In vivo optical biopsy of choroidal osteoma: a swept source optical coherence tomography–based tumor characterization

OBJECTIVE: To study tumor characteristics of choroidal osteoma by swept source optical coherence tomography. METHODS: A retrospective case series done at tertiary referral center in northern India. All patients diagnosed with choroidal osteoma examined on swept source optical coherence tomography were included. Swept source optical coherence tomography images were analyzed for integrity of retinal layers—intraretinal layers, outer retinal layers (photoreceptor), retinal pigment epithelium, and contour abnormalities. Choroidal changes assessed were tumor attributes such as shape, depth of choroidal involvement, tumor mass reflectivity pattern, tumor vascularity, and evolutionary structural abnormalities such as deossification, focal depressions, or choroidal neovascular membrane. RESULTS: A total of 15 eyes of 11 patients were analyzed. Seven of 11 patients were females. Mean age of presentation was approximately 26 years. Tumor was large in nine cases (>7.5 mm). Deossification was seen in 12 eyes. Inner and outer retinal integrity was maintained in 7 and 2 eyes, respectively. Most common internal tumor reflectivity pattern seen was a lamellar appearance (12/15). Increased signal transmission to choroid and focal area of deep excavation was present in 11 and 4 eyes, respectively. Osteoclastic activity was noted in 12 eyes. Choroidal neovascular membrane was seen in 6 eyes. Small lesions showed lamellar pattern of tumor reflectivity with preservation of retinal pigment epithelium and overlying retina. Larger tumors were deossified with 6 irregular tumor contour, disorganization of the outer retina, increased signal transmission to choroid, and areas of osteoclastic activity. CONCLUSION: Swept source optical coherence tomography was helpful in assessing tumor attributes and predicting the different timelines in tumor evolution.