Enhanced depth imaging optical coherence tomography of choroidal osteoma with secondary neovascular membranes: report of two cases Tomografia de coerência óptica com imagem profunda aprimorada de osteoma de coroide com membrana neovascular secundária: relato de 2 casos

Optical coherence tomography (OCT) plays an instrumental role in the diagnosis and follow-up of several retinal and choroidal diseases such as macular degeneration, vascular occlusion, and inflammation. Recently, OCT studies of intraocular tumors evaluated the intrinsic optical characteristics of choroidal tumors imaged using enhanced depth imaging OCT (EDI-OCT). Among body structures, the choroid has one of the highest metabolic rates and supplies oxygen to the photoreceptor layer of the retina, which is also a highly metabolic structure. However, the choroid is one of the most difficult structures to image in vivo because pigments in the retinal pigment epithelium (RPE) and choroid impede image capturing. EDI-OCT provides a more detailed view than spectral-domain OCT (SD-OCT) of deep anatomic structures. The current axial resolution with EDI-OCT is approximately 3.9 micra. Recently, several papers have been published describing the aspects of choroidal tumors revealed with this new technology. With this technology, various choroidal tumors can be imaged and measured. Using EDI-OCT, choroidal nevi and melanomas show a smooth, dome-shaped surface, whereas choroidal metastases display a “lumpy-bumpy,” irregular surface topography and choroidal hemangiomas present a smooth, acutely dome-shaped surface; choroidal lymphomas show a “placid,” rippled, or “seasick” surface. Choroidal osteomas are rare, benign, and usually unilateral intraocular tumors composed of mature bone affecting the choroid. These tumors can be asymptomatic or can produce visual loss because of choroidal neovascularization (CNV) or tumor decalcification, presence of subretinal fluid, and photoreceptor atrophy. CNV is an important cause of vision loss in patients with choroidal osteoma and is reported to occur in 31% of affected eyes by 10 years after the diagnosis. In this study, we evaluated the EDI-OCT features of two cases of choroidal osteoma with neovascular membranes.