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The aim of this study was to develop a fast test for local photoreceptor alignment. Photoreceptor alignment is an important indicator of retinal integrity. Digitized images of fundus reflectance were obtained for 20-30 pupil entry positions with a custom built scanning laser ophthalmoscope (SLO). The data permitted the calculation of curve peakedness of the optical Stiles-Crawford effect (SCE) as a function of retinal 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 anatomy of foveal cones. Additionally, the psychophysical SCE was measured 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 objective way to determine local receptor alignment in the central retina.

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We investigated whether photoreceptor function in amblyopic eyes differed from that in non-amblyopic eyes. Photoreceptor function was assessed with the optical Stiles-Crawford effect (SCE), psychophysical SCE, and foveal visual pigment density in both eyes of ten unilateral amblyopic subjects. Optical SCE and density measurements were carried out with a custom-built scanning laser ophthalmoscope (SLO). Amblyopic and normal eyes did not differ in Stiles-Crawford effect, nor in foveal visual pigment density. Contrary to suggestions in the literature, we found no indication of retinal dysfunction at the level of the cone photoreceptors in amblyopic eyes.

Diagnosing and monitoring of Graves' Orbitopathy (GO) can be supported by use of Ultrasonography (USG) and Computerized Tomography (CT); they provide supplementary information. In this retrospective study we describe 107 clinical GO patients evaluated by B-scan USG and 27 clinical GO patients evaluated by CT scan. Analysis of 236 B-scan USG included measurements of medial, inferior and lateral rectus muscles. The presence of muscle enlargement and increased orbital fat were noted by the radiologist on 27 CT scans. Sensitivity of both B-scan USG and CT scan were calculated. We suggest that B-scan USG has a high sensitivity, which is equal or better than CT scan sensitivity in diagnosing GO. Furthermore USG A and B scan combination is an effective, accurate tool in diagnosing GO, and optic neuropathy, but it also provides essential information about the GO disease activity.