Focal choroidal excavation (FCE) is a localized concave change in the choroid detected by optical coherence tomography (OCT). It is characterized by the absence of posterior staphyloma or scleral ectasia. It was first reported by Jampol in 2006 and named by Margolis et al. in 2011.
FCE morphology is broadly classified into two types.
Conforming type
Definition: A type in which there is no separation between the photoreceptor outer segment and the RPE (retinal pigment epithelium).
Features: The photoreceptors and RPE remain attached and sink together within the excavation. It often follows a relatively stable course.
OCT findings: The RPE and photoreceptor layer in the concavity are displaced together toward the choroid.
Non-conforming type
Definition: A type in which a gap (subretinal fluid or hyperreflective material) is observed between the photoreceptor outer segments and the RPE.
Features: High risk of complications such as macular neovascularization (choroidal neovascularization) and serous retinal detachment.
OCT findings: Fluid accumulation or hyperreflective material is observed between the RPE and photoreceptor layer within the concavity.
Classification by shape (conical, bowl-shaped, mixed) and by location (foveal, extrafoveal) is also used.
Capellan et al. classified FCE into three types based on etiology: type 1 (myopic), type 2 (congenital), and type 3 (acquired/inflammatory). In type 3, the rate of CNV (choroidal neovascularization) reaches 40% 7).
The prevalence in individuals under 40 years is reported to be 0.18% (3 out of 1697 eyes) 1). The prevalence of FCE in patients with central serous chorioretinopathy (CSC) is 2.8–7.8%, higher than in the general population 1). Detection rates are increasing with the widespread use of OCT.
In recent years, FCE has been trending toward exclusion from the pachychoroid disease spectrum. It is now considered an independent condition resulting from inflammatory Bruch’s membrane defects and localized choroidal thinning 8).
Many cases are asymptomatic and discovered incidentally during OCT examination. Symptomatic cases present the following.
In a series of 32 FCE cases, 60–77% of patients reported some visual disturbance.
If there are no symptoms and no macular neovascularization or serous retinal detachment, observation is the basic approach. However, due to the risk of developing macular neovascularization, regular monitoring with OCT and OCTA is recommended (see “Standard Treatment” section for details).
The pathogenesis of FCE has not been fully elucidated, and several hypotheses have been proposed.
The main diseases and risk factors associated with FCE are shown below.
| Category | Disease/Factor | Notes |
|---|---|---|
| Hereditary eye disease | Best disease | FCE occurs in 6% of cases3) |
| Hereditary eye disease | ABCA4-associated retinopathy | Report of progressive deepening7) |
| Systemic disease | Alagille syndrome | JAG1 gene mutation6) |
| Choroidal diseases | Central serous chorioretinopathy/polypoidal choroidal vasculopathy | Prevalence 2.8–7.8%1) |
| Lifestyle | Smoking | Oxidative stress → Bruch’s membrane defect4) |
Other risk factors include myopia, female sex, and Asian ethnicity. Bilaterality was observed in 7 out of 18 cases (38.89%) 1).
OCT is essential for diagnosing FCE. Diagnosis and evaluation are performed using a combination of the following tests.
OCT
Role: Gold standard for diagnosis.
Findings: Focal choroidal excavation. It is possible to distinguish between conforming and non-conforming types. Shape (cone, bowl, mixed) and depth are also measured.
OCTA
Role: Non-invasive detection of macular neovascularization. Diagnosis is possible without contrast agent2).
Findings: Dark flow signal void area in the choriocapillaris layer of the FCE region. When complicated by macular neovascularization, a flower-like net of neovascularization is depicted 2).
FA and ICGA
Other auxiliary tests may include FAF (evaluation of RPE health) and B-mode ultrasound (to differentiate from posterior staphyloma).
Differentiation from the following diseases is important.
For asymptomatic cases without choroidal neovascularization or serous retinal detachment, regular follow-up is the basic policy. Lifelong OCT and OCTA monitoring is recommended 1).
In a bilateral case of FCE complicated with CSC, a combination of focal laser (spot size 50 μm, power 70 mW, duration 0.1 seconds) and SML (Subthreshold Micropulse Laser) resulted in resolution of serous retinal detachment after 5 months 1).
Anti-VEGF therapy is the first-line treatment for cases with choroidal neovascularization. The main treatment outcomes are shown below.
| Study | Drug | Outcome |
|---|---|---|
| Duke 20252) | Bevacizumab 1.25mg/0.05mL | 20/40 to 20/20 after 3 injections |
| Sato 20214) | Aflibercept monthly × 3 months | CNV resolution + FCE resolution, no recurrence at 12 months |
| Literature summary4) | Anti-VEGF overall | 54 of 76 eyes (71%) showed good anatomical response |
Duke RCT et al. (2025) reported a case of a 30-year-old woman with subfoveal choroidal neovascularization (CNV) associated with FCE who received three injections of Bevacizumab, resulting in regression of the flower-like net-shaped CNV on OCTA and improvement in BCVA from 20/40 to 20/202).
Sato et al. (2021) reported a case in which monthly Aflibercept injections for three months led to the disappearance of CNV and the FCE itself4). No recurrence of CNV or FCE was observed during 12 months of follow-up. The disappearance of FCE is presumed to be due to fibrovascular scar formation after anti-VEGF therapy bridging the Bruch’s membrane defect.
Anti-VEGF therapy is effective, with good anatomical response reported in 54 of 76 eyes (71%) 4). In some cases, the FCE itself may disappear 4). However, due to the risk of recurrence, continuous monitoring after treatment is necessary.
The most widely supported theory is the Bruch membrane defect hypothesis. At sites of Bruch membrane weakening or defect, the outer layer of the RPE-Bruch membrane complex protrudes outward due to intraocular pressure (IOP). The internal limiting membrane (ILM) does not shift. This matches the morphological features of FCE observed on OCT 4).
Benson et al. (2022) documented the following course over 8 years of serial OCT in patients with ABCA4-related retinopathy 7).
This observation is direct evidence that conforming and non-conforming types exist on a spectrum and can progress in stages7).
OCTA analysis reveals dark flow signal void areas in the choriocapillaris layer of the FCE region1). This suggests reduced blood flow in the choriocapillaris at the FCE site, and local ischemia may lead to inflammation, Bruch’s membrane fragility, and macular neovascularization2).
The following pathway is estimated: choroidal depression → localized choroidal thinning → ischemia/chronic inflammation → Bruch’s membrane weakening → macular neovascularization 2). In type 3 FCE, the rate of CNV complication has been reported to reach 40% 7), making the classification of FCE types important for clinical risk assessment.
Alagille syndrome (AGS) is a multi-organ disease caused by JAG1 gene mutations (over 97%). Against a background of chorioretinal atrophy due to abnormal Notch signaling pathway, FCE and macular hole have been reported to co-occur 6).
Conventionally, FCE was sometimes included in the pachychoroid disease spectrum, but recent large-scale reviews have led to reclassification. Cheung et al. (2024) proposed excluding FCE from the pachychoroid disease spectrum and positioning it as an independent pathology with inflammatory Bruch’s membrane defects and localized choroidal thinning as the etiology 8).
Benson et al. followed FCE in ABCA4-associated retinopathy with serial OCT over eight years and documented for the first time the natural course of conforming FCE transitioning to non-conforming FCE and eventually leading to macular hole 7). This observation is an important finding for understanding the progression of FCE.
It has been reported that combining OCTA (optical coherence tomography angiography) and SD-OCT (spectral-domain OCT) enables diagnosis of FCE-associated macular neovascularization without the use of contrast agents (fluorescein, ICGA)2). This may reduce dependence on invasive contrast examinations.
Sato et al. (2021) reported the first case of FCE itself disappearing after Aflibercept administration4). Bridging of Bruch’s membrane defects by fibrovascular scar is speculated as the mechanism of FCE disappearance, suggesting that anti-VEGF therapy may also affect morphological changes in FCE.
The three-type classification by Capellan et al. (type 1: myopic, type 2: congenital, type 3: acquired/inflammatory) is attracting attention as a useful framework for risk assessment and treatment decision-making7). Validation through future prospective large-scale studies is expected.
Most FCEs follow a stable course, but the rate of macular neovascularization is reported to be approximately 16% in long-term follow-up 2). In cases with underlying progressive retinal degeneration such as ABCA4-related retinopathy, there are reports of gradual deepening from the conforming type to the non-conforming type, leading to macular hole 7). Lifelong monitoring is recommended 1).
