CE Credit Case Report Reproducibility of Mobile Auto Refractor Measurements in a Colombian Children Population Diana Cristina Palencia Flórez, OD; María Alejandra Calderón Vera, OD; Diana Carolina Navarro Caicedo, OD; Yury Paola Muñoz Chávez, OD; Yerli Katherine García Hernández, OD Summary presented in the mentioned variables, reason for which it is Purpose: To Evaluate the inter-observer reproducibility of fundamental to make periodic evaluations, with the purpose of a mobile pediatric auto refractor in an infant Colombian identifying in a timely manner the appearance of ametropias population. Methodology: Quantitative longitudinal prospective that interfere in the process of emmetropization and generate study. Variables of age, sex, ocular history and refractive defect risk of amblyopia. were measured. The sample size was estimated assuming as values of the intraclass correlation coefficient (ICC). The In addition to the decreased irreversible visual acuity, descriptive statistical analysis of the variables was performed amblyopia is characterized by the effects on the quality of life and the ICC was calculated to evaluate the reproducibility of and the normal development of children, its prevalence varies the data taken independently by two examiners. Results: 138 between 1.39%1 to 5%2. According to several studies, refractive participants were included, median age was 42 months. 51% assessment at an early age and the identification of risk of the sample were females and hypermetropic astigmatism factors associated with amblyopia in a timely manner, followed was the prevalent refractive defect with a 67.39% occurrence. by appropriate treatment, constitute an effective strategy The ICC for sphere, cylinder and axis, showed an almost perfect to reduce the frequency and severity of visual impairment in degree of agreement. Conclusions: A mobile pediatric auto adulthood. refractor brings reliable data when evaluating the refractive status without cycloplegia in children aged 24-67 months. Consequently with the aforementioned, the refractive Although it is suggested to classify the refractive error as the examination of pediatric patients is fundamental; but this average of three consecutive measurements and correlate the procedure is a challenge for the professional, due to the poor result with the clinical history of optometry to define the final collaboration and variability in the magnitude of the refractive formula. error, due to the changes in the fixation point. A successful evaluation is subject to diverse factors, such as: clinical Keywords: Reproducibility, intraclass correlation coefficient, expertise, professional experience and patient collaboration, diagnostic test, auto refractor, refractive error. among others. Such aspects have promoted the search for tools such as auto refractors to streamline the process of Introduction consultation and obtain results about the refractive state, the The refractive state of the eye is determined by the relation of degree of ocular alignment, the pupillary distance and the four variables: corneal power, anterior chamber depth, lens pupillary diameter. power and axial eye length. During eyeball growth, the refractive state undergoes a gradual variation due to the changes When using this type of diagnostic equipment, it is necessary to know the reliability of the obtained results, and one effective way of evidencing it, is inquiring: Is the obtained data the same, when repeating the test under similar conditions? This concern Diana Cristina Palencia Flórez, OD, University of Santo Thomas (USTA), led us to pose the objective of the present study, to evaluate Bucaramanga, Columbia; María Alejandra Calderón Vera, OD, University of the inter-observer reproducibility of the mobile pediatric auto Santo Thomas (USTA), Bucaramanga, Columbia; Diana Carolina Navarro refractor in an infant Colombian population. Caicedo, OD, University of Santo Thomas (USTA), Bucaramanga, Columbia; Yury Paola Muñoz Chávez, OD, University of Santo Thomas (USTA), Bucaramanga, Columbia; Yerli Katherine García Hernández, OD, University of Methods Santo Thomas (USTA), Bucaramanga, Columbia A quantitative longitudinal prospective study was conducted Corresponding author: Diana Cristina Palencia Flórez to evaluate the inter-observer reproducibility of the mobile Mailing address for correspondence: Universidad Santo Tomas Bucaramanga, pediatric auto refractor. This study was approved by the Santo Facultad de Optometría, Cr 27 N° 180 – 395 Floridablanca, Colombia. Tomas University Ethical Committee and followed the tenets E-mail: [email protected] The authors have no financial or proprietary interest in any of the material of the Declaration of Helsinki. The informed consent from the mentioned in this article. parents and / or guardians of the participating minors was This article has been peer reviewed. obtained. Reproducibility of Mobile Auto Refractor Measurements in a Colombian Children Population 195 Table 1. Studied population Characteristics. Bucaramanga, Colombia 2016 Variable Total Male Female n:138 eyes n: 68 eyes n: 70 eyes Age (months)a 42 (20) 44.18 (20) 46.11 (23) 24 a 37 months (%) 27.54 29.41 25.71 38 a 47 months (%) 31.88 29.41 34.29 48 a 62 months (%) 30.43 35.29 25.71 63 a 67 months (%) 10.14 5.88 14.29 Sphere Sample 1 (dpt)b 0.85 (1) 0.99 (1) 0.71 (0.75) Cylinder Sample 1 (dpt) -0.81 (0.75) -0.95 (0.75) -0.66 (0.75) Sphere Sample 2 (dpt) 0.87 (1) 0.97 (1) 0.77 (1) Cylinder Sample 2 (dpt) -0.77 (0.75) -0.95 (0.75) -0.60 (0.50) Refractive Defect (%) Hypermetropic 67.39 66.17 68.57 astigmatism Myopic Astigmatism 7.24 10.29 4.29 Mixed Astigmatism 18.12 20.59 15.71 Hyperopia 4.35 2.94 5.71 Myopic 0.72 0 1.43 Emmetropia 2.17 0 4.29 a. Median (interquartile range) Studied Population b. Dpt: Diopters Children between 24 and 67 months of age from two educational institutions in the city of Bucaramanga (Colombia) were included. We excluded children with a history of congenital To employ the equipment, it should be located one meter away cataract, significant media opacities, retinopathy, strabismus, and requires the pupillary size is between 4.0 and 8.0 mm. nystagmus and a pupil diameter less than four millimeters. A sample size of 138 eyes was estimated, and the SAMPICC Data obtained includes information on refractive status, (Sample Size and Power Estimation for single ICC) command pupillary size, pupillary distance and corneal reflexes. The of the Stata software was used for the calculation, using as average time to obtain the reading is 0.8 second and it is reference data the CCl of 0.81 (P1-Hypothetical Value) and 0.72 possible to evaluate the patient both monocular and binocular. (PO -Value null) reported in the study by Peterseim, et al3. The participants were selected between January and July of 2016 Data Collection using the convenience sampling [Figure 1]. A structured interview was conducted with parents and/or responsible adults of the participants, to obtain information The Equipment about: sex, age in months and ocular antecedents (defined An auto refractor (PLUSOPTIX A 12C), whose optical principle in the exclusion criteria). Subsequently, the participants’ is based on the emission of 820 nm of infrared light, which pupillary diameter was measured and the refractive status was projects into the retina without affecting pupil diameter with evaluated using the auto refractor. Two refractive evaluations visible light emissions was used in this study.4 Depending on were done using the equipment, in which two previously refractive error the light forms a specific brightness pattern trained examiners intervened, who took the data collection and inside the pupil, to calculate the sphere, cylinder and axis recording independently. For the data analysis was randomly component, such process are repeated in three meridians5. selected the information of one eye for each participant. The auto refractor is indicated for children older than six Statistical Analysis months and non-cooperating patients. It handles spherical and The descriptive analysis of the collected variables was cylindrical ranges between -7.0 / + 5.0 dpt in steps of 0.25 dpt, performed in the Stata 12.0 Software, frequencies were used and the axis range is between 1 and 180 in steps of 1 degree. for the nominal variables, mean and standard deviation for the 196 Clinical & Refractive Optometry 31.1, 2020 Table 2. Intraclass correlation coefficient Sphere Cylinder Axis Total 0.83 (0.69 – 0.98)a 0.90 ( 0.79 – 1.01) 0.99 (0.98 – 0.99) Females 0.69 (0.43 – 0.95) 0.92 (0.81 – 1.03) 0.99 (0.98 – 0.99) Males 0.87 (0.75 – 0.98) 0.89 (0.77 – 1.01) 0.99 (0.98 – 0.99) 24 a 37 months 0.66 (0.36 – 0.96) 0.87 (0.69 – 1.05) 0.62 (0.25 – 0.99) 38 a 47 months 0.91 (0.82 – 1.00) 0.93 (0.86 – 1.01) 0.99 (0.98 – 1.00) 48 a 62 months 0.88 (0.76 – 1.01) 0.92 (0.81 – 1.02) 0.92 (0.81 – 1.02) 63 a 67 months 0.75 (0.41 – 1.01 0.74 (0.39 – 1.01) 0.74 (0.39 – 1.01) a. Intraclass correlation coefficient (95% confidence range) variables with normal or median distribution and interquartile the present ametropias, additionally, as it usually occurs, range, in the case of not presenting this distribution. conventional occlusion or penalization is employed and filters the adaptation9,10. When the treatment is not performed in a The normality analysis was performed using the Shapiro Wilk timely manner, the described clinical manifestations become test and the null hypothesis was rejected with an alpha error permanent characteristics that affect the quality of life, of 5%. To evaluate the reproducibility, the general intraclass therefore, it is appropriate to make optometry assessments in correlation coefficient was calculated and stratified by sex and children populations in a timely manner and make efforts to age, with the objective of determining the presence of changes define refractive state.