Abstract
Purpose: :
Pigmentary abnormalities have commonly been described in both non-neovacular age-related macular degeneration (NNVAMD) and pattern dystrophy (PD). The purpose of our study is to describe the optical coherence tomography (OCT) correlates of these pigmentary abnormalities in these disorders.
Methods: :
We retrospectively reviewed the medical history and OCT findings of 50 eyes of 38 patients (32 with NNVAMD and 18 with PD) presenting to the Doheny Retina Centers. All patients underwent OCT imaging using a macular cube protocol (512 x 128) with either a Topcon 3D-OCT 2000 or Zeiss Cirrus OCT. OCTs were graded by two experienced ophthalmologists, for a number of features including the presence of pigment migration as evidenced by intraretinal hyperreflective foci (IHF), subretinal deposits, pigment epithelial detachment, integrity of the RPE band, RPE atrophy, and vitreoretinal interface abnormalities (e.g. epiretinal membrane). For those eyes with IHF, the number of individual B-scans with IHF were quantified, and both the predominant retinal layer involved and the innermost extent of the IHF was determined. The largest hyperreflective focus was also measured using the caliper function as was the height of the largest adjacent pigment epithelial detachment.
Results: :
We observed that 21 patients (65.6%) with NNVAMD and 13 patients (72.2%) with PD had evidence of intraretinal hyperrefective foci (indicating pigment migration) and that 0 patients (0%) with NNVAMD and 11 patients (61.1%) with PD had evidence of subretinal deposits by OCT. For patients who had IHF, the average number of individual scans with IHF was 12.3 in patients with NNVAMD and 3.92 in patients with PD (p-value 0.0018). The average level of highest RPE migration was slightly above the outer plexiform layer in NNVAMD patients and was between the outer nuclear and outer plexiform layers in PD patients (p-value 0.17). The average height of the largest hyperreflective focus was 70.4 microns in NNVAMD patients and 78.6 microns in PD patients (p-value 0.336). The average logMAR visual acuity in patients with NNVAMD was 0.208 and in patients with PD was 0.163 (p-value 0.26).
Conclusions: :
Intraretinal hyperreflective foci/ pigment migration was common both in eyes with NNVAMD and in eyes with PD. IHF in eyes with PD were less extensive and did not migrate as great a distance from the RPE band. Conversely, subretinal deposits were more common in eyes with PD and appeared to co-localize with the pigment abnormalities. These findings suggest that pigment abnormalities in eyes with NNVAMD correspond to intraretinal pigment migration, whereas they correspond to the subretinal lesions in eyes with pattern dystrophy.
Keywords: age-related macular degeneration • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)