Statistically detectable thinning of the optic nerve and macula structures can occur as early as 12 months in patients with optic nerve head drusen (ONHD), according to findings published in Eye (Lond).
“We found significant reduction in the mean and nasal [peripapillary retinal nerve fiber layer] thickness with thinning of the surface nerve fiber layer (hyperreflective space) over the optic nerve head centrally, superiorly and inferiorly,” researchers report. “In the macula area we also found retinal thinning caused by RNFL, [outer nuclear layer] and [outer segment] thinning. Statistically detected changes occurred in a short time over only 1 year.”
Researchers conducted a prospective, cross-sectional observational study to quantify changes in optic disc and macular spectral domain optical coherence tomography (OCT) parameters after 1 year of observation and to assess the effect of age at study enrollment in patients with ONHD.
A total of 35 patients with ONHD (mean age, 42.8±19.9 years, 57% women, 42% men) underwent spectral domain OCT imaging at baseline and after 12 months of follow up.
The researchers found that patients with ONHD displayed significant thinning of the surface nerve fiber layer in the central (P = .03), superior (P = .05) and inferior (P = .04) areas, with mean peripapillary retinal nerve fiber layer (ppRNFL) thinning (P = .04) and ppRNFL thinning in the nasal segment (P = .028).
They also observed retinal thinning in the central (P = .001), inner (P = .01) and outer (P = .002) temporal, outer superior (P = .03) and inferior (P = .02) areas as well as borderline ganglion cell layer thinning (P = .051) and outer nuclear layer (P = .03) thinning in the central retina and outer segment layer thinning nasally (P = .01) in macula.
The team reported no significant correlation between the difference in optic disc and macular parameters with the age at enrollment.
Limitations of the study included the relatively short follow up period and limited axial resolution of the OCT machine, which can cause difficulties in evaluation of some ONHD regions.
Pilat AV, Proudlock FA, Kumar P, Gottlob I. Short-term progression of optic disc and macular changes in optic nerve head drusen. Eye (Lond). Published online July 16, 2022.doi:10.1038/s41433-022-02155-7