Short Report

Limitations in assessing nerve growth factor levels in aqueous humor samples from human eyes

Kakarla V Chalam , Rajesh K Sharma and Ravi K Murthy

Department of Ophthalmology, University of Florida College of Medicine, Jacksonville, Florida

author email corresponding author email

BMC Research Notes 2008, 1:22doi:10.1186/1756-0500-1-22

Published:	5 June 2008

Abstract

Background

Nerve growth factor (NGF) helps in the healing and survival of ganglion cells, photoreceptors, and optic nerve after injury and has been implicated to have a role in pathophysiology of glaucoma. So far, in animal studies, injury to iris in vitro has revealed an increase in NGF levels in aqueous. There is a great interest in investigating the levels of NGF in human aqueous in glaucomatous eyes, as suggested by animal studies, to gain a better understanding of the pathophysiology of glaucoma.

Findings

In this study, we examined the presence of NGF levels in aqueous humor collected from human eyes and the limitations in determining the NGF levels in human samples. NGF was assessed by ELISA immunoassay in undiluted aqueous samples collected from 32 consecutive patients undergoing surgery for cataract (control) or primary open angle glaucoma (POAG). Recombinant NGF was used as positive control. NGF levels were below undetectable levels in aqueous humor from eyes with POAG and controls by immunoassay. Less than 10% of samples had detectable NGF levels and these were considered outliers.

Conclusion

Our result highlights the undetectable levels of NGF in human aqueous samples.