Familial occurrence of artefactual ocular hypertension from thick corneas and of primary open angle glaucoma in a French Canadian kindred

Abstract

We describe the coexistence of artefactual ocular hypertension due to increased central corneal thickness (CCT>585 µm), with primary open angle glaucoma (POAG) in a French Canadian kindred. Seventeen members of the family were examined and classified as to their glaucoma status. The mean CCT for our glaucoma patients (580 µm; n=5) and that for normals (552 µm; n=6) were within two standard deviations of the mean value provided in the literature (531 µm ± SD=29 µm). The mean CCT of 611 µm for the suspect group (n=6) was considerably higher than for the glaucoma and normal groups. All but one of the suspects were classified as ocular hypertensives on the basis of high intraocular pressures (IOPs). When the IOPs for these patients (mean 22.6 mmHg) were corrected for their CCTs, all had pressures of <21 mmHg (mean 16.4 mmHg). Ten of the seventeen family members had thick CCTs, and transmission of thick corneas was seen in two generations. A number of individuals in this family had optic nerve head drusen (9/17) and the mean CCT of these individuals (601 µm) was higher than the mean CCT (560 µm) of the group without drusen (P=0.020 by t test). Artefactual ocular hypertension and POAG can be present in different members of the same family. The presence of a thick cornea appears to be an inherited trait and may be associated with the presence of optic nerve drusen. This association suggests a developmental relationship between thick corneas and optic nerve head drusen which needs to be studied further.