Optical Coherence Tomography Characteristics for Differentiating Scars in Type 1 (Polypoidal Choroidal Vasculopathy (PCV)) and Type 2 (Classical) Macular Neovascularization (MNV) in Age-Related Macular Degeneration (AMD)

TL;DR

This study uses optical coherence tomography to identify differences in scar characteristics between two types of macular neovascularization in age-related macular degeneration.

Contribution

The study identifies OCT features that can differentiate scarred stages of type 1 and type 2 macular neovascularization in AMD.

Findings

Type 2 MNV showed thinner choroid compared to type 1 MNV in most quadrants.

OCT features like outer retinal tubulations and cystoid spaces helped distinguish between the two MNV types.

Choroidal thickness differences were significant in nasal and superior quadrants within specific ranges.

Abstract

Purpose: This study aimed to assess the optical coherence tomography (OCT) characteristics for differentiating scars in the scarred stages of macular neovascularization (MNV) in age-related macular degeneration (AMD).

Methods: Medical records of 20 patients, 10 in each group with type 1 and type 2 MNV, were selected for the study. Participants chosen were above 50 years of age and underwent comprehensive eye examination alongside indocyanine green angiography (ICGA), fundus fluorescence angiography (FFA), and Spectralis optical coherence tomography (SOCT) (Heidelberg Engineering, Germany), respectively. The qualitative and quantitative OCT measurements, such as the frequency of outer retinal tubulations, presence of cystoid spaces, scar area, choroid thickness, retinal thickness, presence of disorganization in retinal layers (DRIL), foveal contour, and involvement of retinal layers in the scar, were meticulously evaluated and compared between the two groups.

Results: Significant disparities between type 1 MNV and type 2 MNV in choroidal thickness were identified in the nasal and superior quadrants within 1 mm, in the superior quadrant within 3 mm, and in all quadrants except the inferior quadrant within 6 mm. Overall, type 2 MNV showed thinner choroid than type 1 MNV.

Conclusion: Although there are several overlapping features noticed between the groups, the OCT was able to pick up characteristic features that aid in differentiating type 1 (polypoidal choroidal vasculopathy (PCV)) and type 2 (classic) MNV in AMD. This precise differentiation has the potential to assist ophthalmologists in making well-informed decisions, thereby enhancing patient care.

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