Multifaceted Amblyopia Screening with blinq, 2WIN, and PDI Check

Figures & data

Table 1 Gold-standard exam criteria of amblyopia risk factors

	AAPOS 2003	AAPOS 2013			AAPOS 2021		Hunter–MEPEDS
Age, young	12	49	31	12	12	49
Age, older	60	72	48	30	18	72	96
Anisometropia	>1.50 D	>1.50 D	>2.00 D	>2.50 D	>1.25 D	>1.25 D	≥1.00 D
Hyperopia	>3.50 D	>3.50 D	>4.00 D	>4.50 D	>4.00 D	>4.00 D	≥4.00 D
Cylinder	>1.50 D	>1.50 D	>2.00 D	>2.00 D	>3.00 D	>1.75 D	≥2.50 D
Myopia	<–3.00 D	<–3.00 D	<–3.00 D	<–3.00 D	<–3.00 D	<–2.00 D	≤−6.00 D
Strabismus	Any	>8 PD	>8 PD	>8 PD	>8 PD	>8 PD	>2 PD heterotopia
Comment	Manifest	Manifest	Manifest	Manifest	Manifest	Manifest	± surgery
Media opacity	>1 mm	>1 mm	>1 mm	>1 mm	>1 mm	>1 mm	History of
Visual acuity	0.4/0.3	>0.3	Not	Not	0.4	0.3	0.2 unilat/0.5–0.3
Intereye					≥2 lines	≥2 lines	≥2 lines
Stereo		Not stereo	Not stereo	Not stereo	Not stereo	Not stereo	≥201 arc sec
Special	Ptosis <1 MRD						Rubric
References	J AAPOS 2003:314–316	J AAPOS 2013 17:4			J AAPOS 2022;		J AAPOS 2021;25:214, Oph Epid. 2006 13:253

Notes: Columns indicate three sets of AAPOS uniform guidelines separated by age-group and also the new set of cutoffs selected from a rubric for “referral-warranted” pediatric eye conditions proposed by David Hunter utilizing risk-factor levels from the Multi-Ethnic Pediatric Eye Disease (MEPEDS) study. Refractive risk factors are given in diopters (D), while strabismus is in prism diopters (PD). Visual acuity is presented in logMAR. In 2003, AAPOS sought ptosis within 1 mm of marginal reflex distance (MRD).

Table 2 Compared and contrasted aspects of the electronic vision-screening devices

	Rebion Blinq	Adaptica 2WIN	PDI Check
Weight	1,800 g	854 g	336 g
Dimensions	21.4×21.4×22.6	8.8×12.2×16.5 cm	1.9×9.0×15.9 cm
AUC (2021 AAPOS ≥4 years)	0.59	0.86	0.69
AUC (Hunter rubric)	0.49	0.60	0.74
Speed	25 seconds	10 seconds	90 seconds
Price	$9,000	$6,500	$300 (v. 0.2.9)
Room lighting	Dim	Dark	Any
Noise/sound	None	On–off warble	None
Version	Model BQ830, Pro version A.2.1	5	0.2.17
Referral output	Clear laterality	Menu options — obscure	Refer not defined
IRC	Refer, pass, timed out, inconclusive	Target 2003 AAPOS chart	Select Va, stereo, and/or color
Screening age	2–3 years to adult	6 months to adult	2–3 years to adult
Mechanism	Infrared radial birefringent scanning	Multiradial infrared eccentric photorefraction	Autostereoscopic barrier parallax screen
Office connect	WiFi — database report	WiFi and reports	WiFi, but no report yet
Targeting strengths	Microstrabismus, strabismic amblyopia	Refractive error, asymmetric corneal reflex, anisocoria	Ocular suppression, disrupted stereopsis, color-vision anomalies, malingering
Targeting weaknesses	Refractive error, bilateral ametropic amblyopia	Optic neuropathy	Refractive error, strabismus
Power	20 V, 1.5 A DC	USB, conventional	USB, special
# Screened on battery charge	>10	>40	>100
Battery life	4–6 hours	4–6 hours	1 week
Breakage risk	High	Fair	Low

Notes: Devices compared on the autostereoscopic Nintendo 3DS screen. AUC, area under the ROC curve; ROC, receiver-operating characteristic; IRC, instrument-referral criteria.

Figure 1 Three vision-screening devices: Rebion blinq birefringent binocular foveation scanner (upper left), Adaptica 2WIN infrared multiradial autorefractor (upper right), and PDI Check dynamic forced-choice vision-screening game on the Nintendo 3DS (bottom).

Figure 2 ROC curves for amblyopia screening. Rebion blinq (gray), Adaptica 2WIN (teal blue), and PDI Check Nintendo 3DS game (orange) performance on detecting high prevalence of amblyopia risk factors and actual amblyopia and strabismus. Of the various exam outcomes, AAPOS 2021 outlined in green on the left and Bosque–Hunter rubric outlined in purple at lower right. Commonly referenced AAPOS 2003 (older triad of 2013) and aspects of manifest strabismus (cover test >8 prism diopters and “any” cases with prior strabismus surgery or chemodenervation) and diminished binocularity are also included.

Figure 3 Refractive comparison between Adaptica 2WIN and optimal refraction. Bland–Altman plots with intraclass correlation (ICC) for vector-transformed astigmatism (J0 and J45) and spherical equivalent (left). ABCD ellipsoid spectacle comparison (right) for anisometropia, astigmatism, spherical equivalent (SphEq), and overall combined ellipsoid. Means ± SD given. The bar chart shows the proportion and number of patient/eyes for which 2WIN scored an A match (blur <1 logMAR), B match (blur 1–3 logMAR), C match (blur 4–6 logMAR), and poor match (7 logMAR and worse) and inconclusive photorefraction results.

Figure 4 PDI Check near results compared to examination. Linear correlations far left, Bland–Altman plots center for stereo (top row; log arc seconds), logMAR visual acuity, and intereye difference (bottom row, logMAR). On the right, PDI Check mean, monocular trichromatic isoluminance gray cone is compared to exam results from Ishihara orange–pink vs gray “35” and “96” plates.