Effect of scoring and termination rules on test-retest variability of a novel high-pass letter acuity chart.

PURPOSE Test-retest variability (TRV) limits our ability to detect clinically significant changes in visual acuity (VA). We wanted to compare the effect of scoring and termination rules on TRV for logMAR charts, employing either conventional or pseudo high-pass (Vanishing Optotype) letters. METHODS VA measurements and TRV were compared in 50 uncorrected normal observers (17 male, mean age 42.8 ± 16.2 years) using both conventional logMAR-style charts and letter charts of the same layout but containing pseudo high-pass letters (Moorfields Acuity Chart [MAC]). Additional charts employing a different 10-letter alphabet to the Sloan set were also tested. Mean spherical refractive error was -0.93 diopters (D; range, -5.38 to +3.00 D). Acuity scores were calculated using three methods: letter-by-letter, with either line- or chart-based termination, and line-by-line scoring. Bland-Altman methods were used to calculate 95% ranges for TRV. RESULTS While acuity thresholds were higher for the MAC, they were less affected by termination criteria and displayed significantly lower 95% TRV values across all scoring techniques. Ordinary least squares regression analysis confirmed a proportional as well as systematic bias between conventional and MAC measurements (r(2) = 0.217, P = 0.001) such that the difference between the two was greater with better VA. CONCLUSIONS TRV was consistently lower for a logMAR chart employing high-pass rather than conventional letters in uncorrected refractive error and was less affected by termination and scoring methods. The MAC was also less affected by optical defocus. Further work is required to determine the usefulness of different charts to differentiate between optical and neural losses of vision.

[1]  I L Bailey,et al.  New Design Principles for Visual Acuity Letter Charts* , 1976, American journal of optometry and physiological optics.

[2]  Bradford Howland,et al.  High-pass spatial frequency letters as clinical optotypes , 1978, Vision Research.

[3]  H F Sanderson,et al.  Observer variation in ophthalmology. , 1980, The British journal of ophthalmology.

[4]  F. Ferris,et al.  New visual acuity charts for clinical research. , 1982, American journal of ophthalmology.

[5]  L O Harvey,et al.  Identification confusions among letters of the alphabet. , 1984, Journal of experimental psychology. Human perception and performance.

[6]  J M Bland,et al.  Statistical methods for assessing agreement between two methods of clinical measurement , 1986 .

[7]  M Sheridan,et al.  The use of accurate visual acuity measurements in clinical anti‐cataract formulation trials , 1988, Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians.

[8]  J. Lovie-Kitchin,et al.  Validity and reliability of visual acuity measurements , 1988, Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians.

[9]  A. Hill,et al.  Vistech VCTS 6500 Charts—Within- and Between-Session Reliability , 1991, Optometry and vision science : official publication of the American Academy of Optometry.

[10]  I L Bailey,et al.  Clinical grading and the effects of scaling. , 1991, Investigative ophthalmology & visual science.

[11]  A Arditi,et al.  On the statistical reliability of letter-chart visual acuity measurements. , 1993, Investigative ophthalmology & visual science.

[12]  J. Lovie-Kitchin,et al.  Repeated Visual Acuity Measurement: Establishing the Patient's Own Criterion for Change , 1993, Optometry and vision science : official publication of the American Academy of Optometry.

[13]  V. M. Bondarko,et al.  What spatial frequency do we use to detect the orientation of a Landolt C? , 1997, Vision Research.

[14]  Michael Wall,et al.  Visual acuity scored by the letter-by-letter or probit methods has lower retest variability than the line assignment method , 1997, Eye.

[15]  I L Bailey,et al.  Repeatability of Visual Acuity Measurement , 1998, Optometry and vision science : official publication of the American Academy of Optometry.

[16]  L N Thibos,et al.  Relationship between acuity for gratings and for tumbling-E letters in peripheral vision. , 1999, Journal of the Optical Society of America. A, Optics, image science, and vision.

[17]  H. Bedell,et al.  Comparison of letter and Vernier acuities with dioptric and diffusive blur. , 1999, Optometry and vision science : official publication of the American Academy of Optometry.

[18]  L N Thibos,et al.  Sampling limits and critical bandwidth for letter discrimination in peripheral vision. , 1999, Journal of the Optical Society of America. A, Optics, image science, and vision.

[19]  C. McMonnies.  Chart construction and letter legibility/readability , 1999, Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians.

[20]  A Ho,et al.  Letter legibility and chart equivalence , 2000, Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians.

[21]  I. Murdoch,et al.  The development of a “reduced logMAR” visual acuity chart for use in routine clinical practice , 2001, The British journal of ophthalmology.

[22]  A Carkeet,et al.  Modeling logMAR Visual Acuity Scores: Effects of Termination Rules and Alternative Forced-Choice Options , 2001, Optometry and vision science : official publication of the American Academy of Optometry.

[23]  Andrew Carkeet,et al.  The Slope of the Psychometric Function for Bailey-Lovie Letter Charts: Defocus Effects and Implications for Modeling Letter-By-Letter Scores , 2001, Optometry and Vision Science.

[24]  David B Elliott,et al.  The Dependency of LogMAR Visual Acuity Measurements on Chart Design and Scoring Rule , 2002, Optometry and vision science : official publication of the American Academy of Optometry.

[25]  D. Rosser,et al.  Development of a clinically feasible logMAR alternative to the Snellen chart: performance of the “compact reduced logMAR” visual acuity chart in amblyopic children , 2003, The British journal of ophthalmology.

[26]  J. Gwiazda,et al.  Repeatability of ETDRS visual acuity in children. , 2003, Investigative ophthalmology & visual science.

[27]  Fred W Fitzke,et al.  How sensitive to clinical change are ETDRS logMAR visual acuity measurements? , 2003, Investigative ophthalmology & visual science.

[28]  S. Cousens,et al.  The effect of optical defocus on the test-retest variability of visual acuity measurements. , 2004, Investigative ophthalmology & visual science.

[29]  L. Thibos,et al.  The filtered Fourier difference spectrum predicts psychophysical letter discrimination in the peripheral retina. , 2004, Spatial vision.

[30]  N. Shah,et al.  Validation of a computerised logMAR visual acuity measurement system (COMPlog): comparison with ETDRS and the electronic ETDRS testing algorithm in adults and amblyopic children , 2007, British Journal of Ophthalmology.

[31]  W. Freeman,et al.  Comparison of visual acuity in macular degeneration patients measured with snellen and early treatment diabetic retinopathy study charts. , 2008, Ophthalmology.

[32]  G. Rubin,et al.  Intersession repeatability of visual acuity scores in age-related macular degeneration. , 2008, Investigative ophthalmology & visual science.

[33]  Peter K Kaiser,et al.  Prospective evaluation of visual acuity assessment: a comparison of snellen versus ETDRS charts in clinical practice (An AOS Thesis). , 2009, Transactions of the American Ophthalmological Society.

[34]  P. Hewson,et al.  Comparison of the ETDRS logMAR, ‘compact reduced logMar’ and Snellen charts in routine clinical practice , 2010, Eye.

[35]  A. Azuara-Blanco,et al.  Lifetime visual prognosis of patients with glaucoma , 2011, Clinical & experimental ophthalmology.

[36]  G. Teichler,et al.  Vergleich von Landoltring- und ETDRS-Buchstaben-Sehschärfe bei Augengesunden und Patienten mit unterschiedlichen Augenerkrankungen , 2011 .

[37]  R. Becker,et al.  [Comparison of visual acuity measured using Landolt-C and ETDRS charts in healthy subjects and patients with various eye diseases]. , 2011, Klinische Monatsblatter fur Augenheilkunde.

[38]  S. Sivaprasad,et al.  Visual acuity outcomes in ranibizumab‐treated neovascular age‐related macular degeneration; stratified by baseline vision , 2011, Clinical & experimental ophthalmology.

[39]  S. Dakin,et al.  Vanishing Optotype acuity: repeatability and effect of the number of alternatives , 2011, Ophthalmic & physiological optics : the journal of the British College of Ophthalmic Opticians.

[40]  Xuxia Meng,et al.  Visual Outcome following Intraocular Foreign Bodies: A Retrospective Review of 5-Year Clinical Experience , 2011, European journal of ophthalmology.

[41]  P. Fesler,et al.  Visual Acuity Outcome and Predictive Factors after Bevacizumab for Central Retinal Vein Occlusion , 2012, European journal of ophthalmology.

[42]  Steven C Dakin,et al.  Effect of optical defocus on detection and recognition of vanishing optotype letters in the fovea and periphery. , 2012, Investigative ophthalmology & visual science.

[43]  A. Joussen,et al.  Visual outcome and complications after posterior iris‐claw aphakic intraocular lens implantation , 2012, Journal of cataract and refractive surgery.

[44]  M. Tsilimbaris,et al.  Comparison of Visual Acuity Charts in Young Adults and Patients with Diabetic Retinopathy , 2013, Optometry and vision science : official publication of the American Academy of Optometry.