Corneal endothelial permeability and aqueous humor flow using a standard protocol.
BACKGROUND
The study was carried out to compare corneal endothelial permeability and aqueous flow values of healthy volunteers measured in different countries with identical fluorophotometers using a standardized protocol.


METHODS
Healthy volunteers aged between 20 and 70 years were studied in five European cities. Fluorescence scans of the anterior segment of both eyes were made using a commercial fluorophotometer. Beginning 4 h after instillation of four drops of fluorescein 10%, 12 scans of the anterior segment of each eye were performed in 2 h. The values of corneal endothelial permeability and aqueous flow were calculated with standardized software from the decay of the fluorescein concentration in the cornea and anterior chamber.


RESULTS
The mean permeability values (x 10(-4) cm.min-1) +/- SD were 3.7 +/- 1.6 (n = 19; Coimbra, Portugal), 4.3 +/- 1.1 (n = 19; Frankfurt, Germany), 3.9 +/- 0.9 (n = 19; Leiden, The Netherlands) and 5.4 +/- 1.2 (n = 10; Milan, Italy). The values were not significantly different (ANOVA, P > 0.3), except those in Milan. The mean flow values (microliters.min-1) +/- SD were 2.3 +/- 0.9 (n = 17; Coimbra), 1.9 +/- 0.7 (n = 10; Cologne, Germany), 2.6 +/- 1.2 (n = 19; Frankfurt), 2.0 +/- 0.6 (n = 19; Leiden) and 1.7 +/- 0.8 (n = 10; Milan). The values were not significantly different (Kruskal-Wallis test, P > 0.1).


CONCLUSIONS
Permeability and flow values in the different cities had similar values and standard deviations. The Concerted Action demonstrated the usefulness of a standardized protocol.
Department of Ophthalmology, University Hospital, Leiden, The Netherlands.
J A
JA
van Best
M
M
Diestelhorst
E
E
Leite
S
S
Fantaguzzi
R
R
Schalnus
D000328:Adult; D000368:Aged; D000869:Anterior Eye Segment / Q000378:metabolism; D001082:Aqueous Humor / Q000378:metabolism*; D004728:Endothelium, Corneal / Q000166:cytology / Q000378:metabolism*; D005260:Female; D019793:Fluorescein; D005452:Fluoresceins / Q000378:metabolism; D015590:Fluorophotometry; D006801:Humans; D008297:Male; D008875:Middle Aged; D010539:Permeability
D005452:Fluoresceins; D019793:Fluorescein