Case Report: Intravitreal Conbercept for Treatment of Choroidal Neovascularisation Secondary to Choriodal Osteoma

Background: Choriodal osteoma is a rare condition. Although anti-VEGF treatment has been reported to be effective in managing choroidal neovascularisation secondary to choriodal osteoma, to the best of our knowledge, this report is the first report of using conbercept in such condition. Case presentation: This report describes a case of choroidal neovascularisation secondary to choriodal osteoma. A 37-year old female presented with decreased vision and distortion in left eye. Fundus image revealed an orange-yellow lesion with clear boundary in the macular area. Fluorescein angiography indicated choroidal neovascularization(CNV). OCT, B-scan and CT scan showed features of choroidal osteoma. Intravitreal Conbercept was given for four times over a period of 10 months, resulting stability of visual acuity and regression of CNV. Conclusions: Intravitreal Conbercept is effective in controlling choroidal neovascularisation secondary to choriodal osteoma.


Background
Choroidal osteoma is a rare, benign tumor which appears as well-defined, orange-red or yellowish subretinal mass. It mainly affects young females. Choroidal osteoma could grow slowly with time. More than half of the patients encounter visual loss.[1-3] Over one third of the patients will develop choroidal neovascularisation(CNV).
[4] CNV secondary to choroidal osteoma used to be treated using focal laser, transpupillary thermotherapy(TTT), [5] and photodynamic therapy(PDT). [4] In recent years, anti-vascular endothelial growth factor(anti-VEGF) therapy has been reported to treat CNV secondary to choroidal osteoma, including  We reported one case of CNV secondary to choroidal osteoma treated by intravitreal Conbercept injection.

Case Presentation
A healthy 37 years old female presented with decreased vision and distortion in left eye for over a month in the retina clinic of The 2nd People's Hospital of Yunnan Province, P.R.China. Best corrected visual acuity(BCVA) was 20/20 in the right eye and 20/33 in the left eye. Past systemic and ocular history was negative. Family history was negative.
Clinical examination found the right eye was normal and an orange-yellow lesion with clear boundary in the posterior pole and sub-retinal haemorrhage on the macular in the left eye (Fig 1). Ultrasound B-scan showed a slightly elevated, high acoustic reflective choroidal mass with shadowing behind (Fig 1). Fundus fluorescein angiography (FFA) showed dot-like hyperfluoresence in the choroidal lesion,blocked fluoresceince due to subretinal hemorrhage and leakage of choriodal neovascularization (Fig 2). Optical coherence tomography(OCT) indicated sub-retinal fluid, CNV and choroid elevation (Fig 2). CT scan showed a high intensity lesion in the left eye with the size of 0.6×0.3cm (Fig 1). A diagnosis of CNV secondary to choroidal osteoma was made. After written consent was achieved, 0.5mg/0.05ml intravitreal Conbercept (KangHong Tnc, China) injection was given to the left eye. A total of four injections were given during a period of 10 months, at intervals ranging from 1-3 months to treat the sub-retinal fluid. One month follow-up after the first injection, the BCVA was improved to 20/25 in the left eye and kept stable afterwards. OCT scan showed the sub-retinal fluid decreased and CNV shrinked with time after injections (Fig 2). FFA indicated the fully regression of CNV at 6 months after presentation (Fig 2). At the last visit, the BCVA was 20/25 in the left eye. The fundus photography showed depigmentation of the choroidal lesion and fully absorption of subretinal hemorrhage (Fig 1). OCT scan revealed some sub-retinal fluid (Fig 2). The patient 4 decided not to get further injection due to asymptomatic feeling.

Discussion And Conclusions
Choriodal osteoma is a rare, slow growing benign tumor. It occurs in all races, however the frequency and exact etiology are unclear. It has young women preference and is unilateral in 80% of cases. The visual prognosis could be poor and is related to multiple

Declarations Ethic approval and consent to participate
This study adheres to the tenets of the Declaration of Helsinki and was approved by the the Ethical Committee of The 2nd People's Hospital of Yunnan Province, China.

Consent for publication
The patient gave written consent to participate in this study and for publication of the data and the images obtained from the patient.

Availability of data and materials
Not applicable.

Funding
Funding: This study is supported by the Natural Science Foundation of Yunnan Province (NO. 2017FE467(-195)). The examination fee of this patient is partially covered by the funding. The funding body had no role in the design of the study and collection, analysis, and interpretation of data and in writing the manuscript.

Competing interests
The author has no financial and non-financial competing interests.

Authors' Contributions
Wu M carried out the case collection and manuscript preparation.