Dynamic Morphological Changes of Focal Choroidal Excavations in Bilateral Choroidal Osteoma.

Purpose: To report the long-term evolution of bilateral focal choroidal excavations in a pediatric patient with choroidal osteoma.

Methods: The patient was referred following incidental findings of yellowish lesions at the posterior pole in both eyes. At presentation, best-corrected visual acuity was 20/20 bilaterally. Multimodal imaging confirmed the presence of bilateral choroidal osteoma. During the 15-year follow-up, no choroidal neovascularization or exudation developed, and visual acuity remained stable. Over time, multiple bilateral focal choroidal excavations were documented.

Results: These excavations demonstrated variable behavior, including progression, regression, and spontaneous resolution. Most focal choroidal excavations remained conforming, with one lesion in the right eye evolving into a non-conforming type before resolving. One of them transformed into a true choroidal depression, associated with tumor decalcification and choroidal thinning.

Conclusion: The findings suggest that these excavations in choroidal osteoma may result from localized structural remodeling and focal decalcification, potentially serving as imaging biomarkers of tumor weakening. The bilateral, dynamic nature of FCEs, even in areas without clear decalcification, suggests that biomechanical or vascular factors may contribute.