*- These authors contributed equally to this work Correspondence to:

Aims: To examine the practical improvement in image quality afforded by a broadband light source in a clinical setting and to define image quality metrics for future use in evaluating spectral domain optical coherence tomography (SD-OCT) images. Methods: A commercially available SD-OCT system, configured with a standard source as well as an external broadband light source was used to acquire 4mm horizontal line scans of the right eye of 10 normal subjects. Scans were averaged to reduce speckling and multiple retinal layers were analyzed in the resulting images. Results: For all layers a significant improvement in the mean local contrast was found, (average improvement by a factor of 1.66) when using the broadband light source. Intersession variability is shown not to be a major contributing factor to the observed improvement in image quality obtained with the broadband light source. We report the first observation of sub-lamination within the inner plexiform layer (IPL) visible with SD-OCT. Conclusion: The practical improvement with the broadband light source was significant, though it remains to be seen what the utility will be for diagnosing pathology. The approach presented here ca