Papilloedema and optic atrophy in chronic hypercapnia.

Two patients are described with hypercapnia of 10 and 13 years duration. Both patients had papilloedema at different stages of their illness and one patient developed optic atrophy. Whether such changes are due to local retinal vascular changes, general change in cerebral vasculature or the result of raised intracranial pressure is unknown. A combination of all seems likely. Computerized axial tomography brain scan on Case 2 was compatible with cerebral oedema and the development of optic atrophy (Case 1) suggests cerebral oedema and consequent raised intracranial pressure as the major factor in the development of papilloedema in hypercapnic patients. Skull radiographic changes have not previously been reported in hypercapnia. The duration of the papilloedema is critical in the development of atrophy.