The Feasibility Study Of Noncycloplegic Photorefraction Screening For Refractive Amblyopia Related Factors In Children

Purpose： The aim of children’s amblyopia screenings is to detectamblyopia or amblyopia related factors in children through valid and reliabletests，so as to timely detect and treat this hidden disease and to reduce it’sprevalence. Refractive amblyopia related factors are a major risk factor foramblyopia. And cycloplegic refraction is Gold standard of detecting refractivestate, which is recognized at home or abroad. But cycloplegic refraction isprofessional and time-consuming, which makes it being restricted inamblyopia screening. Nowadays, worldwide studies has interested in theapplication of noncycloplegic photorefraction. This article is to evaluatenoncycloplegic photorefraction utilizing the screening test indexes. Thepurpose is to realize the feasibility of noncycloplegic photorefraction fordetecting refractive amblyopia related factors, so as to provide accurateclinical data support and guidance and useful theoretical for further research.Methods：In this screening test study,228eyes of114children ages2to13years were screened at the First Hospital of Hebei Medical University from2011~2012after receiving a comprehensive eye examination and cycloplegicrefraction. The average age is5.81±2.72. And there’s56boys and58girls.Before the formal examinations, the specified screening personnel wastrained until the testability reached98%in preliminary experiment. Childrenparticipating in the study were screened by the personnel in noncycloplegicstate utilizing PlusoptiX A09. The cycloplegic refraction was taken by anexperienced optometrist who was also specified. After the noncycloplegicphotorefraction, and under the consent of the guardians, all the subjects wereadministrated one drop of1%Atropine Sulfate Eye Gel to two eyes, two timesa day about five days. At the six day, these children were tested by theoptometrist utilizing cycloplegic retinoscopy. A comprehensive pediatricophthalmic examination was taken by a specified pediatric ophthalmologist with extensive clinical experience. Children participating in the study wereinvestigated and examined including general materials and comprehensiveophthalmological examinations to exclude cases with organic disease andintellectual developmental abnormalities that would affect the results.Examiners were blinded and all the tests have gained consent of guardians.Data collation, entry and analysis are responsible for the author. Thepositive critical value was defined on the basis of AAPOS referral criteriaguidelines. And the gold standard is cycloplegic retinoscopy. According tocycloplegic retinoscopy, subjects were divided into positive and negativegroups. The screening results obtained by the plusoptiX A09were comparedwith the results from CR. Noncycloplegic photorefraction method wasevaluated under the following situations that having at least one refractiveamblyopia factors(it’s marked as RARFs), and also hyperopic, myopic,astigmatism and anisometropic amblyopia related factors. Statisticaldescription including bar chart and stem-leaf plot and normality test was done.Evaluation of noncycloplegic photorefraction method was evaluated utilizingscreening test’s indexes. To further evaluate hyperopic, myopic andastigmatism amblyopia related factors, they were summarized by ROC curveand area under the ROC curve (AUC). In order to get a good sensitivity andspecificity, optimal operating point for these three basic ametropias wascalculated.Results：1The mean age is5.81±2.72years (range,2years to13years). Themedian of spherical equivalent was1.00D for noncycloplegic photorefractionversus+1.25D for cycloplegic refraction. There were21eyes beyond themeasurement range of the photorefractor, and15eyes were no measured data.2Indexes values of noncycloplegic photorefraction screening refractiveamblyopia related factors are as follows. On the whole, sensitivity, specificity,Youden index, positive likelihood ratio, negative likelihood ratio, thecoincidence rate, Kappa value, positive predictive, negative predictive, were85.6%、67.03%、0.53、2.6、0.21、77.8%、0.53678.1%、77.22%. 3Indexes values by noncycloplegic photorefraction screening forhyperopic refractive amblyopia related factors is as follows: Sensitivity75%,specificity97.4%, Youden index0.724, positive likelihood ratio28.85,negative likelihood ratio0.257, Kappa value0.724, positive predictive75%,negative predictive97.4%. Indexes values by noncycloplegic photorefractionscreening for myopic refractive amblyopia related factors is as follows:Sensitivity93.3%, specificity97%, Youden index0.903, positive likelihoodratio31.1, negative likelihood ratio0.069, Kappa value0.783, positivepredictive70%, negative predictive99.5%. Indexes values by noncycloplegicphotorefraction screening for astigmatism refractive amblyopia related factorsis as follows: Sensitivity83.8%, specificity69.8%, Youden index0.536,positive likelihood ratio2.77, negative likelihood ratio0.23, Kappa value0.537, positive predictive71.4%, negative predictive80.7%. Indexes valuesby noncycloplegic photorefraction screening for anisometropic refractiveamblyopia related factors is as follows: Sensitivity75%, specificity88%,Youden index0.63, positive likelihood ratio6.25, negative likelihood ratio0.28, Kappa value0.504, positive predictive47.4%, negative predictive96.1%.4The AUC for noncycloplegic photorefraction detecting hyperopic,myopic and astigmatism amblyopia related factors were0.865,0.986and0.871respectively. And when sensitivity were specified at or beyond90%, thebest diagnostic cut-off point of these three ametropia was+0.625D,-3.125D,±1.125D. At that cut-off point, the sensitivity were100%,92.3%,90.0%, andthe specificity were69.0%,92.3%,66.7%correspondingly.Conclusions：1Noncycloplegic photorefraction proved to be a reliable screeningmethod for large-scale amblyopia screening on the refractive amblyopiarelated factors.2Noncycloplegic photorefraction is the most accurate in terms ofscreening myopia amblyopia related factor. The results proved to be reliableand good in prediction; Screening hyperopic, astigmatism, anisometropic amblyopia related factor, the screening capability of noncycloplegicphotorefraction is gradually decreased.3The best cutoff point of hyperopic, myopic and astigmatism is+0.625,-3.125and±1.125. At these points, the sensitivity increased as thespecificity declined. That mean the detective capability increased and theexclusive capacity isn’t improved. But there is a little change on screening formyopic amblyopia related factor.4Noncycloplegic photorefraction has a good detective ability toscreening for positive cases, but a relative low ability to exclude non-desease.There is a moderate consistency between noncycloplegic photorefraction andcycloplegic refraction. And the predictive ability and the reliability ofnoncycloplegic photorefraction also have a moderate level.5The results by noncycloplegic photorefraction did a myopic shiftphenomenon.