Purchase this article with an account.
Jongwoo Shim, Changhun Park, Eung Kweon Kim, Hyung Keun Lee; Levels Of Endogenous Prostaglandins And Bradykinin In Dry Eye Patients. Invest. Ophthalmol. Vis. Sci. 2011;52(14):6629.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Prostaglandin and bradykinin has been known to as altering the firing threshold of neurons or involving in the mechanism of pain; however, little attention has been paid to these endogenous molecules in the tears of dry eye patients. In this study we determined prostaglandins levels in tears of dry eye patients and investigated the response characteristics of the patients to noxious stimulation.
The patients who were recruited in this study were asked to complete a symptom questionnaire. Approximately 20 microliter of tears were carefully sampled from the lower conjunctival fornix of each eye. Nano-liquid chromatography tandem mass spectrometry was used to compare samples including quantification of molecules know to induced irritation; prostaglandin E2, D2, I2 and bradykinin. For investigating the response characteristics of patients to noxious stimulation, mean irritation thresholds, irritation scores at threshold and at suprathreshold were determined using a standard low pH phosphate buffered solution.
The mean level of PGE2 in the tears of dry eye patients (24.96 ng/ml) was not statistically different compared to the normal control group (25.64 ng/ml). The mean level of PGD2 in the tears of dry eye patients (3.39 ng/ml) was significantly lower than that of the control group (14.77 ng/ml, P<0.05), while PGI2 (141.53 ng/ml) and bradykinin (12.48 ng/ml) were significantly higher than the normal control group (PGI2, 20.00 ng/ml, P<0.01 ; bradykinin, 0.86 ng/ml, P<0.05). In ocular irritation triggering tests, the mean initiation threshold was found to be no different between the dry eye group and control group, but the irritation score at suprathreshold stimuli in dry eye patients was statistically higher than that of controls (P<0.05).
We found the prostaglandin levels in ocular surface were significantly different between normal and dry eye patients. As these molecules are known to be related with pain and irritation triggering, the changes of prostaglandin levels may be responsible for the hyperreactivity to noxious stimulation in dry eye.
This PDF is available to Subscribers Only