Abstract
Abstract: :
Purpose: To present qualitative ERG data recorded in brief general anesthesia in infants and children, revealing a wide spectrum of the final diagnoses. Methods: Retrospective review of charts. ERGs were recorded using a Grass flash in a distance of 30cm. Recordings were done in general anesthesia in outpatients, using Sevoflurane (29 patients), Isoflurane (43 patients) or, in earlier years, Ketamine (108 patients). ERG recordings were done using an LKC UTAS 3000 system or, previously, preamplification and an oscilloscope. The protocol included a short period of dark adaptation (>5 minutes), a red flash (broad band red filter, W 16), a dim (W1) white light flash and a bright (W16) flash. After >1 minutes of light adaptation, a white single flash (W16) and 30 Hz flicker stimulus (W4) were applied. Red light stimulation served for separation of early cone- and later rod-driven b-waves. Fundus photography complemented the ERG whenever possible. Results: The charts of a total of 179 patients were reviewed spanning a time period from 1982 to 2002. All patients were examined without complications. Age ranged from 3 months to 18 years, with the vast majority younger than 5 years. ERG recordings were normal in 94 patients, markedly abnormal in 41 patients and not measurable in 44 patients (52.5%, 23.0%, 24.5% respectively). The three main diagnoses were; (I) for patients with markedly abnormal ERG: achromatopsia, retinitis pigmentosa, retinopathy of prematurity; and (II) for patients with absent ERG: Leber’s congenital amaurosis, retinopathy of prematurity, retinitis pigmentosa. Conclusions: ERG recording in brief general anesthesia is a relatively easy and a safe way to establish an early diagnosis for infants with visual impairment. It allows distinguishing between retinal and non-retinal visual dysfunction. An early diagnosis is important for visual support and adequate education especially in combined deficit of receptive functions (e.g. Usher’s syndrom) or in neuropediatric syndromes. This facilitates informing parents and genetic counseling. A similar diagnostic spectrum for ERGs under anesthesia was reported by Weleber et al at ISCEV meeting in Leuven July 2002.
Keywords: electroretinography: clinical • clinical (human) or epidemiologic studies: sys • retina