Repeated Measures of Intraocular Pressure Result in Higher Heritability and Greater Power in Genetic Linkage Studies
Francis Carbonaro, Toby Andrew, David A Mackey, Terri L Young, Tim D Spector, Christopher J Hammond
INVESTIGATIVE OPHTHALMOLOGY & VISUAL SCIENCE | ASSOC RESEARCH VISION OPHTHALMOLOGY INC | Published : 2009
PURPOSE: To analyze the effect of using one reading, the mean of two readings (from the same eye), or the mean of four readings (two from each eye) on the heritability estimates of intraocular pressure (IOP). This was a cohort study in which 344 pairs of twins, 163 monozygotic (MZ) and 181 dizygotic (DZ), were enrolled. METHODS: IOP was measured using three tonometers: the gold standard Goldmann applanation tonometer (GAT), the Ocular Response Analyzer (ORA; Reichert Buffalo, NY), and the Dynamic Contour Tonometer (DCT, Pascal; Swiss Microtechnology AG, Port, Switzerland). The main outcome measure was the heritability of IOP correlated with the number of measurements. RESULTS: The mean IOPs ..View full abstract
Awarded by National Institutes of Health
Awarded by NATIONAL EYE INSTITUTE
Supported by National Institutes of Health Grant R01EY018246 (TLY, CJH, DAM). CJH is also supported by a Senior Research Fellowship issued by the National Institute for Health Research (NIHR). The views expressed in this publication are those of the authors and not necessarily those of the National Health Service, the NIHR, or the Department of Health.