[Considerations regarding Goldmann's rheologic equation].
OBJECTIVE
The aim of this paper is to verify if Goldmann's rheological concept is still valid. That is because the validity of this concept has been contested. (Beneyto P., Fernandez-Vila P.C., Perez T.M--An experimental approximation to the law of Goldmann: study of the dynamics of the aqueous humor outflow. Ann. Ophthalmol. Glaucoma, 1995, 27, 3, 160-166, Abstract in Glaucoma abstracts 1995, Vol. 6, nr. 3, 63.)


METHODS
The authors sustained that Goldmann's equation has never been verified. On 42 normal eyes and 54 glaucomatous eyes (POAG) they determined aqueous flow by fluorophotometry, IOP by aplanotonometry and considered a value of 9mmHg as normal episcleral veins pressure. The results they obtained showed that in 47% of the cases the fluorophotometric values were with over 1microl/min higher then the calculated values using Goldmann's equation. So, they concluded that Goldmann's equation could be wrong.


METHODS
There are two outflow pathways for the aqueous humor, trabecular and uveoscleral. Obviously, the uveoscleral outflow (Fu) summed with the trabecular outflow (Ftr) must be equal with the aqueous flow (FIN), and the total outflow facility (CTRU) must be the sum of the trabecular outflow facility (Ctr) and uveoscleral facility (Cu). Thereby Goldmann's equation can be written: FIN = Ftr + Fu = (Pio-Pv) * CTRU and Ftr = (Pio-Pv) * Ctr, Fu = (Pio-Pv) * Cu. With the authors' data we verified the previous equations.


RESULTS
There is correspondence between clinical and mathematically deducted parameters.


CONCLUSIONS
1. Goldmann's rheological concept is still valid. 2. With proper modifications Goldmann's equation is still valid.
Constantin
C
C
Vancea
P P
PP
D000465:Algorithms; D001082:Aqueous Humor / Q000502:physiology*; D015590:Fluorophotometry / Q000379:methods; D005901:Glaucoma / Q000503:physiopathology; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D008954:Models, Biological; D012212:Rheology / Q000379:methods; D014065:Tonometry, Ocular / Q000379:methods