Values for macular perimetry using the MP-1 microperimeter in normal subjects

To establish values for the fixation pattern and macular sensitivity to light in healthy subjects using the MP-1 microperimeter (Nideck Technologies, Vigonza, Italy).

A prospective study of 37 healthy subjects (age: 19-71 years), approved by the institutional review board. Full-threshold microperimetry of the central 12 degrees of the retina (the macula) was performed prospectively, utilizing 16 points with the MP-1. The fixation stability was simultaneously recorded during microperimetry testing. The relationship between the fixation pattern and light sensitivity with age was calculated using linear regression analysis.

Microperimetry was performed on 66 eyes. Total mean sensitivity was 18.33 dB (range: 13.0-19 dB). Mean macular sensitivities at 2 degrees , 4 degrees and 6 degrees as measured by the MP-1 were 18.4+/-2.0, 18.2+/-2.3 and 18.2+/-2.1 dB, respectively. The linear regression analysis revealed a 0.019240, 0.0248 and 0.0285 dB per year age-related decline in mean macular sensitivity at 2 degrees, 4 degrees and 6 degrees from the center of the macula, respectively. The total mean fixation stability values within 2 degrees and 4 degrees were 86 and 96%, respectively. The linear regression analysis also revealed a 0.344% and 0.122% per year decline in age-related fixation stability within 2 degrees and 4 degrees , respectively. There were no statistically significant differences between the median retinal sensitivity or fixation stability values for sex or race in the study.

The MP-1 may be a reliable tool to measure macular sensitivity. Among normal healthy subjects, there was a linear decline in light sensitivity with increasing age.