The study aims to quantitative evaluation of parafoveal microvasculature changes in eyes with exudative circumscribed choroidal haemangioma using optical coherence tomography angiography.

Circumscribed choroidal haemangioma (CCH) is an uncommon, potentially congenital benign vascular hamartomas which typically manifests as an elevated mass with reddish-orange pigmentation located posteriorly to the equator, mostly in the macular and peripapillary region. Despite its benign nature, cystoid macular edema (CME) or SRF due to the exudations from the exudative CCH can cause visual impairment. Diagnosis is often suspected clinically, and multimodal imaging is useful for the differential diagnosis of CCH from other malignant tumors such as melanoma. Optical coherence tomography angiography (OCTA) is a rapid, non-invasive, new imaging technology which could provide the capillary density (CD) of superficial and deep capillary plexus as well as the CD of choriocapillaris of the superficial, the latter two of which could not be seen on conventional FA or ICGA. However, little knowledge is known about the parafoveal microvasculature changes in eyes with exudative CCH on OCTA. Therefore, it is necessary to quantitative evaluation of parafoveal microvasculature changes in eyes with exudative CCH compared with healthy eyes without any disease. To the best of our knowledge, this is the first cross-sectional, case-control study to use OCTA to quantitative evaluation of parafoveal microvasculature changes in Eyes with exudative CCH compared with age- and gender-controlled healthy eyes.

Inclusion Criteria:

• For patients with exudative CCH, the inclusion criteria were treatment naïve patients with exudative CCH which caused subfoveal retinal detachment and/or intraretinal fluid. For the healthy eye control group, only one eye (randomized by computer) of a subject was included, and the included eyes should have no ocular diseases and the best-corrected visual acuity (BCVA) should be 20/20 or better.

Exclusion Criteria:

• without any other ocular diseases or any severe uncontrolled systemic diseases, including uncontrolled hypertension, coronary heart disease, liver failure, and kidney failure. all the subjects with high diopter > -6D, long eye axis > 26.0 mm, or the quality of the acquired OCTA images below 7/10 should be excluded from this study.

There are two groups in this study: one is the exudative CCH group,and the other is the healthy eye control group. They performed OCTA at baseline.