Corneal thickness is important because it can mask an accurate reading of the eye pressure, causing doctors to treat you for a condition that that may not really exist or to treat you unnecessarily when things are normal. Actual IOP may be underestimated in patients with thinner CCT, and overestimated in patients with thick CCT. This may be important for your diagnosis; some people originally diagnosed with normal tension glaucoma may in fact be more accurately treated as having regular glaucoma; others diagnosed with ocular hypertension may be better treated as normal based on accurate CCT measurement. In light of this discovery, it is important to have your eyes checked regularly and to make sure your doctor takes your CCT into account for diagnosis.
Central corneal thickness (CCT) acts as a powerful predictor of development of glaucoma. Eyes with corneal thickness of 555 microns or less (i.e. eyes with relatively thin corneas) had a threefold greater risk of developing glaucoma than those who had corneal thickness of more than 588 microns. The implication was that a corneal thickness of less than 555 microns should be viewed as a risk factor for development of glaucoma