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Amblyopia and Strabismus in the Pediatric Patient

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Amblyopia and Strabismus in the Pediatric Patient Dorothy Reynolds, MD 4/1/2013 Prior to Beginning This Lecture On Amblyopia and Strabismus In The Pediatric Patient… Amblyopia and Strabismus In The Pediatric Patient Pediatric eye exam will be outlined (to supplement Basic Eye Examination lecture) Dorothy Reynolds, MD NO recorded lecture accompanies these Stony Brook Medicine initial slides on the Pediatric Eye Exam Department of Ophthalmology Pediatric Ophthalmology and Strabismus Pediatric Ocular History External Inspection Inspection of the head, face, lids, orbits may A history of any of the following may warrant Ophthalmology evaluation: identify: – Glasses – Epiphora (tearing) – Amblyopia (reduced best-corrected vision not fully attributable to a structural issue in the eye) – Blepharospasm (blinking) – Strabismus (eye misalignment) – Photophobia (sensitivity to light) – Ptosis (droopy eyelid) – Leukocoria (pale pupillary red reflex on casual observation or in – Eyelid issue (mass, malposition, asymmetry, or photos) droop) – Ocular tearing, irritation/redness, rubbing –Eye trauma – Proptosis (forward “bulging” of eye(s)) – Previous eye surgery – Facial asymmetry – Parental concern about the eyes – Family history of eye disorder (especially one presenting in infancy – Nystagmus (jiggle of the eyes) or childhood) – Head position (head tilt or turn, chin up or down) External Inspection Red Reflex Test Eye or orbital abnormality on external inspection To identify leukocoria (pallor or whitening of the often requires Ophthalmology evaluation pupillary red reflex) Dim the room lights The clinical triad of photophobia, tearing, and From 1 meter away, view both eyes of child through blepharospasm in an infant or child may be the direct ophthalmoscope paying attention to the red signs of Infantile or Juvenile Glaucoma and reflex require prompt evaluation with Ophthalmology – Look for symmetry, and a full regular reflex – Dark spots, asymmetric color, white reflex, absent reflex, Penlight inspection of the anterior segment diminished reflex are of concern – Abnormality or asymmetry of the anterior segment of Abnormal or absent red reflex requires the eye requires ophthalmology evaluation ophthalmology evaluation – Discussed in Basic Eye Examination Discussed further in lecture that follows 1 Dorothy Reynolds, MD 4/1/2013 Corneal Light Reflex Test . Objective assessment of ocular alignment Pupils . May suggest an ocular misalignment . Helpful in evaluation of pseudostrabismus (appearance of strabismus with normal ocular alignment) Swinging flashlight test . Hold penlight at 33 cm (fixation target) Pupils should be equal in size, round, and . Compare position of corneal light reflex in both eyes equally react to light . Normal: symmetric corneal light reflex located slightly nasal to center of There should NOT be an afferent pupillary both pupils defect . Asymmetric corneal light reflex may indicate ocular misalignment . ***Must evaluate further with cover testing to confirm Assess for: Discussed further in lectures: – Symmetric constriction to light Sluggish or poor reactivity, asymmetric size, or afferent – Basic Eye Examination pupillary defect (Marcus Gunn Pupil) require – Lecture that follows Ophthalmology evaluation Discussed further in Basic Eye Examination Strabismus Tests Vision Testing Corneal light reflex test Divided primarily by age – A guesstimate that may suggest ocular misalignment –Infancy – Evaluate further with cover testing – Preverbal Cover testing –Verbal – Movement of either eye on cover-uncover test is suggestive MONOCULAR test of strabismus Abnormality on corneal light reflex test or cover Tested with glasses in place testing is suggestive of strabismus and requires Visual acuity improves after birth with visual ophthalmology evaluation maturation, so referral criteria are age dependent Vision Testing: Vision Testing: Verbal Child Infants and Preverbal Children Best corrected monocular vision with glasses in place – May sometimes need to encourage child to guess Infancy (first 2 to 3 months of life) – Use a patch or the parent’s hand to cover one eye (children peek) – Assess blink to light in each eye Use the highest cognitive test the child is able to perform (child – Muscle light or direct ophthalmoscope on high and swing light over eye must be able to identify the tested symbols) Blinks to light vision (normal) – Snellen letters (highest cognitive difficulty) Poor blink to light (abnormal) --> requires ophthalmology evaluation – Snellen numbers Preverbal (age 2 to 3 months to around 3 years of age) – Tumbling E – Check each eye for fixation and ability to follow –HOTV – Interesting object or toy held in front of one eye – Allen pictures or LEA symbols (least cognitive difficulty) – Cover the other eye with your hand) – Move toy in various directions noting the child’s fixation and ability to maintain Test vision with ROW of symbols that the child understands fixation and follow the toy – Can have parent point to each symbol along the line if child has difficulty – Assess for: progressing along the row Preference of one eye --> requires ophthalmology evaluation Inability to fix or follow with one or both eye(s) -->requires ophthalmology evaluation – Discussed further in lecture that follows 2 Dorothy Reynolds, MD 4/1/2013 Vision Testing: Verbal Child Extraocular Motility Age based referral criteria **** Examined in 9 positions of gaze – Age less than or equal to 5 years: two line Head is stabilized in primary position difference between the eyes and/or less than 20/40 vision in one or both eyes Move interesting object/toy into one position of – Age 6 years and older: two line difference gaze and then return to primary position between the eyes and/or less than 20/30 vision in Note overactions (excess movement) and one or both eyes underactions (lagging movement) of muscles Discussed further in lecture that follows May identify nerve palsy or restriction of eye(s) Discussed further in lectures: – Basic Eye Examination – Lecture that follows And now the lecture… Please proceed to the recorded Lectures Amblyopia and Strabismus In which include images on slideshow The Pediatric Patient Dorothy Reynolds, MD Stony Brook Medicine Department of Ophthalmology Pediatric Ophthalmology and Strabismus Objectives Amblyopia and Strabismus Obtain examination skills to screen for Amblyopia amblyopia and strabismus – Reduced best-corrected vision not fully Identify clinical signs of amblyopia inducing attributable to a structural issue in the eye risk factors, and clinical characteristics of Strabismus amblyopia and strabismus – Eye misalignment Understand importance of early identification “Lazy eye” and treatment of amblyopia and strabismus – Lay term for amblyopia, strabismus, or ptosis Become familiar with ophthalmology Amblyopia can result in strabismus, AND treatment protocol for amblyopia and strabismus can result in amblyopia… strabismus 3 Dorothy Reynolds, MD 4/1/2013 Amblyopia Amblyopia Decreased best-corrected vision in one (or both) eyes Decreased best-corrected vision in one (or both) eyes Reduced vision is not directly attributable to a Reduced vision is not directly attributable to a structural issue of the eye or posterior vision pathways structural issue of the eye or posterior vision pathways – i.e., if structural abnormality is corrected the amblyopic eye’s – i.e., if structural abnormality is corrected the amblyopic eye’s vision would still be sub-normal (needs treatment) vision would still be sub-normal (needs treatment) Develops PRIOR to maturity of the visual system Develops PRIOR to maturity of the visual system Generally unilateral (can be bilateral) Generally unilateral (can be bilateral) – Difference in best-corrected vision of more than 2 lines – Difference in best-corrected vision of more than 2 lines between the two eyes on vision testing between the two eyes on vision testing Common vision problem in children Common vision problem in children – Responsible for more vision loss in children than – Responsible for more vision loss in children than combination of all other causes combination of all other causes If detected early and treated early, can be correctable If detected early and treated early, can be correctable Amblyopia Onset Amblyopia Amblyopia develops PRIOR to maturity of the visual system Secondary to: Normal visual development: –Strabismus – Continuous process beginning at birth progressing Most common through age 8 to 9 years – Refractive error Most vulnerable period is during the first 2 years of life, Second most common particularly the first 3 months after birth – Stimulus deprivation – During the vision “learning” period the visual Least common…. More about these later… pathways are “plastic” – Visual development requires ONGOING stimulation of vision receptors in the brain, from birth onward Development of Amblyopia Visual stimulation/input is DISRUPTED in an eye during immature visual system period Three Major Types of Amblyopia – Earlier the age of onset the worse the potential amblyopia if not corrected Strabismic amblyopia Eye with an amblyopia-inducing risk factor sends a – Ocular misalignment distorted or blurred image to brain Refractive amblyopia Brain visual cortex selectively ignores/suppresses the – Glasses need distorted/blurred input from that eye Anisometropic (unequal glasses need) Isometropic (high glasses need in both eyes) Brain prefers/favors other eye with better vision Stimulus deprivation amblyopia Vision pathways
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