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. Author manuscript; available in PMC: 2010 Jul 1.
Published in final edited form as: Ophthalmology. 2009 May 8;116(7):1397–1401. doi: 10.1016/j.ophtha.2009.01.019

Table 1.

Mean and standard deviation (SD) of the logarithm of the minimum angle of resolution (logMAR) recognition visual acuity and Snellen equivalent for testing with Early Treatment Diabetic Retinopathy Study (ETDRS) charts in the present study. Subjects were emmetropic children who had ≤ 0.25 diopter (D) of myopia (spherical equivalent), ≤ 1.00 D of hyperopia (spherical equivalent) and ≤ 0.50 D cylinder in both eyes.

5 to <6 yrs n=27 6 to <7 yrs n=28 7 to <8 yrs n=35 8 to <9 yrs n=25 9 to < yrs 10 n=28 10 to <11 yrs n=50 11 to <12 yrs n=39 12 to <13 yrs n=20
Present Mean 0.16 0.09 0.06 0.03 −0.01 0.05 0.04 −0.00
Study SD 0.10 0.08 0.10 0.08 0.08 0.19 0.13 0.18
(letter by letter scoring*) Snellen equivalent [20/29] [20/25] [20/23] [20/21] [20/20] [20/22] [20/22] [20/20]
Present Mean 0.13 0.07 0.04 0.01 −0.05 0.02 0.00 −0.02
Study SD 0.11 0.08 0.10 0.09 0.08 0.20 0.13 0.19
(line by line scoring**) Snellen equivalent [20/27] [20/24] [20/22] [20/20] [20/18] [20/21] [20/20] [20/19]
*

letter by letter scoring – based on number of letters correctly identified

**

line by line scoring – based on smallest line on which child identified at least 3 letters correctly