| Pediatric
Ophthalmology
I
Essentials of Pediatric Eye Examination
Pediatric Vision Screening:
· Purpose:
· Environment in which to perform the exam: · Minimal distractions, dim room for red reflex · Infants/Toddlers < 3 YO: hold upright in parent’s arms, assess visual behavior, not acuity
· Visual History: · Ask parents questions along these lines to get a baseline of the child’s visual behavior: § Does your child see well? § Do the eyes appear to cross or wander? § Does your child hold things close or squint? § Do your child’s eyelids droop? § Have your child’s eyes been injured? · PMHx or Conditions associated with ophthalmologic findings: § Lipid storage disorders, peroxisomal disorders § History of prematurity increases risk for developing amblyopia, high myopia (nearsightedness), and strabismus. § Among children with severe visual impairment, 70 percent have additional handicaps; 10 percent have impaired hearing · Family history of serious childhood eye disease: § childhood cataracts, strabismus, amblyopia, glaucoma, retinal problems, nystagmus
· Visual Inspection of the Eye:
· Occular Alignment: o The corneal light reflex § Shine a light into the eyes of a patient who is staring straight ahead. § Normal eye alignment = symmetric reflex in the center of each pupil. § If the light reflex is inwardly displaced = eye is exotropic § If outwardly displaced = esotropic § If inferiorly displaced = hypertropic o Strabismic gaze = a misalignment of the eyes § may be normal during the first several months of life § Persistent strabismus should be referred to an ophthalmologist
· Pupil Examination o Use a penlight to examine o Is the pupil reactive to light? § No: Think angle-closure glaucoma if fixed in mid-dilation/unreactive to light. Typically 4 to 5 mm in diameter. o Is the pupil small? § Yes: consider corneal abrasion, infectious keratitis, or iritis.
· Red reflex: o Test in a darkened room o Begin at a distance with the beam of light projected onto the upper facial area. o From a distance of approximately 18 inches, visualize the fundi are individually and simultaneously (Bruckner test). § Viewing the retina obliquely, in addition to straight-on, may improve the detection of retinoblastoma o In more darkly pigmented children, the reflex may be more gray than red o Children who have an abnormal red reflex (eg, dark spots, markedly diminished reflex, white reflex, asymmetry) should be referred to an ophthalmologist
· Fundus Examination: o Clearly visualize the optic disk, blood vessels, and more laterally the macula. § Fundus should be pink to red § Hemorrhages à suggest abusive head trauma · Describe the number, the pattern of distribution, and type § Roth Spots (white center) à suggest bacterial endocarditis o Papilledema à indication of increased intracranial pressure § Takes 12 – 24 hrs to develop in patients with increased intracranial pressure following head injury
· Visual Behavior: · Assess in children < 3 YO · Goal: determine if the vision is equal between eyes and to check if behavior is “normal”
· Normal visual behavior:
o A good marker of visual function in most preverbal children o Objects with spatial orientation are essential § < 3-4 months: The human face is the ideal target § > 4 months: Small, colorful toys or stickers placed on the end of tongue depressors are good targets. More than one target may be necessary to keep them interested § Objects to avoid: o White light from a pen light lacks orientation o Targets that make noise provide both visual and auditory cues and distinguishing which cues the child is using to track the object is difficult. o How to test: § The target is moved to and fro while the child’s head remains still § First assess both together, then test separately by occluding one eye at a time § Improve accuracy by repeating several times o Central-steady-maintained (CSM) method: § With one eye occluded, several characteristics of fixation are noted: o Is the fixation central (C) or eccentric/noncentral (NC)? o Is the fixation held steadily on the target as it is held still and slowly moved (S), or not (US)? o Is the child able to maintain fixation with the viewing eye when the other eye is uncovered or through a blink (M), or not (NM)? o Fix-and-follow (F + F) method: § Test each eye separately § Can the child fixate on and follow a target as it is slowly moved through his or her visual space?
· Visual Acuity Tests: o Attempt in all children > 3 YO o General § Improve performance by preteaching children how to do the test § Tests are designed to test the vision in each eye individually. o If unequal visual acuity - test eye with poorest vision first o Retest eye with lower visual acuity § Assess vision with and without glasses § Standard distance for visual acuity testing = 20 feet. o Many children perform better with the test target at 10 if the eye chart is recalibrated for that distance § If grossly normal vision, begin with the row of 20/40 and adjust up or down. If they can identify one figure in a row correctly, the examiner should go to the next row. § If the child misses two figures in a row, the examiner should ask the child to identify all of the figures in the previous row. o Interpretation § Visual acuity for the tested eye = the row above the row in which the child consistently misses two or more figures. § Visual acuity varies with the age of the child o Kids < 4 or 5 may have acuity of 20/40 or 20/50 o Kids ~ 4 or 5 should have acuity of at least 20/30 o Vision should be considered normal if the visual acuity is equal and not severely reduced in the two eyes (ie, better than 20/50). o “Perfect” vision = 20/20 § Most children have better visual acuity than is recorded, but they are not able to maintain attention for the testing of very small letters o Optotype tests: assess the child's ability to see and recognize an optotype (eg, figure or letter) and to communicate that recognition to the examiner. § The Snellen acuity test (the standard letter test) o ** gold-standard ** o Used for children who can identify letters of the alphabet. o The examiner should listen for letters that are consistently misnamed (eg, "E" for "F"); such misnamings may indicate lack of familiarity with the alphabet § Picture optotypes o used for children who do not know the letters of the alphabet o Allen cards: pictures of familiar objects (car, cake, horse, bird) § Present child with a single optotype, typically 20/30 size. Begin at near distance and gradually increase distance until the child can no longer identify the figures. · Directional optotype tests (eg, the tumbling E game, Landolt rings) o require the child to identify the direction the optotype is facing
· Referral indications — Refer to an ophthalmologist if: o Abnormal red reflex à may indicate cataract, glaucoma, retinoblastoma, retinal abnormality, or strabismus, or unequal or high refractive error o History of prematurity or metabolic or genetic disease o Family history of childhood cataract, retinoblastoma, retinal dysplasia, or glaucoma. § Should have a formal ophtho exam in the first weeks or months of life o Strabismus o Pupillary asymmetry of ≥1 mm à suggestive of neurologic condition o Corneal asymmetry à suggestive of glaucoma o Unilateral ptosis/lesions obstructing the visual axis à may cause amblyopia o Eye preference or visual acuity difference of two lines or more between eyes o Visual acuity worse than 20/40 in a child 3-5 YO or worse than 20/30 in a child > 6 years o Nystagmus. o Amblyopia
· References: o American Academy of Pediatrics. Eye Examination in Infants, Children and Young Adults. Vol 111 April 2003 o Bright Futures: Guidelines for Health Supervision of Infants, Children, and Adolescents, 3rd, Hagan JF, Shaw JS, Duncan PM (Eds), American Academy of Pediatrics, Elk Grove Village, IL 2008. o Pediatric ophthalmology, 3rd ed, Nelson, LB, Calhoun, JH, Harley, RD (Eds), Saunders, Philadelphia 1991. o Simon John Commonly Missed Diagnoses in the Childhood Eye Examination American Family Physician Aug. 15, 2001 o Walton, DS., Oski, FA, DeAngelis, CD, Feigin, RD, Warshaw, JB. Eye evaluation in the newborn. Principles and Practice of Pediatrics, Lippincott, Philadelphia 1990. p.468.
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