Does the intraocular pressure effect on optic disc cupping differ by age?

PURPOSE To investigate whether age influences optic disc cupping in addition to the effects of intraocular pressure (IOP). METHODS Population-based study (N = 4,926 at baseline). All measures including fundus photography were done according to standard protocols. Stereoscopic images of the optic disc were graded in masked fashion. RESULTS Cup-to-disc ratios (C/D) were directly related to IOP at baseline. Age of 75 years or older was associated with increase in cupping at a given level of IOP, but the age association was attenuated when including refraction in multivariable models. Change in C/D between baseline and 15-year follow-up was also influenced by age such that those 75 years of age or older were at increased risk of cupping. When refraction was included in this model, age was still significant. CONCLUSIONS People who are at least 75 years of age are at greater risk of developing optic disc cupping, which is associated with greater IOP.