The Fovea-Protective Impact of Double-Layer Sign in Eyes With Foveal-Sparing Geographic Atrophy and Age-Related Macular Degeneration

Abstract

Purpose The purpose of this study was to investigate the impact of double-layer sign (DLS) on geographic atrophy (GA) progression in eyes with foveal-sparing GA and age-related macular degeneration (AMD). Methods This is a retrospective, consecutive case series of eyes with foveal-sparing GA secondary to AMD with more than 6 months of follow-up. The size of the foveal-sparing area was measured on the fundus autofluorescence images at the first and last visits. Each eye was evaluated for the presence or absence of DLS inside the foveal-sparing area. We graded eyes based on the presence of DLS within the foveal-sparing area and compared the progression of GA between two groups (DLS (+) versus DLS (−)). Results We identified 25 eyes with foveal-sparing GA with at least 2 follow-up visits (average interval = 22.7 ± 11.8 months between visits). The mean foveal sparing area was 1.74 ± 0.87 mm 2 (range = 0.42–4.14 mm 2 ) at baseline and 1.26 ± 0.75 mm 2 (range = 0.25–2.92 mm 2 ) at the last visit. Seventeen eyes (65.3%) were graded as DLS (+) within the foveal-sparing area. Square root progression of GA toward the fovea was significantly faster in the DLS (−) eyes (0.149 ± 0.078 mm/year) compared to the DLS (+) group (0.088 ± 0.052 mm/year; P = 0.04). Conclusions The DLS (−) group showed significantly faster centripetal GA progression than the DLS (+) group. Our data suggest that the presence of DLS in the spared foveal area could be a protective factor against foveal progression of GA in eyes with AMD.

Myopic Vascular Changes Revealed by Optical Tomography Angiography and Their Association with Myopic Fundus Manifestations

“…The fovea plays the most crucial role in central vision, at which visual acuity is at its highest; thus, certain protective mechanisms could compensate for the effect of mechanical stretching on the fovea. A similar phenomenon has been reported for foveal-sparing geographic atrophy [ 44 ]. Jonas et al [ 45 ] reported that retinal thinning was most apparent in the equatorial and pre-equatorial regions in myopic axial elongation, whereas foveal retinal thickness was mostly unaffected.…”

Phenotypic characterization of predictors for development and progression of geographic atrophy using optical coherence tomography.

“…As a matter of fact, previous studies reported a protective effect of DLS in atrophy, postulating the existence of a “neochoriocapillaris” that provides support to the outer retina and photoreceptors. 18,27,32…”

“…The sample size calculation was determined considering the previous literature on GA area changes in a population with foveal sparing with or without a DLS. 18 The estimated total sample size was 45 patients (paired t -test, two-sided), with a significance level of 1% and a power of 95%. Quantitative data were reported as mean ± SD.…”

“…4,15,16 Along with the main OCT biomarkers for GA evolution, the presence of a double-layer sign (DLS) has been investigated with conflicting results. 17,18 The contradictory findings were interpreted considering the dual significance of DLS, which can be an unspecific marker for type 1 macular neovascularization (MNV) or originate from the accumulation of basal laminar deposits (BLamDs). 19,20…”

Integrating Machine Learning and Traditional Survival Analysis to Identify Key Predictors of Foveal Involvement in Geographic Atrophy

“…Qualitative SD-OCT assessments included identification of subretinal drusenoid deposits (SDD; ≥ 3 lesions identified on one B-scan), 10 , 11 refractile drusen (≥ 1 lesion identified on one B-scan), 12 and the double layer sign (DLS). 13 , 14 DLS exceeding 1000 µm in length and 100 µm in height on horizontal B-scan, or exhibiting multiple reflective layers between the RPE and the Bruch's membrane (BM), were excluded to mitigate the risk of confounding by non-exudative MNV.…”