TECHNIQUES AND ADVANCES IN VISION SCREENING Neither I nor my - PDF document

DISCLOSURES TECHNIQUES AND ADVANCES IN VISION SCREENING • Neither I nor my immediate family members have a personal financial relationship with a manufacturer of Maanasa Indaram, MD pharmaceutical products or services that will be discussed in this presentation. Assistant Professor Pediatric Ophthalmology and Adult Strabismus University of California San Francisco 18 th Annual Developmental Disabilities: An Update for Health Professionals March 14-145 2019 WHY PERFORM VISION SCREENING? VISION PROBLEMS IN CHILDREN • Amblyopia • 1/4 American school children have vision problems o Refractive • Young children do not realize it and will not be able to tell you o Strabismic o Form deprivation • Primary care providers are the first line of defense to detect vision loss in children • Non-amblyopic refractive error o Timely referral to optometry/ ophthalmology • Non-amblyopic strabismus • Structural eye abnormalities

AMBLYOPIA (AKA: “LAZY EYE”) SCREEN FOR AMBLYOPIA EARLY • Definition: “Reduction of best-corrected distance visual • Risk factors present in early acuity that cannot be attributed to any structural abnormality of childhood (<6 years) the eye or visual pathway .” • Usually does not occur if risk factors develop later because • Neurodevelopmental disorder visual system has already developed o Brain doesn’t receive normal stimulation from one or both eyes • Reversible only in sensitive • 2-3% of children in the U.S. (4.5 million) period: 90% at age 3  nearly Sloper J., J AAPOS 2016 untreatable at age 10 o 2.6x increase at age 8 years if no screening done at age 2 WHY TREAT/ PREVENT AMBLYOPIA? CURRENT RECOMMENDATIONS • Vision screening for all children at least once • Leading cause of monocular vision loss in children between 3-5 years of age to detect the presence of amblyopia or amblyopia risk factors o 75% of pediatric eye visits • Limits educational and career options o The US Preventive Service Task Force • Cost of unilateral vision loss by age 10 o US Public Health Service o American Academy of Ophthalmology, American Academy of o > $67,000 over the lifetime Pediatrics, American Association for Pediatric Ophthalmology and Strabismus o 10% decrease in quality of life o Prevent Blindness America o National Association for School Nurses

WHAT ACTUALLY HAPPENS WHAT DOES SCREENING LOOK FOR? • Requirements for preventive eye care vary broadly o 40 states require any vision screening for school-aged children o Only 16 states require vision screening for preschool-aged children • In 2011, only 40% of children <= 5 years received vision screening o Up from 21% in 1983 • No clear standards in screening protocol: type, frequency, referral, follow-up AMBLYOPIA VS. AMBLYOPIA RISK AAPOS 2003 GUIDELINES FOR FACTORS AMBLYOPIA RISK FACTORS • Amblyopia: determined by measurement of visual acuity • Amblyopia risk factors determined by consensus, not necessarily epidemiologic evidence • Amblyopia Risk Factors (ARF): • Refractive error: anisometropia, isometropia • Only 1/8 children with ARFs developed amblyopia • Strabismus: misalignment of visual axis  competitive/ inhibitory interaction • Form deprivation (e.g. cataract): blockage of visual axis  image degradation • Mixed mechanism

AAPOS 2013 GUIDELINES FOR NORMAL REFRACTION BY AGE AMBLYOPIA RISK FACTORS 1. Separate criteria for different age groups 2. Lower referral rate by raising threshold referral values 3. Use traditional optotype screening for children who can read letters 4. Detection of a constant strabismus at all ages Mayer et al., JAMA Ophthalmology 2001 Jonas et al., U.S. Preventative Task Force 2017 Zadnik et al., CLEERE Study 2003 CONVENTIONAL SCREENING TESTS VISUAL ACUITY NORMS BY AGE Normal adult visual acuity (20/20) is typically achieved between the ages of 5-6 years Mayer et al., IOVS 1995

OPTOTYPE VISUAL ACUITY TESTING OPTOTYPE VISUAL ACUITY TESTING • Prevent Blindness North California • Quantitative test; best method to test how well a o PPV of ARFs: 60% (most experienced child sees screener) o Referral rate: 4% • Detects refractive error and amblyopia (difference between eyes) • Vision in Preschoolers (VIP) Study • Cutoffs for screening: 20/40 o PPV of ARFs: 27% (lay screener) (age 3-4), 20/32 (age 5) o Referral rate: 13% BARRIERS TO CONVENTIONAL BRUCKNER RED REFLEX SCREENING TESTS • Works better in older, cooperative children o Difficult in younger children, developmental delay, behavioral issues • Need highly trained staff for best predictive value • Monocular test  time consuming (4 minutes) • Poor reimbursement for physicians PPV: 89% (experienced examiner)

AUTOMATED VISION SCREENING DEVICES HANDHELD AUTO-REFRACTORS Photorefractors : • Determine refractive status of each eye Autorefractors : o Monocular test  no information about strabismus Foveal birefrigence : o Detects amblyopia risk factors, not actual amblyopia • Takes <1 minute to get result o Requires fixation from subject and well trained screener • Validated in several large studies (VIP, MEPEDS, BPEDS) HANDHELD AUTO-REFRACTORS PHOTOREFRACTORS • Designed to be operated by lay screeners with Retinomax Suresight little training • Sensitivity: 62% • Sensitivity: 61% • Binocular test; done at distance from the subject • Specificity: 90% • Specificity: 90% • Detects ARF (refractive error, misalignment), not actual amblyopia • PPV: 32% vs. 50%* • *Lay screener (VIP) vs. nurse (PBNC) Images courtesy of Dr. Alejandra De Alba

HOW PHOTOREFRACTORS WORK SPOT VISION SCREENER • Infrared scanner • Examines reflection of light off retina using a • Determines refractive state + photograph strabismus • Type/ degree of refractive error affects size/ • Instant interpretation with placement light crescent “Pass” or “Fail” result based on pre-set criteria (AAPOS) • T esting distance: 1 meter PLUSOPTIX • Infrared scanner • 7814 children aged 6 months - 6 years • Determines refractive state + strabismus • Can modify referral criteria settings • Tested by novice operators in daycares and preschools • Instant interpretation with “Pass” or in Southern CA between 2011-2012 “Refer” (few seconds) • PPV for any amblyogenic risk factor: 65.7% • Testing distance: 1 meter • Referral rate: 30.6% • False positive rate: 34%

GOCHECK KIDS • App on Smartphone (uses camera with flash) • 1443 children aged 18 months - 5 years • Determines refractive state • Screened by lay operators at >100 daycare centers and checks visual acuity in Canada between 2015-2016 • Instant interpretation of • PPV for any amblyogenic risk factor: 81.8% results to target referral • Referral rate: 6.1% • Reduces false positives with • False positive rate: 15.4% remote MD review “The revised AAPOS guidelines • 206 children aged 6 months – 6 • 108 children aged 9 months – 12 for defining years screened by at Storm Eye years in a pediatric eye practice in Center (MUSC) risk factors in preschool vision Alaska screening studies • Using 2013 AAPOS guidelines • Using 2003 AAPOS guidelines …divert attention from the goal • PPV for any ARF: 57%* • PPV for any ARF: 92% of screening, which is not to • * UCSF data: PPV ~50% (worse if <12 detect risk factors but to detect mo.) amblyopia and strabismus.”

BLINQ BY REBION NEURAL PERFORMANCE SCANNING • New technology that uses Neural Performance Scanning • Can detect strabismus (<1 o ) AND amblyopia directly (not just ARFs) o 82% amblyopia in < 3 y/o secondary to strabismus (not any other ARFs) COMPARISON OF VISION SCREENERS VA GoCheck Retinomax SPOT PlusOptix Blinq T esting Kids • 300 children aged 2 - 6 years screened with the Pediatric Vision PPV Screener (PVS) at two pediatric eye clinics between 2010-2013 27% (60%) 32% (50%) 65.7% 81.8% 57% 92.9% False Positive Rate - - 34% 15.4% - 12.6% • Sensitivity: 97% Can directly Quick Quick Quick Detects Quick PRO’S • Specificity: 87% detect Accurate with Test from Can change true Familiar interface amblyopia experience distance referral criteria amblyopia • PPV for true amblyopia or strabismus: 92.9% Needs Needs experience Noises/ clown experience CON’S Proximity/ contact Inconclusives face Accuracy? New tech • False positive rate: 12.6% Time Requires fixation Inconclusives Cooperation Additional Cost $0 ~$3000 ~$7000 ~$7000 $60/month ??

CONCLUSIONS • Early vision screening is needed to prevent amblyopia • Automated vision screening can improve efficiency and accuracy of testing, especially in uncooperative children • However, automated techniques have limitations (low PPV) and cannot detect amblyopia directly o Not a surrogate for subjective acuity in cooperative, older children • New technology promises direct detection of amblyopia and strabismus