Handheld VEP in elderly and/or non-verbal, non-mobile Glaucoma Patients

Abstract

Purpose : Visually Evoked Potential (VEP) has been shown to be helpful in examining the integrity of the visual pathways in nonverbal children and adults. The use of a portable, handheld VEP in the setting of elderly, non-mobile and/or non-verbal glaucoma patients has not been well studied.
Purpose: To evaluate VEPs using the RETeval device in elderly, non-mobile, and/or non-verbal glaucoma patients in a clinical setting.

Methods : RETeval (LKC Technologies, Gaithersburg, MD) was used. The RETeval device served as the ganzfeld; flash VEP was performed on patients, using ISCEV¹ guidelines of electrode placement. The RETeval flash VEP followed ISCEV¹ protocol for flash VEP, 3 cd^.s^.m-2. All patients were dilated to 6mm. VEPs were performed in 2016. Inclusion criteria: vision 20/20 to 20/60, glaucoma patients diagnosed by previous eye MD or optometrist, previous VF documenting glaucoma. Inability to sit for visual field, inability to operate hand held remote control for automated visual field testing, inability to speak or communicate with staff. Exclusion criteria: macular laser or previous optic neuritis history.
Control patients: no glaucoma, no optic nerve disease, visual acuity 20/20-20/60. Measurements of P2, N2 performed manually (IK and verified by GW).

Results : 8 Glaucoma patients: 5 females, 3 males, avg age=74.7 yrs (sd=12.5, range=59-94 yrs).
8 Controls : 3 females, 5 males, avg age=66.0 yrs (sd=14.9, range=43-83 yrs).
P2 amp: (Glc) P2 (avg OD and OS)=27.5 uV, sd=11.0, range=18-48 uV; Controls P2 (avg OD and OS)=14.7 uV,( sd=9.7, range=4.75-33.5)
unpaired t-test: p=0.028
P2 Implicit time (P2IT): Glc v C, t-test not significant.

Conclusions : This small study shows that there may be clinical usefulness in the handheld flash VEP in the setting of poorly mobile, elderly and/or non-verbal patients with glaucoma. This handheld VEP holds promise in the follow up of our most vulnerable patients who need eye care.

1 Odom JV, Bach M, Brigell M et al. ISCEV Standard for Clinical Visual Evoked Potentials (2016 update). Doc Ophthalmol 2016; 133:1-9.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.