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Anthony Cappo, Richard Rosen, William Seiple, Matthew Orr, michele arthurs, Trisha Emborgo; A New Method to Depict Central Scotomas: Automated Sterocampimetry. Invest. Ophthalmol. Vis. Sci. 2013;54(15):5023.
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© ARVO (1962-2015); The Authors (2016-present)
Despite high prevalence of central and para-central scotomas and the success of available treatments, no precise automated means to measure the size or shape of the scotoma exists. Such information would be useful for both early detection and following treatment. Standard automated perimetry and microperimetry present stimuli at various intensities to obtain thresholds. The stimuli are typically in a preset grid pattern which fails to give a detailed outline of scotomas. We describe a new technique, Automated Stereocampimetery, that precisely defines the size and shape of a scotoma, and compare the results to Microperimetry and to the underlying image of the damaged retina from SLO.
We tested 30 patients on the Automated Stereocampimeter (AS) and an OCT SLO outfitted with a Microperimeter (MP) without screening for the type of retinal pathology. Both devices require a subjective response from the subject. The MP is part of an OCT SLO which also gives retinal thickness and image of the retina. It is a monocular test and ensures fixation by monitoring any movement of landmarks in the retinal image. The MP presents stimuli in a regular pattern over 30 degrees of visual field and the stimulus points are repeated at various light intensities (full threshold). The AS does not monitor fixation, but uses binocular fixation and animation of the target to improve fixation. To compare the locations and extents of loss, the AS results were superimposed on the MP results.
Of 30 subjects tested on the AS, 12 were found to have well-defined areas of scotomas. Eight of these 12 subjects were able to complete MP Testing. In 6 of these 8 cases the MP result confirmed the AS findings, with additional correspondence of the probable defects identified in the SLO image to the AS-determined scotoma outline. In 2 cases the relationship appeared weaker.
More than half of patients have been able to complete an AS test successfully, and the comparison to the MP data suggests that the AS produced meaningful results that may be useful in following patients with centrally located pathology. Poor results were usually easy to identify, which reduces the chance of false positive tests. Further, the correspondence between discoloration in the retina image and the shape of discovered defect was greater than expected.
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