Author Contributions: Dr de Jong had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.
Study concept and design: Klaver, Hofman, de Jong.
Acquisition of data: van Leeuwen, Boekhoorn, Vingerling, Witteman, Klaver.
Analysis and interpretation of data: van Leeuwen, Boekhoorn, Vingerling, Witteman, Klaver, Hofman, de Jong.
Drafting of the manuscript: van Leeuwen, Klaver.
Critical revision of the manuscript for important intellectual content: Boekhoorn, Vingerling, Witteman, Klaver, Hofman, de Jong.
Statistical analysis: van Leeuwen, Boekhoorn, Klaver.
Obtained funding: Hofman, de Jong.
Study supervision: Vingerling, Witteman, Klaver, Hofman, de Jong.
Financial Disclosures: None reported.
Funding/Support: This study was supported by unrestricted grants from the following organizations: Netherlands Organization for Scientific Research, the Hague; Optimix, Amsterdam; Physico Therapeutic Institute, Rotterdam; Blindenpenning, Amsterdam; Sint Laurens Institute, Rotterdam; Bevordering van Volkskracht, Rotterdam; Blindenhulp, the Hague; Rotterdamse Blindenbelangen Association, Rotterdam; Oogheelkundige Ondersteuning, the Hague; kfHein, Utrecht; Ooglijders, Rotterdam; Prins Bernhard Cultuurfonds, Amsterdam; Van Leeuwen Van Lignac, Rotterdam; Verhagen, Rotterdam; General Netherlands Society for the Prevention of Blindness, Doorn; Landelijke Stichting voor Blinden en Slechtzienden, Utrecht; and Elise Mathilde, Maarn. An unrestricted grant was obtained from Topcon Europe BV, Capelle aan de IJssel.
Role of the Sponsors: The study's sponsors had no role in the design and conduct of the study; in the collection, analysis, and interpretation of the data; or in the preparation, review, and approval of the manuscript.
Acknowledgment: We thank Astrid E. Fletcher, PhD, London School of Hygiene and Tropical Medicine, University of London, and Edwin M. Stone, MD, PhD, Department of Ophthalmology and Visual Sciences, University of Iowa, for their critical and valuable comments.