Peter N. Rosen

Measuring outcomes of cataract surgery using the Quality of Well-Being Scale and VF-14 Visual Function Index.

Purpose: To evaluate the validity and responsiveness of the self‐administered Quality of Well‐Being Scale (QWB‐SA) and the 14‐item Visual Function Index (VF‐14) to assess patients having cataract surgery. Setting: Large Southern California health maintenance organization. Methods: This study comprised 233 adults who had uneventful small‐incision (<3.0 mm) phacoemulsification cataract extraction under local anesthesia. Patients were assessed before surgery as well as 4 to 6 weeks and 4 months after surgery using the QWB‐SA and the VF‐14. Results: Postoperatively, patients reported significant improvements on QWB‐SA (P<.005) and VF‐14 (P<.001) measures. Those grouped by visual acuity in the operated eye and unoperated eye and first‐eye surgery or second‐eye surgery had significant changes in VF‐14 results (P<.001). Improvements on the QWB‐SA were significant except when the preoperative visual acuity was better than 20/40 in the operated eye or 20/50 in the unoperated eye and when patients had first‐eye surgery. The vision‐specific VF‐14 was more sensitive to improvements after surgery than the more general QWB‐SA. Both demonstrated a greater magnitude of change with lower baseline scores and correlated significantly with self‐reported satisfaction and trouble with vision. Conclusions: Both the utility‐based generic QWB‐SA and disease‐specific VF‐14 profile were responsive to changes in quality of life after cataract surgery. The VF‐14 was more sensitive to change but cannot be used for comparison across disease states or for policy analysis. The QWB‐SA can be used to estimate the cost/utility of cataract surgery.

Association Between Rates of Binocular Visual Field Loss and Vision-Related Quality of Life in Patients With Glaucoma

IMPORTANCE It is reasonable to hypothesize that for 2 patients with similar degrees of integrated binocular visual field (BVF) loss, the patient with a history of faster disease progression will report worse vision-related quality of life (VRQOL) than the patient with slowly progressing damage. However, to our knowledge, this hypothesis has not been investigated in the literature. OBJECTIVE To evaluate the association between binocular rates of visual field change and VRQOL in patients with glaucoma. DESIGN Observational cohort study. SETTING Patients were recruited from the Diagnostic Innovations in Glaucoma Study and the African Descent and Glaucoma Evaluation Study. PARTICIPANTS The study included 796 eyes of 398 patients with diagnosed or suspected glaucoma followed up from October 1, 1998, until January 31, 2012, for a mean (SD) of 7.3 (2.0) years. MAIN OUTCOME MEASURES The VRQOL was evaluated using the 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25) at the last follow-up visit. The NEI VFQ-25 was completed for all patients during the period extending from December 1, 2009, through January 31, 2012. Integrated BVFs were calculated from the monocular fields of each patient. Linear regression of mean deviation values was used to evaluate rates of BVF change during the follow-up period. Logistic regression models were used to investigate the association between abnormal VRQOL and rates of BVF change, while adjusting for potentially confounding socioeconomic and demographic variables. RESULTS Thirty-two patients (8.0%) had abnormal VRQOL as determined by the results of the NEI VFQ-25. Patients with abnormal VRQOL had significantly faster rates of BVF change than those with normal VRQOL (-0.18 vs -0.06 dB/y; P < .001). Rates of BVF change were significantly associated with abnormality in VRQOL (odds ratio = 1.31 per 0.1 dB/y faster; P = .04), after adjustment for confounding variables. CONCLUSIONS AND RELEVANCE Patients with faster rates of BVF change were at higher risk of reporting abnormal VRQOL. Assessment of rates of BVF change may provide useful information in determining risk of functional impairment in glaucoma.

Association Between Progressive Retinal Nerve Fiber Layer Loss and Longitudinal Change in Quality of Life in Glaucoma

IMPORTANCE Evaluation of structural optic nerve damage is a fundamental part of diagnosis and management of glaucoma. However, the relationship between structural measurements and disability associated with the disease is not well characterized. Quantification of this relationship may help validate structural measurements as markers directly relevant to quality of life. OBJECTIVE To evaluate the relationship between rates of retinal nerve fiber layer (RNFL) loss and longitudinal changes in quality of life in glaucoma. DESIGN, SETTING, AND PARTICIPANTS Observational cohort study including 260 eyes of 130 patients with glaucoma followed up for a mean (SD) of 3.5 (0.7) years. All patients had repeatable visual field defects on standard automated perimetry (SAP) at baseline. The 25-item National Eye Institute Visual Function Questionnaire (NEI VFQ-25) was performed annually, and spectral-domain optical coherence tomography and SAP were performed at 6-month intervals. A joint model was used to investigate the association between change in NEI VFQ-25 Rasch-calibrated scores and change in RNFL thickness, adjusting for confounding socioeconomic and clinical variables. MAIN OUTCOMES AND MEASURES Association between change in binocular RNFL thickness (RNFL thickness in the better eye at each point) and change in NEI VFQ-25 scores. RESULTS Progressive binocular RNFL thickness loss was associated with worsening of NEI VFQ-25 scores over time. In a multivariable model adjusting for baseline disease severity and the rate of change in binocular SAP sensitivity, each 1-μm-per-year loss of RNFL thickness was associated with a decrease of 1.3 units (95% CI, 1.02-1.56) per year in NEI VFQ-25 scores (P < .001). After adjusting for the contribution from SAP, 26% (95% CI, 12%-39%) of the variability of change in NEI VFQ-25 scores was associated uniquely with change in binocular RNFL thickness. The P value remained less than .001 after adjusting for potential confounding factors. CONCLUSIONS AND RELEVANCE Progressive binocular RNFL thickness loss was associated with longitudinal loss in quality of life, even after adjustment for progressive visual field loss. These findings suggest that rates of binocular RNFL change are valid markers for the degree of neural loss in glaucoma with significant relationship to glaucoma-associated disability.

Driving Simulation for Evaluation and Rehabilitation of Driving After Stroke

Driving is an important activity of daily living. Loss of driving privileges can lead to depression, decreased access to medical care, and increased healthcare costs. The ability to drive is often affected after stroke. In approximately 30% of stroke survivors, it is clear from the onset that driving will no longer be possible. Approximately 33% of survivors will be able to return to driving with little or no retraining, and 35% will require driving-related rehabilitation before they can resume safe driving again. The ability to drive is not routinely evaluated after stroke, and there is no established rehabilitation program for poststroke driving. When driving evaluation does occur, it is not always clear which tests are the most salient for accurately assessing poststroke driving ability. Investigators have examined the efficacy of various methodologies to predict driving performance after stroke and have found mixed results, with each method having unique weaknesses, including poor predictive ability, poor face validity, poor sensitivity or specificity, and limited reliability. Here we review common models of driving to gain insight into why single-construct visual or cognitive off-road measures are inadequate for evaluating driving, a complex and dynamic activity that involves timely interaction of multiple motor, visual, cognitive, and perceptual skills. We also examine the potential for driving simulators to overcome the problems currently faced in the evaluation and rehabilitation of driving after stroke. Finally, we offer suggestions for the future direction of simulator-based poststroke driving evaluation and training.

Driving Simulation as a Performance-based Test of Visual Impairment in Glaucoma

The fundamental goal of glaucoma management is to prevent patients from developing visual impairments sufficient to produce disability in their daily lives and impair their quality of life. Ultimately, patients are interested in how their vision will impact their ability to perform daily activities, such as driving. Although technologic advancements such as automated perimetry and devices for optic nerve imaging have resulted in great improvement in our ability to quantify structural and functional damage in glaucoma, the impact on vision-related quality of life of some of the information acquired from these tests remain elusive. In contrast, performance-based measures may be better correlated to traditional measures of vision health and, more importantly, they provide a more direct measure of disability. Driving simulators can be used as a performance-based test for evaluation of functional impairment in glaucoma. Their use can potentially help in the evaluation of driving safety and performance of diseased subjects and provide insight into the different mechanisms involved in causing driving impairment in this disease. The ability to do this in an experimentally controlled and standardized setting enables testing of a much larger number of hypotheses compared with on-road evaluations. Besides evaluating driver fitness, simulators could also potentially be used as a sophisticated test to evaluate cognitive impairment in the context of an everyday task (driving) that has not been available through traditional neuropsychologic assessment.

Glaucomatous Retinal Nerve Fiber Layer Thickness Loss Is Associated With Slower Reaction Times Under a Divided Attention Task

PURPOSE To examine the relationship between glaucomatous structural damage and ability to divide attention during simulated driving. DESIGN Cross-sectional observational study. METHODS SETTING Hamilton Glaucoma Center, University of California San Diego. PATIENT POPULATION Total of 158 subjects from the Diagnostic Innovations in Glaucoma Study, including 82 with glaucoma and 76 similarly aged controls. OBSERVATION PROCEDURE Ability to divide attention was investigated by measuring reaction times to peripheral stimuli (at low, medium, or high contrast) while concomitantly performing a central driving task (car following or curve negotiation). All subjects had standard automated perimetry (SAP) and optical coherence tomography was used to measure retinal nerve fiber layer (RNFL) thickness. Cognitive ability was assessed using the Montreal Cognitive Assessment and subjects completed a driving history questionnaire. MAIN OUTCOME MEASURES Reaction times to the driving simulator divided attention task. RESULTS The mean reaction times to the low-contrast stimulus were 1.05 s and 0.64 s in glaucoma and controls, respectively, during curve negotiation (P < .001), and 1.19 s and 0.77 s (P = .025), respectively, during car following. There was a nonlinear relationship between reaction times and RNFL thickness in the better eye. RNFL thickness remained significantly associated with reaction times even after adjusting for age, SAP mean deviation in the better eye, cognitive ability, and central driving task performance. CONCLUSIONS Although worse SAP sensitivity was associated with worse ability to divide attention, RNFL thickness measurements provided additional information. Information from structural tests may improve our ability to determine which patients are likely to have problems performing daily activities, such as driving.

Predicting Risk of Motor Vehicle Collisions in Patients with Glaucoma: A Longitudinal Study

Purpose To evaluate the ability of longitudinal Useful Field of View (UFOV) and simulated driving measurements to predict future occurrence of motor vehicle collision (MVC) in drivers with glaucoma. Design Prospective observational cohort study. Participants 117 drivers with glaucoma followed for an average of 2.1 ± 0.5 years. Methods All subjects had standard automated perimetry (SAP), UFOV, driving simulator, and cognitive assessment obtained at baseline and every 6 months during follow-up. The driving simulator evaluated reaction times to high and low contrast peripheral divided attention stimuli presented while negotiating a winding country road, with central driving task performance assessed as “curve coherence”. Drivers with MVC during follow-up were identified from Department of Motor Vehicle records. Main Outcome Measures Survival models were used to evaluate the ability of driving simulator and UFOV to predict MVC over time, adjusting for potential confounding factors. Results Mean age at baseline was 64.5 ± 12.6 years. 11 of 117 (9.4%) drivers had a MVC during follow-up. In the multivariable models, low contrast reaction time was significantly predictive of MVC, with a hazard ratio (HR) of 2.19 per 1 SD slower reaction time (95% CI, 1.30 to 3.69; P = 0.003). UFOV divided attention was also significantly predictive of MVC with a HR of 1.98 per 1 SD worse (95% CI, 1.10 to 3.57; P = 0.022). Global SAP visual field indices in the better or worse eye were not predictive of MVC. The longitudinal model including driving simulator performance was a better predictor of MVC compared to UFOV (R2 = 0.41 vs R2 = 0.18). Conclusions Longitudinal divided attention metrics on the UFOV test and during simulated driving were significantly predictive of risk of MVC in glaucoma patients. These findings may help improve the understanding of factors associated with driving impairment related to glaucoma.

United States Version of the Stroke Driver Screening Assessment: A Pilot Study

Abstract Background: Most stroke survivors who resume driving in the United States do so within the first year. More than 87% of these individuals resume driving without a formal evaluation of their fitness to drive because of the absence of standard practices and generally accepted and valid screening tools. The Stroke Driver Screening Assessment (SDSA) is an established battery for predicting stroke survivors’ driving performance but is not currently used in the United States. This pilot study investigated the predictive ability of the US version of the battery in a US-based cohort of stroke survivors. Method: Fifteen first-ever stroke survivors (age, 52±12 years) and 16 healthy adults (age, 40±16 years) were administered the US version of the SDSA in a standardized format. Performance on the SDSA was compared with driving performance in a high-fidelity driving simulator. Results: Stroke and healthy participants’ driving performance was predicted with 87% and 88% accuracy, respectively. Conclusion: The US version of the SDSA battery has the potential to be a good predictor of driving performance of mildly impaired stroke survivors. Larger studies are needed to further establish its predictive accuracy.

A Portable Platform for Evaluation of Visual Performance in Glaucoma Patients

Purpose To propose a new tablet-enabled test for evaluation of visual performance in glaucoma, the PERformance CEntered Portable Test (PERCEPT), and to evaluate its ability to predict history of falls and motor vehicle crashes. Design Cross-sectional study. Methods The study involved 71 patients with glaucomatous visual field defects on standard automated perimetry (SAP) and 59 control subjects. The PERCEPT was based on the concept of increasing visual task difficulty to improve detection of central visual field losses in glaucoma patients. Subjects had to perform a foveal 8-alternative-forced-choice orientation discrimination task, while detecting a simultaneously presented peripheral stimulus within a limited presentation time. Subjects also underwent testing with the Useful Field of View (UFOV) divided attention test. The ability to predict history of motor vehicle crashes and falls was investigated by odds ratios and incident-rate ratios, respectively. Results When adjusted for age, only the PERCEPT processing speed parameter showed significantly larger values in glaucoma compared to controls (difference: 243ms; P<0.001). PERCEPT results had a stronger association with history of motor vehicle crashes and falls than UFOV. Each 1 standard deviation increase in PERCEPT processing speed was associated with an odds ratio of 2.69 (P = 0.003) for predicting history of motor vehicle crashes and with an incident-rate ratio of 1.95 (P = 0.003) for predicting history of falls. Conclusion A portable platform for testing visual function was able to detect functional deficits in glaucoma, and its results were significantly associated with history of involvement in motor vehicle crashes and history of falls.