Sequential imaging of a case of choroidal osteoma using swept-source OCT and optical coherence tomography angiography: A 4-year follow-up study

Clinical Observation of Choroidal Osteoma Using Swept-Source Optical Coherence Tomography and Optical Coherence Tomography Angiography

Choroidal neovascularization (CNV) secondary to choroidal osteoma (CO) can cause profound visual loss, but detecting CNV and the tumor’s feeder vessels using traditional fluorescent angiography imaging is challenging. Newly developed TowardPi swept-source optical coherence tomography (SS-OCT) and OCT angiography (SS-OCTA) enable ultra-high resolution, enhanced penetration with longer wavelength (1060 nm), a rapid scan rate (400 KHz), reduced loss of signal strength with increasing depth, and 120° angular widefield of fundus view, enabling a nearly histological description of the retina and choroid. We therefore used this SS-OCT and SS-OCTA platform to observe the intrinsic features of osteoma in 23 eyes of 21 patients. It was found that the borders of CO were clearly demarcated from the adjacent choroidal Sattler’s and Haller’s layers, while on a corresponding B-scan the blood flow of the CO was detected mainly within the choriocapillaries and partly within Sattler’s layer. The CNV was identified as numerous branching or radiating vessels connecting with intrinsic feeder vessels displaying various patterns including ginseng, instant noodle, growth ring, tangle, spider web, medusa, seafan, and irregular shape. Moreover, tumor-like tissues were found to grow above the disrupted Bruch’s membrane. SS-OCTA can be used to detect the tumor vasculature in CO.

CORRELATION BETWEEN FOCAL CHOROIDAL EXCAVATION AND UNDERLYING RETINOCHOROIDAL DISEASE: A Pathological Hypothesis From Clinical Observation

PURPOSE

To evaluate focal choroidal excavation (FCE) in eyes with various diseases using multimodal imaging modalities and to investigate the correlation of FCE and underlying chorioretinal diseases.

METHODS

This retrospective observational study included 62 eyes from 56 patients who were identified by optical coherence tomography as having FCE. All included patients underwent comprehensive clinical examinations and multimodal imaging to identify and detect the characteristics of FCE and its correlation with underlying chorioretinal diseases.

RESULTS

All included patients were of Chinese descent, and the median age at diagnosis was 43 years (range: 15-66). Seventy-three FCEs appeared in these included eyes. Most FCEs were formed at sites with anatomical changes caused by various chorioretinal diseases. Choroidal osteoma, punctate inner choroidopathy, and central serous chorioretinopathy were the most common etiologies of FCE. During follow-up, 14 eyes (22.58%) exhibited a pattern change and three eyes (4.84%) developed new-onset choroid neovascularization.

CONCLUSION

Focal choroidal excavation is a common sign found in a variety of chorioretinal diseases. Processes that involve impairment or tissue loss of the outer retina and inner choroid and disrupt the balance of intraocular pressure and choroidal pressure because of mechanical disturbance may play a role in FCE formation.

Focal choroidal excavation: review of literature

Focal choroidal excavation (FCE) is defined as an area of concavity in choroid detected on optical coherence tomography. These are mostly present in macular region without evidence of accompanying scleral ectasia or posterior staphyloma. Though initially considered to be congenital, increasing number of cases have been identified in association with other choroidal pathologies such as central serous choroidopathy, choroidal neovascularisation, polypoidal choroidal vasculopathy, choroiditis, choroidal tumours. In this review article, we aim to elaborate on the morphology, pathogenesis and differential diagnosis of FCE and specifically discuss the spectrum of diseases with known association along with the impact of their treatment on FCE