Abstract
Purpose:
Blue-yellow visual evoked potentials (BY-VEPs) may be used for diagnostics of functional ganglion cell damage in glaucoma and other ocular diseases. In this study we investigated the impact of lenticular opacities on BY-VEPs by examining patients before and after cataract surgery.
Methods:
18 patients with moderate cataract were included in a prospective study. Transient on/off isoluminant blue-yellow 2° checks were used for short-wavelength stimulation (BY-VEP), transient large 1° (M1) and small 0.25° (M2) black-white checks for standard pattern reversal VEPs. VEPs were acquired before (24 ±30 days) and after cataract surgery (14 ±16 days). The contralateral eye was used as a control.
Results:
Amplitude and latency of M1 and M2 peaks did not change significantly from before to after surgery. The amplitude of the BY-VEPs did not change significantly after cataract surgery (pre-surgery: -7.42 ±3.43µV, post surgery: -7.93 ±3.65µV, p=0.42), yet the latency of the main negative peak showed a significant decrease (pre-surgery: 143.9 ±12.9ms, post-surgery: 133.2 ±7.7ms, p=0.0006). The BCVA improvement was significant from before to after cataract surgery (pre-surgery: 0.344 ±0.125 LogMAR, post-surgery: 0.224 ±0.179 LogMAR, p=0.013) yet not correlated to the absolute decrease in latency of the BY-VEP after surgery (r=0.309, p=0.22). No significant changes were found in the contralateral eye.
Conclusions:
The BY-VEP is sensitive to lenticular opacities of the human lens, presumably due to the increased short wavelength absorption in the aging eye. This fact should be considered when applying BY-VEPs for diagnostics.
Keywords: 507 electrophysiology: clinical •
445 cataract •
567 intraocular lens