Establishment and verification of the multi-dimensional peripheral contrast sensitivity function measurement based on Bayesian probability estimation algorithm

Objective

To evaluate the feasibility and accuracy of a multi-dimensional peripheral quick contrast sensitivity function (pqCSF) measurement established based on Bayesian probability estimation algorithm.

Methods

A cross-sectional study was conducted.Nineteen eyes of 12 healthy emmetropic subjects in Zhongshan Ophthalmic Center of Sun Yat-sen University from September 2017 to March 2018 were included, with an average age of (22.92±2.91) years.The average spherical power and cylindrical power were (-0.34±0.52)D and (-0.30±0.42)D, respectively, and the average uncorrected vision acuity was≥1.0.Based on the Bayesian probability algorithm, the peak contrast sensitivity γ_max, the peak spatial frequency ƒ_max, the bandwidth β and the low contrast intercept δ were used to quickly describe the contrast sensitivity function (CSF) curve of the full spatial frequency through multi-dimensional pqCSF method.The 16 peripheral visual field positions of all subjects were tested at 6°, 12°, 18° and 24° eccentricity of the superior, inferior, the temporal and nasal visual field by the pqCSF method, but the 18° eccentricity of temporal field, which was near the physiological blind spot, was excluded.The area under Log CSF (AULCSF) of different peripheral visual fields and the Log CSF of 19 spatial frequencies (distributed at equal intervals in logarithmic units) were compared.This study followed the Declaration of Helsinki, and the study protocol was approved by an Ethics Committee of Zhongshan Ophthalmic Center of Sun Yat-sen University (No.2018KYPJ017). Written informed consent was obtained from each subject prior to any examination.

Results

With the increase of eccentricity in different visual fields, the AULCSF decreased gradually, and there were significant differences in AULCSF between different eccentricities (all at P<0.05). The AULCSF of the nasal and temporal visual field at 6°, 12° and 24° eccentricity was significantly larger than that of the superior and inferior visual field (all at P<0.05). As the distance from the fovea was increased, the pqCSF, the AULCSF, and the high-frequency cutoff were all decreased, and the standard deviation of AULCSF was increased gradually.

Conclusions

The pqCSF method can depict a relatively complete peripheral CSF curve of a wide peripheral visual field, and reflect the function quality of the peripheral vision comprehensively and accurately.