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

BACKGROUND: Novel devices target different facets of amblyopia risk factors (ARFs). Through birefringence, the Rebion blinq assesses binocular foveation. The Adaptica 2WIN is a multiradial infrared photorefractor that also estimates ocular alignment. PDI Check is a forced-choice, dynamic near-vision game for the autostereoscopic Nintendo 3DS. METHODS: New and returning patients to a pediatric ophthalmology clinic had concomitant confirmatory exams after all three vision screens had been validated with ROC curves, Bland-Altman plots, and Alaska Blind Child Discovery ellipsoid grades. Exam outcomes were classified by ARF visual acuity, strabismus, binocularity, and refractive errors following the 2021 AAPOS guidelines and Bosque-Hunter rubric for the blinq. RESULTS: A total of 202 ethnically diverse students aged 10±4 (4-19) years, 33% treatment-naïve, had a high (58%) prevalence of ARFs. Linear logMAR visual acuity, intereye differences, stereo and three-cone color correlated well between PDI Check and exams. Mean score on the 2WIN matched sphero-cylinder exam with ellipsoid scoring was 2.1±1.5. For AAPOS 2021 refractive plus strabismus, sensitivity/specificity for PDI Check was 68%/59%, 2WIN 72%/95%, and blinq 87%/32%. For the amblyopia or strabismus rubric, PDI Check was 79%/68%, 2WIN 56%/65%, and blinq 94%/37%. CONCLUSION: Each device had advantages and disadvantages in screening this cohort of older, high-prevalence students, many of whom had already been treated. Validation methods should cover more than just refraction, as the new 2021 AAPOS guidelines do.

Cox regression was used to compare the measurement error of two tests vs. a gold standard.

OBJECTIVE: The use of survival analysis has been proposed to compare the diagnostic performance of two tests. We expanded it to compare two tests with a gold standard simultaneously. STUDY DESIGN AND SETTING: In this diagnostic study, the spherical equivalent component of refraction was measured with the PowerRefractor and the Canon R-50 autorefractor. The reference test was Canon R-50 autorefraction with cycloplegic blockage of accommodation. The error of the two index tests was compared with Cox regression analysis with robust standard error estimation to take into account repeated measures on the same subject. We evaluated 1,559 children aged 5-6 from 25 schools in three urban locations in Ecuador. RESULTS: The main strength of survival analysis was that it does not assume a specific distribution of measurement errors, which were not normally distributed in this study. The proportional hazards assumption, a requirement of Cox regression, was met only after removal of the bias of each test. When this was done, noncycloplegic autorefraction was better than the PowerRefractor regardless of the magnitude and direction of the error. CONCLUSION: The potential of Cox regression can be applied to diagnostic studies that compare more tests with a gold standard.

PowerRefractor versus Canon R-50 Autorefraction to assess refractive error in children: a community-based study in ecuador.

PURPOSE: To compare the agreement of the PowerRefractor with Canon R-50 autorefraction for measuring refractive error in a community of Ecuadorian children. METHODS: We examined 1564 children aged 5 to 6 years from two ethnically and geographically similar regions of the Ecuadorian highlands. Results of a refraction obtained without cycloplegia with the PowerRefractor and with the Canon R-50 autorefractor (NCAR) were compared with the gold-standard examination, cycloplegic autorefraction (CAR) with the Canon R-50 autorefractor. Power vectors were used to analyze refractive error. Bland-Altman limits of agreement were obtained. RESULTS: Although the mean difference in the spherical equivalent refractive error between the PowerRefractor and CAR was small (-0.03 D +/- 0.05 D), the 95% limits of agreement were wide (+/-2.03 D). On the other hand, NCAR showed a greater bias (0.97 D +/- 0.04 D) and smaller limits of agreement (+/-1.49 D). The limits of agreement of the PowerRefractor were also wider than NCAR for measuring astigmatism. When the mean difference was stratified by the subgroups of refractive error vectors, the PowerRefractor was found to have poorer limits of agreement than NCAR for hyperopic defects. CONCLUSION: The PowerRefractor is accurate, but not as precise for measuring refractive error as compared to the Canon R-50 autorefractor, especially for high hyperopia.

Trastornos de la motilidad ocular en una población de niños escolares de la Sierra Ecuatoriana / Ocular motility disorders in a population of school children in the Sierra Ecuatoriana

Propósito: El objetivo del siguiente trabajo fue el de determinar la prevalencia y los distintos tipos de trastornos de la motilidad ocular en una población escolar de la sierra ecuatoriana. Material y métodos: Se examinaron 6143 niños de entre 4 y 16 años de edad de dos áreas geográficas étnicamente similares de la Sierra del Ecuador. De la población examinada, 2775 fueron de sexo femenino y 3368 de sexo masculino. A cada niño se le efectuó un examen oftalmológico que comprendía: inspección, estudio de la motilidad ocular, reflejos pupilares, estereopsis, agudeza visual sin corrección y con corrección en aquellos niños portadores de lentes, examen de ojo externo, autorrefractometria y videorrefractometria. Se efectuó autorrefractometria con cicloplejia y examen de fondo de ojo a todos los niños con niveles de agudeza visual menor a 0.8 en alguno de sus ojos, a todos los niños entre 4 y 6 años y en forma randomizada al 10 por ciento del total de los niños. El examen de la motilidad ocular consistió en evaluación de la excursión ocular hacia las 9 posiciones de la mirada, Cover test para lejos y cerca con y sin corrección, test de Hirschberg y determinación de la presencia o no de un tortícolis. Resultados: De los 6143 niños examinados 371 (6 por ciento) presentaba algún trastorno en su motilidad ocular. Estrabismos latentes (forias) fueron encontrados en 253 niños (4.11 por ciento). De ellos, 249 casos tenían exoforias y solo 4 presentaron endoforias. Esotropias pudieron observarse en 22 niños (0.35 por ciento). Exotropias se presentaron en 17 de los niños examinados (0.27 por ciento). Se presentaron 8 casos con anisotropía en V e hiperfunción de oblicuos inferiores y 55 pacientes con anisotropía en Y sin disfunción de músculos oblicuos. Dos pacientes presentaron desviación vertical disociada. Presentaron nistagmus sin estrabismo 5 niños y parálisis del IV nervio pudieron observarse en 2 casos

Purpose: The purpose of this paper is to determine the prevalence and different types of ocular motility disorders in a population of school children of the Highlands of Ecuador. Patient and Methods: 6143 children with ages between 4 and 16 where examined in two etnically similar areas of the Highland region of Ecuador. 2775 where females and 3368 males. Every child underwent an opthalmological examination that included: Inspection, evaluation of ocular motility, pupilar reflexes, stereopsis, visual acuity without correction and with correction in all the children wearing glasses, external examination, autorrefractometry and videorrefractometry. Autorrefractometry with cycloplegia and retinal examination were performed in all children with vision levels less than 0.8 in a least one eye, to ocular motility evaluation consisted in assement of the eyes excursion in all 9 positions, of gaze Cover test for distance and near, Hirschber test and determining the presence of an anomalous head posture. Results: Of the 6143 children evaluated, 371 (6 percent) presented with some type of ocular motility disturbance. Of theses, 253 (4.11 percent) where latent strabismus. 249 suffered from exophorias and only 4 had esophoses. There where 8 children with V pattern and overaction of inferior obliques and 55 with Y pattern and no disfuction of oblique muscle.