1 TITLE: Development and validation of the Greek version of the MNREAD acuity chart AUTHORS: Asimina Mataftsi*, Areti Bourtoulamaiou*, Anna-Bettina Haidich§, Antonis Antoniadis*,¶, Vassilis Kilintzis *,†, Ioannis T.Tsinopoulos*, Stavros A.Dimitrakos* * II nd Department of Ophthalmology, Medical School, Aristotle University of Thessaloniki, Greece. § . Department of Hygiene and Epidemiology, Medical School, Aristotle University of Thessaloniki, Greece. ¶ Electrical Engineer, IT Department of Drama Prefecture † Laboratory of Medical Informatics, Medical School, Aristotle University of Thessaloniki, Greece. Running title: Greek version of the MNREAD acuity chart Corresponding author: Asimina Mataftsi, MD, MRCOphth IInd Department of Ophthalmology, Medical School, Aristotle University of Thessaloniki, “Papageorpiou” Hospital, N.Efkarpia 56429 Greece. mataftsi@doctors.org.uk Key words: acuity chart, MNREAD, reading acuity, reading speed, critical print size, Greek Disclosure of funding sources: None Disclosure of potential conflict of interest: None 2 Background. The aim of this study was to develop MNREAD acuity charts in the Greek language (MNREAD-GR) and establish their repeatability in a normal-sighted population. Methods. 180 Greek sentences were constructed based on the design principles of the Minnesota Low Vision Reading Test. The software used to validate them for width was adjusted to the parameters of the non-Latin characters used in the Greek Language (MNTest-GR), and width-validated sentences were then checked for literacy by 2 language teachers. Pilot testing followed in 20 adults and 2 groups of 20 children each. Subsequently, three versions of MNREAD-GR chart were printed and validated for repeatability: 20 adults read MNREAD-GR charts 1, 2 and 3 in randomized order over two sessions. A linear mixed-model analysis was performed for near visual acuity (VA), maximum reading speed (MRS) and critical print size (CPS) to identify the contribution of each source (individual subject, session, chart and residual error) to the total variance. Subject variance determined the intraclass correlation coefficient (ICC). Results. 100 of the initial 180 sentences were validated with MNTest-GR and approved for literacy correctness. Of those, 57 sentences were selected after pilot testing, and used in the final printed chart, in random distribution among 3 versions. The ICC was 0.72 for VA, 0.87 for MRS and 0.46 for CPS. The between-charts within-session within-subject component accounted for maximally 5% of the variance. The between-sessions withinsubject component had a maximum of 1%. The coefficient of repeatability was 0.08 logMAR for VA, 46.96 words per minute for MRS, and 0.10 logMAR for CPS. Conclusion. The created MNREAD-GR acuity chart is a standardized clinical test that can be used reliably to measure near acuity, reading speed and critical print size in Greek-speaking literate patients of all ages. 288 words 3 Reading is closely linked to the quality of life1 of an individual, and assessing a subject’s reading ability is an important part of the examination of the eyes. It is essential that this assessment is done in a standardized way that ensures reliable, repeatable results which actually reflect visual performance in real circumstances. While near acuity is a cardinal element, other factors such as the visual field, binocular status, contrast sensitivity, and dark adaptation, also significantly influence reading ability2,3. A test that allows measurement of reading speed and critical print size, i.e. the smallest print that can be read with maximum speed, indirectly evaluates the effect of some of these factors too, and helps evaluate macular function more distinctly4,5. Assessing reading ability through all three parameters allows a more comprehensive measure of this activity of daily living that has a central role in patients’ self-reported satisfaction with vision, and more closely reflecting everyday life visual performance 7-9. Among all available near acuity charts, those developed in 1995 by Minnesota Low Vision Laboratory10, seem to present significant advantages. Measurements are possible on a logMAR scale, the test is crowded, and it can measure reading speed and critical print size in addition to near acuity. Radner reading charts11 also present these advantages, but although sentences used in this test are standardized and highly comparable in terms of lexical difficulty, syntax, word length and position, spatial layout is not, i.e. crowding in the horizontal axis is not calibrated amongst sentences, and this is an important disadvantage, as reading is limited by crowding12,13. Assessing near vision with MNREAD is appropriate and reliable for both adults and children14, normally sighted as well as low vision subjects6,10,15. MNREAD charts have become available in several languages (Japanese16, Italian14, Spanish 17, French 18 and Portuguese 19) giving vision care providers in many countries a useful clinical and research tool. Our No near vision test with the advantages of the MNREAD charts was available in Greek, so the aim of the present study was to produce and validate the test in the Greek language. 4 METHODS The MNREAD chart was developed based on a series of design principles, and these were followed these to construct its Greek version (Table 1). It contains a series of sentences printed in a sequence of decreasing print sizes and in a proportionally-spaced font, representative of the print found in everyday reading material6. The presence of continuous text allows measurement of the near visual acuity (VA), but also of the maximum reading speed (MRS) and of the critical print size (CPS,) which is the level of print size beyond which reading speed significantly decreases7. Text is crowded, and comes in decreasing print sizes at 0.1 logMAR steps, also noted in M units. The logarithmic scale keeps the size ratio between adjacent sentences the same regardless of viewing distance. i) Construction of sentences A sufficient pool of sentences was created to allow for production of three versions of the chart. The MN-test software was adapted for the Greek language and was then used for width validation of 180 candidate sentences. Words, phrases and notions were drawn from school books for 7- and 8-year old children, the aim being to produce sentences that are understandable and appropriate for the paediatric as well as the adult population. These were then assessed for grammar, syntax and literacy of context by two Greek language teachers ii) Pilot testing of candidate sentences with adults and children; The developed sentences were 1) subjectively scored and objectively tested on 20 normal-sighted adults, and 2) objectively tested on 20 normal-sighted 8-year old school students. This age was chosen as it was judged to be the youngest at which reading skills have been achieved, and so a reading test is appropriate for monitoring near vision. Subjective assessment was based on the way the 20 adults evaluated the sentences by providing a score (1 to 5). Objective assessment was based on the reading time (mean and 5 SD) and mistakes made while reading out the sentences, in both adults and children. All tests were performed with the subject’s optimal correction. The protocol was approved by the Bioethics Committee of the Aristotle University of Thessaloniki. Sentences were printed in 24 point size Times New Roman (corresponding to 2.5 M units) in groups of 7 per A4 page, for pilot testing in the adult group. Best corrected near visual acuity was tested with Birkhäuser near acuity chart at 33cm and adults with acuity less than decimal 0.9 with optimal correction, were excluded. Subjects were asked to read out and subjectively score each sentence for appropriate and interesting context (1=poor, 2=inadequate, 3=adequate, 4=good, 5=very good) bearing in mind that this would be addressed to ages 8 years and above. At the same time, reading time and mistakes made while reading were recorded for each sentence, for mean reading time and standard deviation (SD) to be calculated. Each subject was instructed by an examiner to read each sentence aloud after hearing the words “ready…go” while, simultaneously, the sentence was revealed with a hiding sheet. A stopclock was used to record the time taken to read each sentence to the nearest 0.1 sec. A second examiner made note of all words read with mistakes or with difficulty. The reading times were measured and the reading speed (words per minute) was then calculated for each sentence read as the number of words read correctly divided by the time taken to read the sentence: reading speed = 60 ´ (10 – errors) / (time in seconds)6 Sentences selected from pilot testing in adults were then printed in 24 point size Times New Roman (corresponding to 2.5 M units) in groups of 12 per A4 page, for pilot testing in normal-sighted 8-year old students. The test took place in the school environment after informed parental consent. Best corrected visual acuity was tested with crowded Kay’s pictures at 3 m and 33 cm and a cover test was performed to exclude intermittent heterotropias. Children with acuity poorer than 0.0 logMAR for distance or near, abnormal cover test, marked reading difficulties according to their teacher or whose mother-tongue was not Greek, were excluded. 6 In order to minimize the possibility of fatigue during reading, two subgroups of 37 sentences each were randomly formed, and each subgroup was read by 20 students. The procedure of testing was the same as described above, in the adults pilot testing, except that the children were not asked to subjectively score the sentences. iii) Chart creation and validation The chosen sentences were randomly distributed, based on their relative difficulty, to create 3 printed versions of MNREAD-GR chart (printed according to standards of the prototype- see table 1). These were validated with testing on 20 normal-sighted adults (inter-chart, intra-subject repeatability for reading acuity, critical print size, and maximum reading speed). Subjects with best corrected near binocular decimal acuity worse than 0.9 (tested with the Birkhäuser acuity chart at 33cm) were excluded. Testing was carried out with the chart placed on a stand at a distance of 40cm from the subject’s eyes, in a well-lit room that allowed at least 80 cd/m2 on the chart surface. Each subject was shown all 3 versions of the chart (MNREAD-GR1, GR2 and GR3) at 2 sessions with a 30-minute interval. The order of presentation of the three charts was random and was changed between sessions. Reading time and errors were recorded and reading speed was measured as described above. Maximum reading speed (MRS) was obtained by averaging the speed of the sentences with print size larger than the CPS, and CPS was identified as the print size of the sentence fulfilling this criterion: all following sentences were read at a speed that was 1.96 times the standard deviation below the average of the largest preceding sentences (i.e. the MRS)6,11. Sample size, for both the pilot testing and the validation phase, was based on previous work in this area5,14,15. iv) Statistics 7 A linear mixed-model analysis was performed for near visual acuity, maximum reading speed and critical print size to identify which part of the total variability of the MNREAD charts could be attributed to which source21-23. The sources of variation were: individual subject (n=20), session (n=2), chart (n=3) and residual error, which were considered to be random effects. The time within-session order was considered a fixed effect22,23. The contribution of each source to the total variability was calculated as a percentage. The relative contribution of subject variance to the total variance determines the reliability of the measurement, known as the intraclass correlation coefficient (ICC)21,23. The variance components were obtained by the method of restricted maximum likelihood. The standard error of measurement (SEM) was defined as the square root of the sum of the within-subject variance components due to session, chart, and residual error. The reproducibility was determined as 1.96√2 = 2.77 times the SEM, representing the maximum absolute difference between two measurements within the same subject that may be due to chance with 95% probability24. For example, when the differences between measurements of a subject are within the reproducibility range, there is no improvement or deterioration on this scale. The repeatability is the same as the reproducibility but excluding the session component in the SEM21-23. The SEM, reproducibility, and repeatability have the same dimension as the variable considered, whereas the ICC is a dimensionless number. The reproducibility can be considered the proper generalization of the limits of agreement introduced for duplicate measurements by Bland and Altman21,25. Statistical analyses were conducted in SPSS version 18.0 (PASW). 8 RESULTS i) Construction of sentencesWe adapted tThe MN-test software program of validating the length (width) of the candidate sentences was adapted for the Greek characters. According to the design principles by the developers, print size is defined by the height of a lowercase letter that has no ascenders or descenders, so that it subtends 5' at a viewing distance of 40cm. The greek letter “ο” has such characteristics, and it is very similar to latin “o” which was used for normalisation in the prototype MNREAD, so it was used as a comparison for normalizing the width of all Greek alphabet characters, both lowercase and uppercase. The expected minimum and maximum width of a sentence was then calculated based on the frequency of appearance of each letter in the Greek language (Table 2). A minimum-length sentence was defined as one that has 19 lowercase characters of which 4 are spaces, and a maximum-length sentence was defined as one that has 21 characters of which 4 are spaces and one is uppercase. The mean expected sentence length was L=(min+max)/2. According to the program’s software the accepted range of lengths was 3%, i.e. the maximum-length sentence would be 1.03 times the mean length and the minimum-length sentence would be 0.97 times the mean length. This was the basis for validating each sentence’s spatial layout. The Greek letters of the alphabet were incorporated in the source code (uppercase and lowercase) using the proper frequency, as shown in Table 2. The font Times New Roman in Greek was used, as was the case in the English version. We then used tThe program was then used to evaluate whether or not the criteria were met for each candidate sentence (number of characters, length). Sentence input was made in the form of three verses and each one was assessed independently in terms of length. The number of characters in each verse is also displayed on the screen (Figure 1). Subsequently, the total number of characters and an overall assessment of the sentence is shown. 9 A total of 180 sentences with the appropriate number of words and characters were tested with the adapted MN-test software, and 105 of these were length validated. Two Greek language teachers subsequently assessed the 105 sentences for literacy approval and grammar/syntax corrections, and excluded 5 of them. ii) Pilot testing of candidate sentences with adults and children; 1) adults A total of 100 sentences were first tested on 20 adults (mean age 32.1, standard deviation (SD) 8.5, range 25-59 years, 8 males) Sentences were plotted according to reading time to form a normal distribution with a positive skewness of 0.281 (Figure 2). After removal of the 7 sentences at the right end of the plot (those with the longest reading time, which were also the ones with the biggest SD values) skewness decreased to 0.003, in effect 0. The new reading time distribution essentially does not differ at all from a standard normal distribution (μ = 0). An additional 19 sentences were excluded based on subjective scoring of <3 for context appropriateness. 2) children 74 selected sentences were pilot tested in 2 groups of 20 children each (aged 8 years, 20 males). Mean reading speed and SD values were calculated for each sentence. Sentences read at minimum or maximum speed (those below 10th or above 90th percentile), and sentences with the highest SDs (above 90th percentile) were excluded. A few more sentences were excluded based on the repeatability of errors due to difficulties in pronunciation, text flow or misleading contextual cues. Of note is the fact that several sentences highly scored by the adult group were excluded due to consistent errors made by the children. iii) Chart creation and validation 10 The 57 remaining sentences were distributed for printout into three versions of the MNREAD-GR chart (19 sentences each). Three sentences with an interesting content were chosen for the top of each chart, so as to draw the attention and facilitate cooperation when using the chart on children (Figure 3). Sentences with reading speed values and SDs close to the mean were first distributed randomly in the three charts, and the remaining sentences were then distributed in the three charts, also randomly. Finally, the sentences within each chart were also placed in random order. The three MNREAD-GR charts were validated by testing on 20 normal-sighted adults (aged 21-60 years, mean 35.4, SD 9.7 years, 9 males). The mean measured near visual acuity of the 20 adults was 0.03 (SD 0.06), their mean maximum reading speed (MRS) was 198.10 wpm (SD 30.93), and mean critical print size (CPS) was 0.09 (SD 0.10).For near visual acuity and maximum reading speed the subject (between-subjects component) contributed the major part to the variance (72% and 87%, respectively), hence the ICC was 0.72 and 0.87 in the total group (Table 3). For the CPS, the subject accounted for 45.5% of the total variance (ICC 0.46). The between-charts within-session within-subject component accounted for maximally 5% of the variance. The between-sessions within-subject component had a maximum of 1%. SEM without session and SEM results were similar because the session variability was negligible, this also resulted to similar reproducibility and repeatability coefficients.The coefficient of repeatability was 0.08 logMAR for VA, 46.96 words per minute for MRS, and 0.10 logMAR for CPS. DISCUSSION Testing near vision has been somewhat under-represented in most major studies aiming to assess treatment effects in ocular diseases; this may well reflect the fact that no 11 near vision optotype has been as widely used as the ETDRS (Early Treatment for Diabetic Retinopathy Study) optotype used for distance acuity measure. In the quest of a standardised near vision test in Greek, a choice was made to develop and validate the MNread chart in the Greek language, according to the design principles of the prototype. This near vision test presents major advantages, such as assessing acuity in a logMAR scale, with a wide range of acuities (between logMAR 1.3 and -0.5), and in a crowded fashion, as well as allowing the measurement of reading speed and critical print size. So far, MNREAD charts have been developed in languages other than English, reflecting the need for such a test in the international scientific community. The task of developing the charts in a different language is far more complicated than translating phrases. Particularities of Greek characters, grammar and syntax, were taken into account so that the sentences would reflect everyday reading needs and so that all principles of construction of the original were met. Additionally, composition of candidate sentences adapted for all ages and pilot testing in both adults and children made the test appropriate for using in both populations. However, further work is needed to determine repeatability in children. Finally, the development of three equivalent versions of the chart provides the possibility for testing e.g. binocular, right eye, and left eye visual performance in one session. All three versions of the charts were proven to be reproducible, given the negligible between-sessions, as well as between-charts, variability. They were shown to be very reliable for measuring near visual acuity (VA) and maximum reading speed (MRS) (ICC 0.72 and 0.87 respectively), and less so for measuring critical print size (CPS) (ICC 0.46). The ICC of the CPS in the present study is almost half of that reported by Maaijwee et al. (0.91)21, but comparable to that of Burggraaff et. al (0.39 to 0.62)23 and Stifter et al. (interchart reliability 0.47 to 0.79 and test-retest reliability 0.39 to 0.71)22. The CPS is not an objective measurement such as the near acuity and the reading speed. It necessarily depends on the examiner’s subjective evaluation and this fact probably contributes to the 12 high unidentified sources of variability22,23. However, the coefficient of repeatability of CPS in our study (0.10 log MAR) was similar to that reported by Subramanian et al. (0.12 logMAR)15who also tested normal-sighted adults, whereas it was higher in subjects with impaired vision (in the study by Burggraaf et al. 0.44 logMAR23, in Patel et al. 0.55 logMAR27) The subject component accounted for the major part of the variance, indicating that the charts accurately depict the personal performance of a tested individual. The developed charts can therefore be regarded as standardized and usable in the same way as the prototype, giving the possibility for direct comparison of one’s practice or research with findings in internationally produced studies. The range of applications in Greek-speaking literate subjects of all ages is obviously very wide, for both clinical and research purposes. Acknowledgement We would like to especially thank Professor Gordon E. Legge and Professor J. Steven Mansfield for their precious advice and support in the current study. 13 REFERENCES 1. Chia EM, Wang JJ, Rochtchina E, Smith W, Cumming RR, Mitchell P. Impact of bilateral visual impairment on health-related quality of life: the Blue Mountains Eye Study. Invest Ophthalmol Vis Sci 2004;45:71-6. 2. Whittaker SG, Lovie-Kitchin J. Visual requirements for reading. Optom Vis Sci. 1993;70(1):54-65. 3. Han Y, Ciuffreda KJ, Kapoor N. Reading-related oculomotor testing and training protocols for acquired brain injury in humans. Brain Res Brain Res Protoc. 2004;14(1):1-12. 4. Elliott DB, Patel B, Whitaker D. Development of a reading speed test for potential-vision measurements. Invest Ophthalmol Vis Sci. 2001;42(8):1945-9. 5. Pesudovs KP, Patel B, Bradbury JA, Elliott DB. Reading speed test for potential central vision measurement. Clin Exp Ophthalmol 2002;30:183-186. 6. Mansfield JS, Legge GE. (2007). The MNREAD Acuity Chart. in Legge GE. "The Psychophysics of Reading in Normal and Low Vision", Mahwah, NJ & London, Lawrence Erlbaum Associates, 2007. 7. Mansfield JS, Legge GE, Bane MC. Psychophysics of reading. 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Pelli DG, Tillman KA, Freeman J, Su M, Berger TD, Majaj NJ. Crowding and eccentricity determine reading rate. J Vis. 2007 Oct 26;7(2):20.1-36. 14. Virgili G, Cordaro C, Bigoni A, Crovato S, Cecchini P, Menchini U. Reading Acuity in Children: Evaluation and Reliability Using MNREAD Charts. Invest Ophthalmol Vis Sci. 2004;45:3349-3354. 15. Subramanian A, Pardhan S. Repeatability of reading ability indices in subjects with impaired vision. Invest Ophthalmol Vis Sci. 2009;50:3643-7. 16. Fujikado T, Asonuma S, Ohji M, Kusaka S, Hayashi A, Ikuno Y, Kamei M, Oda K, Tano Y. Reading ability after macular translocation surgery with 360-degree retinotomy. Am J Ophthalmol. 2002;134(6):849-56. 17. Bohórquez V, Alarcon R. Long-term reading performance in patients with bilateral dualoptic accommodating intraocular lenses. J Cataract Refract Surg. 2010;36(11):1880-6. 18. Calabrèse A, Bernard JB, Hoffart L, Faure G, Barouch F, Conrath J, Castet E. Wet versus dry age-related macular degeneration in patients with central field loss: different effects on maximum reading speed. Invest Ophthalmol Vis Sci. 2011 14;52(5):2417-24. 19. Castro CT, Kallie CS, Salomão SR. Development and validation of the MNREAD reading acuity chart in Portuguese. Arq Bras Oftalmol. 2005;68(6):777-83. 20. http://gandalf.psych.umn.edu/groups/gellab/MNREAD/MNREAD2000/mntest.html, and http://legge.psych.umn.edu/mnread/index.html, 21. Maaijwee KJM, Mulder P, 15 Radner W, Van Meurs JC. Reliability testing of the Dutch version of the Radner Reading Charts. Optom Vis Sci 2008;85:353–358. 22. Stifter E, Konig F, Lang T, Bauer P, Richter-Muesck S, Velikay-Parel M, Radner W. Reliability of a standardized reading chart system: variance component analysis, test-retest and inter-chart reliability. Graefes Arch Clin Exp Ophthalmol 2004;242:31–39. 23. Burggraaff MC, van Nispen RMA, Hoek S, Knol DL, van Rens GHMB. Feasibility of the Radner reading charts in low-vision patients. Graefes Arch Clin Exp Ophthalmol 2010;248:1631–1637. 24. Bland JM, Altman DG. Measuring agreement in method comparison studies. Stat Methods Med Res 1999; 8:135-160. 25. Bland JM, Altman DG. Statistical methods for assessing agreement between two methods of clinical measurement. Lancet 1986;1: 307–10. 26. Simon Singh. The Code Book, published in 1999. Translated in Greek in 2001 by Kyriazopoulos Nasos, Ed. Traylos P. 27. Patel PJ, Chen FK, Da Cruz L, Rubin GS, Tufail A. Test-retest variability of Reading performance metrics using MNREAD in patients with age-related macular degeneration. Invest Ophthalmol Vis Sci 2011;52:3854-3859. 16 Table 1. Summary of MNread chart design principles10,20 1) Text passages closely resemble normal everyday reading, vocabulary and grammar are adapted for all reading ages 2) Each sentence has the same number of characters (60 per sentence, i.e. 10 standard-length words) and the same spatial layout (displayed on 3 lines, total padding <0.5 mean character widths to ensure uniformity of word-to-word spacing) 3) Print size is defined by the height of a lowercase letter that has no ascenders or descenders, so that it subtends 5' at a viewing distance of 40cm. The greek letter “ο”, was used. 4) Print sizes from logMAR –0.5 to 1.3, at 0.1 logMAR steps, (corresponding to Snellen 20/6.3 to 20/400) when viewed from a reading distance of 40 cm 5) Crowding Effect: Vertical distance between sentences = 5 x point print size of the next sentence 6) Typographic concern: photo typesetting method with a resolution of 3600 dots/inch, high luminance contrast (>85%), normal contrast polarity (black letters on white background), printed on a matte surface (like newspaper). 7) Typeface commonly used in everyday printed material such as books, magazines, and newspapers. Times New Roman was chosen. 8) Text: accents on letters were used where they naturally occur in text, vocabulary selected from high-frequency words in reading material for 8-year-old children, declarative sentences, independent from each other in their semantic content Table 2. Frequency of use for each Greek character in the Greek language26 Letter Frequency (%) Letter Frequency (%) A 12 Λ 3.3 O 9.8 Η 2.9 T 9.1 Γ 2 E 8 Δ 1.7 N 7.9 Ω 1.6 I 7.8 Χ 1.4 Π 5.024 Θ 1.3 Ρ 5.009 Φ 1.2 Σ 4.9 Β 0.8 Μ 4.4 Ξ 0.6 Υ 4.3 Ζ 0.5 Κ 4.2 Ψ 0.2 17 Table 3. Data on the inter-chart and test-retest results Variable SD Variability SEM Reproducibility SEM Repeatability without %subject %session %chart %error VA 0.06 session 72.02 0.77 0.70 26.51 0.03 Average 31.52 87.03 0.00 0.00 12.97 0.00 4.95 49.51 0.08 0.03 0.08 16.95 46.96 16.95 46.96 0.04 0.04 0.10 MRS (wpm) CPS 0.09 45.53 0.10 VA: Visual acuity for near (log MAR), MRS: Maximum reading speed, wpm: words per minute, CPS: critical print size. The standard deviation (SD) is the square root of the total variance (sum of subject, session, chart and error variance); the variability (% of total variance) being introduced by each parameter: the individual subject, the reading chart (three charts per session), session (two sessions) and unidentified sources (error); the standard error of measurement (SEM) equals the within-patient SD, defined as the square root of the sum of the within-patient variance components due to session, chart and error; the reproducibility is defined as 1.96√2=2.77 times the SEM, which is the maximum absolute within-patient difference due to chance (“limits of agreement”); the repeatability is the same as the reproducibility with exclusion of the session component in the SEM (SEM without session)21-23 18 Figure 1. Screenshot of the adapted for the Greek language MN-test program Figure 2. Mean reading time of candidate sentences when tested on adults. Figure 3. One of the produced versions of the MNREAD-GR (front and back surface)