Purpose
To evaluate the use of the 30 Hz RETeval(TM) handheld ERG device in diabetic and glaucoma patients in the office setting.
Methods
The RETeval(TM) (LKC Gaithersburg, MD) is a small handheld ERG device using adhesive skin electrodes in lieu of contact lens electrodes to assess cone function in patients without mydriasis. The RETeval(TM) is currently in Phase 2 and 3 clinical trials (US FDA, and EC, respectively). RETeval(TM) (REv) was used in patients with diabetes mellitus and glaucoma patients in a retina practice in San Jose, CA. Inclusion criteria: Diabetic pts HbA1c > 6.0 mg/dL or FBS > 100 mg/dL; Glaucoma patients were verified by visual field findings. Visual acuity was 20/15-20/40. The Stata statistical software program was used. For each patient, ERG data from only one eye was used, based on randomization by coin toss. Informed consent was obtained.
Results
A total of 50 patients and controls were enrolled over 3 months: Control (C): n=22: age range 23-75 yrs, avg=47.9, sd=16.3; Diab (DM): n=12: age range 23-77 yrs, avg=55.8,sd=14.6; Glaucoma (G) n=17: age range=37-76 yrs, avg=59.2, sd=11.95. ERG photopic implicit times were prolonged in both diabetic and glaucoma patients: 2 tailed t-test: Control mean 33.2 msec vs DM mean 34.6 msec, implicit time p=0.045; Control mean 33.2 msec vs G mean 35.4 msec, implicit time p=0.0009. No significant differences were noted between implicit times in the diabetic and glaucomatous patients or for difference in response in amplitude: C vs DM: p=0.26.
Conclusions
This small study suggests that prolongation of flicker implicit times in diabetes and glaucoma can be discerned with the RETeval(TM) in a clinical setting. The RETeval(TM) may thus be of value as a screening tool in nursing homes or facilities where ophthalmic exams are not available.
Keywords: 498 diabetes •
509 electroretinography: clinical •
465 clinical (human) or epidemiologic studies: systems/equipment/techniques