Patient-centred outcomes of cataract surgery in Australia.

Pager et al. should be commended for attempting the challenging global cataract surgery outcome study reported in the August issue of Clinical and Experimental Ophthalmology . 1 The inclusion of visual disability, quality of life and satisfaction measures is an important approach that, as the authors state, has rarely been made. Patientcentred measures are needed where impairment is not fully captured by clinical measures. High contrast visual acuity (VA) may fail to fully characterize visual impairment because it is relatively insensitive to optical degradation due to cataract. 2,3 However, the validity of VA as an outcome measure depends upon methodology; detection of change depends upon retest reliability. Factors affecting the retest reliability of VA include chart type (Snellen, logMAR), scoring system (by-line, by-letter), forced-choice testing and endpoint criterion. 4