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Ling Lin, Corina van de Pol, Srividhya Vilupuru; Normative Contrast Sensitivity for Emmetropic Presbyopia Subjects using the Back-lit F.A.C.T. Chart. Invest. Ophthalmol. Vis. Sci. 2014;55(13):761.
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© ARVO (1962-2015); The Authors (2016-present)
To develop the normative contrast sensitivity (CS) curves for emmetropic presbyopia subjects under monocular and binocular testing conditions for day and night luminance levels with and without glare.
400 eyes from 400 presbyopic subjects between 45 to 60 years old enrolled in 19 sites (11 US and 8 OUS) as a subgroup in the US IDE study of the KAMRA corneal inlay were measured with the F.A.C.T. chart (OPTEC® 6500 Vision Tester) under five CS testing conditions across monocular and binocular, day (photopic) and night (mesopic), with and without glare. Testing was performed with the subjects’ best corrected for distance vision. Four of five provided spatial frequencies were used in each testing condition: 1.5, 3, 6 and 12 cycles/degree were used for mesopic conditions; 3, 6, 12 and 18 cycles/degree were used for photopic conditions. Test results were represented in terms of the log10 Unit of CS. The lower and upper limits of normative values were developed by taking two standard deviations from the means. The influence of site, age, gender, race, eye, photopic pupil size and mesopic pupil size on normative CS was examined.
Contrast sensitivity was higher in photopic than mesopic conditions, higher in binocular than monocular conditions, and higher in without glare than with glare conditions. The difference between photopic and mesopic conditions was more pronounced in binocular than monocular viewing conditions. The site variation was found to be most influenced by one site and therefore this site was excluded from further analysis. General linear model analysis showed a significant influence on CS curves from race in all five testing conditions (p<0.0001), and from gender and age in some testing conditions. Eye and pupil size were not found to have an influence on CS measurements.
We established the normative contrast sensitivity values for the F.A.C.T. chart in five testing conditions for presbyopic population based on a large sample. The results provide reference CS curves for clinics to use for the examination of patients in their standard clinical environment. Analyses provided insight into the variation in CS measurements. Both the normative CS curves and the influencing variables would be useful in the investigation of the impact of ophthalmic procedures on CS.
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