Download Diapositivo 1 - NEBM - Universidade de Lisboa

Sinais Biológicos e Fisiologia do Olho
Ferreira,
[1]
André ;
Madeira, Francisco
[1];
Gonçalves,
[1]
Rafael ;
Neves,
[2]
C.M. ;
[1] Instituto Superior Técnico – Universidade Técnica de Lisboa; [2] Instituto de fisiologia da Faculdade de Medicina – Universidade de Lisboa
Glaucoma:
Well, the diagnosis glaucoma is given when is detected an optic nerve neuropathy with particular changes of the optic nerve head and with
the loss of retinal ganglion cells (specific cells from eye’s retina) and corresponding retinal nerve fibers that form the optic nerve.
“Problem”:
We were given the following task: study a small population of patients with this type of glaucoma and see their blood pressure (systolic,
diastolic and mean) and their intraocular pressure and see how these values vary when the patients are submitted to the cold pressure test.
Exams:
In this exam, the patient has to put his hand in a recipient full of ice at the temperature of 4ºC and maintain it there for three minutes. At
the same time, we are going to measure his/her intraocular pressure with a tonometer, with the purpose of calculating the ocular mean
perfusion pressure, with which we’ll do the study to solve our question.
This study was done with a sample of
10 patients, whose average and
standard deviation of the ages are 57
and 9.5, respectively. These patients
have a mean weight of 69 kg and a
mean height of 164 cm.
Graphic obtained, with
GPIS, related to the systolic
blood pressure.
Task Force® Monitor (TF) PASCAL® Dynamic Contour Tonometer.
Graphic obtained, with
GPIS, related to the intraocular pressure.
1. TF – Analyze the 30 most stable seconds of the
basal period.
2. PASCAL – Recover the intra-ocular pressure of the
most stable 30 seconds of the basal period.
3. Analyze statistically the data obtained.
4. Repeat previous steps relatively to the 30 seconds
before the maximum response.
5. Compile this data acquired on the GraphPad InSat
(GPIS) in order to obtain the statistic values
represented to the right.
Graphic obtained, with
GPIS, related to the diastolic
blood pressure.
Graphic obtained, with
GPIS, related to the mean
blood pressure.
Graphic obtained, with
GPIS, related to the mean
perfusion blood pressure.
With the comparison of the systolic blood pressure in a basal period with the one in the cold pressure test period, we can see that
the mean of the systolic pressure on the cold pressure test is superior than the one relative to the mean blood pressure on a basal
period.
We can see an increase on the mean blood pressure considering this it’s easy to understand that the mean blood pressure has itself
a significant statistic value since it includes the Systolic Pressure. Therefore, we can set the mean blood pressure as a way to
differentiate the two periods, the basal and the cold pressure test ones.
We can notice a slight increase of the perfusion pressure from the period where the patients were absent of any stimulation (Basal
Period), to the period where the patients were submitted to a cold pressure test, although we can see that this increase is statistically
not significant.