Abstract
Purpose: :
To validate a French version of the SKREAD test, developed by D. Fletcher (Smith Kettlewell Eye Research Institute) to test French speaking patients with central vision loss and reading difficulties. SKREAD utilizes non contextual, ambiguous words. This design induces confusions and facilitates the verbalization of mistake during reading with scotoma. The pattern of verbalized mistake can help to differentiate left or right sided scotoma interference.
Methods: :
We developed a French version of the SKREAD test (acuity reading test). It contains 16 blocks of 60 characters each per text size block (single letters and words). 59 patients (61 eyes), aged 68.6±19, with AMD and 10 control subjects, aged 70±8.6, were enrolled in the study. Monocular scotoma size (deg2) and PRL location were measured by microperimeter (MP1) Nidek© in all patients. ETDRS (VA), Mars Perceptrix Contrast Sensitivity test (CS), MNREAD and our new test were administered to all participants (monocular assessment). Mean number of mistake per text (MMT) in both our test and MNREAD and types of mistakes (TM) (left, right or mixed errors in the word) in both groups were recorded. A matching coefficient (%) between TM and PRL location with MP-1 was calculated.
Results: :
Mean AV were respectively 0.04±0.02 logMar and 0.78±0,28 logMar for control subjects and patients with central scotoma. For normal subjects, MMT was respectively 0.07±0.07 and 0.37±0.21 mistakes for MNREAD and SKREAD test. For patients with central scotoma, MMT increased significantly with SKREAD test (3.1±1.67) against MNREAD test (0.79±0.77). MMT was independent of VA, CS or scotoma size in AMD group. Distributions of PRL (MP1-data) were respectively 43%, 21% and 36% for central, vertical and horizontal fixations. In 70% of our cases, the types of mistake made on SKREAD was in accordance with the location of the PRL developed by the patients.
Conclusions: :
This study validated the French version of SKREAD. This test can identify the presence of central scotoma through reading errors. It allows localization of the relative position of scotoma in relation to the fixation area used for reading. In 70 % of the patients the pattern of error in the new test confirms the fixation area that was found with MP1
Keywords: low vision • age-related macular degeneration • reading