Discussion: Assessing Retrobulbar Hyaluronidase as a Treatment for Filler-Induced Blindness in a Cadaver Model

Causes and management of sight threatening complications of dermal filler injections: A review

Injectable dermal fillers continue to increase in popularity in aesthetic medicine. Although rare, vision loss secondary to filler injections is a devastating complication associated with a poor visual prognosis. The mechanism for vision loss is thought to be related to retrograde embolization of the dermal filler from peripheral vessels in the face into the ophthalmic arterial system. Early recognition and prompt management are essential if vision is to be salvaged. The use of retrobulbar hyaluronidase is still contentious, however when administered by a specialist, this treatment gives the best chance at visual recovery and should be considered for all cases.

Retrobulbar Hyaluronidase Injection: Does It Reach the Eye?

PURPOSE

To determine if retrobulbar injection of hyaluronidase reaches the vitreous cavity, and to determine its concentration in the vitreous.

METHODS

Prospective case-control study. Patients undergoing evisceration with implant for noninfective blind eyes were enrolled in the study. Before the evisceration, a retrobulbar injection of 3,000 IU of hyaluronidase (2 ml) was injected. Time from injection to in vivo sampling of posterior vitreous was noted. Vitreous samples from controls were obtained from patients undergoing vitrectomy for retinal detachment or diabetic retinopathy. Concentration of hyaluronidase was assessed in all 30 samples. An ELISA-based microtiter-technique was used to evaluate the activity of hyaluronidase by an avidin-peroxidase-based procedure using an ELISA reader. Incubations were carried out at room temperature and at 37°C. All the samples were analyzed in duplicates, and the mean of each sample was plotted on a scatter plot.

RESULTS

Total of 30 vitreous samples were analyzed, of which 15 were controls and 15 were test samples. Of the 15 test samples, injection-to-sampling time was 0 to 20 minutes in 4 samples, 20 to 40 minutes in 6 samples, and 40 to 60 minutes in 5 samples. The highest concentration of hyaluronidase detected in control and test samples were 2.9 and 3.0 µg/ml, and the lowest concentration was 1.7 and 1.5 µg/ml (SD 0.3), respectively. There was no significant difference between control and test groups.

CONCLUSION

Retrobulbar injection did not result in higher concentration of hyaluronidase in the posterior vitreous compared with controls when measured up to 60 minutes following injection.

Blindness After Filler Injection: Mechanism and Treatment

Dermal fillers remain popular for facial rejuvenation but with its increasing use, the potential for more complications including blindness is present. This article focuses on the mechanism of filler-associated blindness, possible treatments, and future directions. Unfortunately, to date there is no proven treatment to reverse filler-induced blindness or visual compromise. It is essential for all injectors to discuss the potential ocular risks including blindness with their patients and obtain informed consent before filler injection.

Examining the Role of Retrobulbar Hyaluronidase in Reversing Filler-Induced Blindness: A Systematic Review

PURPOSE

To provide a systematic review of the literature concerning retrobulbar hyaluronidase injections as a treatment for hyaluronic acid gel filler-induced blindness and evaluate the level of evidence for this proposed therapy.

METHODS

The authors performed a search of English language articles published on the use of retrobulbar hyaluronidase to reverse vision loss precipitated by hyaluronic acid gel fillers. Articles reviewed included case reports/series, experimental investigations, expert opinion commentaries, and major reviews. To date, there have been no case-control, cohort, or randomized control studies to evaluate this treatment. Five anecdotal descriptions of hyaluronic acid gel filler blindness treated specifically with retrobulbar hyaluronidase were identified, for a total of 9 patients. One hundred twelve articles in total on this treatment and related topics, including filler-induced blindness and alternative treatments, were identified and reviewed.

RESULTS

Of the 9 documented cases of patients treated with retrobulbar hyaluronidase for hyaluronic acid-induced blindness, visual improvement was demonstrated in 2 cases. The successes, however, are undermined by inconsistent pretreatment ophthalmic assessment and documentation. Animal studies demonstrate mixed results. Laboratory studies document the inability of hyaluronidase to cross the optic nerve sheath.

CONCLUSIONS

There is not currently enough evidence to support retrobulbar hyaluronidase as a treatment for filler-induced blindness. Additional studies are needed to further evaluate its efficacy and explore alternative treatments.

Endovascular Hyaluronidase Application Through Superselective Angiography to Rescue Blindness Caused by Hyaluronic Acid Injection

BACKGROUND

Blindness is a rare but catastrophic complication of facial hyaluronic acid (HA) injection. Although various means to rescue visual impairment have been employed, no consensus regarding effective treatment has yet been reached. We organized a multidisciplinary team to address this emergency situation by means of endovascular hyaluronidase application.

OBJECTIVES

The aim of this study was to investigate the direct delivery of hyaluronidase to ophthalmic artery occlusion through endovascular cannulation to resolve HA-induced blindness.

METHODS

Four patients with visual impairments caused by HA filler embolization were subjected to sequential treatments. Through superselective angiography, a microcatheter was introduced along a guidewire from the femoral artery to the ophthalmic artery to directly deliver hyaluronidase to the HA embolism. The safety and efficiency of this treatment were systematically analyzed.

RESULTS

Selective cerebral angiography demonstrated that the endovascular application of hyaluronidase significantly alleviated occlusion in 3 patients. One patient showed slight visual improvement, whereas the other patients showed no improvement in their visual function during a follow-up period of more than 3 months. One patient suffered from cerebral infarction in the left middle cerebral artery during the intervention surgery. Moreover, 2 patients showed multiple lacunar cerebral infarctions after the operation, whereas none exhibited symptoms of hemiplegia during follow-up.

CONCLUSIONS

Although the endovascular application of hyaluronidase could partially recanalize the occluded branches of the ophthalmic artery, it had limited effects on restoring vision. Considering the risks of vascular intervention surgery, this approach should be considered with caution.

LEVEL OF EVIDENCE: 5