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ABSTRACT Objective: To assess the performance of a portable autorefractor as refractor and screening tool for refractive errors in schoolchildren. Methods: Cross-sectional observational study. Refractometric measurements of children between 5 and 10 years old were obtained through four methods: 2WIN under non-cycloplegic conditions, and 2WIN, conventional autorefractor, and retinoscopy, under cycloplegic conditions. Correlations and agreement between the methods and accuracy of the portable autorefractor to define whether to prescribe glasses were assessed. Results: The mean age ± standard deviation was 6.87 ± 1.42 years. The portable autorefractor without cycloplegia showed a high correlation with retinoscopy (0.77) but tended to underestimate hyperopia and overestimate high astigmatism. Regarding screening for prescription of glasses in comparison with the reference method "retinoscopy," the sensitivity of the portable autorefractor without cycloplegia was calculated to be 100,00% and the specificity, 34.3%. Conclusion: The portable autorefractor should be used as a screening tool and, when prescribing glasses, the tendency of underestimating hyperopia and overestimating high astigmatism should be kept in mind.
RESUMO Objetivo: Avaliar o desempenho de um autorrefrator portátil como refrator e ferramenta de triagem para erros de refração em crianças em idade escolar. Métodos: Estudo observacional transversal. As medidas refratométricas de crianças de 5 a 10 anos foram obtidas por meio de quatro métodos: 2WIN em condições não cicloplégicas e 2WIN, autorrefrator convencional e retinoscopia, em condições cicloplégicas. Foram avaliadas as correlações e a concordância entre os métodos e a acurácia do autorrefrator portátil para definir a prescrição de óculos. Resultados: A média de idade ± desvio-padrão foi de 6,87 ± 1,42 anos. O autorrefrator portátil sem cicloplegia apresentou alta correlação com a retinoscopia (0,77), mas tendeu a subestimar a hipermetropia e a superestimar o alto astigmatismo. Em relação à triagem para prescrição de óculos em comparação com o método de referência retinoscópio, a sensibilidade do autorrefrator portátil sem cicloplegia foi calculada em 100,00% e a especificidade, em 34,3%. Conclusão: O autorrefrator portátil deve ser usado como ferramenta de triagem e, ao se prescreverem óculos, deve-se ter em mente a tendência de subestimar a hipermetropia e superestimar o alto astigmatismo.
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?AIM: To assess the consistency of refractive errors measured by two autorefractors in myopia screening of school-age Chinese children.?METHODS: Topcon RM- 8900 and Tianle RM - 9000 autorefractors were utilized to measure refractive errors under noncycloplegic condition in students aged 6 to 16 years old who were cluster sampled from four primary and secondary schools in Dongli district, Tianjin. Sperman correlation analysis and Bland-Altman method were used to evaluate the consistency of spherical diopters, cylindrical diopters and spherical equivalents measured by the two methods, and the axial difference distribution of astigmatism measured by the two methods was analyzed.?RESULTS:A total of 2276 eyes of 1138 subjects with a mean age of 10.49± 2.66 a were finally enrolled. Spearman correlation analysis showed that sphere ( r = 0.958, P<0.0001) , cylinder ( r= 0.769, P<0.0001 ) , and spherical equivalent ( r=0.962, P<0.0001) measured by Tianle RM-9000 were highly correlated with those measured by Topcon RM-8900, respectively. Bland-Altman analysis showed spherical diopters measured by Tianle RM-9000 were significantly more hyperopic ( P< 0.0001 ) with a mean difference of 0. 44 D ( SD: 0.37;95％ CI: -0.27, 1.16) while the maximum absolute value ( 1.13 D) of the difference within the 95％ CI was above the clinically acceptable range;however, no significant difference ( P=0.83) was found between cylindrical diopters measured by the two methods with a mean difference of -0.01 D ( SD: 0.31;95％ CI= -0.62, 0.61 ) while the maximum absolute value ( 0.62 D ) of the difference within the 95％CI was clinically acceptable. The proportion of the axial deviation within ± 20° was 84.6％( 1503/1777) in eyes with cylinder ≤-0.25D while that rose to 96.4％ ( 853/885) in eyes with cylinder ≤-0.75D.?CONCLUSION: Spherical diopters measured by Tianle RM-9000 have a significant hyperopia bias than those measured by Topcon RM-8900 while the consistency of cylindrical diopters and cylindrical axes is clinically acceptable.
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@#AIM: To assess the consistency of refractive errors measured by two autorefractors in myopia screening of school-age Chinese children.<p>METHODS: Topcon RM-8900 and Tianle RM-9000 autorefractors were utilized to measure refractive errors under noncycloplegic condition in students aged 6 to 16 years old who were cluster sampled from four primary and secondary schools in Dongli district, Tianjin. Sperman correlation analysis and Bland-Altman method were used to evaluate the consistency of spherical diopters, cylindrical diopters and spherical equivalents measured by the two methods, and the axial difference distribution of astigmatism measured by the two methods was analyzed.<p>RESULTS:A total of 2 276 eyes of 1 138 subjects with a mean age of 10.49±2.66 a were finally enrolled. Spearman correlation analysis showed that sphere(<i>r</i>=0.958, <i>P</i><0.0001), cylinder(<i>r</i>=0.769, <i>P</i><0.0001), and spherical equivalent(<i>r</i>=0.962, <i>P</i><0.0001)measured by Tianle RM-9000 were highly correlated with those measured by Topcon RM-8900, respectively. Bland-Altman analysis showed spherical diopters measured by Tianle RM-9000 were significantly more hyperopic(<i>P</i><0.0001)with a mean difference of 0.44 D(SD: 0.37; 95% <i>CI</i>: -0.27, 1.16)while the maximum absolute value(1.13 D)of the difference within the 95% <i>CI</i> was above the clinically acceptable range; however, no significant difference(<i>P</i>=0.83)was found between cylindrical diopters measured by the two methods with a mean difference of -0.01 D(SD: 0.31; 95% <i>CI</i>=-0.62, 0.61)while the maximum absolute value(0.62 D)of the difference within the 95% <i>CI</i> was clinically acceptable. The proportion of the axial deviation within ±20° was 84.6%(1 503/1 777)in eyes with cylinder ≤-0.25D while that rose to 96.4%(853/885)in eyes with cylinder ≤-0.75D. <p>CONCLUSION: Spherical diopters measured by Tianle RM-9000 have a significant hyperopia bias than those measured by Topcon RM-8900 while the consistency of cylindrical diopters and cylindrical axes is clinically acceptable.
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Purpose: Variant myopia (VM) presents as a discrepancy of >1 diopter (D) between subjective and objective refraction, without the presence of any accommodative dysfunction. The purpose of this study is to create a clinical profile of VM. Methods: Fourteen eyes of 12 VM patients who had a discrepancy of >1D between retinoscopy and subjective acceptance under both cycloplegic and noncycloplegic conditions were included in the study. Fourteen eyes of 14 age- and refractive error-matched participants served as controls. Potential participants underwent a comprehensive orthoptic examination followed by retinoscopy (Ret), closed-field autorefractor (CA), subjective acceptance (SA), choroidal and retinal thickness, ocular biometry, and higher order spherical aberrations measurements. Results: In the VM eyes, a statistically and clinically significant difference was noted between the Ret and CA and Ret and SA under both cycloplegic and noncycloplegic conditions (multivariate repeated measures analysis of variance, P < 0.0001). A statistically significant difference was observed between the VM eyes, non-VM eyes, and controls for choroidal thickness in all the quadrants (Univariate ANOVA P < 0.05). The VM eyes had thinner choroids (197.21 � 13.04 ?) compared to the non-VM eyes (249.25 � 53.70 ?) and refractive error-matched controls (264.62 � 12.53 ?). No statistically significant differences between groups in root mean square of total higher order aberrations and spherical aberration were observed. Conclusion: Accommodative etiology does not play a role in the refractive discrepancy seen in individuals with the variant myopic presentation. These individuals have thinner choroids in the eye with variant myopic presentation compared to the fellow eyes and controls. Hypotheses and clinical implications of variant myopia are discussed.
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@#AIM:To compare the results of computer optometry and manifest refraction after mydriasis and prescription for refractive error in juveniles and explore the emphasis and notes of juvenile optometry. <p>METHODS: Totally 334 ametropic eyes of juveniles(including 212 myopic eyes and 122 hypermetropic eyes)were examined with computer optometry and manifest refraction after mydriasis. The manifest refraction was done again after the pupil recovered to obtain the prescription for refractive error. The results of computer optometry and manifest refraction after mydriasis and prescriptions for refractive error were compared and analyzed retrospectively. <p>RESULTS: When comparing computer optometry and manifest refraction after mydriasis, the differences of spherical power and cylindrical axis in general group, the differences of spherical power, cylindrical power and axis in myopia group and cylindrical axis in hyperopia group were all statistically significant(<i>P</i><0.05). The differences of spherical power and cylindrical axis between computer optometry and manifest refraction after mydriasis and prescriptions in general and hyperopia group were statistically significant(<i>P</i><0.05). The spherical power of computer optometry and manifest refraction after mydriasis in hyperopia group was greater than that of prescription and there was statistically significant difference in cylindrical power between manifest refraction after mydriasis and prescription(<i>P</i><0.05). In myopia group the differences in spherical power, cylindrical power and axis between computer optometry after mydriasis and prescription were statistically significant(<i>P</i><0.05)and the differences in cylindrical power and axis between manifest refraction after mydriasis and prescription were statistically significant(<i>P</i><0.05). The Bland-Altman analysis in three groups showed the good consistency of spherical and cylindrical power between computer optometry and manifest refraction after mydriasis and that the differences between them were acceptable clinically. It also showed the poor consistency of cylindrical axis between them. The Bland-Altman analysis in general and hyperopia groups showed the poor consistency of spherical power and cylindrical axis and the good consistency of cylindrical power between computer optometry and manifest refraction after mydriasis and prescription. In myopia group the spherical and cylindrical power between computer optometry and manifest refraction after mydriasis and prescription revealed good consistency and the cylindrical axis presented poor consistency.<p>CONCLUSION: The results of computer optometry and manifest refraction after mydriasis cannot be used as prescription. There was statistically significant difference between computer optometry and manifest refraction after mydriasis, but the spherical and cylindrical power between them revealed good consistency clinically. The cylindrical axis between computer optometry and manifest refraction after mydriasis presented poor consistency and so did the cylindrical axis between them and prescription. In conclusion, the cylindrical axis should be paid much attention to in optometry and glasses taking.
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PURPOSE: To compare the corneal refraction, astigmatism, and corneal marking for toric intraocular lens measured with a VERION® Image Guided System and an autorefractor in order to precisely determine the toric intraocular lens target. METHODS: The medical records of 29 eyes of 29 patients were retrospectively reviewed to compare the corneal refraction, axis, and amount of astigmatism measured with a VERION® Image Guided System and an autorefractor. We compared the difference in marked axis for toric intraocular lenses as measured by a VERION Digital Marker and a manual marker. RESULTS: The average corneal refraction and amount of astigmatism were greater with the VERION® Image Guided System than with the autorefractor. The average difference in axis of astigmatism was 9.62°. The difference in axis of astigmatism in patients with more than 1.0 D of astigmatism (18 eyes) was 2.82 ± 2.27°, while that in patients with less than 1.0 D of astigmatism (11 eyes) was 20.27 ± 28.14°. The average difference in marked axis for toric intraocular lens measured by the VERION® Digital Marker and manual marker was 2.50° (0°-9.27°). CONCLUSIONS: The corneal refraction and amount of astigmatism were significantly higher with the VERION® Image Guided System, so careful concern and comparison of surgical outcomes between the two devices is needed in biometry.
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Humanos , Astigmatismo , Biometría , Lentes Intraoculares , Registros Médicos , Estudios RetrospectivosRESUMEN
AIM:To compare the difference between diopter of refration measured after cycloplegic mydriasis with retinoscopy and hand-held autorefractor so as to explore the feasibility of using hand - held autorefractor for refraction screening in cadet candidates. METHODS:Respectively using hand-held autorefractor and streak retinoscope to do optometry examination in 317 cadet candidates students ( 634 eyes ) after mydriasis. Main index of refraction values ( spherical, cylindrical mirror degree and axial) were analyzed by difference test and correlation analysis. And the elimination rate was comparatively analyzed. RESULTS: Diopters of sphere and cyclic refraction measured by hand-held autorefration were significantly higher than those by retinoscopy ( P 0. 05 ). The disqualifying rate using autorefraction was much higher than that using retinoscopy. It was easy to be wrongly eliminated. CONCLUSION:Because of the high correlation between diopters of autorefraction measured by retinascopy and autorefractor, autorefraction has application value in refraction screening in cadet candidates with normal vision.
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Objective To compare the differences of corneal keratometry and corneal astigmatism measured by Len?star LS900 and KR-1 auto-refractor of age-related cataract. Methods Seventy-six patients with cataract (76 eyes) were in?cluded in this study. Flat keratometry (K1), steep keratometry (K2), mean keratometry (Km) and astigmatism were measured before operation by Lenstar LS900 and KR-1 auto-refractor. The parameters of astigmatism were transformed into J0 and J45 by Fourier vector transform, and which was compared. Results Values of K1, K2, Km, J0 and J45 were (43.960±1.440) D, (44.901±1.319)D, (44.430±1.336)D, 0.043±0.402 and 0.017±0.425 measured by Lenstar LS900, respectively, and which measured by KR-1 auto-refractor were (44.007 ± 1.400)D, (44.859 ± 1.338)D, (44.433 ± 1.330)D,-0.058 ± 0.322 and 0.031 ± 0.419, respectively. There was no statistical difference between these values measured by two instruments ( P>0.05). The Bland-Altman plots showed that two devices had coincident results for corneal parameters. Conclusion Lenstar LS900 and KR-1 auto-refractor can be applied in the measurement of corneal astigmatism of age-related cataract before surgery.
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PURPOSE:To compare the accuracy of myopic refraction using an aberrometer (WaveScan, Visx, Santa Clara, CA, USA) with manifest refraction using retinoscopy and an autorefractor. METHODS: The medical records of 200 eyes in 100 patients who visited our clinic from February 2005 to February 2007 for refractive surgery were reviewed retrospectively. We compared the refractive errors obtained using an aberrometer, retinoscopy, and an autorefractor (KR-7100, Topcon, Tokyo, Japan). All of the measured refractive errors were converted to power vectors for statistical analysis. The power vectors consisted of the M vector (M), J0 vector (J0), and J45 vector (J45). RESULTS: The mean sphere was -4.75 diopters (D) and the mean cylinder was -0.66D with retinoscopy. Power vectors of the aberrometer (PVw) were highly correlated with power vectors of retinoscopy (PVr) and the autrorefractor (PVa). The correlation coefficients (R2) between PVw and PVr were 0.960 (M), 0.852 (J0), and 0.679 (J45) and the correlation coefficients between PVw and PVr were 0.963 (M), 0.685 (J0), and 0.516 (J45). Mean differences were -0.247+/-0.412D (M), 0.034+/-0.120D (J0), and -0.017+/-1.07D (J45) between PVw and PVr, and were -0.068+/-0.403D (M), -0.055+/-0.194D (J0), and -0.052+/-0.165D (J45) between PVw and PVa. CONCLUSIONS: The measurement of refractive errors using a WaveScan aberrometer seems to be reliable and accurate, although some myopic shift was observed.
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Humanos , Ojo , Registros Médicos , Errores de Refracción , Procedimientos Quirúrgicos Refractivos , Retinoscopía , Estudios Retrospectivos , TokioRESUMEN
PURPOSE: We analyzed the difference in values between noncycloplegic and cycloplegic autorefraction and refraction, as measured by ophthalmologist, in children according to age. METHODS: We classified the 84 children (153 eyes) whose best corrected visual acuity was better than 0.6 into four groups according to age. The first age group ranged from 29 to 57 months (36 eyes); the second age group ranged from 58 to 75 months (47 eyes); the third age group ranged from 76 to 95 months (36 eyes); and the fourth age group ranged from 96 to 121 months (34 eyes). The children were examined with an autorefractometer (Canon Auto Ref RK-2) and a retinoscope before and after cycloplegia. RESULTS: The children in all age groups tend to show more myopia in autorefraction than refraction regardless of cycloplegia. Also, differences in spherical component and spherical equivalents in noncycloplegic autorefraction and cycloplegic refraction were regarded as significant statistically (P<0.05) in all age groups. However, in all groups, none of the refractive values in cycloplegic autorefraction and refraction were statistically significant. CONCLUSION: Refraction measurement should be recommended for cycloplegic refraction in children. It is suggested that cycloplegic autorefraction could be useful for the refraction partially.
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Niño , Humanos , Miopía , Retinoscopios , Agudeza VisualRESUMEN
PURPOSE: We tried to evaluate the reliablility of refractive measurement by hand-held autorefractor (HHAR). METHODS: Ninety patients (180 eyes) with simple refractive error were divided into three groups (30 patients each) according to their ages. Group I is under 6 years old; group II, from 7 to 15 years old; and group 3, over 16 years old. Under cycloplegics, three measuring methods of refraction using table top autorefractor (Model 599, Zeiss Humphrey, USA), hand-held autorefractor (Retinomax K-plus, Nikon, Japan) and skiascope (Heine beta 200, Germany) were performed and we compared each spherical and cylindrical value in 3 groups. RESULTS: There was no significant difference in both spherical and cylindrical value between HH-AR and skiascope in all groups (PI, sph=0.579, PI, cyl=0.708, PII, sph=0.801, PII , cyl=0.730, PIII , sph=0.816, PIII, cyl=0.754) . But there was significant difference in both spherical and cylindrical value between table top autorefractor and skiascope in group I (PI,sph=0.019, PI,cyl=0.030, PII,sph=0.405, PII,cyl=0.392, PIII,sph=0.876, PIII,cyl=0.747). CONCLUSIONS: We believe that hand-held autorefractor can be a useful instrument to measure refractive power without serious error, especially in patients who have difficulty with table top autorefractor.
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Adolescente , Niño , Humanos , Midriáticos , Errores de RefracciónRESUMEN
We analysed the difference of values between noncycloplegic and cycloplegic autorefractionand refraction by ophthalmologist in children. We classified the 109 children [218 eyes] who did not have strabismus or amblyopia into five groups according to the age. Their age ranged from 3 to 12. They were examined with Canon RK-3 autorefractor before and after cycloplegia and then, cycloplegic and post-cycloplegic refraction were performed by ophthalmologist. Discrepancies beyond 0.5D in spherical and cylindrical power and 10 degree in cylindrical axis were regarded as significant. The percentages of discrepancy were greater in spherical power between noncycloplegic autorefraction and refraction by ophthalmologist especially in young age groups[p<0.05]. The percentages of discrepancy were greater in spherical and cylindrical power between cycloplegic autorefraction and refraction by ophthalmologist especially in young age groups[p<0.05]. The percentages of discrepancy of cycloplegic autorefraction showed a tendency to be greater than those of noncycloplegic autorefraction in spherical power as compared with refraction by ophthalmologist. In conclusion, the refractive measurements of cycloplegic autorefractor is not close to those of refraction by ophthalmologist in children. The refraction by ophthalmologist must be recommended for correction of refractive errors in children.
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Niño , Humanos , Ambliopía , Vértebra Cervical Axis , Errores de Refracción , EstrabismoRESUMEN
We analysed the differences between the values of noncycloplegicautomated refraction and manifest refraction by ophthalmologist 150 patients(274 eyes)were studied. We divided these patients into five groups according to the age; Group 1 included patients under 10 yea(n=50 eyes), Group 2 from 10 yrs to 19 yrs(n=74 eyes), Group 3 from 20 yrs to 39 yrs(n=66 eyes), Group 4 from 40 yrs to 49yrs(n=39 eyes), Group 5 over 50 yrs(n=46 eyes); We used Canon Auto Ref R-10 autorefractor and ophthalmologist's refractions were the results of both subjective refraction by retinoscope and objective refraction used by cross cylinder. Between the two examinations, the percentages of eyes of disagreement beyond +/-0.5D were 22%(group 1), 39.2%(group 2), 14.1%(group 3), 15.8%(group 4), 17.4%(group 5) in spherical power; 18%, 23%, 27.3%, 29%, 15.2% in cylindrical power respectively; 20%, 31.9%, 18.2%, 15.8%, 19.6% in spherical equivalent respectively and the percentages of eyes of disagreement beyond +/-10 degrees in cylindrical axis were 25%, 42.6%, 39.2%, 40%, 52.9% respectively. There was no statistic significance between the age groups when we compared the absolute differences of values between two examinations. Conclusively, this study revealed that there were large differences between the values of noncycloplegic automated refraction and manifest refraction by ophthalmologist in the large amout of patients and then our results indicated that automated refraction was dangerous to patient's eyes and subjective refinement was needed by ophthalmologist if patients wanted the spectacle or contact lens.