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Clarissa Kum, Philip B. Kruger, Mitchell W. Dul, Lawrence R. Stark; Is A Deep Foveal Pit A Specialized Wavefront Vergence Detector For Accommodation?. Invest. Ophthalmol. Vis. Sci. 2011;52(14):840. doi: https://doi.org/.
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© ARVO (1962-2015); The Authors (2016-present)
To determine whether variation in foveal pit depth among observers explains wide inter-subject variation in ocular accommodation to wavefront vergence.
Foveal pit images were obtained from 20 normal observers (ages 21-27 yrs) using the Cirrus Spectral Domain HD-OCT set to a scan setting of 512x128 macular cube. The pit depths were measured using the digital calipers provided in analysis mode on the Cirrus Spectral Domain HD-OCT.Accommodation was recorded at a frequency of 100 Hz with observers viewing a high contrast Maltese cross in a Badal optical system through a 3 mm artificial pupil, while wavefront vergence (Zernike defocus) changed sinusoidally (1-3 D) at 0.2Hz. Six trials were run in broadband white light (3000K; 20 cd/m2) and six in monochromatic light (550 nm: 12nm bandwidth; 20 cd/m2) to eliminate chromatic aberration. Each trial lasted 40.96 seconds.Fast Fourier transform was used to extract the dynamic gains and temporal phase-lags at the stimulus frequency of 0.2Hz. Mean gains and temporal phase-lags were calculated for monochromatic and chromatic conditions separately.
Foveal pit depths ranged from 99 to 209 microns and accommodation gain varied widely between 0.04 and 0.66.Linear regression showed no significant correlation between foveal pit depth and accommodation to wavefront vergence for this group of 20 subjects (r2=0.112).
Foveal pit depth does not explain the wide inter-subject variation in dynamic accommodation gain to changing wavefront vergence.
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