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OCT Angiography Characteristics of Choroidal Osteoma
Report OCT Angiography Characteristics of Choroidal Osteoma Choroidal osteoma is a rare benign ossifying tumor of the choroid. Clinically, it appears as an irregular, flat, or slightly elevated lesion commonly in the juxtapapillary or macular region.1 The lesion is orange-red in color in its early stage and subsequently turns yellow-white. This color change is due to atrophy of overlying retinal pigment epithelium.2 The ultrasonography, fundus fluorescein angiography, and OCT characteristics of the tumor are well described. But the appearance of osteoma on OCT angiography (OCTA) is less well known. We describe OCTA features of 2 cases with choroidal osteoma. Institutional review board approval was not required, because our study was categorized as a case report.
Case 1 A 33-year-old female patient presented to our outpatient department with sudden onset diminution of vision in her left eye. Fundus evaluation of the left eye showed the presence of an active choroidal neovascular membrane (CNV) and associated subretinal hemorrhage at the macula. An independent yellowish-orange elevated lesion was seen adjacent to the CNV complex. A circumferential zone of retinal pigment epithelial atrophy was seen around this lesion (Fig 1). Ultrasonography of the lesion confirmed the presence of calcification. The observed features were suggestive of choroidal osteoma with secondary choroidal neovascular membrane. On indocyanine green angiography (ICGA), a branching vascular network was seen in the center of the osteoma. A major trunk from this network continued superiorly to form the vasculature of the CNV (Fig 1). However, the feeder vessel to the osteoma could not be identified. On OCTA imaging, an osteoma was differentiated from the rest of the choroid as an area of dark background with multiple punctate bright spots. A cluster of linear vessels, probably representing the feeder vessels, was seen extending into the osteoma at the level of deeper sections of the choroid (Fig 1). Within the osteoma, an arborizing network of vessels was seen at the level of superficial sections of choroid (Fig 1). The vascular network of the CNV complex was seen in the outer retina (Fig 1). The communicating vessels between the CNV and osteoma were also seen in OCTA imaging.
Case 2 A 42-year-old female patient with choroidal osteoma and associated CNV in her right eye, which was treated with an antievascular endothelial growth factor injection about 3 years previously, presented to us for follow-up examination. Fundus examination showed an osteoma located superotemporal to the disc, with chorioretinal atrophic changes nasal to fovea (Fig 2A, available at www.ophthalmologyretina.org).
On OCTA images, the tumor could be well differentiated from the rest of choroid as an area of dark background with multiple punctate bright spots. Feeder vessels from the normal choroid were seen extending up to the edge of the tumor, nasally at the level of deeper sections of the choroid (Fig 2B, available at www.ophthalmologyretina.org). The vascular network was sparse within the tumor. The inferior margin of the osteoma had scant vessels at the level of superficial sections of the choroid (Fig 2C, available at www.ophthalmologyretina.org). OCTA can delineate osteoma from the rest of the normal choroid by its distinctive dark background. Multiple tiny and bright punctate spots in the superficial and deep segment of the tumor were seen in both cases. This observation may represent vessels within the haversian canal. The CNV complex appears as a vascular network in the superficial part of the osteoma and is well identified on OCTA images. Intrinsic vascular network and feeder vessels of the tumor are seen prominently in its early stage. A layer of vessels arranged in a Medusa-head appearance represents the vascular network within the tumor.3 Feeder vessels in both patients were seen as a cluster of vessels extending into the tumor from the normal choroid at the level of deeper choroidal sections in OCTA images. This was not seen on ICGA images. Thus, feeder vessels of the tumor enter at a deeper level and form the intrinsic vasculature. A major trunk from this intrinsic vascular network grows to the surface to communicate with the CNV. This is supported by the absence of communication between the major trunk of the tumor and the normal choroid on ICGA images. The communication between the tumor vasculature and the CNV was better defined in ICGA than OCTA images. En face visualization by OCTA can differentiate vasculature of CNV from tumor vasculature. In 1 report, OCTA could even identify a CNV that was not clinically evident.4 OCTA can distinctly identify the intrinsic vascularity and feeder vessels in osteoma and help in better understanding of the tumor vascularity in relation to the CNV. Hence, OCTA can be used as an ancillary tool to diagnose or to differentiate osteoma from normal choroid and to further differentiate a concurrent CNV in ambiguous cases.
PRADEEP SAGAR, MD MAHESH SHANMUGAM, DO, FRCS RAJESH RAMANJULU, MD, DNB VINAYA KUMAR KONANA, DNB Department of Vitreo-retina and Ocular Oncology, Sankara Eye Hospital, Bangalore, India The manuscript was invited by the board for resubmission to Ophthalmology Retina. Financial disclosure: None Conflict of interest: None Abbreviations and Acronyms: CNV ¼ choroidal neovascular membrane; ICGA ¼ indocyanine green angiography; OCTA ¼ optical coherence tomography angiography.
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Ophthalmology Retina Volume -, Number -, Month 2017
Figure 1. Case 1. A, Color photograph of the osteoma with choroidal neovascular membrane. B, An optical coherence tomography angiography (OCTA) image (outer retina) showing the vascular network of the choroidal neovascular membrane. C, An OCTA image of the superficial choroid (averaging from 83.2 mm superficial to basement membrane and 83.2 mm from the basement membrane deep into the choroid) showing the tumor vascular network in the center (red arrow). An OCT image shows the reference lines corresponding to 83.2 mm and 83.2 mm. D, An OCTA image of the deeper choroid (averaging from 36.4 mm to 231.4 mm from basement membrane deep into the choroid) showing feeder vessels. An OCT image shows the reference lines corresponding to 36.4 mm and 231.4 mm. E, Indocyanine green angiography image of osteoma with the choroidal neovascular membrane.
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Report Correspondence: Mahesh Shanmugam, DO, FRCS, Sankara Eye Hospital, Varthur Road, Kundalahalli Gate, Bangalore 560037, India. E-mail: maheshshanmugam@ gmail.com.
References 1. Alameddine RM, Mansour AM, Kahtani E. Review of choroidal osteomas. Middle East Afr J Ophthalmol. 2014;21: 244e250.
2. Chen J, Lee L, Gass JD. Choroidal osteoma: Evidence of progression and decalcification over 20 years. Clin Exp Optom. 2006;89:90e94. 3. Azad SV, Takkar B, Venkatesh P, Kumar A. Swept source: optical coherence tomography angiography features of choroidal osteoma with choroidal neovascular membrane. BMJ Case Rep. 2016;2016. 4. Szelog JT, Bonini Filho MA, Lally DR, et al. Optical coherence tomography angiography for detecting choroidal neovascularization secondary to choroidal osteoma. Ophthalmic Surg Lasers Imaging Retina. 2016;47:69e72.
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Case 1 A 33-year-old female patient presented to our outpatient department with sudden onset diminution of vision in her left eye. Fundus evaluation of the left eye showed the presence of an active choroidal neovascular membrane (CNV) and associated subretinal hemorrhage at the macula. An independent yellowish-orange elevated lesion was seen adjacent to the CNV complex. A circumferential zone of retinal pigment epithelial atrophy was seen around this lesion (Fig 1). Ultrasonography of the lesion confirmed the presence of calcification. The observed features were suggestive of choroidal osteoma with secondary choroidal neovascular membrane. On indocyanine green angiography (ICGA), a branching vascular network was seen in the center of the osteoma. A major trunk from this network continued superiorly to form the vasculature of the CNV (Fig 1). However, the feeder vessel to the osteoma could not be identified. On OCTA imaging, an osteoma was differentiated from the rest of the choroid as an area of dark background with multiple punctate bright spots. A cluster of linear vessels, probably representing the feeder vessels, was seen extending into the osteoma at the level of deeper sections of the choroid (Fig 1). Within the osteoma, an arborizing network of vessels was seen at the level of superficial sections of choroid (Fig 1). The vascular network of the CNV complex was seen in the outer retina (Fig 1). The communicating vessels between the CNV and osteoma were also seen in OCTA imaging.
Case 2 A 42-year-old female patient with choroidal osteoma and associated CNV in her right eye, which was treated with an antievascular endothelial growth factor injection about 3 years previously, presented to us for follow-up examination. Fundus examination showed an osteoma located superotemporal to the disc, with chorioretinal atrophic changes nasal to fovea (Fig 2A, available at www.ophthalmologyretina.org).
On OCTA images, the tumor could be well differentiated from the rest of choroid as an area of dark background with multiple punctate bright spots. Feeder vessels from the normal choroid were seen extending up to the edge of the tumor, nasally at the level of deeper sections of the choroid (Fig 2B, available at www.ophthalmologyretina.org). The vascular network was sparse within the tumor. The inferior margin of the osteoma had scant vessels at the level of superficial sections of the choroid (Fig 2C, available at www.ophthalmologyretina.org). OCTA can delineate osteoma from the rest of the normal choroid by its distinctive dark background. Multiple tiny and bright punctate spots in the superficial and deep segment of the tumor were seen in both cases. This observation may represent vessels within the haversian canal. The CNV complex appears as a vascular network in the superficial part of the osteoma and is well identified on OCTA images. Intrinsic vascular network and feeder vessels of the tumor are seen prominently in its early stage. A layer of vessels arranged in a Medusa-head appearance represents the vascular network within the tumor.3 Feeder vessels in both patients were seen as a cluster of vessels extending into the tumor from the normal choroid at the level of deeper choroidal sections in OCTA images. This was not seen on ICGA images. Thus, feeder vessels of the tumor enter at a deeper level and form the intrinsic vasculature. A major trunk from this intrinsic vascular network grows to the surface to communicate with the CNV. This is supported by the absence of communication between the major trunk of the tumor and the normal choroid on ICGA images. The communication between the tumor vasculature and the CNV was better defined in ICGA than OCTA images. En face visualization by OCTA can differentiate vasculature of CNV from tumor vasculature. In 1 report, OCTA could even identify a CNV that was not clinically evident.4 OCTA can distinctly identify the intrinsic vascularity and feeder vessels in osteoma and help in better understanding of the tumor vascularity in relation to the CNV. Hence, OCTA can be used as an ancillary tool to diagnose or to differentiate osteoma from normal choroid and to further differentiate a concurrent CNV in ambiguous cases.
PRADEEP SAGAR, MD MAHESH SHANMUGAM, DO, FRCS RAJESH RAMANJULU, MD, DNB VINAYA KUMAR KONANA, DNB Department of Vitreo-retina and Ocular Oncology, Sankara Eye Hospital, Bangalore, India The manuscript was invited by the board for resubmission to Ophthalmology Retina. Financial disclosure: None Conflict of interest: None Abbreviations and Acronyms: CNV ¼ choroidal neovascular membrane; ICGA ¼ indocyanine green angiography; OCTA ¼ optical coherence tomography angiography.
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Ophthalmology Retina Volume -, Number -, Month 2017
Figure 1. Case 1. A, Color photograph of the osteoma with choroidal neovascular membrane. B, An optical coherence tomography angiography (OCTA) image (outer retina) showing the vascular network of the choroidal neovascular membrane. C, An OCTA image of the superficial choroid (averaging from 83.2 mm superficial to basement membrane and 83.2 mm from the basement membrane deep into the choroid) showing the tumor vascular network in the center (red arrow). An OCT image shows the reference lines corresponding to 83.2 mm and 83.2 mm. D, An OCTA image of the deeper choroid (averaging from 36.4 mm to 231.4 mm from basement membrane deep into the choroid) showing feeder vessels. An OCT image shows the reference lines corresponding to 36.4 mm and 231.4 mm. E, Indocyanine green angiography image of osteoma with the choroidal neovascular membrane.
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Report Correspondence: Mahesh Shanmugam, DO, FRCS, Sankara Eye Hospital, Varthur Road, Kundalahalli Gate, Bangalore 560037, India. E-mail: maheshshanmugam@ gmail.com.
References 1. Alameddine RM, Mansour AM, Kahtani E. Review of choroidal osteomas. Middle East Afr J Ophthalmol. 2014;21: 244e250.
2. Chen J, Lee L, Gass JD. Choroidal osteoma: Evidence of progression and decalcification over 20 years. Clin Exp Optom. 2006;89:90e94. 3. Azad SV, Takkar B, Venkatesh P, Kumar A. Swept source: optical coherence tomography angiography features of choroidal osteoma with choroidal neovascular membrane. BMJ Case Rep. 2016;2016. 4. Szelog JT, Bonini Filho MA, Lally DR, et al. Optical coherence tomography angiography for detecting choroidal neovascularization secondary to choroidal osteoma. Ophthalmic Surg Lasers Imaging Retina. 2016;47:69e72.
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