Visual field defects and retinal nerve fiber layer damage in buried optic disc drusen: a new insight

To assess the association between buried optic disc drusen (BODD) location using spectral-domain optical coherence tomography (SD-OCT) and the location of associated visual field defects (VFD) using the Garway-Heath mapping.

This monocentric retrospective cross-sectional study was led at the authors' institution. Adult patients diagnosed with BODD who had complete records with a reliable Humphrey^® 24-2 visual field, macular, and papillary OCT were enrolled. Fisher's exact test was used to measure the association between BODD location and VFD distribution according to Garway-Heath's mapping.

Totally 20 eyes of 15 patients were included (60% females). The median age (interquartile range) was 63 (43)y and the median best corrected visual acuity (BCVA) was -0.08 (0.08) log MAR. BODD were mostly located in zones A, E, and F. The minimal rim width (MRW) was globally preserved. The retinal nerve fiber layer (RNFL) was predominantly altered in zones D, E, and F. There was a significant correlation between BODD location and that of RNFL alterations in zones D (P=0.03) and E (P=0.025); Moreover, the presence of BODD in the E zone was significantly related to damaged RNFL in the neighbouring sectors D and F (P=0.012; P=0.02 respectively). Sixty-three percent (12/19) of visual fields were abnormal and there was a significant match (Phi=0.7, P=0.009) between drusen location and VFD only in zone D.

BODD do not only affect young patients and can be more harmful than usually expected, as we found VFD in 63% of cases. There is a correspondence between BODD location, RNFL damage, and VFD distributions. The presence of BODD induces the overestimation of MRW, thereby disrupting its sensitivity as an early indicator of ganglion fibers damage.