Abstract
Abstract: :
Purpose: Several reports in the literature have documented how visible optic disc drusen can affect central visual acuity and peripheral visual fields. Now that ultrasonographic methods are available to detect buried optic disc drusen, these same parameters can be redefined with a larger population of patients. In this study we characterized visual signs and symptoms relating to visible and buried optic disc drusen. Methods: A retrospective analysis of 75 eyes from 47 patients with definitive visual, angiographic, or ultrasonographic evidence of optic disc drusen seen at the University of Minnesota from July 1, 2001 to June 30, 2002. Eyes were excluded if they had incomplete records or had a coexisting ocular diagnosis that could affect the optic nerve or visual field analysis. We collected the following data: demographics, presenting symptom(s), visual acuity, refractive error, intraocular pressure, presence of an afferent pupillary defect, cup to disc ratio, appearance of the optic nerve, and visual field. Results: Forty-eight (64%) of the eyes were symptomatic: 65% of these had visual obscurations, 48% had subjective visual field defects, and 29% had an associated headache. Visual acuity ranged from 20/15 to 20/60 with a mean logMAR of 0.02 ± 0.11 (20/20). Sixty-four (85%) of the optic discs appeared abnormal on ophthalmoscopy: 47% of these had visible drusen, 36% appeared elevated, and 17% displayed anomalous vasculature. Forty-two (56%) of the eyes had a visual-field deficit: 74% of these were nerve fiber bundle type, 21% displayed generalized constriction, and 5% had only an increased blind spot. Of the 31 eyes with a nerve fiber bundle type deficit, 36% were inferonasal sectoral defects, 32% were inferior arcuate defects, 19% were superonasal sectoral defects, 19% were superior arcuate defects and 3% were superotemporal sectoral defects. Overall, 73% of optic discs with visible drusen had abnormal visual fields compared with only 44% of optic discs with buried drusen. Conclusions: Our study suggests that a majority of patients with optic disc drusen have non-specific symptoms such as visual obscurations, visual field defects and headaches despite maintaining good visual acuity. Most of the optic discs appeared abnormal, but visible drusen were observed in less than half. Approximately half had visual field deficits; these were primarily nerve fiber bundle defects in the inferonasal sector and inferior arcuate distributions. Our findings also suggest that buried optic disc drusen have a lower frequency of visual field defects than visible optic disc drusen.
Keywords: optic disc • visual impairment: neuro-ophthalmological dise • clinical (human) or epidemiologic studies: pre