Portable acuity screening for any school: validation of patched HOTV with amblyopic patients and Bangerter normals.

BACKGROUND: We needed to validate and calibrate our portable acuity screening tools so amblyopia could be detected quickly and effectively at school entry. METHODS: Spiral-bound flip cards and download pdf surround HOTV acuity test box with critical lines were combined with a matching card. Amblyopic patients performed critical line, then threshold acuity which was then compared to patched E-ETDRS acuity. 5 normal subjects wore Bangerter foil goggles to simulate blur for comparative validation. RESULTS: The 31 treated amblyopic eyes showed: logMAR HOTV = 0.97(logMAR E-ETDRS)-0.04 r2 = 0.88. All but two (6%) fell less than 2 lines difference. The five showed logMAR HOTV = 1.09 ((logMAR E-ETDRS) + .15 r2 = 0.63. The critical-line, test box was 98% efficient at screening within one line of 20/40. CONCLUSION: These tools reliably detected acuity in treated amblyopic patients and Bangerter blurred normal subjects. These free and affordable tools provide sensitive screening for amblyopia in children from public, private and home schools. Changing "pass" criteria to 4 out of 5 would improve sensitivity with somewhat slower testing for all students.

Calibration and validation of the 2WIN photoscreener compared to the PlusoptiX S12 and the SPOT.

PURPOSE: Pediatricians are interested in the amblyopia detection ability of photoscreeners, whereas ophthalmologists ponder their value as autorefractors. The 2WIN (Adaptica, Padova, Italy) is a new device capable of estimating refractive error and ocular alignment by infrared photoscreening. METHODS: Sequential pediatric eye patients with a high (56% to 60%) prescreening prevalence of amblyopia risk factors were screened with the PlusoptiX S12 (PlusoptiX, Inc., Atlanta, GA), SPOT (PediaVision, Lake Mary, FL), and 2WIN photoscreeners before confirmatory examination adhering to American Association for Pediatric Ophthalmology and Strabismus guidelines and Alaska Blind Child Discovery institutional review board protocol. Instrument referral guidelines determined through phase 1 comparison was then applied on additional patients for validation in phase 2. RESULTS: Sixty-two children (age: 1 to 10 years, mean: 5.2 years) were screened with all three devices before cycloplegic examination. Refractive results were inconclusive due to pupil size, cooperation, and out-of-range values. Values for sensitivity (91% and 78%), specificity (71% and 59%), and inconclusive rate (10% and 13%) were found for PlusoptiX and SPOT. The 2WIN was calibrated for this age range (phase 1), yielding 71% sensitivity, 67% specificity, and a 5% inconclusive rate. Regression compared to examination for the PlusoptiX, SPOT, and 2WIN, respectively, were sphere (r(2): 0.76, 0.87, and 0.58), cylinder power (r(2): 0.67, 0.56, and 0.50), and cylinder axis (r(2): 0.71, 0.41, and 0.40). A preferred 2WIN instrument criteria set was determined from the receiver operating characteristic curve. In phase 2, with 117 patients comparing 2WIN to PlusoptiX A-09, sensitivity was 73% and 85%, specificity was 76% and 73%, and inconclusive rate was 8% and 12%, respectively. The three instant-interpreting photorefractors performed well on amblyopic children, with the 2WIN having low inconclusive results. The PlusoptiX outperformed the SPOT and 2WIN as an autorefractor, particularly with respect to astigmatism power and axis. CONCLUSIONS: The new 2WIN is a promising addition to portable photoscreeners for amblyopia detection and estimating refractive error.

Performance of four new photoscreeners on pediatric patients with high risk amblyopia.

PURPOSE: A new study by the American Academy of Pediatrics touts the benefits of photoscreening, especially in preverbal children who cannot yet perform monocular acuity screening. Emerging devices have not been compared in young and developmentally challenged children. METHODS: Consecutive patients in a pediatric eye practice had a comprehensive eye examination and four photoscreens: PlusoptiX (PlusoptiX, Nuremburg, Germany), SPOT (PediaVision, Lake Mary, FL), iScreen (iScreen, Memphis, TN), and the GoCheckKids application (Gobiquity, Aliso Viejo, CA) for the iPhone 4s (Apple, Cupertino, CA) with Delta Center Crescent interpretation. They were validated according to the 2003 American Association for Pediatric Ophthalmology and Strabismus uniform guidelines. RESULTS: One hundred eight children aged 1 to 12 years participated, with 56% having amblyopia risk factors and 10% having autism. For the four devices, sensitivity, specificity, and inconclusive results were as follows: PlusoptiX (83%, 86%, 23%), SPOT (80%, 85%, 4%), iScreen (75%, 88%, 13%) and iScreen (with Delta Center Crescent) (92%, 88%, 0%), and GoCheckKids (with Delta Center Crescent) (81%, 91%, 3%). CONCLUSIONS: Even in high risk and young children, current instrument-based screeners can reliably screen for refractive and strabismic risk factors that lead to amblyopia. Some devices can reduce the proportion of inclusive results in challenging cases.

Pediatric photoscreeners in high risk patients 2012: a comparison study of Plusoptix, Iscreen and SPOT.

BACKGROUND: New photoscreening models promise to detect amblyopia risk factors early in hopes of reducing permanent pediatric monocular and binocular vision impairment. The 3 commercially available interpreted photoscreeners had not yet been compared. METHODS: This is a prospective, observational screening study following AAPOS guidelines on pediatric patients with and without developmental delays. 270 patients in a pediatric eye practice aged 4.7 +/- 4 years with 7% special needs. From December 2011 through March 2012, the Plusoptix, the iScreen, and the Pediavision SPOT were applied before confirmatory exam in a clinical pediatric eye practice. RESULTS: The inconclusive rate ranged from 1-4% (iScreen) to 12% (Plusoptix). Sensitivity ranged from 72% (iScreen) to 84% (Plusoptix) and specificity ranged from 68% (SPOT) to 94% (Plusoptix). The iScreen can provide results in 99% of high risk patients. CONCLUSIONS: In this cohort with high pre-screening prevalence, the 2011 photoscreeners had favorable validation that is expected to improve with further clinical study. Pediatricians have practical technology with a recognized procedure code to assist in amblyopia reduction.

Predictive value from pediatrician plusoptix screening: impact of refraction and binocular alignment.

BACKGROUND: The positive predictive value (PPV) of conventional preschool acuity screening is about 50% whereas previous Polaroid photoscreening with experienced interpretation can achieve PPV greater than 85%. The Plusoptix photoscreener has immediate computer interpretation and a CPT code available to pediatricians. METHODS: Two Plusoptix SO9 were used in two pediatric group practices with previously validated refractive criteria and new manufacturer's binocular alignment criteria. CPT billing was monitored. Referred patients had prior gold-standard AAPOS examinations. RESULTS: 12% of 675 photoscreened preschoolers were referred. Of the 39 with AAPOS gold-standard exams, the PPV from strabismus referrals was 17%, while 26 of 27 refractive referrals had true amblyopia risk factors (PPV 96%). Screening CPT code 99174 reimbursement rose from zero to half of insurers in 15 months. CONCLUSION: Plusoptix photoscreening is valid after adjusting the binocular alignment criteria. Such photoscreening should be employed by pediatric practices to detect and ultimately to reduce amblyopia vision impairment in children.

Overcoming barriers to pediatric visual acuity screening through education plus provision of materials.

PURPOSE: The American Academy of Pediatrics (AAP) recommends that LEA and HOTV optotypes be used for vision screening and that adhesive tape be used to occlude one eye during testing. We have developed an educational program designed to improve the quality and efficiency of vision screening. The purpose of this study was to ascertain the effectiveness of this program. METHODS: All 672 pediatric doctors and nurses in the state of Alaska were surveyed by mail to assess their screening protocol and the number of patients cared for annually. Respondents received educational material, including an instructional video, eye patches for visual acuity testing, and a critical line HOTV test box. Subjects were resurveyed 3 months later to determine whether the instructional intervention altered their established protocol. RESULTS: Of the 672 practitioners contacted for the survey, 239 (35.6%) responded, representing 31,000 patients, or 62% of all preschool children in Alaska. Use of recommended optotypes was rare (Lea, 3%, HOTV, 7%) compared with the use of nonrecommended optotypes (including use of the E test by 40% of respondents). The postintervention survey was answered by 107 (16%) practitioners. Of these, 24 (23%) reported that they had begun using an adhesive patch for visual acuity testing, whereas 19 (18%) had begun using AAP-recommended testing optotypes. CONCLUSIONS: In-office video education and provided adhesive eye patches increased the use of patches in primary care preschool vision screening. Mail delivery was less effective than anticipated.

Tent photoscreening and patched HOTV visual acuity by school nurses: validation of the ASD-ABCD protocol. (Anchorage School District- Alaska Blind Child Discovery program).

BACKGROUND: Novel objective tests of risk factors for amblyopia offer an alternative for preschool vision screening. We compared the merits of photoscreening versus portable patched acuity testing in elementary schools. Photoscreening may outperform routine acuity testing in pediatric offices; however, both have fairly good validity when performed by specialists in preschool vision screening. METHODS: School nurses performed patched HOTV surround acuity testing and two types of photoscreening (MTI and Gateway DV-S20) in a portable tent near each classroom. RESULTS: 1700 children (696 1st grade, 710 Kindergarteners and 271 special-needs pre-Kindergarten). 14% had comprehensive exams and another 65% had normal photoscreens combined with patched acuities of 20/20 or better OU. We estimate the overall sensitivity/specificity using AAPOS guidelines for the modalities to be 39%:99% for patched HOTV acuity, 77%:99% for MTI photoscreening, and 85%:98% for Gateway photoscreening. The specificity of acuity testing was particularly low in pre-K due to 33% unable to complete the test, but about 80% of initial acuity failures were able to pass with pinhole. CONCLUSION: Tent photoscreening in younger elementary school children was more sensitive and faster than patched acuity particularly in developmentally delayed pre-K children.

Preverbal photoscreening for amblyogenic factors and outcomes in amblyopia treatment: early objective screening and visual acuities.

BACKGROUND: Previous studies have suggested that infant photoscreening yields better results than visual acuity screening in preschool-aged children. With conventional vision screening, the patient must be able to provide monocular visual acuity cooperation, whereas objective screening for amblyogenic factors can be done at much younger ages. METHODS: From February 1996 through February 2006, Alaska Blind Child Discovery photoscreened 21,367 rural and urban Alaskan children through grade 2, with an 82% positive predictive value (ie, true number of those referred); 6.9% were referred for a complete eye examination and treatment. All "referred" interpreted images for children younger than 48 months who were then followed up and treated for more than 2 years were reviewed to determine whether treatment was successful. RESULTS: Of 411 "positive" screening photos from children younger than 4 years, 94 patients had more than 2 years follow-up. The 36 children photoscreened before age 2 years had a mean treated visual acuity of 0.17 logarithm of the minimum angle of resolution (logMAR), which was significantly better than that of 58 children screened between ages 25 and 48 months (mean, 0.26 logMAR). Despite similar levels of amblyogenic risk factors, the proportion of children failing to reach a visual acuity of 20/40 was significantly less among those screened before age 2 years (5%) than in those screened from ages older than 2.0 years and younger than 4.0 years (17%). CONCLUSION: Very early photoscreening yields better visual outcomes in amblyopia treatment compared with later photoscreening in preschool-aged children.

The cost and yield of photoscreening: impact of photoscreening on overall pediatric ophthalmic costs.

BACKGROUND: Approximately 5% of preschool-age children suffer from amblyopia. Many of them have high or unequal hyperopia. Amblyogenic risk factors frequently can be detected by photoscreening. METHODS: Free photoscreening was offered to Alaskan children ages 1 to 5 from urban and rural screening hubs. Screened images were mailed to the Alaska Blind Child Discovery coordinating center for physician photoscreen interpretation, specifically seeking latent or anisometropic hyperopia. Parents and screeners then were mailed results and information about amblyopia. Follow-up examination data were tallied, and a cost-consequence analysis was developed for various vision screening paradigms and eye care. RESULTS: From 1996 through 2003, a total of 13,255 screenings were performed with a positive interpretation rate of 4.7%. Penetrance of screening was 22% in urban and 44% in rural communities. Positive predictive value was estimated to be more than 90%. Average cost to screen and inform an Alaskan preschooler was approximately 10.67 dollars, and cost to detect amblyogenic risk factors by photoscreening in an Alaskan was approximately 206 dollars. Compared to American Academy of Pediatrics (AAP) 1995 guidelines, implementing photoscreening added 9%, while mandating complete prekindergarten examination added 49% to overall eye care. CONCLUSIONS: MTI photoscreening achieved high community penetrance and high positive predictive value for latent hyperopia and other amblyogenic factors. When follow-up costs are considered, adding photoscreening to current AAP guidelines may add 112 dollars per child over 10 years, but probably would assist in the reduction of amblyopia. Penetrance of urban photoscreening likely will remain low unless pediatric vision screening guidelines and reimbursement are revised.

The Receiver-Operator Curve for Flip-Card Surround HOTV in Younger School Children: Validation of a Simple Flip Card for School Acuity Testing.

BACKGROUND: The AAP vision screening guidelines are not uniformly delivered. Moderate amblyopia can be successfully treated in children 7 years of age and older. The ideal method and threshold of vision and/or acuity testing in school is not known. METHODS: 1700 students from first grade, kindergarten, and pre-kindergarten were screened with a flip-card, surround HOTV protocol with other eye patched combined with photoscreening; 234 students had "Gold Standard" confirmatory exams from which AAPOS standards were validated. RESULTS: Receiver Operator Curves were constructed by adjusting referral criteria by grade. A cutoff of 20/25 yielded fairly good (50%) sensitivity and 90% specificity for first grade and kindergarten, but many of the pre-kindergarten were unable to complete the testing. CONCLUSION: Patched surround HOTV flip-card acuity is useful in starting school children and a cut-off of 20/25 passing acuity is suggested. Pre-kindergarten are not well acuity screened due to high inconclusive rate.

Duration and effect of single-dose atropine: paralysis of accommodation in penalization treatment of functional amblyopia.

BACKGROUND AND PURPOSE: Atropine dilates the pupil and paralyzes the ciliary muscle accommodation, blurring vision, and therefore is an effective penalization of the sound eye in the treatment of functional amblyopia of the other eye. The degree of blur induced is a function of the amount of the patient's uncorrected hyperopia and the distance from the eye of the viewed material or object. Another factor determining effectiveness of atropine penalization is the duration of the effect of the atropine. It is the purpose of this study to investigate these factors. METHODS: Six normal children underwent complete eye exam with cycloplegic refraction several days before deliberate instillation of atropine 1% in the sound, or right eye. Distance and near acuity was then tested after 30 minutes, and on subsequent days. Additional data points were derived by placing known minus lenses in front of the tested eye. In addition, we also studied one successfully treated amblyopic patient when he terminated chronic daily atropine in his normal, sound eye. RESULTS: Atropine initially produced a linear reduction in logMAR acuity (blur) at distance of about 0.2 logMAR lines per diopters of uncorrected hyperopia. The magnitude of the blur was greater for near, but the effect of increased hyperopia was slightly greater for distance measurements. This blurring of acuity lasted just less than 48 hours for normal subjects, and just over 48 hours following prompt cessation of chronic daily atropine in that one subject. Regression formulae were derived relating uncorrected hyperopia and time interval following atropine cessation on distance and near acuity in children of amblyopic age range. CONCLUSION: The degree of penalization is highly dependent on the uncorrected hyperopic refractive error. A significant penalization effect is present only for one day or so. Daily atropine is therefore indicated for penalization. To better tailor penalization therapy to target sound eye acuity blur, these formulae and graphs can be used, specifically, in addition, to determine the amount of deliberate spectacle hyperopic undercorrection to maximize the penalization effect.

Amblyopia detection by camera: Gateway to portable, inexpensive vision screening (calibration and validation of inexpensive, pocket-sized photoscreeners).

BACKGROUND: Photoscreening can allow early detection of amblyopia. The Gateway DV-S20, and similar models of miniature, digital flash cameras, have similar optical dimensions to existing photoscreeners for less than $200. METHODS: These cameras were calibrated on known, threshold amblyogenic refractive errors induced by placing minus and toric contact lenses on a normal subject's left eye. The DV-S20 was then applied to known amblyopic patients. Students under age 7 were vision screened with patched acuity and sequential photoscreeners (MTI and Gateway). RESULTS: The digital cameras and the MTI photoscreeners produced similar magnitude interpretable crescents for amblyopiagenic refractive errors. They had very similar validation with sensitivities of 80-90% and specificities of 98% for serious eye disorders in known patients and school-aged children. CONCLUSION: Combined with careful interpretation, pocket-sized, digital flash cameras provide a portable and inexpensive digital alternative for pediatric photoscreening. A category 3 CPT code (0065T) can be used for this valid, public health technique: Amblyopia Detection By Camera (ADBC).