CAPACITY OF RING AND LIGHT SENSE PERIMETRY IN THE TOPICAL DIAGNOSIS OF THE VISUAL PATHWAY

Ring perimetry is a novel method which determines peripheral resolutio n rather than differential light sensitivity (DLS). The authors invest igated the capacity of ring perimetry in the topical diagnosis of neur o-ophthalmological lesions in comparison to that of DLS perimetry. Sev enty-five patients with an established diagnosis of a single ophthalmo logical disorder were chosen for the study. They underwent a full clin ical examination and both the 'ring test' with the ring perimeter Opht himus (High-Tech-Vision Inc.) and the GI-program with the Octopus I-2- 3 (Interzeag Inc.). The main investigator who knew all clinical findin gs and the history ascribed each pair of visual fields to one of seven different topical diagnoses: (I) optic media, (2) retina, (3) optic d isc, (4) optic nerve, (5) chiasm, (6) retrochiasmal pathway, and (7) n ormal. He selected five or six sample fields of each group and showed them to two experienced ophthalmologists. They had to assign the field s to one of the seven topical diagnoses. The whole test was repeated s ix weeks later. With ring perimetry 64%, and with DLS perimetry 65% of the assignments were correct. Hence, the efficacy of both methods was very similar, but the time needed for the ring perimetry (5.5 min) wa s about half that needed for the DLS perimetry (II.5 min).