Clinical features of focal choroidal excavation subtypes and their association with choroidal neovascularization

This study aimed to propose a new classification of focal choroidal excavation (FCE), summarize the clinical and multimodal imaging characteristics of FCE subtypes, and explore the relationship between FCE and choroidal neovascularization (CNV).

In this retrospective observational study, patients diagnosed with FCE using spectral-domain optical coherence tomography (SD-OCT) were included. FCE was classified according to associated retinochoroidal diseases. Clinical and multimodal imaging features, as well as the association of CNV, were investigated for different subtypes of FCE.

The study included 105 eyes with FCE from 93 Chinese patients, with a mean age of 41.66 years (range: 15-75 years). Among the 93 eyes with comprehensive multimodal imaging data, FCE subtypes were classified as retractive (34.41 %), inflammatory (18.28 %), pachychoroidal (23.66 %), atrophic (9.68 %), and idiopathic (13.97 %). Idiopathic FCE patients had significantly better best-corrected visual acuity compared to those with retinochoroidal disease-associated FCE (P < 0.001). Inflammatory FCE was associated with higher myopia (median refractive error:6.00 D, P < 0.001) and reduced choroidal thickness (P = 0.014), whereas pachychoroidal FCE showed increased choroidal thickness. Retractive FCE exhibited the highest CNV rate at baseline (P < 0.001), with CNV more likely in larger greatest linear dimension (GLD) (P = 0.004) and female patients (P = 0.016). Although CNV was present in 50.54 % of cases at baseline, it grew within FCE during follow-up in only 8.60 % of cases, and 9.68 % experienced CNV recurrence.

Different FCE subtypes exhibit distinct clinical features. Idiopathic FCEs are generally stable, while the emergence of secondary CNV is linked to anatomical alterations caused by FCE and associated retinochoroidal diseases.