Abstract
Purpose :
Optics differ between central and peripheral vision. This implies suboptimal peripheral image formation if the refraction correction is optimal for central vision, and interferes with perimetry. Additionally, when the natural lens is replaced by an artificial intraocular lens (IOL), during cataract surgery, the quality of the peripheral optics is modified. The aims of this study were to determine if perimetry performed with central refraction differs from perimetry performed with optimal correction, and compare the differences between central and peripheral correction between phakic and pseudophakic glaucoma patients and healthy subjects.
Methods :
Cross-sectional study with 20 glaucoma patients and 20 age-similar (50-75 years) healthy subjects, 10 phakic and 10 pseudophakic eyes per group. Threshold perimetry was performed twice with optimal correction for fovea and periphery, respectively, with a minimized testing grid (fovea, ±10 and ±25 degree at the horizontal meridian). Thresholds for Goldmann size III stimuli were obtained with the ZEST Bayesian strategy on an OPI-driven Octopus 900. Aberrations were measured for each test location using a scanning peripheral Hartmann-Shack wavefront sensor.
Results :
Overall, there was an improvement in retinal sensitivity when peripherally corrected compared to testing the periphery with central correction (P=0.01). The average gain was 1.1 dB in healthy and 0.3 dB in glaucoma. The difference between peripheral and central refraction did not depend on the presence of glaucoma (P=0.20), nor on IOL status (P=0.32).
Conclusions :
Perimetric sensitivity can be improved by using optimal refraction for each test location, but the difference (~1 dB) is of limited clinical significance.
This is a 2020 ARVO Annual Meeting abstract.