Glaucoma and Neurodegeneration

Patient-Centered Outcomes in Severe Peripheral Field Loss 

Vision rehabilitation may improve patients’ quality-of-life functional abilities through the use of assistive devices and educational strategies. However, the effectiveness of rehabilitation options for patients with peripheral vision loss is poorly known since most prior research has focused on patients with central vision loss. In order to evaluate and compare the effectiveness of low vision rehabilitation strategies for patients with peripheral vision loss, a valid and reliable method for measuring vision-dependent functioning is needed. The proposed research will use the insights of patients with glaucoma and retinal dystrophy, their caregivers and their vision care providers to develop a patient-reported outcome measure that assesses functioning in patients with severe peripheral vision loss. Our ultimate goal is to use this outcome measure in future work to determine the effectiveness of low vision services, rehabilitation strategies and models of care delivery. 

Grant Support

NIH/NEI 1K23EY027848
Role: PI
09/01/2017 – 08/31/2022
Addressing Low Vision due to Severe Peripheral Field Loss: Development and Validation of a Patient-Centered Outcome Measure

Head-Mounted Display Technology in Low Vision 

Few interventions exist to improve the vision-dependent functioning of patients with severe peripheral vision loss. For this reason, our team is exploring the potential benefits of head-mounted display technology for this low vision population. We are examining the effect of this technology on a host of clinical, gait, mobility and quality-of-life outcomes. We are also working to optimize this technology so that it will best meet the needs of our patients. 

Grant Support

Michigan Institute for Clinical and health Research
Role: PI
12/1/2016-11/30/2017
Optical Head-Mounted Display Technology for Low Vision Rehabilitation

Aging with Vision Impairment 

As we confront an aging population, the prevalence of vision impairment (VI) will continue to increase. We are interested in understanding the relationship between VI and physical problems such as frailty and falls; socioemotional problems like isolation and decreased quality-of-life; and functional impairment. To understand these issues, our team is using an array of health services research methodologies, ranging from big data to survey research to qualitative interviews. Our hope is that the insights we gain will allow us to address specific barriers to eye care among older adults and to better deliver patient-centered care that meets the needs of an aging population.

Alpha-crystallin proteins are chaperone proteins that we and others have shown to be protective in multiple conditions, including neurodegenerative disorders. Using a combination of transgenic mice lacking those proteins, and viral vectors inducing specific overexpression in specific cell types of the retina, we are characterizing the implication and role of alphaA- and alphaB-crystallin proteins in multiple retinal neurodegenerative disorders. Using cell models, both cell lines and primary cells, we are dissecting the molecular mechanisms of the protective role of alpha-crystallins in retinal neurons as well as glial cells as we demonstrated that they are expressed in both cell-types. 

In treating patients who have glaucomatous damage that is progressing despite low intraocular pressure (IOP) and intensive therapy with medications, it is possible to achieve an even lower and more steady IOP utilizing an incisional surgical procedure.  With several decades of follow-up of a cohort of patients who underwent thermal sclerostomy, our research is studying the outcomes of this procedure in achieving low IOP and preserving vision. In addition, we are studying the short and long term complications of the procedure.

Using the extensive data collected from 607 participants in the Collaborative Initial Glaucoma Treatment Study, we are addressing three aims that deal with the impact of glaucoma and its treatment on how well the person rather than the eye functions, as follows: (1) To evaluate depression in newly diagnosed glaucoma patients from diagnosis through 9 years of follow-up with respect to prevalence and predictors of depression. (2) To explore the relationship of visual function measures assessed binocularly with methods used to combine monocular visual function measures to represent binocular visual function. (3) To relate reported ocular and systemic symptoms to both (a) specific medical treatments and (b) commonly used combinations of treatments over time.

This project is supported by a grant from the NIH National Eye Institute (R21EY025719), and includes co-investigators Drs. Brenda Gillespie, Nancy Janz, and Paul Lichter, and biostatistician Leslie Niziol.

The Xu lab is investigating on the roles of aqueous humor outflow pathways in glaucoma by mapping the mechanical properties of individual tissue components in the eye.