Focal choroidal excavation (FCE), once a curiosity of isolated case reports, is now recognized as a distinct clinical entity with significant ties to the pachychoroid spectrum and potential for progression into vision-threatening complications like choroidal neovascularization (CNV). A recent large-scale study of 19,048 individuals in a health-screening cohort provides new clarity on the prevalence of FCE and, more importantly, how its funduscopic appearance correlates with structural complexity.
Prevalence in a Younger Population
The study identified an overall FCE prevalence of 1.0%. Interestingly, the highest prevalence (1.4%) was observed in individuals aged 30 to 39 years, with a progressive decline in older age groups. This suggests that FCE may be a congenital or early-onset structural anomaly that remains morphologically stable in most cases, rather than an age-dependent accumulation.
Ocular Associations: Beyond the Excavation
When comparing FCE patients to matched controls, several distinct ocular profiles emerged. Eyes with FCE demonstrated:
- Significantly lower intraocular pressure (IOP) (P = 0.026).
- Greater choroidal thickness (P < 0.001).
- Higher prevalence of macular degeneration (P = 0.002).
No significant associations were found with systemic comorbidities such as diabetes, hypertension, or dyslipidemia, suggesting FCE is primarily an isolated ocular structural phenomenon.
The “Visibility” Paradigm: Triage through Fundus Photography
One of the most clinically relevant findings of this study is the distinction between fundus-visible and fundus-invisible lesions. Fundus-visible FCEs (observed as subtle pigmentary changes, yellowish-white lesions, or contour irregularities) often serve as markers for more advanced structural remodeling.
Compared to invisible lesions, fundus-visible FCEs were:
- Larger and Deeper: Exhibiting significantly greater median horizontal diameter (681.0 µm vs. 518.0 µm) and depth (69.5 µm vs. 45.0 µm).
- Centrally Located: More frequently found in the foveal (35.9%) and parafoveal regions.
- Structurally Complex: More likely to have steep slopes (62.5%), outer nuclear layer (ONL) thickening (61.7%), and subretinal hyperreflective material (SHRM).
Morphological Markers of Remodeling
The researchers identified several key OCT markers that indicate active or unstable forms of FCE:
- The “Omega Sign”: A novel feature described as a dome-shaped elevation of the retinal pigment epithelium (RPE) connected to the FCE margin.
- Structural Alterations: Visible lesions more frequently involved the ellipsoid zone and outer plexiform layer (OPL), and occasionally presented with localized retinoschisis or subretinal fluid.
- Pachychoroid Features: The presence of pachyvessels adjacent to or beneath the excavation was noted in a high percentage of cases (81.3% of visible lesions), reinforcing FCE’s place within the pachychoroid disease spectrum.
Clinical Takeaway for the Ophthalmologist
While fundus photography alone is insufficient to detect all FCEs—nearly half of the visible lesions were only appreciable upon OCT-guided review—it remains a valuable triage tool. The presence of even subtle pigmentary or contour irregularities in a younger patient should prompt targeted OCT evaluation.
Because visible, centrally located FCEs mirror the structural complexity seen in longitudinal cases that evolve into pathologic states (such as CNV or conforming-to-nonconforming transitions), these patients may warrant closer clinical observation. Early identification through subtle funduscopic clues can enable the monitoring of high-risk morphologic features even in asymptomatic individuals with good vision.
Reference Kim E, Song SJ. Focal Choroidal Excavations in a Screening Cohort: Fundus Visibility and Structural Remodeling in Younger Adults. Retina. 2026;46(6):1124–1135.
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