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Phenylephrine 5% added to Tropicamide 0.5% eye drops does not influence retinal oxygen saturation values or retinal vessel diameter in glaucoma patients
Author(s) -
Vandewalle Evelien,
Abegão Pinto Luis,
Olafsdottir Olof Birna,
Stalmans Ingeborg
Publication year - 2013
Publication title -
acta ophthalmologica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.534
H-Index - 87
eISSN - 1755-3768
pISSN - 1755-375X
DOI - 10.1111/j.1755-3768.2012.02545.x
Subject(s) - tropicamide , retinal , phenylephrine , ophthalmology , glaucoma , medicine , optometry , oxygen saturation , materials science , oxygen , optics , chemistry , blood pressure , pupil , physics , organic chemistry
. Purpose: To test whether adding topical phenylephrine 5% to tropicamide 0.5% eye drops in the protocol for pupil dilation affects the retinal vessel oximeter measurements in patients with glaucoma. To test whether phenylephrine 5% has an influence as a vasoconstrictor on the retinal vessel width and can improve the proportion of high‐quality retinal images in patients with glaucoma. Methods: Retinal images of 66 patients with chronic open‐angle glaucoma were obtained before and after the administration of phenylephrine 5% eye drops to patients already dilated with tropicamide 0.5% with the Oxymap Retinal Oximeter (Oxymap ehf, Reykjavik, Iceland). Specialized software, Oxymap Analyzer, analysed the images and measured the oxygen saturation and vessel diameter. Oxygen saturation was measured in first‐ and second‐degree vessels. A Mann–Whitney U ‐test was used to compare both groups. Quality of the images was assessed, and a Fisher’s exact test was used to compare the proportion of high‐ and poor‐quality images. Results: There was no significant difference in arterial and venous oxygen saturation in patients with glaucoma whether dilated by tropicamide alone or a combination of tropicamide and phenylephrine (97 ± 6% versus 96 ± 5%, p = 0.88 for arterial saturation and 66 ± 6% versus 67 ± 6%, p = 0.78 for venous saturation, n = 27). There was no significant difference in vessel diameter between both conditions for the different vessels (p = 0.61 for arterial saturation and p = 0.51 for venous saturation, n = 27). The proportion of high‐quality images was significantly higher after the combination regimen compared with tropicamide only (p = 0.0001). Conclusion: The addition of topical phenylephrine 5% after tropicamide 0.5% improved the proportion of high‐quality retinal oximetry images without influencing the retinal oxygen saturation values or the retinal vessel diameter in patients with glaucoma.