Vol 5 (2020): Continuous Publishing
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Published online: 2020-07-09

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Comparison between traditional and electronic ETDRS charts

Claudio Campa1
Ophthalmol J 2020;5:46-50.


Background: The aim of the study was to compare the visual acuity (VA) score obtained in both normal subjects and patients with different eye diseases by using TOPCON CP-22 electronic ETDRS charts (i.e. E-ETDRS) and standard ETDRS charts (S-ETDRS).

Material and methods: The primary outcome of this observational prospective study was the difference in median VA score (in letters) recorded in 60 patients by using both E-ETDRS and S-ETDRS. There were 60 subjects enrolled in the study: 20 normal, 20 with diabetic retinopathy and 20 with age-related macular degeneration.

Results: Median number of letters read was 72.5 S-ETDR and 77 for E-ETDR (p < 0.01). A subgroup analysis disclosed that the difference in VA score between the 2 devices was more pronounced (p < 0.01) when considering healthy subjects compared to patients affected by diabetic retinopathy (p = 0.02) or age-related macular degeneration (p = 0.04).

Conclusions: Small but significant discrepancies between the 2 devices have been detected, especially when recording high VA values.

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