Performance of the Spot vision screener for thedetection of amblyopia risk factors in childrenDavid I. Silbert, MD, FAAP, and Noelle S. Matta, CO, CRC

PURPOSE To compare the accuracy of the Spot photoscreener (Pediavision Holdings LLC Lake

Author affiliations: Vision SciencPennsylvaniaSubmitted December 21, 201Revision accepted November 8Correspondence: Noelle S. Ma

Group, 2110 Harrisburg Pike SNoelleMatta@gmail.com).Copyright � 2014 by the Am

Strabismus.1091-8531/$36.00http://dx.doi.org/10.1016/j.ja

Journal of AAPOS

Mary, FL) in detecting amblyopia risk factors in children to the 2003 and 2013 referralcriteria of the American Association for Pediatric Ophthalmology and Strabismus(AAPOS).

METHODS Themedical records of children 1-6 years of age who underwent vision screening at a single

clinic from February 2012 through May 2012 were retrospectively reviewed. Participantswere screened with the Spot photoscreener on the same day as a pediatric ophthalmologyexamination. Visual acuity examination, ocular alignment testing, and cycloplegic refrac-tion were performed that day or within the preceding 6 months for all included subjectsby one pediatric ophthalmologist. Sensitivity and specificity of the Spot photoscreening re-sults were compared to the 2003 and to the recently revised 2013 AAPOS referral criteria.

RESULTS A total of 151 children were included. The Spot had a sensitivity of 80% and specificity of

74%. With the revised 2013 AAPOS referral criteria, the sensitivity was 87% and speci-ficity was 74%.

CONCLUSIONS The Spot is a fully portable, automated tool for the detection of amblyopia risk factors in

children. In this study cohort it was found to reliably detect amblyopia risk in childrenwhen compared to the 2003 and 2013 AAPOS referral criteria. ( J AAPOS 2014;18:169-172)

Amblyopia is a sight-threatening disorder that if leftundetected and untreated in childhood can lead toirreversible vision loss.1 It affects 1.6% to 3.6% of

pupils simultaneously and generates information on noncy-cloplegic refractive status, pupil size, interpupilary distance,and gaze deviation in real time. The examiner holds the de-

the population2 and is the leading cause of vision loss inchildren and a frequent cause of vision loss in working-age adults.3 It disproportionately affects economicallydisadvantaged children.4 The cost to society of untreatedamblyopia is greater than the cost for treatment.5 Ambly-opia also has noneconomic costs, including decreasedself-esteem, and risk for unrelated loss of vision later inlife in the nonamblyopic eye.6,7 Untreated amblyopia hasbeen shown to adversely affect school performance,including reading and mathematic skills.8

The Spot photoscreener (Pediavision Holdings LLCLake Mary, FL) is a newly available, handheld, portable,infrared photoscreener designed to screen children foramblyopia risk factors. It is similar to other infrared photo-screeners, measuring noncycloplegic refraction in partiallydark-adapted mid-dilated pupils. It records images of both

e Department, Family Eye Group, Lancaster,

2., 2013.tta, CO, CRC, Vision Science Department, Family Eyeuite 215, Lancaster, Pennsylvania 17601 (email:

erican Association for Pediatric Ophthalmology and

apos.2013.11.019

vice approximately 1 meter from the child. The device pro-duces noise to attract the child’s attention and fixation.The device will not record data until the image is properlyfocused; it provides the examiner with visual cues to assistin focusing. An image can be obtained rapidly with multiple(23) readings taken in three separatemeridians in a matter ofseconds.

The device uses internal software that refers a patient ifthe measurements suggest significant refractive error,anisometropia, anisocoria, or if the pupillary centers arediscordant, indicating strabismus. The device is also de-signed to detect ptosis. In severe unilateral ptosis the pupilis not fully visible to the camera, leaving it unable to recordproperly, generating a referral. It has the potential to detectmedia opacity but has not been validated for this capabilityand thus currently does not report this data.

A report can be printed for the parents and includes adiagrammatic representation of the eyes showing anymisalignment, an estimate of refractive error, and a graph-ical presentation of refractive or alignment issues ofconcern in the child. Previous studies of similar deviceshave shown infrared photoscreeners to be effective foramblyopia, high refractive error, and nonintermittent stra-bismus.9 The purpose of this study was to evaluate the ac-curacy of the Spot photoscreener in detecting amblyopiarisk factors in children compared to the 2003 referral

169

Table 1. Manufacturers referral criteria for the Spot photoscreener (software version 1.0.3)

Age, months Anisometropia, D Astigmatism, D Myopia, D Hyperopia, D Anisocoria, mm

Gaze, degrees

Vertical Nasal Temporal Asymmetry

6-12 1.5 2.25 2 3.5 1 5 5 8 613-36 1 2 2 3 1 5 8 8 637-72 1 1.75 1.25 2.5 1 5 8 8 673-240 1 1.5 0.75 2.5 1 5 8 8 62401 1 1.5 0.75 1.5 1 5 8 8 6

D, diopters.

170 Silbert and Matta Volume 18 Number 2 / April 2014

criteria of the American Association for Pediatric Ophthal-mology and Strabismus (AAPOS) and the 2013 referralcriteria, revised to improve specificity and decrease false-positive readings of objective vision screeners.

Subjects and Methods

This study received approval from the Lancaster General Hospi-

tal Institutional Review Board and was granted a waiver of con-

sent because of the low risk of this research; appropriate

guidelines of the Health Insurance Portability and Accountability

Act of 1996 were followed.

Referral data from noncycloplegic images from the Spot photo-

screener was compared with data obtained from a comprehensive

examination performed by one pediatric ophthalmologist (DS).

All children examined with the Spot had a pediatric ophthalmic

examination performed on the same day. A cycloplegic refraction

was performed on the same day or within the past 6 months. An

ophthalmic technician or a certified orthoptist performed the

Spot photoscreening on all patients prior to cycloplegia. Consec-

utive patients 1-6 years of age who were tested with the Spot and

who received a full cycloplegic examination at Family Eye Group,

Lancaster, from February 2012 throughMay 2012 were included.

Although the referral criteria for the Spot can be modified with

the help of the manufacturer to suit the goals of an individual

screening program, this study used the preset internal criteria

provided by the manufacturer (Table 1). The manufacturer’s

criteria vary among age groups. For each group, the manufacturer

provides referral criteria for anisometropia, astigmatism, myopia,

hyperopia, gaze (nasal, vertical, temporal, and asymmetry), and

anisocoria. Spot photoscreening referrals were compared with re-

sults of a comprehensive ophthalmology examination in each

child using the 2003 and 2013 AAPOS referral criteria. Sensi-

tivity, specificity, positive predictive value, negative predictive

value, and the accuracy rates were calculated.

Results

A total of 151 patients between the ages of\1-6 years oldwere examined. The clinic patients studied were a popula-tion enriched for pathology, with 106 (70%) of the patientsfound to have amblyopia or amblyopia risk factors based onthe 2003 AAPOS referral criteria10: anisometropia (spher-ical or cylindrical) 1.5 D, any manifest strabismus, hyper-opia 3.50 D in any meridian, myopia magnitude 3.00 D inany meridian, any media opacity 1 mm in size, astigmatism

1.5Dat 90� or 180� or 1.0D in oblique axis (10� eccentric to90� or 180�), and ptosis 1 mm margin reflex distance.

The Spot photoscreener referred 97 children (Table 2).Compared to the cycloplegic pediatric ophthalmology ex-amination, the Spot had a positive predictive value of 88%,a negative predictive value of 61%, a sensitivity of 80%, anda specificity of 74%.The Spot had an accuracy rate of 78%.The results of the spot agreed with the 2013 AAPOSreferral criteria 82% of the time.

The Spot photoscreener agreed with the pediatricophthalmic examination in 79% of the cases. Of the chil-dren who failed the ophthalmological examination basedon the 2003 referral criteria, 59% had significant refractiveerror and 36% had strabismus.

The accuracy of the Spot photoscreener was thencompared to the 2013 AAPOS referral criteria designedto limit over-referrals of children with amblyopia risk fac-tors who either do not have amblyopia, are low risk foramblyopia, or who have only mild amblyopia which canbe identified in future screenings (Table 3).11

With the 2013 criteria, 65% of the children were foundto have amblyopia risk. The results of the Spot agreed withthe 2013 AAPOS referral criteria 85% of the time.

Compared to the cycloplegic pediatric ophthalmologyexamination, the positive predictive value of the Spot todetect 2013 AAPOS referral criteria was 86%; the negativepredictive value, 75%; the sensitivity, 87%; and the speci-ficity, 74%. Of these children who failed the ophthalmicexamination, 56% had significant refractive error and32% had strabismus.

Twelve children were an “unable” on the Spot: 3 had alarge-angle esotropia, 1 had a large-angle esotropia and acongenital cataract, 2 had congenital ptosis, 1 had an iriscoloboma, 1 had an intermittent exotropia and was unco-operative during the test, 1 had nystagmus, 1 had a normalexamination except for a NLDO and moderate astigma-tism, 1 had a normal examination except for vernalconjunctivitis with excessive tearing, and 1 had a normalexamination with no other findings.When the device is un-able to obtain autorefraction readings the device automat-ically flags the child as a referral.

There were 74 children felt to have clinical amblyopiaand/or strabismus (children actively being followed for stra-bismus and/or treated for amblyopia with glasses and/or oc-clusion therapy). Of these, 19 children passed the Spotphotoscreening; 2 did not meet the 2003 referral criteria

Journal of AAPOS

Table 2. Reasons for referral on photoscreening by the Spot compared to 2003 and 2013 AAPOS referral criteria

Reasons for referralReferred onSpot (n)

Found to have2003 amblyopiarisk factors PPV

Found to have2013 amblyopiarisk factors PPV

Anisocoria 1 1 100% 1 100%Anisometropia 3 2 67% 2 67%Astigmatism 18 16 89% 15 83%Gaze 6 5 83% 5 83%Hyperopia 1 1 100% 1 100%Myopia 1 1 100% 0 0%Unable to obtain an image 12 11 92% 9 75%Anisometropia, gaze 3 3 100% 3 100%Anisometropia, hyperopia 3 3 100% 3 100%Anisometropia, myopia 2 2 100% 2 100%Astigmatism, gaze 5 5 100% 5 100%Myopia, gaze 2 2 100% 2 100%Anisometropia, astigmatism, gaze 1 1 100% 1 100%Anisometropia, astigmatism, hyperopia 1 1 100% 1 100%Anisometropia, gaze, hyperopia 2 2 100% 2 100%Anisocoria, anisometropia, hyperopia, myopia 1 1 100% 1 100%Anisometropia, gaze, myopia 2 2 100% 2 100%Anisometropia, astigmatism, gaze, myopia 1 1 100% 1 100%

PPV, positive predictive value.

Table 3. 2013 AAPOS referral criteria

Criteria

Age, months

12-30 31-48 .48

Astigmatism, D .2.00 .2.00 .1.50Hyperopia, D .4.50 .4.00 .3.50Anisometropia, D .2.5 .2.00 .1.50Myopia, D �3.50 �3.00 �1.50Manifest strabismus inprimary position, PD

.8 .8 .8

Media opacity, mm .1 .1 .1

D, diopters; PD, prism diopters.

Volume 18 Number 2 / April 2014 Silbert and Matta 171

and 4 did notmeet 2013 referral criteria. Of 77 childrenwhowere not found to have clinical amblyopia and/or strabismuson examination, 8 were referred by the Spot photoscreener:allwere found tobepositive for 2003AAPOSreferral criteriabut none were positive for 2013 AAPOS referral criteria (e-Supplements 1-2, available at jaapos.org).

Discussion

Detection and treatment of amblyopia has been shown to becost effective.The cost of detecting and treating amblyopia isquite reasonable with a ratio of cost to quality-adjusted lifeyears for amblyopia screening estimated at $6,000.12 Thisis significantly less than the estimated $231,000 for annualscreening for diabetic retinopathy in adults.12 Well-constructed photoscreening programs can have referral ratesless than 10%with high sensitivity and specificity for detect-ing amblyopia and low cost per child screened.13 Neverthe-less, fewer than 37% of children are screened before age 6.14

Although recent studies have shown that detection andtreatment of amblyopia at anolder age is possible, it is knownthat detecting amblyopia at an early age allows for rapid andcomplete treatment.15 Although young children can be

Journal of AAPOS

screened with recognition acuity starting at 3 years of age,recent studies have shown poor sensitivity and specificity(MattaNS, SilbertDI. Flip chart acuity screening comparedto the plusoptiX S09 photoscreener performed by a layscreener. International Orthoptic Congress, Toronto, June26, 2012). The Spot photoscreener advantages include itssmall size and true portability. The infrared design is welltolerated by children. It performed reasonably well whencompared to the 2003 and 2013 AAPOS referral criteria.As the device’s internal referral criteria was not calibratedfor the new AAPOS referral criteria, this will likely beimproved with future modification of internal referralcriteria and improvements in the software of the device.

Recent studies have shown the 2003 AAPOS amblyopiarisk factors to be more prevalent in the population than theexpected 1.6% to 3.6% rate of amblyopia and strabismus.The AAPOS Vision Screening Committee has publishednew criteria to address these concerns. These criteria areintended to decrease over-referral of children with risk fac-tors but no amblyopia. With the revisions to the AAPOSreferral criteria, the sensitivity of the Spot improved,whereas the specificity dropped slightly.

This study was limited by the ophthalmology clinicsetting and the screening of an enriched population.

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4. Smith LK, Thompson JR, Woodruff G, Hiscox F. Social deprivationand age at presentation in amblyopia. J Public Health Med 1994;16:348-51.

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13. Longmuir SQ, Pfeifer W, Leon A, Olson RJ, Short L, Scott WE.Nine-year results of a volunteer lay network photoscreening programof 147 809 children using a photoscreener in Iowa. Ophthalmology2010;117:1869-75.

14. National Center for Health Statistics. 2002 National Health Inter-view Survey. Hyattsville, MD: USDepartment of Health and HumanServices, CDC, National Center for Health Statistics; 2003.

15. US Preventative Service Task Force. Vision screening for children 1to 5 years of age: US Preventative Services Task Force recommenda-tion statement. Pediatrics 2011;127:340-46.

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