A handheld retinal oximeter has high sensitivity to changes in inhaled oxygen concentration and provides similar measurement values as the Oxymap T1, according to research published in Acta Ophthalmologica.
Researchers aimed to evaluate the sensitivity of a handheld oximeter (Corimap Camera, Demcon Focal BV) and compare it with the current standard of care, Oxymap T1 (Oxymap ehf). To accomplish this, researchers measured the oxygen saturation in retinal vessels both during normoxia and isocapnic hyperoxia with both a handheld oximeter and the Oxymap T1 retinal oximeter in the same group of patients.
Thirteen healthy participants (78% women, mean age, 25±2 years) were included in the study. Participants had a median Snellen visual acuity of 1.2 (range, 1.1 to 1.2). During hyperoxia, oxygen saturation in the retinal arterioles was mildly increased, measured via both oximeters (P =.001 for the handheld oximeter and P <.001 for the Oxymap T1).
A large change in venous oxygen saturation and arteriovenous difference was also measured with both oximeters (P <.001 for both). Normalized measurements during recovery stages also demonstrated a significant difference between arterioles and venules (P <.001 for both).
A significant decrease in vessel within both arterioles and venules in pixels during hyperoxia for both oximeters (P <.05). Sensitivity analyses via Bland-Altman Plots demonstrated comparable sensitivity.
While both oximeters are similar, the prototype Corimap Camera includes additional features, like handheld use for applicability in a wider patient population, a mobile and stand-alone nature in a hospital setting, and the use of polarized light which may have a beneficial effect on oxygen measurements.
“The handheld Corimap Camera is sensitive to oxygen changes in retinal vessels and reliably measures oxygen saturation in retinal vessels in both normoxia and hyperoxia oxygen environments,” the research concludes. “The Corimap Camera performs well in comparison with the current gold standard of retinal oximetry, the Oxymap T1.”
Disclosure: Several study authors declared affiliations with the biotech or pharmaceutical industries. Please see the original reference for a full list of authors’ disclosures.
Vehmeijer WB, Jonkman K, Hardarson SH, et al. Retinal oximetry with a prototype handheld oximetry during hyperoxia. Acta Ophthalmol. Published online March 1, 2021. doi:10.1111/aos.14817