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International Society for Clinical Electrophysiology of Vision (ISCEV)
June 18, 2018 - June 23, 2018
LKC is happy to be a gold sponsor of the 56th ISCEV Symposium with the French Society of Exploration of Vision and Electrophysiology (SEVE). Quentin Davis, PhD & Olga Kraszewska, PhD will be presenting during the human and animal courses on June 18-19 and a poster during the conference. Read below or contact us to learn more.
Wednesday, June 20 – 1:15 – 3:15pm
Session 3: Poster Session 1
Title: Diagnostic performance of photopic ERGs in a population who visits optometrists and ophthalmologists (3.18)
Presented by: Dr. Quentin Davis, PhD & Dr. Olga Kraszewska, PhD
Purpose: To assess the utility of photopic ERGs as an objective aid to detect any retinal disease in a population who visits optometrists and ophthalmologists.
Methods: In three ophthalmology and two optometry centers in the USA, all patients coming for a normally-scheduled visit were asked to participate. Subjects were tested with dilated or natural pupils based on what was required for their normal examination. Subjects with dilated eyes had one randomly-selected eye tested, while natural pupil subjects had both eyes tested. Dilated subjects were tested with eight constant-luminance (candela-based) protocols and two ISCEV-equivalent Troland-based protocols that compensate for pupil size. Natural pupil subjects were tested with 11 Troland-based protocols. Pediatric subjects less than eight years of age used a shorter test set; subjects aged 8–12 years old were given a choice as to the testing length.
Subjects were classified as normal if the following criteria were met for both eyes: best corrected visual acuity (BCVA) of 20/25 (0.1 logMAR) or better, optic nerve cupping < 50 %, no glaucoma or retinal diseases, no prior intraocular surgery (excepting non complicated cataract or refractive surgery performed more than one year before), intra-ocular pressure ≤ 20 mm Hg, no diabetes, and no diabetic retinopathy as determined by the ophthalmologist or optometrist. Eyes were classified as diseased if the physician detected glaucoma, diabetic retinopathy, or other retinal diseases in either eye. Clinicaltrials.gov identification NCT03065881.
Results: To date, 594 subjects have been tested, 253 of whom were classified as normal and 158 of whom were classified as diseased. Self-reported race was 49% Caucasian and 34% African American in the normal group and 28% Caucasian and 64% African American in the diseased group. About 13/18% selfreported as Hispanic in the normal / diseased groups. The gender distribution was 65/61 % female in the normal/diseased groups. At the time of testing, 38/61% of subjects had been artificially dilated in the normal/diseased groups. The most common diseases were glaucoma (47%), diabetic retinopathy (30%), optic atrophy (17%), hypertensive retinopathy (10%), age-related macular degeneration (AMD, 6%), and retinal vein occlusion (RVO, 4%). Reference ranges were determined using the normal subjects. Subject’s ERGs were considered abnormal if either the amplitude was smaller than a given percentile in the reference data or if the peak times were longer than the same percentile. Brief flash flicker tests best separated diseased from healthy, with an area under the receiver operating curve (ROC) of 85% for the 16 td s flicker ERG. One point on that ROC curve had a sensitivity of 81% and a specificity of 83%.
Conclusions: We considered the utility of a simple photopic ERG as an initial aid to the doctor in assessing the presence of retinal disease (e.g., in a general office visit). As shown here, a 16 td s flicker ERG may have sufficient performance to meet this need. We are continuing to test subjects to increase the confidence in these measurements and plan to determine if combinations of ERG tests and/or visual acuity can improve diagnostic performance. Limitations of the study include imperfect racial matching between diseased and healthy groups, and our disease distribution may not be representative of the disease distribution everywhere.