Clinical evaluation of factors affecting soft toric lens orientation.

Purpose: To evaluate the comparative orientation characteristics of currently available silicone hydrogel torics.

Methods: The re-orientation characteristics of four toric lenses were assessed: three prism-ballasted (PB) designs, Purevision Toric (PVT), Air Optix Toric (AOT), Proclear Toric (PCT), and an "Accelerated Stabilization Design" (ASD) ACUVUE ADVANCE for Astigmatism (AAfA). In the first part of the study, the toric lenses were rotated, approximately 45 degrees in the infero-temporal direction and a video recording of lens reorientation was made from which blink-by-blink measurements of lens orientation were taken.

Toric lens orientation and visual acuity in non-standard conditions.

Purpose: To evaluate and compare the effect of gravity and gaze direction on toric lens orientation and visual acuity (VA).

Method: This was a 14 subject, randomised, unmasked, non-dispensing study, relating to the effect of gaze direction and posture on toric lens orientation and VA. Four lens types were assessed: Acuvue Oasys for Astigmatism (AOfA), Purevision Toric (PVT), Air Optix for Astigmatism (AOT) and Proclear Toric (PCT).

Vision and self-reported mobility performance in patients with low vision.

Background: As vision plays a significant role in mobility performance, it is usual to refer low vision patients, particularly those who complain of mobility difficulties, for orientation and mobility (O&M) training to help them maintain safe independent travel. Our study aimed to determine whether there was a relationship between measures of vision and self-reported mobility, and the applicability of a patient-based mobility assessment in patients with heterogeneous causes of visual loss.

Method: We assessed the high and low contrast visual acuity, visual field and scanning ability of 30 patients with low vision.