Insights into Retinal Metastasis from Systemic Carcinoma: A Systematic Review of Clinical and Multimodal Imaging Characteristics.

Background/Objectives: Retinal metastasis (RM) is an exceptionally rare clinical condition, comprising less than 1% of ocular metastasis cases. This study aims to investigate the clinical features of RM originating from systemic carcinoma. Methods: A systematic review (PROSPERO ID: CRD42022344724). Results: The systematic review revealed 58 cases involving 61 eyes. Most of the cases (82.8%) had a known primary malignancy before RM was diagnosed. The main primary sites were the lung (45.8%), gastrointestinal tract (23.7%), and breast (16.9%). The lung was the most common (80.0%) carcinoma in cases with unknown primary sites. The median survival after RM diagnosis was 11 months. The main clinical patterns were patchy retinal infiltrates (35.7%), an elevated retinal mass (63.8%), and punctate retinal infiltrates (7.1%). Subretinal fluid, vitreous seeding, and choroidal invasion were noted in 57.4%, 41.0%, and 6.6% of eyes, respectively. Key multimodal imaging features were early hypofluorescence with mid-to-late hyperfluorescence on fluorescein angiography (84.6%) and hyper-reflectiveness on optical coherence tomography (70.8%). A final best-corrected visual acuity of ≤20/200 was noted in 66.7% of the eyes. Conclusions: Patchy retinal infiltrates, an elevated retinal mass, and punctate retinal infiltrates are the major clinical patterns of RM from systemic carcinoma. The primary carcinoma sites are the lung, gastrointestinal tract, and breast. Systemic and visual prognoses were unfavorable.