Purpose: The assessment of repeatability and reproducibility of retinal straylight measurements with the C-Quant straylight meter (Oculus AG, Germany) and the effect of patient's age on the instrument performance are tested with a series of experiments.
Methods: First, 20 eyes of 20 subjects (mean age 26.9±2.7 years, mean refractive error -1.34±2.72 D) were examined with the C-Quant straylightmeter, taking 10 consecutive readings. Five subjects were also examined on 5 consecutive days to assess reproducibility. Additionally, repeated measures of straylight from 84 subjects of ages ranging from 19 to 86 years (mean±SD: 42.4±24.0 years) were retrospectively analysed to assess the effect of patient's age on repeatability.
Results: The results failed to show significant differences between the readings taken within the same session (mean SD 0.07, p>0.05) or between sessions (mean SD 0.05, p>0.05). Variability of intrasession measurements was not significant for subjects of different age (p=0.094).
Conclusion: It may be concluded then that the C-Quant straylightmeter is repeatable and reliable for the assessment of retinal straylight in human eyes. Age of the patient does not decrease repeatability even though they feel more insecure about their ability to perform the test