Abstract:
Background: Since the prevalence of late age-related macular degeneration (AMD)
is increasing, investigating the role of the choroid in the pathogenesis of the disease is
particularly important.
Purpose: To examine swept-source optical coherence tomography (SS-OCT)-derived
subfoveal choroidal thickness (SFCT) in patients differing in phenotypic manifestations
of AMD.
Material and Methods: Fifty-five AMD patients (67 eyes; age, 64 to 75 years) and 8
comparably matched-aged healthy controls (13 eyes) underwent SS-OCT measurement of
SFCT. They were divided into 6 groups: healthy individuals without signs of AMD and
patients with drusen; type 1 choroidal neovascularization (CNV); serous retinal pigment
epithelium (RPE) detachment; type 1 CNV; and geographic atrophy (GA). Statistical
analyses were conducted using Statistica software, version 13.5.0.17. Both parametric
and non-parametric techniques were used.
Results: Mean SFCT in patients with GA was 47.8% lower than in controls, 45.7% lower
than in patients with drusen, and 51.7% lower than in patients with type 1 CNV (p < 0.05).
We found no significant difference in mean SFCT between patients with GA and those with
RPE detachment, or between the former and those with type 2 CNV. Patients with AMD and
age-matched healthy controls were divided into four clusters based on choroidal thickness
(cluster I, 105 ± 4.8 μm; cluster II, 188 ± 3.5 μm; cluster III, 266 ± 4.6 μm; and cluster
IV, 408 ± 14.9 μm). There was no difference in cluster distribution between eyes with type
1 CNV and normal age-matched eyes. Of the eyes with drusen, most (81.8%) were from
cluster II. A statistically significant majority of eyes with serous RPE detachment, type 2
CNV, and dry AMD were assigned to clusters I and II (p < 0.05).
Conclusion: Patient groups differing in phenotypic manifestations of AMD were found
to differ in the mean magnitude of SS-OCT-derived SFCT, and could be classified into 4
clusters on the basis of their value of SFCT.
