Ophthalmology: As we know from the OHTS, the central corneal thickness (CCT) has a dramatic effect on IOP measurement and risk of glaucoma, and checking the CCT is essential in managing glaucoma. Some researchers have tried to create nomograms , where one can add or subtract from the IOP measured, in order to get a “true” IOP and thus a better idea of the risk. Wrong. Even with this adjustment, researchers were unable to better predict glaucoma. It seems the CCT exerts an independent factor. In my practice, I don’t use these nomograms- I simply am more aggressive when I see a thin CCT.