Risk of Blindness From Temple Filler Injections: Investigating Vascular Anastomoses Between the Deep Temporal and Ophthalmic Arteries.

Purpose: Soft-tissue filler injections, particularly hyaluronic acid, are popular for temple volume restoration. Although uncommon, this area poses risk for vision loss from embolic occlusion. Guidelines recommend injecting into the supraperiosteal plane for safety; however, the deep temporal arteries (DTAs) in this plane pose a risk. This study investigates potential pathways from the DTA to the ophthalmic artery (OA) and mechanisms of filler travel.

Methods: Retrospective analysis of carotid angiograms from patients with marked carotid artery stenosis or vascular malformations, given that collaterals are more visible in the presence of vascular blockages. Select cases were identified by the neurosurgery team.

Results: Four anastomotic pathways between the DTA and OA were identified, displaying a combination of anterograde and retrograde flow. Case 1 shows direct DTA-lacrimal artery anastomosis. In cases 2 to 4, the DTA is shown originating from the internal maxillary artery (IMAX) following its anatomical course. Retrograde flow from the DTA into the IMAX can then lead to anterograde flow into branches connecting to the IMAX including the superficial temporal artery, infraorbital artery, and middle meningeal artery. These arteries then form collaterals with the OA.

Conclusions: Our study is the first to elucidate 4 potential routes for filler-induced OA occlusion originating from DTAs in the supraperiosteal plane. These pathways involve retrograde flow, a mechanism previously suggested for filler-induced occlusion. Notably, the likelihood of these pathways being traversed may be low due to their length and amount of filler volume required; however, it is not impossible.