The transconjunctival oxygen monitor.

The transconjunctival oxygen monitor, mounted on a polymethylmethacrylate conformer, continuously measures the tissue oxygen tension of the palpebral conjunctiva. It is preferable to transcutaneous monitors because it requires no heat and correlates arterial oxygen in cerebral blood flow by monitoring a tissue bed vascularized by the internal carotid artery. We used it on 19 adult patients. The monitor was valuable in correlating arterial oxygen in hemodynamically compromised and uncompromised patients. However, the measurements decreased abruptly when the conjunctival temperature fell below 33 C in the compromised patients. The only ocular complications were conjunctival chemosis and mild punctate keratopathy in some patients; these resolved within 48 hours. This device may be useful in monitoring tissue oxygen tensions in critically ill patients and neonates at risk for retinopathy.