Retinal Pigment Epithelial and Outer Retinal Atrophy in Age-Related Macular Degeneration: Correlation with Macular Function

Abstract

The purpose of this study was to investigate the relationship between the retinal pigment epithelium (RPE) and outer retina changes, expressed in terms of sub-RPE illumination (SRI) on optical-coherence tomography (OCT), and central retinal function, measured by visual acuity and focal electroretinogram (fERG), in patients with non-exudative age-related macular degeneration (neAMD). In this retrospective study, 29 eyes of 29 patients affected by early (24.14%), intermediate (41.38%), and advanced (34.48%) neAMD were evaluated. All enrolled eyes were studied with OCT to measure the total area of SRI, by using an automated standardized algorithm. Visual acuity and fERG were assessed. The area of SRI was negatively correlated with fERG amplitude (r ≤ −0.4, p ≤ 0.02) and best-corrected visual acuity (BCVA) (r ≤ 0.4, p ≤ 0.04). Our results indicate that the severity of retinal pigment epithelium and outer retina atrophy (RORA), indirectly quantified through the detection of SRI areas by commercial OCT algorithms, is correlated with central retinal dysfunction, as determined by visual acuity and fERG, supporting the combined use of structural exams and functional tests as valid tools to detect the extent of RPE and photoreceptors’ disruption.

Biomarkers in Early Response to Brolucizumab on Pigment Epithelium Detachment Associated with Exudative Age-Related Macular Degeneration

“…The role of an abnormal choriocapillaris perfusion of the macular area also has been recently reported to be a contributing factor to the progression of non-exudative AMD [33]. The investigation of retinal pigment epithelial and outer retinal atrophy (RORA) is continuously developing and can be considered a prognostic factor for atrophy progression or change to an exudative form of AMD [29,34,35].…”

Subretinal Pigment Epithelium Illumination Combined With Focal Electroretinogram and Visual Acuity for Early Diagnosis and Prognosis of Non-Exudative Age-Related Macular Degeneration: New Insights for Personalized Medicine

“…The results showed that microanatomic abnormalities of the macula were correlated with abnormalities in functional parameters (acuity, fERG), indicating early losses in retinal function. 13 , 21 In addition, the extent of RORA, a parameter correlated with visual acuity and fERG amplitude, significantly predicted the progression of disease at 12 months. Our findings support the diagnostic power and predictivity of morphofunctional assessments in ne-AMD eyes.…”

“…The advanced RPE analysis software was used to determine the areas of SRI (mm 2 ) for increased light penetration through atrophic RPE and choriocapillaris by means of sub-RPE slab tools derived from segmentation. 13 The SRI identifies bright areas of increased light transmission beneath the RPE, indicating RPE atrophy, and is averaged over a circular area of 5 mm around the fovea by the automated OCT software as previously reported. 13 The automated software provides two types of values: (1) the average of the total SRI area in a circle of 5 mm centered on the fovea, and (2) the closest distance to the fovea in millimeters.…”

“… 13 The SRI identifies bright areas of increased light transmission beneath the RPE, indicating RPE atrophy, and is averaged over a circular area of 5 mm around the fovea by the automated OCT software as previously reported. 13 The automated software provides two types of values: (1) the average of the total SRI area in a circle of 5 mm centered on the fovea, and (2) the closest distance to the fovea in millimeters. For this second measurement, we considered the value to be 0 when the software provided the value of xxx , indicating that 0 was the distance from the fovea.…”

“…These parameters may play an important role in defining the features of early AMD and its progression. 13 The relationship between functional and anatomic parameters in early AMD and potentially predictive parameters for the progression of disease currently remain unclear. 18 , 19 …”