearance test. Fluorescein dye placed in the eye disappears down the nasolacrimal duct within five minutes but remains if the duct is obstructed.

Misalignment of a child’s eyes (squint or strabismus)

This is a common presenting complaint. Variable, brief, and intermittent squint is often seen during the first three months of life,7 but persisting eye misalignment requires referral to the hospital eye service to seek poor vision (amblyopia), lack of stereovision, and possible ocular pathology in the squinting eye.8

One can accurately identify a manifest squint by shining a light at the child’s eyes and observing the location of the small white light reflection—the “corneal reflex.” This should be in the centre of the pupils. If it is displaced from the centre in one eye, then a squint is likely (fig 2). Each millimetre of displacement equates to 8° of squint.

Figure2

Fig 2 In this 9 month old baby, the “corneal reflex” is in the centre of the pupil in the left eye but is displaced temporally by 2-3 mm in the right eye. This represents a right esotropia of 16-24°

If a squint is suspected, cover the apparently “straight” fixing eye while showing the child a toy, then uncover it, looking for one of three responses:

  • Movement of the head to avoid the cover indicates low or absent vision in the squinting eye.

  • Movement of the uncovered eye to look at the toy confirms the presence of squint, whereas lack of eye movement may indicate absent or very low vision. (Red reflexes are therefore looked for in all cases of squint.)

  • Return of the squinting eye to its original position as the cover is removed indicates low vision in that eye, whereas transfer of the squint to the other eye (alternation) indicates that vision in each eye is likely to be equal.

These observations are negative in pseudo-squint owing to broad epicanthic folds.

Strabismus and ptosis

An unusual looking eye or eyes

Congenital cataract and retinoblastoma are two important causes of a white pupil (leukocoria) (fig 3).9 Use a direct ophthalmoscope, set at zero, to view each eye from between 10 and 20 cm to elicit red reflexes. If you see asymmetry or lack of a red reflex, set the ophthalmoscope to +10 or +20 and view the eye from 10 or 5 cm respectively (where these lenses focus clearly). This magnifies the structures at the front of the eye and helps to distinguish cataract from pathology behind the lens.

Figure3

Fig 3 In this 7 month old child, a white pupil of the right eye was consistently noticed in family photographs. The family doctor made an urgent referral to the local eye department for cataract and retinoblastoma to be excluded. The diagnosis was cataract

A keyhole pupil due to a section of missing iris (coloboma), lack of an iris due to aniridia, and red light trans-illuminating through the iris due to marked albinism can also be seen on red reflex examination.

A white pupil reflex due to light reflecting from the optic disc in flash photographs (fig 2)10 and racial pigmentation of the retina are common reasons for false positive referral for a questionable pupil reflex. However, all cases in which uncertainty exists need to be referred.

Appearance of large or small eyes and ptosis

A small eye (microphthalmos) is identified using a transparent ruler to estimate the corneal diameters. An inter-ocular difference or a measurement of less than 10 mm is likely to be pathological. Microphthalmos is associated with cataract and can be bilateral.1

Microphalmos and coloboma

Ptosis can give the illusion of a smaller eye but is identified by a difference in vertical distance between the corneal light reflexes and the upper lids. Ptosis, especially due to haemangioma, needs careful follow-up to monitor for potential rapid tumour growth, as this can cause amblyopia.11 Ptosis and a small pupil can indicate Horner’s syndrome (fig 4).

Figure4

Fig 4 In this newborn baby, the parents thought that the left eye was smaller than the right. Examination showed symmetrical corneal diameters but with a left sided ptosis and small pupil indicative of Horner’s syndrome. Referral to the ophthalmologist was made. Asymmetry of the corneal light reflexes shows the eyes also to be slightly divergent; variable eye alignment for a few weeks following birth is common, and this was the cause here

A large eye (or eyes) (corneal diameter >11 mm) due to congenital glaucoma is typically but not always accompanied by photophobia, hazy cornea, and watering. A normal eye can falsely appear enlarged owing to contralateral ptosis or microphthalmos.

What if the child is asleep?

Do not wake a deeply sleeping child; this gives the opportunity to take a history and examine each eye (while gently retracting each eyelid with a finger) and its adnexae. Complete the examination later when the child is awake and cooperative.

Is there a place for restraint?

To avert future fear induced “pavlovian” reactions, do not use restraint to examine a young child’s eyes. If the condition is not urgent, arrange for the non-cooperative child to return later. However, parents may need to briefly hold a child with a red irritable eye to enable you to look for a corneal foreign body, abrasion, or dendritic ulcer (after instilling fluorescein dye).

When to refer

Most eye conditions in children warrant referral to a paediatric ophthalmologist. Urgently refer children with abnormal red reflexes, suspected glaucoma, or apparent lack of vision in one or both eyes. Those with confirmed low vision or blindness need prompt specialist management in the community.

The importance of good communication

The emotional impact of having a child with a significant eye condition or visual impairment is considerable, and parents appreciate empathy, good explanation, and informative correspondence and literature, with referral to appropriate local parent led support groups where available and appropriate.

Notes

Cite this as: BMJ 2015;350:h1716

Footnotes

  • Contributors: Both authors made substantial contributions to the conception, drafting, and critical revision of the work; have given final approval of the version to be published; and agree to be accountable for all aspects of the work.

  • Competing interests: We have read and understood the BMJ policy on declaration of interests and declare the following interests: None.

  • Provenance and peer review: Commissioned; externally peer reviewed.

  • Patient consent: Obtained.

References

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