Purchase this article with an account.
Pouya Alaghband, Evgenia Kanonidou, Laura Beltran-Agullo, Darryl R. Overby, K Sheng Lim; The Relationship between Central Corneal Thickness, Tonographic Outflow Facility, and Intraocular Pressure. Invest. Ophthalmol. Vis. Sci. 2012;53(14):1987.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Central corneal thickness (CCT) is known to be associated with onset and progression of glaucoma and can possibly potentiate the influence of tonographic outflow facility (TOF) that maintain intraocular pressure (IOP). This study investigates the correlation between CCT, TOF and IOP.
This is a retrospective analysis of patients who were recruited in our aqueous studies from 2006-2009 at St Thomas’ Hospital, London, UK. All studies were approved by local ethics committee within hospital.Eighty nine newly diagnosed patients with OHT/POAG attending our department have been offered to have baseline outflow facility measurement as part of their glaucoma investigations since 2006. We identified patients who had reliable baseline outflow facility. There were 34 healthy volunteers as part of these trials as well.Measurements: 1) Outflow facility measured by electronic Schiotz tonometer 2) IOP measured by Goldmann applanation tonometry 3) CCT measured by handheld ultrasonic pachymeter
One hundred and twenty three patients were found to have a reliable tonographic outflow facility. Sixty three were male and 60 female. There were 58 white individuals. Baseline characteristics of these patients as a whole are shown in Fig1. Multiple regression analysis showed strong statistically significant association between CCT and IOP (beta=0.24, p=0.005, 95% CI=0.009-0.05) and also TOF and IOP (beta=-0.38, p<0.001, 95% CI= -33.15_13.14). This association remained the same after adjustment for age in all groups. In subgroup analysis, the association between CCT and IOP remained significant in OHT/POAG group (beta=0.23, p=0.04, 95%CI=0.001-0.038) and also in healthy individuals (beta=0.52, p=0.001, 95% CI=0.02-0.06). Overall, there is no significant linear correlation between CCT and TOF in all groups.
Higher CCT is related to higher IOP, and higher IOP is related to lower TOF. After accounting for these relationships, however, there was no observed relationship between CCT and TOF. These data suggest that TOF is an independent aqueous parameter that can be measured without bias caused by CCT.
This PDF is available to Subscribers Only