Purchase this article with an account.
C. J. Wolsley, A. Turpin, P. J. Morrow, B. Scotney, R. S. Anderson; Comparing Localised Retinal Function From Multifocal Electroretinography With Estimates of Cone Density From in vivo Imaging of the Photoreceptor Mosaic Using a Modified Heidelberg Retina Tomograph. Invest. Ophthalmol. Vis. Sci. 2009;50(13):1397.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To investigate the relationship between multifocal electroretinography (mfERG) responses and measures of cone packing density from in vivo imaging of the retinal photoreceptor layer using a modified commercially-available scanning laser ophthalmoscope.
A Heidelberg Retina Tomograph, (HRT1) was modified to give 1x1° and 2x2° high resolution images of the retinal photoreceptor mosaic without adaptive optics in two normal subjects. Individual cone cells were identified from retinal images of the parafoveal region out to 4mm eccentricity and used to determine cone density as a function of retinal eccentricity. This was compared to the spatial variation in retinal function, determined in the same subjects from mfERG responses to a high resolution (241-element) stimulus array.
The modified HRT1 device produced reliable images of central cone mosaic structure in each subject. Estimates of cone density ranged from around 19,000 to 5,000 cells/mm2 between 0.6mm and 3mm retinal eccentricity. Cone density was strongly linearly correlated (r=0.97) with mfERG amplitude within the central retina.
The variation of cone photoreceptor packing density with retinal eccentricity compared well with published data from histology and adaptive optics imaging. Retinal function determined from mfERG amplitude appears to directly reflect the density of the cone cells. There is a need to more fully explore the potential and clinical utility of the modified HRT to produce retinal cone counts in diseases that affect photoreceptor density and investigate how this relates to changes in local retinal function.
This PDF is available to Subscribers Only