Psychometrics

Research by its developers showed that the MLVAI demonstrated good internal reliability with a Cronbach’s alpha of 0.96, and an intra-class correlation coefficient of 0.95 for overall reliability (Haymes et al., 2001b). The Spearman’s correlation coefficient for test–retest reliability was 0.94 and the inter-rater reliability was 0.90 or higher for 10 practitioners (Haymes et al., 2001b). Overall, there was a moderately high correlation with vision impairment (r = –0.68); however, when each section of the test was examined individually it was determined to be r = –0.80 for part A visual acuity and r = -0.49 for part B basic self-care ADLs, suggesting that the MLVAI is a valid instrument for detecting the effects of low-vision on occupational performance (Haymes et al., 2001b). A second study also by its creators found that age, near word acuity, results of an administered Melbourne Edge Test, contrast sensitivity, and visual field accounted for 82.2% of the variance of MLVAI total scores, thus validating the content of the exam (Haymes et al., 2002). A subsequent study of a modified version was evaluated, which entails weighting each item (ADL) by importance to the person being tested along a 5-level scale from 0 to 4 where the study of 97 subjects indicated an internal reliability of 0.94 (Haymes et al., 2001b). Further results determined a strong correlation with near-word acuity at 0.78, followed by Melbourne Edge Test contrast sensitivity at –0.72, and visual field at –0.52 (Haymes et al., 2001a).

Advantages

The MLVAI is unique in that it is an ADL/vision-specific assessment, thus making it relevant to the occupational therapy profession. Also, there is potential for the interested researcher to use the MLVAI in future validation studies due to the limited amount of research in support of its clinical use.

Disadvantages

There is an insufficient amount of research pertaining to the MLVAI outside of that involving its creators, as well as a lack of comparison with other gold standard assessments to adequately establish its content validity as an effective measure of the low-vision panacea. Thus, its author suggests that items on the assessment should be used and adapted as necessary during the development of the client’s occupational profile.

Administration

In part A (16 items) the clinician observes and rates client functional performance along a 5-point scale (0 to 4) where examples include telling time with a wrist watch, using a telephone book, reading newspaper print, reading a medicine label, reading a digital display, and recognizing faces, which are scored as (0) very unsatisfactory, (1) unsatisfactory, (2) borderline, (3) satisfactory, or (4) very satisfactory. In part B the client subjectively rates their performance across 9 tasks/items. The maximum possible score of the MLVAI is 100.