Abstract
Abstract: :
Purpose: To investigate the effect of retinal adaptation of the contralateral eye on frequency doubling perimetry (FDP). Methods: The sample consisted of 10 clinically normal volunteers with a mean age of 26.1 years (SD: 6.7; Range: 23-43 years; 5 women). Subjects performed 13 trials using the FDP, program N30, on the right eye. Following an initial learning field there were 3 tests performed sequentially using 4 separate examination conditions at 4 separate visits: i. Dark room, no patch; ii. Light room (54cdm2), black patch on the contralateral, non-tested eye; iii. Light room, white patch on contralateral eye; and iv. Light room, no patch. Two additional experiments were performed in order to investigate the effect of light and dark adaptation on a typical, bilateral clinical sequence, i.e. in a light room with and without a black patch. Results: All tests for all subjects in which the contralateral eye was dark adapting, i.e. black patch or black room conditions, demonstrated a reduction in sensitivity over the duration of the 3 examinations. The group mean difference between the 1st and 3rd examination was 3.9dB. Conversely all conditions in which the contralateral eye was light adapted, gave no reduction in FDP sensitivity, with a group mean difference of 0dB. In the supplementary experiments in which both eyes were tested, the left eye gave a reduction of 2.2dB when the black patch was used, but no difference and a significantly reduced variance when light adapted. Conclusion: Dark adaptation of the contralateral eye during FDP has a deleterious affect on frequency doubling sensitivity. Dark room conditions should be avoided when performing FDP and if patching is required, white patches and maintenance of light adaptation are recommended. Performing FDP in light adapted conditions improves test variance and nullifies the second eye sensitivity reduction incorporated into the normal database.
Keywords: 624 visual fields • 384 dark/light adaptation • 511 perimetry