Choroidal osteoma: Spontaneous Resolution of Subretinal Detachment Unresponsive to Anti-VEGF Agent and multimodal imaging.

Dear Editor, Choroidal osteoma (CO) is a rare benign ossifying choroidal tumor that typically affects young female patients [1]. While there is no standard treatment for CO, patients with complications, such as choroidal neovascularization (CNV) and serous retinal detachment (SRD), require treatment [2]. Several reports have discussed the role of antivascular endothelial growth factor (anti-VEGF) agents in the treatment of SRD with or without CNV, associated with CO [2,3]. We describe the spontaneous resolution of SRD in a patient with CO, that was unresponsive to intravitreal anti-VEGF treatment. The patient provided informed consent for publication of the research details and clinical images. A healthy 9-year-old female patient presented with blurred vision in the left eye. The best-corrected visual acuity (BCVA) was 20 / 25 in the left eye. Funduscopic examination of the left eye revealed a juxtafoveal yellow-orange subretinal lesion with distinct borders (Fig. 1A). Fundus f luorescein angiography (FFA) revealed an early patchy hyperf luorescent choroidal filling pattern, dye staining in the area of retinal pigment epithelium (RPE) decompensation overlying the CO, pooling hyperfluorescence in the late phase, and no evidence of CNV (Fig. 1B, 1C). En face optical coherence tomography (OCT) showed the tumor border (Fig 1D, 1E). OCT angiography demonstrated the paucivascular tumor at the level of choroid, and absence of CNV (Fig. 1F). OCT showed SRD, a disrupted photoreceptor layer, and a hyperreflective mass posterior to the RPE (Fig. 1G). Therefore, the patient was diagnosed with CO with subretinal fluid in the absence of CNV. To resolve the SRD, an intravitreal injection of bevacizumab (1.25 mg/0.05 mL, Avastin, Genentech) was administered to her left eye. One month after bevacizumab treatment, her BCVA decreased to 20 / 100, and OCT showed an increased SRD and intraretinal fluid (Fig. 1H). Because the lesion was unresponsive to bevacizumab, the patient was closely monitored without additional treatment. After 4 months, the SRD decreased spontaneously, leading to an improved BCVA of 20 / 50. After 1 year, complete resolution of SRD and intraretinal fluid was confirmed on OCT (Fig. 1I). However, disruption of the photoreceptor layer was detected, and the final BCVA remained unchanged at 20 / 50. SRD, associated with CO, frequently occurs in the absence of CNV. It possibly resulted from multiple pinpoint RPE leakages over the osteoma noted on FFA [4]. Alternatively, the gradual atrophy of the RPE and Bruch’s membrane likely decreased the capacity of the RPE to remove subretinal fluid from the disrupted outer blood-retinal barrier [3]. While it has been established to treat SRD with CNV, the significance of anti-VEGF in treating SRD without CNV remains controversial. Song et al. [3] reported that 83% of patients with CO and SRD did not present with signs of CNV. Following bevacizumab treatment, all patients showed a substantial decrease in SRD based on OCT, and 80% of the patients experienced improved visual acuity. Korean J Ophthalmol 2023;37(1):82-84 https://doi.org/10.3341/kjo.2022.0113