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Published on: April 24, 2020
Heritability of intraocular pressure: a classical twin study
F Carbonaro1, T Andrew, D A Mackey
1Twin Research and Genetic Epidemiology Unit, King's College London School of Medicine, London, UK. francis.carbonaro@kcl.ac.uk
The British Journal of Ophthalmology
|July 26, 2008
Summary
Intraocular pressure (IOP) heritability is significant, with genetic factors explaining a substantial portion of its variation. Different measurement instruments yield varying heritability estimates for IOP.
Area of Science:
- Ophthalmology
- Genetics
- Twin Studies
Background:
- Intraocular pressure (IOP) is a key factor in glaucoma pathogenesis.
- Understanding the heritability of IOP is crucial for identifying genetic predispositions and environmental influences.
Purpose of the Study:
- To estimate the heritability of intraocular pressure (IOP) using a classical twin study design.
- To investigate the influence of different measurement instruments on IOP heritability calculations.
Main Methods:
- Recruited twin pairs from the TwinsUK Adult Twin Registry.
- Measured IOP using Goldmann applanation tonometry (GAT), Ocular Response Analyser (ORA), and Dynamic Contour Tonometer (DCT).
- Employed genetic modeling to compare IOP covariance in monozygotic (MZ) and dizygotic (DZ) twins.
Main Results:
- Analyzed data from 422 twin pairs (211 MZ, 211 DZ).
- Observed significantly higher IOP correlations in MZ twins compared to DZ twins across all instruments (GAT, DCT, ORA).
- Genetic modeling indicated heritability estimates for IOP ranging from 62% (GAT) to 74% (ORA IOPg).
Conclusions:
- Genetic factors play a significant role in determining intraocular pressure.
- The choice of instrument influences IOP heritability estimates, with GAT, DCT, and ORA yielding different genetic contributions (62%, 63%, 74% respectively).
- Environmental factors account for the remaining variation in IOP.
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