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 Table of Contents  
ORIGINAL ARTICLE
Year : 2020  |  Volume : 32  |  Issue : 3  |  Page : 268-273

Performance of plusoptix A09 photo screener in refractive error screening in school children aged between 5 and 15 years in the southern part of India


Department of Optometry, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal, Karnataka, India

Date of Submission02-Jul-2019
Date of Decision17-Apr-2020
Date of Acceptance27-Apr-2020
Date of Web Publication04-Jul-2020

Correspondence Address:
Avinash V Prabhu
Department of Optometry, Manipal College of Health Professions, Manipal Academy of Higher Education, Manipal - 576 104, Karnataka
India
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/JOCO.JOCO_76_20

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  Abstract 


Purpose: To evaluate the performance of Plusoptix A09 in detecting ametropia, warranted against frequently-used technique of retinoscopy in children attending school (5–15 years) and its probability as a screening tool.
Methods: This study was the subset of a larger epidemiological study visual acuity refractive error squint conducted in schools to determine the prevalence of ocular morbidity among the 5–15 years' school children population. Every 7th student in the class (each school had mean value of 100 students) was randomly selected for this study after ascertaining their eligibility as per the inclusion criteria. A cohort of a total of 150 children within the age group of 5–15 (mean, 10.21 ± 2.83) years were recruited from 11 schools of Udupi district. Students with best corrected visual acuity of 20/20, refractive error within ±5.00 diopter (D), without any eccentric fixation, and no history of ocular pathology or seizures were recruited. Refractive error was tested by Plusoptix photorefractor followed by non-cycloplegic and cycloplegic retinoscopic techniques. The examiners performing these tests were masked and unware of the findings. Bland Altman plotted the agreement between the techniques, followed by the receiver operating characteristic curve (ROC), and sensitivity of Plusoptix.
Results: One-way analysis of variance calculated statistical differences among Plusoptix, objective retinoscopy, and cycloplegic retinoscopy for mean spherical value (1.12 ± 1.16 D, 0.65 ± 0.69 D, and 0.8 ± 0.82 D), cylindrical value (−0.83 D ± 1.27, −0.32 D ± 0.86, and −0.34 D ± −0.93), and spherical equivalent value (0.71 D ± 1.06, 0.45 D ± 0.7, and 0.61 D ± 0.81), with P = 0.0001, 0.0001, and 0.097, respectively. Bland Altman plots showed good agreement for spherical equivalent values of Plusoptix and objective retinoscopy. However, the area under the ROC curve (0.386) suggests that lower diagnostic ability of this device in this age group population in comparison to retinoscopy (0.575) with the sensitivity and specificity of Plusoptix was 69.2% and 84.8%.
Conclusions: This study fails to report ideal sensitivity mandated for a screening tool, although good specificity and agreement are observed. Along with retinoscopy, this tool will be effective in screening a children's population aged between the age group of 5 and 15 years.

Keywords: Plusoptix, Refractive errors, Retinoscopy, School children, Sensitivity


How to cite this article:
Prabhu AV, Thomas J, Ve RS, Biswas S. Performance of plusoptix A09 photo screener in refractive error screening in school children aged between 5 and 15 years in the southern part of India. J Curr Ophthalmol 2020;32:268-73

How to cite this URL:
Prabhu AV, Thomas J, Ve RS, Biswas S. Performance of plusoptix A09 photo screener in refractive error screening in school children aged between 5 and 15 years in the southern part of India. J Curr Ophthalmol [serial online] 2020 [cited 2020 Oct 26];32:268-73. Available from: http://www.jcurrophthalmol.org/text.asp?2020/32/3/268/288947




  Introduction Top


Globally, uncorrected refractive errors continue to be the leading cause of visual impairment.[1],[2] Around 12.8 million children aged from 5 to 15 years are visually impaired due to uncorrected refractive errors, as reported by the World Health Organization.[3],[4] A significant proportion of visual impairment in the urban and rural areas of India are due to uncorrected refractive error.[5],[6] The quicker method of identifying children with uncorrected refractive errors is through school vision screening.[7],[8],[9]

There has been a wide expansion of screening tools for the pediatric population. The most commonly used is Plusoptix photo screener, a screening tool simultaneously assessing both eyes with greater acceptability among the practitioner and children. The infrared images captured by this device based on the red eye reflex estimate the refractive error, media opacities, ocular deviations, and inter pupillary distance at one measurement.

Studies have reported the effectiveness of photo screening devices for vision screening of children in the detection of anisometropia, hyperopia, myopia, and astigmatism.[10],[11],[12],[13],[14] Recently, studies globally are reporting the comparison of various types of photo screeners with forms of retinoscopy in the pediatric age group. Thus, the awareness on usability of photo screeners and verification of testability is taking place globally.[15],[16],[17],[18],[19]

Retinoscopy is still considered to be the gold standard in determining the refractive error in children.[20],[21] Nevertheless, retinoscopy is limited by the need to maintain fixation, object distance, control over the accommodation, and precise scoping of the visual axis which accounts for the variability in its values. The ease of execution in photo screener as Plusoptix has made it popular for refractive error assessment in young children and individuals with intellectual disabilities. Moreover, Indian eyes have been found to be structurally different in comparison to their Chinese and Caucasian counterparts in terms of their axial length, lens thickness, corneal curvature, and anterior chamber depth which primarily governs the refractive error.[22],[23],[24],[25]

This study tried to evaluate the performance of Plusoptix A09 in detecting ametropia, warranted against the frequently-used technique of retinoscopy in children attending school (5–15 years) and its probability as a screening tool.


  Methods Top


A cohort of a total of 150 children within the age group of 5–15 (mean, 10.21 ± 2.83) years were enrolled from 11 schools of the Udupi district. This was the subset of an epidemiological study visual acuity refractive error squint conducted in 11 schools to determine the prevalence of ocular morbidity among the 5–15-year-old population of school children. Every 7th student in the class (each school had mean value of 100 students) was randomly selected for this study after ascertaining their eligibility as per the inclusion criteria. The study was conducted in accordance with the 1975 declaration of Helsinki. Permissions from the Institutional Ethical Committee (Manipal Academy of Higher Education), District Health Administration Board, and concerned school authorities were obtained. Written consents from parents and verbal consents from participants were also obtained. The study setting was the respective school, taking into consideration, the standard lighting condition for Plusoptix to operate. The study duration was from May 2013 to February 2014.

Children with best corrected visual acuity (BCVA) of 20/20 and refractive error within ±5.00 diopter (D) without any specific ocular pathology, strabismus, and seizures (the instillation of cycloplegic drug may trigger the condition) were recruited in the study. Students with BCVA < 20/20 were not recruited, considering the chances of amblyopia and other blinding retinal conditions. Students with significant phoria (2 prism diopters) or any eccentric fixation noticed were excluded since it would alter the Plusoptix reading.[26]

The procedure included visual assessment using Bailey Lovie LogMAR chart, refractive error measurement with photo refraction (Plusoptix A09, Germany) followed by non-cycloplegic (objective) and cycloplegic retinoscopy (REF 18240, NY USA Welch Allyn). Measurement with Plusoptix was done twice, and the average of its value was considered for the analysis. However, retinoscopic measurements were performed once.

The child was asked to sit at a distance of 3 m from the instrument during Plusoptix measurement and fixate at the smiley face at the center of the device. Meanwhile, the examiner re-aligned the instrument in the visual axis of child and captured the scan. The measurements were taken twice, and the average values were considered. A non-cycloplegic retinoscopy followed it. Three drops of cyclopentolate 1%, administered in 5-min intervals, followed. After 30 min, with 6 mm dilated pupil, cycloplegic retinoscopy was performed. To reduce the examiner bias, Plusoptix was performed and documented by a trained optometry intern, and the non-cycloplegic and cycloplegic retinoscopy was performed by a senior optometrist. Plusoptix values were masked from the senior optometrist. Due to the high incidence of aberrations in dilated pupils and inducing error measurement during photo screening, cycloplegic refraction using Plusoptix was not performed. The right eye measurements were considered for the analysis.

Myopia was considered when the measured objective refraction was more than or equal to −0.75 spherical equivalent diopters in one or both eyes. Participants were categorized as hyperopic when the measured objective refraction was >+2.00 spherical equivalent diopters in one or both eyes, provided that no eye was myopic. Astigmatism was considered to be visually significant if ≥1.00 D.[27]

Data analysis and tabulation were done using the SPSS software for Windows version 16 (SPSS Inc., Chicago, IL, USA). Analysis of variance (one-way ANOVA) was used to compare the mean sphere, cylinder, and spherical equivalents. Bonferroni correction was used to check the significance between the groups. We estimated the test–retest variability with repeatability coefficient (RC), coefficient of variation (CV), and intraclass correlation coefficient (ICC). RC, defined as “2.77 × within subject standard deviation (Sw),” is an estimated average of measurement variability in a population.[28] The Sw is the square root of the within-subject mean square of error (the unbiased estimator of the component of variance due to random error). CV was defined as 100 × Sw/overall mean.[29]

ICC was interpreted as <0.75 represents poor-to-moderate reliability, 0.75–0.90 represents good reliability, and >0.90 represents excellent reliability for the clinical measures.[30]

Bland Altman plots were used to display the agreement of the measurements and to assess the difference in refraction between the three techniques. The area under the receiver operating characteristic curve (ROC) was used to assess the ability of the instrument to differentiate the refractive errors in spherical equivalent against eyes without refractive error. The ROC was used to select the best cut-off points related to the sensitivity and specificity based on the technique described by Unal et al.[31] The point closest to (0, 1) corner in the ROC plane defined the optimal cut-point as the point minimizing the Euclidean distance between the ROC curve and the (0, 1) point. Area under the ROC curve (AUC) of 1.0 represented perfect discrimination, and 0.5 represented chance discrimination. P < 0.05 was considered to be statistically significant.

Sample size was estimated using G*Power 3.1 power analysis software (Faul, Erdfelder, Buchner, & Lang, 2007) which showed that to attain a power of 0.95, with a moderate effect size of 0.3 and α error probability of 0.05, the sample size required was 134. A post hoc power calculation using the same effect size and α error probability and sample size of 150 had a power (1−β error probability) of 0.969 for this study.


  Results Top


Out of the 150 children, 8 myopes, 34 astigmates, and 140 hypermetropes were observed. The mean age of 150 participants was 10.21 (±2.83) years, ranging from 5 to 15 years (46% boys and 54% girls). Statistical significance was observed for sphere and cylinder values between three methods (P = 0.0001), with ANOVA analysis having Bonferroni correction of 0.04. Spherical equivalent failed to show any statistical significance [Table 1].
Table 1: Comparison between the Plusoptix A09, objective retinoscopy, and cycloplegic retinoscopy for spherical, cylindrical, and spherical equivalent values

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Variance of coefficient and standard deviation were larger for the spherical values (40.54, 0.45). Interclass correlation was found to be good (0.92) and (0.99) for spherical power and cylindrical power among the three methods, suggesting the interchangeability of these techniques, whereas poor correlation (0.70) was observed for the cylindrical axis. The RC was 1.26 diopter sphere (DS) (1.12–1.40) for spherical error, 0.5 diopter cylinder (DC) (0.45–0.56) for cylinder error, and 96.44° (85.52–107.35) for cylinder axis. This suggests that the absolute difference between any two future measurements made by Plusoptix on the spherical power, cylindrical power, and cylindrical axis is estimated to be no >1.26 DS, 0.5 DC, and 96.44° on 95% of occasions, respectively. Cylindrical axis depicted greater CV 45.57 (40.42–50.73), followed by 40.54 (35.96–45.11) and -21.76 (−19.31–24.21) for cylindrical power and spherical power. Least standard deviation was observed for cylindrical power 0.18 (0.16–0.20), followed by spherical power 0.45 (0.40–0.51), and cylindrical axis 34.79 (30.85–38.73) [Table 2].
Table 2: Values on interobserver repeatability coefficient, coefficient of variance, within subject standard of deviation, and intraclass correlation of Plusoptix A09 spherical power, cylindrical power and axis

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Bland Altman plot showed good agreement for Plusoptix sphere-objective sphere (2.2, −1.3) [Figure 1], Plusoptix sphere-cyclo sphere (2.0, −1.7) [Figure 2], Plusoptix spherical equivalent-objective spherical equivalent (1.74, −1.30) [Figure 3], and Plusoptix spherical equivalent-cyclo spherical equivalent (1.60, −1.40) [Figure 4]. AUC (0.386) suggests that lower diagnostic ability of this device in this age group of the population in comparison to retinoscopy (0.575) with the sensitivity and specificity of Plusoptix was 69.2% and 84.8% [Figure 5].
Figure 1: Agreement between Plusoptix sphere and objective retinoscopy sphere using Bland Altman plot

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Figure 2: Agreement between Plusoptix sphere and cycloretinoscopy sphere using Bland Altman plot

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Figure 3: Agreement between Plusoptix spherical equivalent and objective retinoscopy spherical equivalent using Bland Altman plot

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Figure 4: Agreement between Plusoptix spherical equivalent and cycloretinoscopy spherical equivalent using Bland Altman plot

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Figure 5: Receiver operating characteristics curve to plot the sensitivity and specificity of Plusoptix. Area under the curve: 0.614, 95% confidence interval: 0.444–0.783, Standard error: 0.086

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  Discussion Top


Early visual screening plays a significant role in reducing the prevalence of visual impairment. It is important to adopt newer and quicker techniques with promising sensitivity and specificity for this task. This study evaluated the performance of the Plusoptix A09 in detecting refractive errors in school children aged 5–15 years. Photorefraction and retinoscopy (with and without cycloplegia) were used to determine the refractive error. Significance was found for spherical and cylindrical contents between the three techniques, whereas no significance was observed for spherical equivalent values.

Photorefraction without cycloplegia was performed considering the manufacturer's recommendation as dilated pupil would induce peripheral aberrations leading to off-axis refraction. Furthermore, the accuracy of cylindrical power and axis is compromised for cycloplegic photorefraction.[32]

The current study showed the 95% intraclass correlation between Plusoptix and objective retinoscopy techniques for spherical and cylindrical power to be 0.92 and 0.99, suggesting the interchangeability of these techniques. Bland Altman plots showed agreements for Plusoptix sphere-objective sphere, Plusoptix sphere-cyclo sphere, Plusoptix spherical equivalent-objective spherical equivalent, and Plusoptix spherical equivalent and cycle spherical equivalent.

However, in terms of sensitivity and specificity (69.2% and 84.8%), the Plusoptix device failed to show a promising outcome. Considerable low measures were observed for this device. Since Plusoptix was the point of concern in this study, the accuracy measure checks were confined only to Plusoptix.

The accuracy of the screening test was summarized by the AUC and compared with retinoscopy. AUC (0.386) suggests lower diagnostic ability of this device in this age group of the population in comparison to retinoscopy (0.575). These results are also contradicting to a study performed under 7 years at a different geographical location.[33] The refractive cut-off values used here were as per the AAPOS guidelines.[27] A modification in the referral criteria (for myopia, hypermetropia, and astigmatism) could improve the sensitivity and specificity values. One of the studies had modified the referral criteria for hypermetropia (+1.12 D and +2.60 D instead of +2.00 D and +3.50 D) to get a revised sensitivity value (65.38% to 84.62% and from 46.15% to 69.23%).[34] Few studies have reported the underestimation of refractive error and having higher accuracy in myopia than hyperopia in the pediatric population.[34],[35] In this study, an overall hyperopic shift in the values was observed in comparison to retinoscopy. As per AAPOS, ≥+0.50 DS was considered hyperopic. This could be due to the strong, uncontrolled accommodation of children.

Regarding the cylindrical results, studies agree with the consistency of the cylindrical power between the Plusoptix and cycloretinoscopy.[34] A similar phenomenon was observed here with 0.50 DC higher results in comparison to retinoscopy.

The Plusoptix has been reported to be a useful screening tool compared to Suresight, SPOT, Retinomax, and MTI[18],[36],[37],[38] by various researchers. However, at this setup, we could not substantiate the use of Plusoptix as standalone test for screening. Probably, the age group, levels of refractive error, and testing conditions could have contributed in this varied result.

This study could not recruit children from the secondary grades due to the rigorous academic schedule of these higher grades. Factor of uncontrolled accommodation was observed which could have been controlled by the standard measures.

In conclusion, this study failed to report ideal sensitivity mandated for a screening tool, although good specificity and agreement were observed. Revised referral criteria cut-offs could further improve the sensitivity value. However, in conjunction with retinoscopy, this tool would be effective in the screening of refractive errors in a population aged between 5 and 15 years, especially myopia and astigmatism within the refractive error range of ±5.00 D.

Acknowledgments

This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors. The authors thank Ms Juthika Taludkar, Department of Public Health, Manipal Academy of Higher Education and Ms Alstreed Pinto, Department of Optometry, Manipal Academy of Higher Education to have supported us in execution of the study.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
  References Top

1.
Pizzarello L, Abiose A, Ffytche T, Duerksen R, Thulasiraj R, Taylor H, et al. VISION 2020: The right to sight: A global initiative to eliminate avoidable blindness. Arch Ophthalmol 2004;122:615-20.  Back to cited text no. 1
    
2.
Foster A, Resnikoff S. The impact of vision 2020 on global blindness. Eye (Lond) 2005;19:1133-5.  Back to cited text no. 2
    
3.
Resnikoff S, Pascolini D, Mariotti SP, Pokharel GP. Global magnitude of visual impairment caused by uncorrected refractive errors in 2004. Bull World Health Organ 2008;86:63-70.  Back to cited text no. 3
    
4.
Sharma A, Congdon N, Patel M, Gilbert C. School-based approaches to the correction of refractive error in children. Surv Ophthalmol 2012;57:272-83.  Back to cited text no. 4
    
5.
Dandona R, Dandona L, Srinivas M, Sahare P, Narsaiah S, Muñoz SR, et al. Refractive error in children in a rural population in India. Invest Ophthalmol Vis Sci 2002;43:615-22.  Back to cited text no. 5
    
6.
Murthy GV, Gupta SK, Ellwein LB, Muñoz SR, Pokharel GP, Sanga L, et al. Refractive error in children in an urban population in New Delhi. Invest Ophthalmol Vis Sci 2002;43:623-31.  Back to cited text no. 6
    
7.
Limburg H, Kansara HT, D'Souza S. Results of school eye screening of 5.4 million children in India – A five-year follow-up study. Acta Ophthalmol Scand 1999;77:310-4.  Back to cited text no. 7
    
8.
Jose R, Sachdeva S. School eye screening and the National Program for Control of Blindness. Indian Pediatr 2009;46:205-8.  Back to cited text no. 8
    
9.
Limburg H, Vaidyanathan K, Dalal HP. Cost-effective screening of schoolchildren for refractive errors. World Health Forum 1995;16:173-8.  Back to cited text no. 9
    
10.
Atkinson J, Braddick O, Robier B, Anker S, Ehrlich D, King J, et al. Two infant vision screening programmes: Prediction and prevention of strabismus and amblyopia from photo- and videorefractive screening. Eye (Lond) 1996;10(Pt 2):189-98.  Back to cited text no. 10
    
11.
Schimitzek T, Haase W. Efficiency of a video-autorefractometer used as a screening device for amblyogenic factors. Graefes Arch Clin Exp Ophthalmol 2002;240:710-6.  Back to cited text no. 11
    
12.
Schmidt P, Maguire M, Dobson V, Quinn G, Ciner E, Cyert L, et al. Comparison of preschool vision screening tests as administered by licensed eye care professionals in the vision in preschoolers study. Ophthalmology 2004;111:637-50.  Back to cited text no. 12
    
13.
Ying GS, Kulp MT, Maguire M, Ciner E, Cyert L, Schmidt P, et al. Sensitivity of screening tests for detecting vision in preschoolers-targeted vision disorders when specificity is 94%. Optom Vis Sci 2005;82:432-8.  Back to cited text no. 13
    
14.
Donahue SP, Arnold RW, Ruben JB; AAPOS Vision Screening Committee. Preschool vision screening: What should we be detecting and how should we report it? Uniform guidelines for reporting results of preschool vision screening studies. J AAPOS 2003;7:314-6.  Back to cited text no. 14
    
15.
Bogdănici CM, Săndulache CM, Vasiliu R, Obadă O. Difference of refraction values between standard autorefractometry and Plusoptix. Rom J Ophthalmol 2016;60:249-54.  Back to cited text no. 15
    
16.
Yan XR, Jiao WZ, Li ZW, Xu WW, Li FJ, Wang LH. Performance of the Plusoptix A09 photoscreener in detecting amblyopia risk factors in Chinese children attending an eye clinic. PLoS One 2015;10:e0126052.  Back to cited text no. 16
    
17.
Ozdemir O, Özen Tunay Z, Petriçli IS, Ergintürk Acar D, Erol MK. Comparison of non-cycloplegic photorefraction, cycloplegic photorefraction and cycloplegic retinoscopy in children. Int J Ophthalmol 2015;8:128-31.  Back to cited text no. 17
    
18.
Yilmaz I, Ozkaya A, Alkin Z, Ozbengi S, Yazici AT, Demirok A. Comparison of the Plusoptix A09 and Retinomax K-Plus 3 with retinoscopy in children. J Pediatr Ophthalmol Strabismus 2015;52:37-42.  Back to cited text no. 18
    
19.
Saini V, Raina UK, Gupta A, Goyal JL, Anjum R, Saini P, et al. Comparison of Plusoptix S12R photoscreener with cycloplegic retinoscopy and autorefraction in pediatric age group. Indian J Ophthalmol 2019;67:1555-9.  Back to cited text no. 19
[PUBMED]  [Full text]  
20.
Erdurmus M, Yagci R, Karadag R, Durmus M. A comparison of photorefraction and retinoscopy in children. J AAPOS 2007;11:606-11.  Back to cited text no. 20
    
21.
Steele G, Ireland D, Block S. Cycloplegic autorefraction results in pre-school children using the Nikon retinomax plus and the welch allyn suresight. Optom Vis Sci 2003;80:573-7.  Back to cited text no. 21
    
22.
Saw SM, Chua WH, Gazzard G, Koh D, Tan DT, Stone RA. Eye growth changes in myopic children in Singapore. Br J Ophthalmol 2005;89:1489-94.  Back to cited text no. 22
    
23.
Bhardwaj V, Rajeshbhai GP. Axial length, anterior chamber depth-a study in different age groups and refractive errors. J Clin Diagn Res 2013;7:2211-2.  Back to cited text no. 23
    
24.
Tideman JW, Polling JR, Vingerling JR, Jaddoe VW, Williams C, Guggenheim JA, et al. Axial length growth and the risk of developing myopia in European children. Acta Ophthalmol 2018;96:301-9.  Back to cited text no. 24
    
25.
Rudnicka AR, Owen CG, Nightingale CM, Cook DG, Whincup PH. Ethnic differences in the prevalence of myopia and ocular biometry in 10- and 11-year-old children: The Child Heart and Health Study in England (CHASE). Invest Ophthalmol Vis Sci 2010;51:6270-6.  Back to cited text no. 25
    
26.
Lyon DW, Goss DA, Horner D, Downey JP, Rainey B. Normative data for modified Thorington phorias and prism bar vergences from the Benton-IU study. Optometry 2005;76:593-9.  Back to cited text no. 26
    
27.
Donahue SP, Arthur B, Neely DE, Arnold RW, Silbert D, Ruben JB, et al. Guidelines for automated preschool vision screening: A 10-year, evidence-based update. J AAPOS 2013;17:4-8.  Back to cited text no. 27
    
28.
British Standard. Precision of Test Methods. BS 5497-1 1987, ISO 57251986 Part 1 Guid Determ Repeatability Reprod a Stand Test Method by Inter-Laboratory Tests BS ISO 5725-21994 Accuracy (Trueness Precision) Meas Methods Results – Part 2; 1988.  Back to cited text no. 28
    
29.
Leung CK, Ye C, Weinreb RN. An ultra-high-speed Scheimpflug camera for evaluation of corneal deformation response and its impact on IOP measurement. Invest Ophthalmol Vis Sci 2013;54:2885-92.  Back to cited text no. 29
    
30.
Portney LG, Watkins MP. Foundation of clinical research application to practice, Norwalk, CT, Appleton and Lange, 1993;680-89.  Back to cited text no. 30
    
31.
Unal I. Defining an optimal cut-point value in ROC analysis: An alternative approach. Comput Math Methods Med 2017;2017:3762651.  Back to cited text no. 31
    
32.
Schimitzek T, Lagrèze WA. Accuracy of a new photorefractometer in young and adult patients. Graefe's Arch Clin Exp Ophthalmol 2005;243:637-45.  Back to cited text no. 32
    
33.
Zhang X, Wang J, Li Y, Jiang B. Diagnostic test accuracy of Spot and Plusoptix photoscreeners in detecting amblyogenic risk factors in children: A systemic review and meta-analysis. Ophthalmic Physiol Opt 2019;39:260-71.  Back to cited text no. 33
    
34.
Rajavi Z, Sabbaghi H, Baghini AS, Yaseri M, Sheibani K, Norouzi G. Accuracy and repeatability of refractive error measurements by photorefractometry. J Ophthalmic Vis Res 2015;10:221-8.  Back to cited text no. 34
[PUBMED]  [Full text]  
35.
Payerols A, Eliaou C, Trezeguet V, Villain M, Daien V. Accuracy of PlusOptix A09 distance refraction in pediatric myopia and hyperopia. BMC Ophthalmol 2016;16:72.  Back to cited text no. 35
    
36.
Peterseim MM, Papa CE, Wilson ME, Cheeseman EW, Wolf BJ, Davidson JD, et al. Photoscreeners in the pediatric eye office: Compared testability and refractions on high-risk children. Am J Ophthalmol 2014;158:932-8.  Back to cited text no. 36
    
37.
Silbert D, Matta N, Tian J, Singman E. Comparing the SureSight autorefractor and the plusoptiX photoscreener for pediatric vision screening. Strabismus 2014;22:64-7.  Back to cited text no. 37
    
38.
Matta NS, Arnold RW, Singman EL, Silbert DI. Comparison between the plusoptiX and MTI Photoscreeners. Arch Ophthalmol 2009;127:1591-5.  Back to cited text no. 38
    


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