LOCAL PHOTORECEPTOR ALIGNMENT MEASURED WITH A SCANNING LASER OPHTHALMOSCOPE

The aim of this study was to develop a fast test for local photorecept or alignment. Photoreceptor alignment is an important indicator of ret inal integrity. Digitized images of fundus reflectance were obtained f or 20-30 pupil entry positions with a custom built scanning laser opht halmoscope (SLO). The data permitted the calculation of curve peakedne ss of the optical Stiles-Crawford effect (SCE) as a function of retina l location. We found that the peakedness is low in the central 0.5 deg , reaches a maximum at an eccentricity of 1-2 deg and gradually drops with increasing eccentricity. These data are in conformity with the an atomy of foveal cones. Additionally, the psychophysical SCE was measur ed with red light and an 8 deg stimulus. The mean peak position of the SCE in the pupil plane for both methods was similar, but the optical SCE was clearly steeper. The SLO provides a fast, reliable and objecti ve way to determine local receptor alignment in the central retina. Co pyright (C) 1996 Elsevier Science Ltd