Abstract
Purpose :
Optic Nerve Head Drusen (ONHD) is 3.4 per 1,000 in clinical studies with higher rates of 10-20 per 1,000 in autopsy studies. Fundus Auto Fluorescence (FAF) can identify superficial ONHD. Ocular Coherence Tomography with Angiography (OCT/OCTA) can confirm 3-dimensional size. ONHD can cause visual field defects by disrupting the Retinal Nerve Fiber Layer (RNFL) and causing Ganglion Cell Complex (GCC) loss. In this study, we examine ONHD structural changes utilizing OCT/OCTA over a 6-year period.
Methods :
Three ONHD patients were evaluated in this study. Visual acuity, Body Mass Index (BMI), IOP non-contact puff tonometry, color and FAF photography using a non-mydriatic retinal camera was performed. T1DM duration was recorded. Visual fields (VF) were assessed via peripheral 60-4 and central 24-2 threshold tests on a Zeiss Humphrey Field Analyzer. A Canon OCTA H-100 and Avanti OCTA were used to measure RNFL and GCC thickness over 4 years.
Results :
Subject 1 is a 22 y/o Female with T1DM. Color photography showed irregular optic nerve margins OS and FAF confirmed ONHD at 6 o’clock. OD photography appeared normal. OCT confirmed ONHD OU. GCC loss over 6 years was greatest in the OS superior quadrant, while RNFL loss measured over 2 years was greatest OS inferiorly (Table 2). On average, there was a 2.8% GCC loss per year while RNFL loss per year was 12.5% in the OS superior quadrant. The 24-2 central threshold VF demonstrated a glaucoma hemifield test outside normal limits with a pattern standard deviation of 2.14dB (P<5%). Subjects 2 and 3 are 30 and 50 y/o females without T1DM. Both FAF and OCT confirmed presence of ONHD. GCC thickness decreased in both cases (Table 1, Table 2) similarly to subject 1. Subject 2 had a 5.8-8% OU GCC loss per year over 2 years (Table 2). In all 3 cases, the size of the ONHDs has remained constant during follow up and no superficial vascular changes were noted.
Conclusions :
Since ONHD are often associated with retinal flame hemorrhages, more frequent retinal evaluations should be performed in T1DM. Our results indicate that OCT/OCTA along with FAF should be included when evaluating patients as it can identify buried ONHDs and evaluate GCC and RNFL loss, thus allowing for improved follow up and a better understanding of the natural history of ONHD and the role of future interventions.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.