Preliminary Evaluation of Two Digital Image Processing Strategies for Head-Mounted Magnification for Low Vision Patients.

Purpose: In an observational clinical outcome study, we tested the effectiveness and use of the combination of two innovative approaches to magnification: a virtual bioptic telescope and a virtual projection screen, implemented with digital image processing in a head-mounted display (HMD) equipped with a high-resolution video camera and head trackers.

Methods: We recruited 30 participants with best-corrected visual acuity <20/100 in the better-seeing eye and bilateral central scotomas. Participants were trained on the HMD system, then completed a 7- to 10-day in-home trial.

Clinically Meaningful Rehabilitation Outcomes of Low Vision Patients Served by Outpatient Clinical Centers.

Importance: To facilitate comparative clinical outcome research in low vision rehabilitation, we must use patient-centered measurements that reflect clinically meaningful changes in visual ability.

Objective: To quantify the effects of currently provided low vision rehabilitation (LVR) on patients who present for outpatient LVR services in the United States.

Design, Setting, And Participants: Prospective, observational study of new patients seeking outpatient LVR services.

Visual ability of patients seeking outpatient low vision services in the United States.

Importance: Most patients with low vision are elderly and have functional limitations from other health problems that could add to the functional limitations caused by their visual impairments.

Objective: To identify factors that contribute to visual ability measures in patients who present for outpatient low vision rehabilitation (LVR) services.

Design, Setting, And Participants: As part of a prospective, observational study of new patients seeking outpatient LVR, 779 patients from 28 clinical centers in the United States were enrolled in the Low Vision Rehabilitation Outcomes Study (LVROS) from April 25, 2008, through May 2, 2011.

Baseline traits of low vision patients served by private outpatient clinical centers in the United States.

Objective: To characterize the traits of low vision patients who seek outpatient low vision rehabilitation (LVR) services in the United States.

Methods: In a prospective observational study, we enrolled 764 new low vision patients seeking outpatient LVR services from 28 clinical centers in the United States. Before their initial appointment, multiple questionnaires assessing daily living and vision, physical, psychological, and cognitive health states were administered by telephone.

Self-reported importance and difficulty of driving in a low-vision clinic population.

Purpose: To validate estimates of self-perceived driving ability from difficulty ratings of driving tasks and to determine the association of the importance and difficulty of driving with the magnitude of visual impairments.

Methods: A consecutive series of 851 patients at a low-vision clinic rated the importance of driving on a four-point scale. Those who gave nonzero importance ratings then rated driving difficulty on a five-point scale.

The Activity Inventory: an adaptive visual function questionnaire.

Purpose: The Activity Inventory (AI) is an adaptive visual function questionnaire that consists of 459 Tasks nested under 50 Goals that in turn are nested under three Objectives. Visually impaired patients are asked to rate the importance of each Goal, the difficulty of Goals that have at least some importance, and the difficulty of Tasks that serve Goals that have both some importance and some difficulty. Consequently, each patient responds to an individually tailored set of questions that provides both a functional history and the data needed to estimate the patient's visual ability.

Visual disability variables. II: The difficulty of tasks for a sample of low-vision patients.

Objectives: To test the validity and reliability of measures of visual ability and to evaluate the relation between measurements made at the task level and measurements made at the goal level of a hierarchical model for visual disability.

Design: Validation of a telephone-administered functional assessment instrument using Rasch analysis on self-assessment ratings.

Setting: Telephone interviews of respondents in their homes.

Visual disability variables. I: the importance and difficulty of activity goals for a sample of low-vision patients.

Objective: To test the validity and reliability of latent trait measures estimated from ratings by low-vision patients of the importance and difficulty of selected activity goals.

Design: Validation of a telephone-administered functional assessment instrument using Rasch analysis of self-assessment ratings.

Setting: Telephone interviews of respondents in their homes.

Rehabilitation of hospital inpatients with visual impairments and disabilities from systemic illness.

Objectives: To describe the comorbidity of visual impairment and disability among patients hospitalized for systemic illness and to discuss rehabilitation.

Design: Retrospective study.

Setting: Hospital-based, academic tertiary medical center with referring neurology, ophthalmology, and rehabilitation units.