The incidence of neovascular membranes and visual field defects from optic nerve head drusen in children

Abstract

Purpose: To evaluate the incidence of visual field defects and choroidal neovascular membranes (CNVM) in a cohort of pediatric patients with optic nerve head drusen (ONHD).

Methods: The medical records of children with ONHD seen at a single center from January 2012 to July 2014 were retrospectively reviewed to identify patients who had a dilated fundus examination, fundus photography, spectral domain optical coherence tomography (SD-OCT)/enhanced-depth imaging (EDI) of the optic nerve head (ONH), SITA fast 24-2 Humphrey visual field (HVF) testing, lumbar puncture, and ocular ultrasound. A masked neuro-ophthalmologist analyzed fundus photographs, OCT, and fields. Retinal nerve fiber layer (RNFL) data were compared to age-matched controls.

Results: A total of 52 children (98 eyes) were included. Mean age was 10.8 ± 3.3 years. Of these, 42 patients had visual fields (57 eyes deemed reliable), and 19 eyes had documented visual field deficits (8 were reproducible across ≥1 sitting [frequency 14%]). After correction of plotting errors (40 eyes), RNFL thickness was 111.9 ± 17.9 μm. CNVM were present in 24 of 98 eyes (24.5%), with 21 of 24 located nasally (87.5%). Neither RNFL thinning nor identification of ONHD on fundus photography correlated with the presence of visual field defects.

Conclusions: Visual field defects due to ONHD can be reliably identified in children. In eyes of children with ONHD, RNFL protocol is frequently unreliable and may overestimate RNFL thickness. EDI scans through the ONH revealed peripapillary CNVM in nearly a quarter of the patients. Further longitudinal studies looking at the progression of CNVM and visual field deficits are warranted.