Subclinical Angioid Streaks with Pseudodrusen: A New Phenotype of Age-Related Macular Degeneration

Abstract

Introduction To describe subclinical angioid streaks (AS) as a frequent, peculiar age-related macular degeneration (AMD) phenotype, comparing features of eyes with subclinical AS with those of eyes with AMD without AS. Methods This was a retrospective, observational study. Among a patient cohort with AMD, we selected patients without known causes for AS whose eyes showed signs of angioid streaks (AS) on structural optical coherence tomography (OCT) but not on fundus examination. Selected OCT features of AS were Bruch’s membrane (BM) breaks and large BM dehiscences. Results Among 543 eyes of 274 patients with AMD (mean ± standard deviation: 82 ± 7 years), 73 eyes of 46 patients (81 ± 7 years; p = 0.432) showed AS features on OCT (OCT AS) that were not visible on fundus examination. Estimated prevalence of subclinical age-related AS was 13.4% (95% confidence interval 10.3–16.3%) in this AMD population. Fifty-three eyes (73%) with AS features were affected by peripapillary atrophy, often with a “petaloid-like” pattern, similar to typical features of AS disease. Almost all cases (97%) presented reticular pseudodrusen (RPD), with (41%) or without (59%) drusen showing a significant difference in RPD prevalence in OCT AS eyes in comparison to AMD eyes without subclinical AS using generalized estimating equations ( P < 0.001). Among the 73 subclinical AS cases, 71 were affected by late AMD (57 with macular neovascularization, 14 with geographic atrophy), showing a more advanced AMD stage in comparison with AMD eyes without subclinical AS ( P < 0.001). The following OCT features were disclosed: BM breaks in 100% of cases and BM dehiscences in 37%. Conclusions Subclinical AS in eyes with AMD is a peculiar phenotype of the disease, with features suggesting a primary involvement of Bruch’s membrane and clinical similarities with mild, late-onset pseudoxanthoma elasticum.

Macular Neovascularization Secondary to Subclinical Angioid Streaks in Age-Related Macular Degeneration: Treatment Response to Anti-VEGF at 2-Year Follow-up

“…Subclinical AS is a recently reported phenotype of AMD that affects about 13.4% of patients with AMD [ 7 ]. This new phenotype is characterized by a predominant involvement of BM as a driving factor.…”

“…Therefore, we supported that the different percentage of macular atrophy development between the two groups was due to the different phenotypes of the disease, reflecting a different pathogenetic background. As previously reported, subclinical AS was supposed to be characterized by a predominant involvement of the Bruch’s membrane, in contrast to the supposed choriocapillaris and RPE/photoreceptor loss of the other phenotype of AMD [ 3 – 7 , 25 ]. Furthermore, the group of AMD with subliclinical AS was characterized by the presence of RPD in almost all cases and a significantly thinner choroidal thickness compared to the control group.…”

“…We included patients with the following features: (1) 50 years of age and older; (2) diagnosis of AMD; (3) presence of subclinical AS; (4) presence of treatment-naïve MNV at the baseline; (5) treatment with anti-VEGF injections (aflibercept as first choice) using a rigorous pro-re-nata (PRN) regimen; (6) 2-year follow-up. The presence of subclinical AS was defined according to the previously published criteria (i.e., BM breaks, and/or large dehiscences of BM using structural OCT and absence of AS employing fundus examination) [ 7 ]. For our clinical practice standards, all patients treated using a PRN regimen were treated with a loading phase of 3 monthly consecutive injections, and, after that, they were evaluated every 8 weeks (using aflibercept).…”

“…Recently, our group described a new AMD phenotype, namely subclinical angioid streaks (AS). Subclinical AS are characterized by structural OCT findings typical of AS [Bruch’s membrane (BM) undulations, BM breaks, and large dehiscences of BM] but with the absence of AS employing fundus examination (for this reason “subclinical”) in patients with landmarks of AMD [i.e., drusen and reticular pseudodrusen (RPD)] [ 7 ]. The primary involvement of the BM using structural OCT and the concomitant high prevalence of RPD suggested the predominant involvement of BM as a driving factor of this new phenotype.…”