Comparison of Snellen and Early Treatment Diabetic Retinopathy Study charts using a computer simulation
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摘要
AIM:To compare accuracy,reproducibility and test duration for the Snellen and the Early Treatment Diabetic Retinopathy Study(ETDRS)charts,two main tools used to measure visual acuity(VA).·METHODS:A computer simulation was programmed to run multiple virtual patients,each with a unique set of assigned parameters,including VA,false-positive and false-negative error values.For each virtual patient,assigned VA was randomly chosen along a continuous scale spanning the range between 1.0 to 0.0 log MAR units(equivalent to 20/200 to 20/20).Each of 30 000virtual patients were run ten times on each of the two VA charts.·RESULTS:Average test duration(expressed as the total number of characters presented during the test±SD)was12.6±11.1 and 31.2±14.7 characters,for the Snellen and ETDRS,respectively.Accuracy,defined as the absolute difference(±SD)between the assigned VA and the measured VA,expressed in log MAR units,was superior in the ETDRS charts:0.12±0.14 and 0.08±0.08,for the Snellen and ETDRS charts,respectively.Reproducibility,expressed as test-retest variability,was superior in the ETDRS charts:0.23±0.17 and 0.11±0.09 log MAR units,for the Snellen and ETDRS charts,respectively.·CONCLUSION:A comparison of true(assigned)VA to measured VA,demonstrated,on average,better accuracy and reproducibility of the ETDRS chart,but at the penalty of significantly longer test duration.These differences were most pronounced in the low VA range.The reproducibility using a simulation approach is in line with reproducibility values found in several clinical studies.
AIM: To compare accuracy, reproducibility and test duration for the Snellen and the Early Treatment Diabetic Retinopathy Study(ETDRS) charts, two main tools used to measure visual acuity(VA).·METHODS: A computer simulation was programmed to run multiple virtual patients, each with a unique set of assigned parameters, including VA, false-positive and false-negative error values. For each virtual patient,assigned VA was randomly chosen along a continuous scale spanning the range between 1.0 to 0.0 log MAR units(equivalent to 20/200 to 20/20). Each of 30 000 virtual patients were run ten times on each of the two VA charts.·RESULTS: Average test duration(expressed as the total number of characters presented during the test ±SD) was12.6 ±11.1 and 31.2 ±14.7 characters, for the Snellen and ETDRS, respectively. Accuracy, defined as the absolute difference(±SD) between the assigned VA and the measured VA, expressed in log MAR units, was superior in the ETDRS charts: 0.12 ±0.14 and 0.08 ±0.08, for the Snellen and ETDRS charts, respectively. Reproducibility,expressed as test-retest variability, was superior in the ETDRS charts: 0.23±0.17 and 0.11±0.09 log MAR units, for the Snellen and ETDRS charts, respectively.·CONCLUSION: A comparison of true(assigned) VA to measured VA, demonstrated, on average, better accuracy and reproducibility of the ETDRS chart, but at the penalty of significantly longer test duration. These differences were most pronounced in the low VA range. The reproducibility using a simulation approach is in line with reproducibility values found in several clinical studies.
AIM: To compare accuracy, reproducibility and test duration for the Snellen and the Early Treatment Diabetic Retinopathy Study(ETDRS) charts, two main tools used to measure visual acuity(VA).·METHODS: A computer simulation was programmed to run multiple virtual patients, each with a unique set of assigned parameters, including VA, false-positive and false-negative error values. For each virtual patient,assigned VA was randomly chosen along a continuous scale spanning the range between 1.0 to 0.0 log MAR units(equivalent to 20/200 to 20/20). Each of 30 000 virtual patients were run ten times on each of the two VA charts.·RESULTS: Average test duration(expressed as the total number of characters presented during the test ±SD) was12.6 ±11.1 and 31.2 ±14.7 characters, for the Snellen and ETDRS, respectively. Accuracy, defined as the absolute difference(±SD) between the assigned VA and the measured VA, expressed in log MAR units, was superior in the ETDRS charts: 0.12 ±0.14 and 0.08 ±0.08, for the Snellen and ETDRS charts, respectively. Reproducibility,expressed as test-retest variability, was superior in the ETDRS charts: 0.23±0.17 and 0.11±0.09 log MAR units, for the Snellen and ETDRS charts, respectively.·CONCLUSION: A comparison of true(assigned) VA to measured VA, demonstrated, on average, better accuracy and reproducibility of the ETDRS chart, but at the penalty of significantly longer test duration. These differences were most pronounced in the low VA range. The reproducibility using a simulation approach is in line with reproducibility values found in several clinical studies.
引文
1 Mitchell P,Bressler N,Tolley K,Gallagher M,Petrillo J,Ferreira A,Wood R,Bandello F;RESTORE Study Group.Patient-reported visual function outcomes improve after ranibizumab treatment in patients with vision impairment due to diabetic macular edema:randomized clinical trial.JAMA Ophthalmol 2013;131(10):1339-1347.
2 Sivaprasad S,Crosby-Nwaobi R,Heng LZ,Peto T,Michaelides M,Hykin P.Injection frequency and response to bevacizumab monotherapy for diabetic macular oedema(BOLT Report 5).Br J Ophthalmol 2013;97(9):1177-1180.
3 Christen WG,Glynn RJ,Manson JE,MacF adyen J,Bubes V,Schvartz M,Buring JE,Sesso HD,Gaziano JM.Effects of multivitamin supplement on cataract and age-related macular degeneration in a randomized trial of male physicians.Ophthalmology 2014;121(2):525-534.
4 Wilkins MR,Allan BD,Rubin GS,Findl O,Hollick EJ,Bunce C,Xing W;Moorfields IOL Study Group.Randomized trial of multifocal intraocular lenses versus monovision after bilateral cataract surgery.Ophthalmology2013;120(12):2449-2455.el.
5 Reddy KP,Kandulla J,Auffarth GU.Effectiveness and safety of femtosecond laser-assisted lens fragmentation and anterior capsulotomy versus the manual technique in cataract surgery.J Cataract Refract Surg2013;39(9):1297-1306.
6 Albrecht E,Richards JC,Pollock T,Cook C,Myers L.Adjunctive use of intravitreal dexamethasone in presumed bacterial endophthalmitis:a randomised trial.Br J Ophthalmol 2011;95(10):1385-1388.
7 Sia RK,Ryan DS,Edwards JD,Stutzman RD,Bower KS.The U.S.Army Surface Ablation Study:comparison of PRK,MMC-PRK,and LASEK in moderate to high myopia.J Refract Surg 2014;30(4):256-264.
8 Chen AH,Norazman FN,Buari NH.Comparison of visual acuity estimates using three different letter charts under two ambient room illuminations.Indian J Ophthalmol 2012;60(2):101-104.
9 Bailey IL,Lovie JE.New design principles for visual acuity letter charts.Am J Optom Physiol Opt 1976;53(11):740-745.
10 Vesely P,Synek S.Repeatability and reliability of the visual acuity examination on logM AR ETDRS and Snellen chart.Cesk Slov Oftalmol2012;68(2):71-75.
11 Shah N,Laidlaw DA,Rashid S,Hysi P.Validation of printed and computerised crowded Kay picture logM AR tests against gold standard ETDRS acuity test chart measurements in adult and amblyopic paediatric subjects.Eye(Lond)2012;26(4):593-600.
12 Shah N,Laidlaw DA,Shah SP,Sivasubramaniam S,Bunce C,Cousens S.Computerized repeating and averaging improve the test-retest variability of ETDRS visual acuity measurements:implications for sensitivity and specificity.Invest Ophthalmol Vis Sci 2011;52(13):9397-9402.
13 Kuo HK,Kuo MT,Tiong IS,Wu PC,Chen YJ,Chen CH.Visual acuity as measured with Landolt C chart and Early Treatment of Diabetic Retinopathy Study(ETDRS)chart.Graefes Arch Clin Exp Ophthalmol2011;249(4):601-605.
14 Laidlaw DA,Abbott A,Rosser DA.Development of a clinically feasible logM AR alternative to the Snellen chart:performance of the"compact reduced logM AR"visual acuity chart in amblyopic children.Br JOphthalmol 2003;87(10):1232-1234.
15 Ruamviboonsuk P,Tiensuwan M,Kunawut C,Masayaanon P.Repeatability of an automated Landolt C test,compared with the early treatment of diabetic retinopathy study(ETDRS)chart testing.Am JOphthalmol 2003;136(4):662-669.
16 Spenceley SE,Henson DB.Visual field test simulation and error in threshold estimation.Br J Ophthalmol 1996;80(4):304-308.
17 Turpin A,McK endrick AM,Johnson CA,Vingrys AJ.Development of efficient threshold strategies for frequency doubling technology perimetry using computer simulation.Invest Ophthalmol Vis Sci 2002;43(2):322-331.
18 Vesti E,Spry PG,Chauhan BC,Johnson CA.Sensitivity differences between real-patient and computer-stimulated visual fields.J Glaucoma2002;11(1):35-45.
19 Turpin A,McK endrick AM,Johnson CA,Vingrys AJ.Properties of perimetric threshold estimates from full threshold,ZEST,and SITA-like strategies,as determined by computer simulation.Invest Ophthalmol Vis Sci 2003;44(11):4787-4795.
20 McN aught AI,Crabb DP,Fitzke FW,Hitchings RA.Modelling series of visual fields to detect progression in normal-tension glaucoma.Graefes Arch Clin Exp Ophthalmol 1995;233(12):750-755.
21 Vesti E,Johnson CA,Chauhan BC.Comparison of different methods for detecting glaucomatous visual field progression.Invest Ophthalmol Vis Sci2003;44(9):3873-3879.
22 Gardiner SK,Crabb DP.Examination of different pointwise linear regression methods for determining visual field progression.Invest Ophthalmol Vis Sci 2002;43(5):1400-1407.
23 Anderson DR,Patella VM.Automated static perimetry.St.Louis:CVMosby,1990;10-35.
24 Rosser DA,Cousens SN,Murdoch IE,Fitzke FW,Laidlaw DA.How sensitive to clinical change are ETDRS logM AR visual acuity measurements?Invest Ophthalmol Vis Sci 2003;44(8):3278-3281.
25 Rosser DA,Laidlaw DA,Murdoch IE.The development of a"reduced logM AR"visual acuity chart for use in routine clinical practice.Br JOphthalmol 2001;85(4):432-436.
26 Siderov J,Tiu AL.Variability of measurements of visual acuity in a large eye clinic.Acta Ophthalmol Scand 1999;77(6):673-676.
27 Lim LA,Frost NA,Powell RJ,Hewson P.Comparison of the ETDRSlogM AR,'compact reduced logM ar'and Snellen charts in routine clinical practice.Eye(Lond)2010;24(4):673-677.
28 Ricci F,Cedrone C,Cerulli L.Standardized measurement of visual acuity.Ophthalmic Epidemiol 1998;5(1):41-53.
2 Sivaprasad S,Crosby-Nwaobi R,Heng LZ,Peto T,Michaelides M,Hykin P.Injection frequency and response to bevacizumab monotherapy for diabetic macular oedema(BOLT Report 5).Br J Ophthalmol 2013;97(9):1177-1180.
3 Christen WG,Glynn RJ,Manson JE,MacF adyen J,Bubes V,Schvartz M,Buring JE,Sesso HD,Gaziano JM.Effects of multivitamin supplement on cataract and age-related macular degeneration in a randomized trial of male physicians.Ophthalmology 2014;121(2):525-534.
4 Wilkins MR,Allan BD,Rubin GS,Findl O,Hollick EJ,Bunce C,Xing W;Moorfields IOL Study Group.Randomized trial of multifocal intraocular lenses versus monovision after bilateral cataract surgery.Ophthalmology2013;120(12):2449-2455.el.
5 Reddy KP,Kandulla J,Auffarth GU.Effectiveness and safety of femtosecond laser-assisted lens fragmentation and anterior capsulotomy versus the manual technique in cataract surgery.J Cataract Refract Surg2013;39(9):1297-1306.
6 Albrecht E,Richards JC,Pollock T,Cook C,Myers L.Adjunctive use of intravitreal dexamethasone in presumed bacterial endophthalmitis:a randomised trial.Br J Ophthalmol 2011;95(10):1385-1388.
7 Sia RK,Ryan DS,Edwards JD,Stutzman RD,Bower KS.The U.S.Army Surface Ablation Study:comparison of PRK,MMC-PRK,and LASEK in moderate to high myopia.J Refract Surg 2014;30(4):256-264.
8 Chen AH,Norazman FN,Buari NH.Comparison of visual acuity estimates using three different letter charts under two ambient room illuminations.Indian J Ophthalmol 2012;60(2):101-104.
9 Bailey IL,Lovie JE.New design principles for visual acuity letter charts.Am J Optom Physiol Opt 1976;53(11):740-745.
10 Vesely P,Synek S.Repeatability and reliability of the visual acuity examination on logM AR ETDRS and Snellen chart.Cesk Slov Oftalmol2012;68(2):71-75.
11 Shah N,Laidlaw DA,Rashid S,Hysi P.Validation of printed and computerised crowded Kay picture logM AR tests against gold standard ETDRS acuity test chart measurements in adult and amblyopic paediatric subjects.Eye(Lond)2012;26(4):593-600.
12 Shah N,Laidlaw DA,Shah SP,Sivasubramaniam S,Bunce C,Cousens S.Computerized repeating and averaging improve the test-retest variability of ETDRS visual acuity measurements:implications for sensitivity and specificity.Invest Ophthalmol Vis Sci 2011;52(13):9397-9402.
13 Kuo HK,Kuo MT,Tiong IS,Wu PC,Chen YJ,Chen CH.Visual acuity as measured with Landolt C chart and Early Treatment of Diabetic Retinopathy Study(ETDRS)chart.Graefes Arch Clin Exp Ophthalmol2011;249(4):601-605.
14 Laidlaw DA,Abbott A,Rosser DA.Development of a clinically feasible logM AR alternative to the Snellen chart:performance of the"compact reduced logM AR"visual acuity chart in amblyopic children.Br JOphthalmol 2003;87(10):1232-1234.
15 Ruamviboonsuk P,Tiensuwan M,Kunawut C,Masayaanon P.Repeatability of an automated Landolt C test,compared with the early treatment of diabetic retinopathy study(ETDRS)chart testing.Am JOphthalmol 2003;136(4):662-669.
16 Spenceley SE,Henson DB.Visual field test simulation and error in threshold estimation.Br J Ophthalmol 1996;80(4):304-308.
17 Turpin A,McK endrick AM,Johnson CA,Vingrys AJ.Development of efficient threshold strategies for frequency doubling technology perimetry using computer simulation.Invest Ophthalmol Vis Sci 2002;43(2):322-331.
18 Vesti E,Spry PG,Chauhan BC,Johnson CA.Sensitivity differences between real-patient and computer-stimulated visual fields.J Glaucoma2002;11(1):35-45.
19 Turpin A,McK endrick AM,Johnson CA,Vingrys AJ.Properties of perimetric threshold estimates from full threshold,ZEST,and SITA-like strategies,as determined by computer simulation.Invest Ophthalmol Vis Sci 2003;44(11):4787-4795.
20 McN aught AI,Crabb DP,Fitzke FW,Hitchings RA.Modelling series of visual fields to detect progression in normal-tension glaucoma.Graefes Arch Clin Exp Ophthalmol 1995;233(12):750-755.
21 Vesti E,Johnson CA,Chauhan BC.Comparison of different methods for detecting glaucomatous visual field progression.Invest Ophthalmol Vis Sci2003;44(9):3873-3879.
22 Gardiner SK,Crabb DP.Examination of different pointwise linear regression methods for determining visual field progression.Invest Ophthalmol Vis Sci 2002;43(5):1400-1407.
23 Anderson DR,Patella VM.Automated static perimetry.St.Louis:CVMosby,1990;10-35.
24 Rosser DA,Cousens SN,Murdoch IE,Fitzke FW,Laidlaw DA.How sensitive to clinical change are ETDRS logM AR visual acuity measurements?Invest Ophthalmol Vis Sci 2003;44(8):3278-3281.
25 Rosser DA,Laidlaw DA,Murdoch IE.The development of a"reduced logM AR"visual acuity chart for use in routine clinical practice.Br JOphthalmol 2001;85(4):432-436.
26 Siderov J,Tiu AL.Variability of measurements of visual acuity in a large eye clinic.Acta Ophthalmol Scand 1999;77(6):673-676.
27 Lim LA,Frost NA,Powell RJ,Hewson P.Comparison of the ETDRSlogM AR,'compact reduced logM ar'and Snellen charts in routine clinical practice.Eye(Lond)2010;24(4):673-677.
28 Ricci F,Cedrone C,Cerulli L.Standardized measurement of visual acuity.Ophthalmic Epidemiol 1998;5(1):41-53.