Geographic Atrophy Secondary to Subclinical Angioid Streaks in Age-Related Macular Degeneration: Progression of the Disease at 2-Year Follow-Up.

Background: The purpose of the study is to characterize the rate of progression of geographic atrophy (GA) areas in patients with age-related macular degeneration (AMD) with subclinical angioid streaks (AS), compared to patients with AMD without subclinical AS.

Methods: This is a retrospective, longitudinal, case-control study. Among a cohort of patients with AMD, we selected patients with GA with subclinical AS and followed them for a 2-year follow-up. An age- and sex-matched control group with GA secondary to AMD without subclinical AS was selected. Demographics and differences in the GA progression between the two groups were analyzed.

Results: Among 60 eyes of 60 patients affected by GA secondary to AMD, 20 eyes of 20 patients (mean age 82 ± 5 years old) were included in the subclinical AS group, whereas 40 eyes of 40 patients (mean age 79 ± 6 years old, p = 0.077) were in the control group. All 20 eyes of subclinical AS group showed reticular pseudodrusen at the baseline compared to 73% of patients without AS (p = 0.002). In the subclinical AS group, 90% of eyes showed peripapillary atrophy in comparison to 63% in the control group (p = 0.026). Subclinical AS eyes showed a significantly lower subfoveal choroidal thickness in comparison to the control group (124 ± 60 μm vs. 161 ± 84 μm, respectively, p = 0.043). At 2-year follow-up, the rate of progression was higher in the patients with subclinical AS; the yearly growth rate was 0.41 ± 0.17 mm/year after the square root transformation in the subclinical AS group, in comparison to 0.32 ± 0.14 mm/year in the control group (p = 0.017).

Conclusions: Patients with subclinical AS showed a more aggressive phenotype of GA in comparison to AMD patients without subclinical AS, characterized by a higher rate of progression of GA areas during a 2-year follow-up.