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Comparison of an Italian Chart with an Iranian Chart in Visual Acuity Measurement

Haleh Kangari, Alireza Akbarzadeh Bagheban, Atiyeh Khomamizadeh, Saeed Rahmani




Background: Taking visual acuity is an important part of an eye routine examination. This study was conducted to compare visual acuity measured using an Iranian digital tumbling E chart with visual acuity measured using an Italian digital tumbling E chart as a familiar foreign chart.

Materials and Methods: This study was carried out on 200 participants (400 eyes; healthy n=40, glaucoma n=40, retinal disorders n=40, post lasik n=40, corneal n=40) with mean age 44.28 years. Visual acuity of both eyes of half of the subjects (n=100, n=20 from each group), was first measured using the Italian digital chart and then measured using Iranian digital chart. Visual acuity of the rest of subjects (n=100, n=200 from each group) was first measured using the Iranian digital chart and then measured using the Italian digital chart. Measured visual acuities were recorded in logMAR notation.

Results: The mean of the Iranian and Italian Tumbling E chart is 0.280±0.012 and 0.277±0.012, respectively. Paired t-test used to evaluate the mean difference between two groups (p=0.721) indicated that there was no statistically significant difference between means of the two tests. Spearman correlation coefficient for the results of both tests was 0.942 (p<0.001), which was statistically significant and could be categorized as a strong positive correlation.

Conclusion: The two digital Tumbling E charts acted similarly at different levels of acuity in different disorders. However, the Iranian chart requires a more accurate design for optotypes of the lower acuity lines in order to obtain more accurate measurement of visual acuities in healthy subjects.


Tumbling E chart - Visual acuity – Digital chart


Eskridge JB, Amos JF, Barlett JD. 1st ed Clinical Procedures in optometry. Philadelphia: Lippincott; 1991.p. 20.

Plainis S, Tzatzala P, Orphanos Y, Tsilimbaris MK. A Modified ETDRS Visual Acuity Chart for European-Wide Use. Optometry and vision science. 2007;84:647-53.

Benjamin WJ. Borish IM. Borish’s Clinical Refraction, 2nd ed. Missouri: Butterworth–Heinemann. 2006;217-46.

Visual Acuity measurement Standard. International Council of Ophthalmology.– ICO 1984.

Grosvenor Th. Primary care Optometry. 5th ed. Missouri: Butterworth–Heinemann. 2006;134-35.

Plainis S, Kontadakis G, Feloni E, Giannakopoulou T, Tsilimbaris MK, Pallikaris IG, Moschandreas J. Comparison of visual acuity charts in young adults and patients with diabetic retinopathy. Optom Vis Sci. 2013;90(2):174-8.

Becker R, Teichler G, Gräf M. [Comparison of visual acuity measured using Landolt-C and ETDRS charts in healthy subjects and patients with various eye diseases]. Klin Monbl Augenheilkd. 2011;228(10):864-7.

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 Ophthalmol. 2011;249(4):601-5.

Kaiser PK. Prospective evaluation of visual acuity assessment: a comparison of snellen versus ETDRS charts in clinical practice (An AOS Thesis). Trans Am Ophthalmol Soc. 2009;107:311-24.

Beck RW, Moke PS, Turpin AH, Ferris FL 3rd, SanGiovanni JP, Johnson CA, Birch EE, Chandler DL, Cox TA, Blair RC, Kraker RT. A computerized method of visual acuity testing: adaptation of the early treatment of diabetic retinopathy study testing protocol. Am J Ophthalmol. 2003;135(2):194-205.

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 J Ophthalmol. 2003;136(4):662-9.

Bourne RR, Rosser DA, Sukudom P, Dineen B, Laidlaw DA, Johnson GJ, Murdoch IE. Evaluating a new logMAR chart designed to improve visual acuity assessment in population-based surveys. Eye (Lond). 2003;17(6):754-8.

Horiguchi M, Suzuki H, Kojima Y, Shimada Y. New visual acuity chart for patients with macular hole. Invest Ophthalmol Vis Sci. 2001;42(12):2765-8.

Rosser DA, Laidlaw DA, Murdoch IE. The development of a "reduced logMAR" visual acuity chart for use in routine clinical practice. Br J Ophthalmol. 2001;85(4):432-6.

Shah N, Laidlaw DA, Rashid S, Hysi P.Validation of printed and computerised crowded Kay picture logMAR tests against gold standard ETDRS acuity test chart measurements in adult and amblyopic paediatric subjects. Eye (Lond). 2012;26(4):593-600.

Varadharajan S, Srinivasan K, Kumaresan B. Construction and validation of a Tamil logMAR chart. Ophthalmic Physiol Opt. 2009;29(5):526-534.

DOI: https://doi.org/10.22037/nbm.v3i1.6595