Influencing Factors
- Central corneal thickness (CCT)
The thickness of the cornea affects most non-invasive methods by varying resistance to the tonometer probe. A thick cornea gives rise to a greater probability of an IOP being overestimated (and a thin cornea of an IOP being underestimated), but the extent of measurement error in individual patients cannot be ascertained from the CCT alone. The Ocular Response Analyzer and Pascal DCT Tonometers are less affected by CCT than the Goldmann tonometer. Conversely, non-contact and rebound tonometers are more affected. Corneal thickness varies among individuals as well as with age and race. It is reduced in certain disease and following LASIK surgery.
Read more about this topic: Ocular Tonometry
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