Choroidal osteomas are rare benign calcific masses of the globe.
Choroidal osteomas are typically found in young Caucasian women 1. A number of familial cases have been reported 3.
These lesions are usually unilateral (75%), and result in painless and gradual visual loss, although in some instances rapid central visual loss may occur 1,3.
Fourier-domain optical coherence tomography (FD-OCT)
FD-OCT imaging may show a distinctive latticework pattern of reflectivity resembling the spongy bone structure seen histopathologically 6.
Blue-light fundus autofluorescence (bAF)
Relatively well spared 6.
Choroidal osteomas are composed of mature bone including marrow like spaces. They are located in the peripapillary choroid 1,3.
Their aetiology remains unknown. Some consider them to be benign neoplasms 1. Others define them as choristomas, whilst others still think of them as secondary ossification of another underlying process (e.g. trauma, inflammation) 3.
Choroidal osteomas are typically unilateral (in around 75% of cases 7) and located on the posterior wall of the globe, near, but usually not involving, the optic disc. They are calcified and plaque-like.
Plaque-like echogogenic foci, with acoustic shadowing.
Calcific curvilinear regions on the posterior aspect of the globe, usually sparing the optic disc.
Reported signal characteristics include 5
- T1: hyperintense signal
- T2: area of relative low intensity
- T1 C+ Gd: shows enhancement
Treatment and prognosis
Choroidal osteomas are benign and in many instances (46-60% of cases) remain unchanged in size 3. They may be complicated by choroidal neovascularisation (CNV) which may lead to loss of vision, and in such cases photocoagulation therapy may be of benefit, although overall response is poor 3. Some publications report a benefit with Intravitreal bevacizumab 9.
History and etymology
The term ‘choroidal osteoma’ was coined by Gass in 1978 9.
In general the differential is that of other causes of calcification of the globe including:
- 1. Imaging of the Head and Neck. Mahmood F. Mafee, Galdino E. Valbasson, Minerva Becker, J. S. Lewin, S. G. Nour (Contributor), A. L. Weber (Contributor), M. Becker (Contributor). Thieme Medical Publishers ISBN:1588900096 (find it at amazon.com)
- 2. McNicholas MM, Power WJ, Griffin JF. Sonography in optic disk drusen: imaging findings and role in diagnosis when funduscopic findings are normal. AJR Am J Roentgenol. 1994;162 (1): 161-3. AJR Am J Roentgenol (abstract) [pubmed citation]
- 3. Aylward GW, Chang TS, Pautler SE et-al. A long-term follow-up of choroidal osteoma. Arch. Ophthalmol. 1998;116 (10): 1337-41. doi:10.1001/archopht.116.10.1337 [pubmed citation]
- 4. Bryan RN, Lewis RA, Miller SL. Choroidal osteoma. AJNR Am J Neuroradiol. 1983;4 (3): 491-4. AJNR Am J Neuroradiol (abstract) - Pubmed citation
- 5. DePotter P, Shields JA, Shields CL et-al. Magnetic resonance imaging in choroidal osteoma. Retina (Philadelphia, Pa.). 1991;11 (2): 221-3. Pubmed citation
- 6. Navajas EV, Costa RA, Calucci D et-al. Multimodal fundus imaging in choroidal osteoma. Am. J. Ophthalmol. 2012;153 (5): 890-895.e3. doi:10.1016/j.ajo.2011.10.025 - Pubmed citation
- 7. Kadrmas EF, Weiter JJ. Choroidal osteoma. Int Ophthalmol Clin. 1998;37 (4): 171-82. Pubmed citation
- 8. Browning DJ. Choroidal osteoma: observations from a community setting. Ophthalmology. 2003;110 (7): 1327-34. doi:10.1016/S0161-6420(03)00458-5 - Pubmed citation
- 9. Pandey N, Guruprasad A. Choroidal osteoma with choroidal neovascular membrane: Successful treatment with intravitreal bevacizumab. Clin Ophthalmol. 2011;4: 1081-4. doi:10.2147/OPTH.S13730 - Free text at pubmed - Pubmed citation
- 10. Grand MG, Burgess DB, Singerman LJ et-al. Choroidal osteoma. Treatment of associated subretinal neovascular membranes. Retina (Philadelphia, Pa.). 1984;4 (2): 84-9. Pubmed citation