Mesopic Testing

Mesopic Contrast Sensitivity Testing with the CSV-1000

The CSV-1000 can be easily used for testing mesopic contrast sensitivity. The CSV-1000 instrument automatically maintains a consistent and uniform testing light level through proprietary auto-calibration technology that monitors and adjusts the test lighting. For photopic testing, the unit automatically and continually calibrates test lighting to 85 cd/m2. When mesopic filters are used, as described below, the testing light level is held constant at a light level of 3 cd/m2, the mesopic light level recommended for FDA to simulate night driving conditions in clinical trials.

Mesopic Filters Available in Different Formats

The mesopic filters are available as trial lenses, which can be placed in the phoropter or in trial frames, alternatively, the lenses can be purchased in their own frame. See images below.

mesopicfilters

Data for Mesopic Testing

Many studies have been performed with the CSV-1000 for evaluating mesopic contrast sensitivity. The data below is from a refractive surgery study conducted in a multi-center trial by investigators evaluating the Alcon excimer laser technology.

Population Norms
(Younger Age Group: 20 – 55 Years of Age):

The following tables show data collected as base line (preoperative) measurements in an FDA clinical trial for refractive surgery. These results are based on the evaluation of 156 normal eyes (79 patients) with an age range of 21 – 55 years of age (36.6 yo + 9.02 years). Average preoperative acuity for these patients was 20/16 + 2.35 (number of letters: 45.07 + 3.08).


Photopic Conditions

Spatial Frequency Log Average (Contrast Level) Standard Deviation
Row A (3 cpd) 1.84 (6.38) .14 (0.93)
Row B (6 cpd) 2.09 (6.67) .16 (1.08)
Row C (12 cpd) 1.76 (6.46) .17 (1.15)
Row D (18 cpd) 1.33 (6.50) .19 (1.31)
Spatial Frequency Log Average (Contrast Level) Standard Deviation
Row A (3 cpd) 1.84 (6.38) .14 (0.93)
Row B (6 cpd) 2.09 (6.67) .16 (1.08)
Row C (12 cpd) 1.76 (6.46) .17 (1.15)
Row D (18 cpd) 1.33 (6.50) .19 (1.31)

Mesopic Conditions

Spatial Frequency Log Average (Contrast Level) Standard Deviation
Row A (3 cpd) 1.61 (4.85) .21 (1.43)
Row B (6 cpd) 1.66 (3.77) .23 (1.50)
Row C (12 cpd) 1.08 (2.33) .32 (1.56)
Row D (18 cpd) 0.56 (1.97) .35 (1.52)
Spatial Frequency Log Average (Contrast Level) Standard Deviation
Row A (3 cpd) 1.61 (4.85) .21 (1.43)
Row B (6 cpd) 1.66 (3.77) .23 (1.50)
Row C (12 cpd) 1.08 (2.33) .32 (1.56)
Row D (18 cpd) 0.56 (1.97) .35 (1.52)