A Computed Tomographic Investigation of the Ophthalmic Artery Volume and Its Relevance to Soft Tissue Filler Injections

Abstract

Background The measured intra-arterial volume of cadaveric ophthalmic arteries was used for safety recommendations during facial soft tissue filler injections. However, its clinical practicability and model applicability has become questionable. Objectives To measure the volume of the ophthalmic artery in living individuals by utilizing computed tomography (CT) imaging technology. Methods A total of n = 40 Chinese patients (23 males, 17 females) were included in this study with a mean age of 61.0 (14.2) years and a mean body mass index of 23.7 (3.3) kg/m2. Patients were investigated using CT-imaging technology to evaluate the bilateral length, diameter and volume of the ophthalmic artery as well as the length of the bony orbit resulting in a total of n = 80 investigated ophthalmic arteries and orbits. Results Independent of gender, the average length of the ophthalmic artery was 80.6 (18.7) mm, the calculated volume of the ophthalmic artery was 0.16 (0.05) cc and the minimal and maximal internal diameter of the ophthalmic artery was 0.50 (0.05) mm and 1.06 (0.1) mm, respectively. Conclusions Considering the results obtained from the investigation of n = 80 ophthalmic arteries it needs to be concluded that current safety recommendations must be re-evaluated. The volume of the ophthalmic artery seems to be 0.2 cc rather than 0.1 cc as previously reported. In addition, it seems to be not practical to limit the volume of soft tissue filler bolus injections to 0.1 cc due to the aesthetic requirements of each individual patient and treatment plan.

Is constant needle motion during soft tissue filler injections a safer procedure? A theoretical mathematical model for evaluating patient safety

“…It has to be emphasized that despite previous studies have measured the intra-arterial volume of the ophthalmic artery (between 0.1 and 0.2 cc), 11,12 Based on the results obtained it can be concluded that the constant needle motion technique is not a safer procedure when administering facial soft tissue filler injections. The odds of encountering an artery within the covered soft tissue volume and the odds of injecting a volume into the arterial blood stream that is greater than zero increases with the number of performed injection passes.…”

“…It has to be emphasized that despite previous studies have measured the intra‐arterial volume of the ophthalmic artery (between 0.1 and 0.2 cc), 11,12 no threshold value for soft tissue filler injections is currently available. No study to date has clinically or theoretically investigated whether there is such lower threshold value, and it therefore must be concluded that any volume of intra‐arterially placed soft tissue filler greater than zero is detrimental.…”

“…This subsequently increases the risk for adverse vascular events with tissue loss or IRVC. Additionally, it has to be noted that currently no threshold for a tolerable amount of intra‐arterial product administration is available despite recent research has provided some values for the intra‐arterial ophthalmic artery volume 11,12 . Therefore, it has to be assumed that any amount greater than zero can cause adverse vascular events; this is understandable when the arterial vascular system is viewed as a tubular system with decreasing internal lumina toward a capillary bed.…”

“…7,8 To avoid adverse events from occurring and to account for factors resulting in poor aesthetic outcomes, various precautionary measures have previously been recommended. Some of these measures include: performing pre-injection aspiration, 9 injecting with low plunger pressure and slow injection speed, 10 injecting small amounts of material during bolus injections, 11,12 and continuous needle motion within the facial soft tissues during product application. 13 The rationale underlying the latter safety measure is as follows: when a needle is inserted into facial soft tissue there is a risk for the tip to enter an artery.…”

Commentary on: A Computed Tomographic Investigation of the Ophthalmic Artery Volume and its Relevance to Soft Tissue Filler Injection

“…The intent of this paper by Lin et al is, first, to determine more accurately the average volume of the ophthalmic artery in 40 living individuals (80 ophthalmic arteries) by undertaking a detailed contrast agent–enhanced computed tomography topographic study. 1 The authors feel that measuring the ophthalmic artery volume in cadaveric specimens has multiple limitations, and therefore inaccuracies, making it difficult to reach definite conclusions based on such studies.…”