Objectively measured limitations in daytime activity levels appear to be inextricably linked with sleep disturbances in retinitis pigmentosa (RP) patients, as well as associated with unemployment status and central vision loss. Innovative interventional strategies should be developed to help improve these issues and overall quality of life for RP patients.
Novel sensor devices are emerging as valuable tools to objectively assess behavior. We used validated measures of wrist accelerometry to determine relationships between sleep, vision, and physical activity in RP subjects.
For one week, 33 RP adults wore a wrist Actiwatch to detect movement during the day (average total activity counts) and disturbed sleep at night. They completed Early Treatment Diabetic Retinopathy Study visual acuity testing, Pelli-Robson contrast sensitivity, Goldmann V4e visual fields, and sleep diaries and validated questionnaires to assess their sleep and general health.
Greater wake after sleep onset time measured with actigraphy (i.e., sleep disruption) (P = .01), loss of visual acuity (P = .009), and nonemployment/student status (P = .002) were all significant predictors of reduced daytime average total activity counts in a multiple linear regression model, after adjusting for contrast sensitivity as a cooperative suppressor variable (P = .01) (R 2 = 0.54). Fragmentation measured with actigraphy (i.e., restlessness during sleep) (P = .07) and decreased sleep quality ratings reported upon awakening by the participants in a sleep diary (P = .06) were each marginally associated with reduced daytime average total activity counts, whereas nonemployment/student status, reduced visual acuity, and contrast sensitivity were still significant predictors. Objective and subjective measures of sleep or daytime activity were not statistically significantly correlated (P > .05).
We find nonemployment/student status and sleep disturbances appear to be related to reduced daytime activity levels in adults with central vision loss due to RP. These findings underscore the importance of developing and evaluating interventions to help RP patients maintain engagement in productive activities and improve their disturbed sleep.
1College of Optometry, Nova Southeastern University, Ft. Lauderdale, Florida
2Wilmer Eye Institute, Johns Hopkins University, Baltimore, Maryland
3Department of Psychiatry and Behavioral Sciences, Johns Hopkins University, Baltimore, Maryland
4College of Osteopathic Medicine, Nova Southeastern University, Ft. Lauderdale, Florida *firstname.lastname@example.org
Submitted: December 31, 2017
Accepted: May 7, 2018
Funding/Support: National Eye Institute (K23 EY018356; to AKB).
Conflict of Interest Disclosure: None of the authors have reported a financial conflict of interest in connection with the work.
Author Contributions and Acknowledgments: Conceptualization: AKB, JAH, MTS; Data Curation: AKB; Formal Analysis: AKB; Funding Acquisition: AKB; Investigation: AKB; Methodology: AKB, JAH, MTS; Project Administration: AKB; Resources: MTS; Software: MTS; Supervision: JAH, MTS; Visualization: AKB, JAH, CP, MTS; Writing – Original Draft: AKB, CP; Writing – Review & Editing: JAH, MTS.
The authors thank Erin McInrue for her assistance with the analysis of the actigraphy data.