In vivo imaging of the photoreceptor mosaic in retinal dystrophies and correlations with visual function.
OBJECTIVE
To relate in vivo microscopic retinal changes to visual function in patients who have various forms of retinal dystrophy.


METHODS
The UC Davis Adaptive Optics (AO) fundus camera was used to acquire in vivo retinal images at the cellular level. Visual function tests consisting of visual fields, multifocal electroretinography (mfERG), and contrast sensitivity were measured in all subjects by using stimuli that were coincident with areas imaged. Five patients with different forms of retinal dystrophy and three control subjects were recruited. Cone densities were quantified for all retinal images.


RESULTS
In all images of diseased retinas, there were extensive areas of dark space between groups of photoreceptors, where no cone photoreceptors were evident. These irregular features were not seen in healthy retinas, but were apparent in patients with retinal dystrophy. There were significant correlations between functional vision losses and the extent to which these irregularities, quantified by cone density, occurred in retinal images.


CONCLUSIONS
AO fundus imaging is a reliable technique for assessing and quantifying the changes in the photoreceptor layer as disease progresses. Furthermore, this technique can be useful in cases where visual function tests provide borderline or ambiguous results, as it allows visualization of individual photoreceptors.
Choi
Stacey S
SS
Department of Ophthalmology & Vision Science, University of California Davis, Sacramento 95817, USA. sschoi@ucdavis.edu
Doble
Nathan
N
Hardy
Joseph L
JL
Jones
Steven M
SM
Keltner
John L
JL
Olivier
Scot S
SS
Werner
John S
JS
D000293:Adolescent; D000328:Adult; D002452:Cell Count; D015350:Contrast Sensitivity / Q000502:physiology; D003941:Diagnostic Techniques, Ophthalmological; D004596:Electroretinography; D005260:Female; D006801:Humans; D008297:Male; D010781:Photography / Q000379:methods*; D017949:Retinal Cone Photoreceptor Cells / Q000473:pathology*; D012162:Retinal Degeneration / Q000175:diagnosis* / Q000503:physiopathology; D014786:Vision Disorders / Q000175:diagnosis* / Q000503:physiopathology; D014794:Visual Fields / Q000502:physiology