Quantitative determination of aqueous flare and cells in healthy eyes.

We studied 263 eyes of 141 normal subjects, 33 men and 108 women, including 129 Finns and 12 Ibero-Americans, with the age ranging between 12 and 89 (mean 43.0 +/- 20.4) years using the Kowa FC-1000 laser flare cell meter. The mean photon count/ms was 4.5, it was 3.1 in the age groups of 10-19 years and 11.5 in the age group of 80 years or over; the increase with age was statistically significant (p = 0.0001). There were no significant differences in the photon count/ms between right and left eyes (p = 0.75), between sexes (p = 0.61), or between Ibero-Americans and age-matched Finns (p = 0.62). The mean cell count was 1.1 and there were no significant changes between the right and left eyes (p = 0.56) or between different age (p = 0.38), sex (p = 0.32) and race (p = 0.64) groups. There were no significant differences in the mean photon count/ms (p = 0.97) and cell counts (p = 0.35) between the first and second measurements 5 min later. There was no subject-within variability after 24 h and 7 days in the flare (p = 0.95) and cell counts (p = 0.89).

Measurement of protein concentration of aqueous humour in vivo: correlation between laser flare measurements and chemical protein determination.

We studied the correlation between laser flare cell meter photon count/ms and actual protein concentration both in vitro and in vivo. Laser flare cell meter measurement of human albumin concentrations of 0 to 10 g/l showed photon counts/ms from 0.3 +/- 0.3 to 78.9 +/- 3.9. There was a statistically highly significant linear correlation between photon count/ms and human albumin concentration (r = 0.98, p = 0.0001). Laser flare cell meter measurements were done on 39 cataract patients with the mean age of 77.9 +/- 6.7 years. Aqueous humour obtained by peroperative paracentesis was analysed for total protein. The mean photon count/ms before pupillary dilatation was 11.93 +/- 6.03. There was a significant linear correlation (r = 0.4, p = 0.019) between the photon count/ms after pupillary dilatation (mean 14.73 +/- 12.9, range 2.6-62.4) and anterior chamber protein concentration (mean 0.62 +/- 0.27, range 0.23-1.3 g/l) with the linear regression formula being y = 0.231 x -1.105 where y = log protein concentration (g/l) and x = log of photon count/ms. Laser flare cell meter photon counts/ms may be converted into an equivalent anterior chamber total protein concentration using this formula.