Abstract
Purpose::
Pigment-epithelium-derived-factor (PEDF) is a known inhibitor of angiogenesis in the eye. Until now, its presence in tears has however not been reported. Our initial results, based on the analysis of diluted tear fluid samples, even indicated the absence of this factor in human tears. Because of the clinical importance of PEDF as a regulator of vascularisation, we decided to investigate undiluted human tear fluid.
Methods::
Samples of sixteen individuals were collected as previously described and analyzed using a commercial ELISA assay.
Results::
PEDF concentrations were below the detection limit (ie < 0,1ng/ml) in the majority of samples. However, PEDF was discovered in three of the samples taken with significant concentrations up to 53 ng/ml with a mean concentration of 29 ng/ml with repeated positive concentrations in one individual.
Conclusions::
PEDF may be found in measurable amounts in human tear fluid and may therefore also play a role in effects and regulation of PEDF at the ocular surface.
Keywords: cornea: tears/tear film/dry eye • lacrimal gland • neovascularization