A microperimeter that provides fixation pattern and retinal sensitivity measurement

Abstract

Purpose: To investigate a microperimeter (MP-1) that can independently measure fixation status and microperimetry of retinal threshold sensitivity by comparing the results obtained by the MP-1 with those obtained by scotometry using scanning laser ophthalmoscopy (SLO).

Methods: Fourteen patients (15 eyes) with a macular disorder were examined by the MP-1 fixation test, MP-1 microperimetry, and SLO scotometry. The scotoma size seen in MP-1 microperimetry was compared with that observed in SLO scotometry. The location of the preferred retinal locus (PRL) and the fixation stability, which were obtained from the fixation test in MP-1, were also compared with those obtained in SLO scotometry.

Results: The scotoma size, which was not seen with 0 dB in MP-1 microperimetry, was larger than that in SLO scotometry in 8 of the 15 eyes. Retinal threshold sensitivity decreases were found using MP-1 microperimetry within a sensitive area of SLO scotometry in all eyes. The PRL in the MP-1 fixation test and in SLO scotometry agreed in all eyes. Fixation stability in the MP-1 fixation test significantly correlated with that in SLO scotometry (P = 0.0192).

Conclusions: The results of MP-1 microperimetry do not completely agree with those of SLO scotometry owing to the difference in stimulus intensity. The MP-1 fixation test is useful for measuring PRL and fixation stability in a short time. MP-1 might be helpful to evaluate the foveal function in patients with macular disorders without severely damaged macular function.