Purchase this article with an account.
J. S. Kroisamer, C. Simader, W. Geitzenauer, U. Schmidt-Erfurth; Evaluation of Microperimetric Findings in Normal Individuals: Shape and Size of Fixation Target. Invest. Ophthalmol. Vis. Sci. 2009;50(13):3277.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Automated static threshold microperimetry has been established in clinical practice to evaluate macular function, disease progression and effectiveness of new therapeutic strategies. The aim of this comparative study was to evaluate, if microperimetric findings are affected by shape or size of the fixation target.
Central macular function of 35 dilated eyes of volunteers without any history of ocular diseases, other than ametropia were evaluated by static threshold perimetry four times a day using the MP1 microperimeter (Nidek-Technologies, Softwareversion 1.4.2). The chosen fixation targets were a 1° circle, a 5° circle, a 1° cross and a 6° cross. The examination setting did not vary, a standardized grid with 25 stimuli was used, and room light intensity was constant. The sequence of examination was randomized to avoid bias by learning effects. The microperimetric findings were analysed by SPSS for Windows 11.5.
In 12 of 13 stimuli locations, the Oneway-Anova analysis showed a significant difference (p<0.05) between the mean light threshold results of the four examinations when the stimulus was located on the fixation target at least one time. In comparison to these findings we could not discover a significant difference in those 12 stimuli positions, which were never located on a fixation target.
The results indicate a significant effect of shape and size of fixation target on macular function evaluation using the Nidek MP1 system, if the stimulus is located on the fixation target. Therefore a constant fixation target is recommended in order to obtain comparable results.
This PDF is available to Subscribers Only