Abstract
Abstract: :
Purpose: To assess a new clinical research methodology for static and dynamic ground level performance of presbyopic correction. Methods: A series of ground level tasks were developed to establish clinical performance of two progressive addition lens brands (PAL 1 & PAL 2). In addition, high and low contrast LogMAR visual acuity (VA) in down gaze and in peripheral down gaze was assessed at ground level. The ground level tasks included the following subjective assessments: approaching and scanning stairs, walking up and down stairs, walking on and off an evaluated platform simulating a curb, identifying money on the ground, maneuvering through a crowded office space and viewing a vertical display from the ground up. Subjects were fit with spectacles requiring fitting heights between 18 – 22 mm. Results:Thirty seven subjects showed a significant mean monocular VA improvement with PAL 1 in all four conditions ranging from –0.03 to –0.1 LogMAR and a binocular VA improvement in all four conditions ranging from –0.04 to –0.09 LogMAR. PAL 1 was preferred (p<0.05) over PAL 2 in all 6 ground level subjective tasks and overall 5:1 (p<0.05). Conclusions: We have established a protocol that includes a series of tasks that assess ground level performance and visual acuity. The study results show significant differences between two PAL brands. Ground level performance is important to the presbyopic patient’s visual comfort, confidence and mobility while performing ground level tasks. Ground level testing such as described here should be considered when assessing presbyopic correction because of its importance in quality of life and safety in the aged population.
Keywords: clinical research methodology • optical properties • visual acuity