TY - JOUR
T1 - Analysis of visual pigment by fundus autofluorescence
AU - Theelen, T.
AU - Berendschot, T.T.
AU - Boon, C.J.
AU - Hoyng, C.B.
AU - Klevering, B.J.
PY - 2008/1/1
Y1 - 2008/1/1
N2 - This study investigated changes of short-wavelength fundus autofluorescence (SW-AF) by retinal bleaching effects. All measurements were performed with the Heidelberg Retina Angiograph 2 (HRA 2). Initially, experimental imaging was done on a healthy eye after dark adaptation. Photopigment was bleached within the central 30 degrees of the fundus by HRA 2 excitation light. Then SW-AF imaging of this region was performed, and SW-AF of the surrounding, unbleached 25 degrees fundus region was subsequently studied by a wide-field lens. Next, another 30 degrees SW-AF image of the posterior pole was obtained after complete dark adaptation. Then an extra SW-AF examination was performed with 15 degrees temporal eccentricity, overlapping the original examination area. Finally, a successive image series was carried out on the dark-adapted eye to test for bleaching kinetics. The second and third experiments were also performed on eyes with macular dystrophies. Distinct regions of increased SW-AF were observed after strong illumination with the blue excitation light in all eyes studied. During light adaptation mean gray levels showed a saturation plateau after an initial steep increase. The resulting gray-value maps showed significant differences of pixel intensities between bleached and unbleached parts of the fundus. Two-dimensional density difference maps allowed analysis of visual pigment distribution and density in both healthy eyes and eyes with macular dystrophies. Our observations highlight the viability of objective, non-invasive evaluation of visual pigment in the healthy and diseased human retina by means of confocal fundus autofluorescence.
AB - This study investigated changes of short-wavelength fundus autofluorescence (SW-AF) by retinal bleaching effects. All measurements were performed with the Heidelberg Retina Angiograph 2 (HRA 2). Initially, experimental imaging was done on a healthy eye after dark adaptation. Photopigment was bleached within the central 30 degrees of the fundus by HRA 2 excitation light. Then SW-AF imaging of this region was performed, and SW-AF of the surrounding, unbleached 25 degrees fundus region was subsequently studied by a wide-field lens. Next, another 30 degrees SW-AF image of the posterior pole was obtained after complete dark adaptation. Then an extra SW-AF examination was performed with 15 degrees temporal eccentricity, overlapping the original examination area. Finally, a successive image series was carried out on the dark-adapted eye to test for bleaching kinetics. The second and third experiments were also performed on eyes with macular dystrophies. Distinct regions of increased SW-AF were observed after strong illumination with the blue excitation light in all eyes studied. During light adaptation mean gray levels showed a saturation plateau after an initial steep increase. The resulting gray-value maps showed significant differences of pixel intensities between bleached and unbleached parts of the fundus. Two-dimensional density difference maps allowed analysis of visual pigment distribution and density in both healthy eyes and eyes with macular dystrophies. Our observations highlight the viability of objective, non-invasive evaluation of visual pigment in the healthy and diseased human retina by means of confocal fundus autofluorescence.
U2 - 10.1016/j.exer.2007.10.022
DO - 10.1016/j.exer.2007.10.022
M3 - Article
C2 - 18096158
SN - 0014-4835
VL - 86
SP - 296
EP - 304
JO - Experimental Eye Research
JF - Experimental Eye Research
IS - 2
ER -