Choroidal osteoma is a rare clinical entity of unknown aetiology, characterized by the formation of mature cancellous bone within the choroid. It typically affects young females, with no racial predilection. Vision loss occurs mainly due to photoreceptor degeneration secondary to decalcification and/or development of choroidal neovascularization especially if located at the subfoveal area.
A 9-year-old Indian (Indo-Aryan) boy diagnosed as having pan-sinusitis was referred to us from an Ear, Nose, and Throat (ENT) department with complaints of swelling over the left side of his face involving left the lower lid to rule out any ocular manifestation. He gave a history of swelling over the left side of his face of approximately 10 days’ duration. It was insidious in onset, gradually progressive in nature, and involved the left lower lid; it was not associated with pain and fever. There was no associated systemic disease. On examination, the best corrected visual acuity (BCVA) for his left eye was hand movement and for his right eye, it was 6/6. He was unaware of diminished vision in his left eye. On dilated fundus examination we observed two yellowish-white lesions with well-demarcated borders located superotemporally indicative of active lesions, which were associated with nearby areas of RPE depigmentation and pigment clumps extending into the macular area, which were suggestive of degeneration of overlying retinal layers indicative of decalcified lesions in his left eye (Fig. 1). Fundus of his right eye was normal.
Fundus fluorescein angiography (FFA) revealed areas of early granular hyperfluorescence corresponding to the areas of RPE depigmentation and late hyperfluorescence over the calcified lesion with some interspersed areas of hypofluorescence corresponding to the areas of pigment clumps in the left eye (Fig. 2).
Spectral-domain optical coherence tomography (SD-OCT) was performed and revealed high reflectivity from the choroid with marked thinning of overlying retinal layers including photoreceptor inner/outer segment junction (Fig. 3).
Examination of his right eye was normal. All routine blood investigations were normal including serum calcium and parathyroid hormone level. As there was already a setup of decalcification with loss of RPE/photoreceptor and marked diminished vision, and the lesion extended into the foveal region, we asked our patient to attend follow-ups at monthly intervals to monitor the subsequent progression or regression of the tumour, because of the non-availability of a reliable treatment option.
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