[Effectiveness and interest of retrobulbar hyaluronidase injections in the treatment of blindness complicating facial hyaluronic acid injections: A literature review]. / Efficacité et intérêt des injections rétrobulbaires de hyaluronidase dans le traitement des cécités compliquant une injection faciale d'acide hyaluronique : revue de la littérature.

INTRODUCTION: Hyaluronic acid injections are becoming increasingly common among both the general public and the medical community, but they are not without risks. The occurrence of blindness, although rare, is a tragic event for both the patient and the practitioner. One of the treatments proposed in the literature is to inject hyaluronidase as close as possible to the site of ischemia, retrobulbarly. The aim of our study is to evaluate the effectiveness and potential benefits of retrobulbar hyaluronidase injections. MATERIALS AND METHODS: A literature review was conducted using the PubMed database. Only articles addressing retrobulbar hyaluronidase injections for the treatment of blindness following hyaluronic acid injections were included. RESULTS: We identified 12 case reports or series, comprising a total of 16 patients. Among these 16 patients, 3 regained their vision. Hyaluronidase was injected between 20minutes and 7days after the onset of the complication, with injected doses ranging from 3×150IU to 3×1500IU. DISCUSSION: Literature reveals only 3 cases of successful treatment out of the 16 reported injections. The time interval before retrobulbar injection, as well as the dose and the experience of the injecting practitioner, may influence the success rate of this treatment. Other treatments, such as intravascular hyaluronidase injections, remain to be explored.

INTERNATIONAL IMPACT OF THE COVID-19 PANDEMIC LOCKDOWN ON INTRAVITREAL THERAPY OUTCOMES: Fight Retinal Blindness Registry.

PURPOSE: To evaluate the impact of the COVID-19 pandemic lockdowns on the outcomes of eyes treated for neovascular age-related macular degeneration, diabetic macular edema, and retinal vein occlusion in eight countries. METHODS: A multicenter international database study of 5,782 eyes (4,708 patients) receiving intravitreal antivascular endothelial growth factor injections before, during, and after national lockdowns. The baseline visit was defined as the last visit within 3 months before lockdown, and prelockdown and postlockdown periods were defined as 6 months before and after the lockdown date. RESULTS: Eyes with neovascular age-related macular degeneration (n = 4,649) lost vision in all countries in proportion to the reduced number of injections. The mean visual acuity change postlockdown ranged from -0.4 to -3.8 logarithm of the minimum angle of resolution letters, and the median number of injections/visits decreased from 4-5/4-7 to 2-4/2-4 postlockdown. The diabetic macular edema (n = 654) and retinal vein occlusion (n = 479) eyes' mean visual acuity change ranged from -2.8 to +1.7 letters and -1.6 to +0.1 letters, and the median number of injections/visits decreased from 2.5-5/4-6 to 1-3/2-4 and from 3-5.5/4-5 to 1-3.5/2-3.5, respectively. The 6-month dropout rates postlockdown were 20% for neovascular age-related macular degeneration, 27% for diabetic macular edema, and 28% for retinal vein occlusion. CONCLUSION: This international study provides estimates of the impact of COVID-19 pandemic lockdown on intravitreal therapy and suggests that prioritizing neovascular age-related macular degeneration eyes seems appropriate.

Creation of a neovascular age-related macular degeneration national database using a web-based platform: Fight Retinal Blindness Spain. Report 1: Visual outcomes.

BACKGROUND: To study the visual outcomes of neovascular AMD (nAMD) treated with anti-vascular endothelial growth factor (VEGF) drugs at national level. METHODS: Multicenter national database of nAMD eyes treated with anti-VEGF intravitreal injections (ranibizumab, aflibercept, bevacizumab) in fixed bimonthly (FB) or treat-and-extend (TAE) regimens. Demographics, visual acuity (VA) in logarithm of the minimum angle of resolution (logMAR) ETDRS letters at baseline and subsequent visits, number of injections and visits data were collected using a validated web-based tool (Fight Retinal Blindness!). RESULTS: 1273 eyes (1014 patients) were included, 971 treatment naïve (TN) and 302 previously treated (PT). Baseline VA (mean ± SD) was 57.5 (±19.5) and 62.2 (±17) (p > 0.001), and 24 months final VA was 60.4 (±21.2) and 58.8 (±21.1) (p = 0.326), respectively. Mean VA change at 12/24 months was +4.2/+2.9 letters in TN eyes and +0.1/-3.4 letters in PT eyes (p < 0.001/p < 0.001). The percentage of ≥15 letters gainers/losers at 24 months was 24.8%/14.5% in TN, and 10.3%/15.7% in PT eyes. The median number of injections/visits at 12 months was 7/9 in TN and 6/8 in PT (p = 0.002/p < 0.001) and at 24 months was 11/16 in TN and 11/14 in PT (p = 0.329/p < 0.001). Study drugs included ranibizumab (39.5%), aflibercept (41.2%) and bevacizumab (19.3%). CONCLUSION: Independent, large-scale national audits are feasible if committed health care professionals are provided with efficient information technology systems to do them. The results described here represent an adequate measurement of the quality of care delivered nationwide and benchmark the clinical management of nAMD at a country level compared to other real-world international cohorts.

New Aspects on the Treatment of Retinopathy of Prematurity: Currently Available Therapies and Emerging Novel Therapeutics.

Retinopathy of prematurity (ROP) is a rare proliferative ocular disorder in preterm infants. Because of the advancements in neonatal care, the incidence of ROP has increased gradually. Now, ROP is one of the leading causes of blindness in children. Preterm infants with immature retinal development are exposed to supplemental oxygen inside an incubator until their cardiopulmonary system is adequately developed. Once they are returned to room air, the relatively low oxygen level stimulates various angiogenesis factors initiating retinal neovascularization. If patients with ROP are not offered adequate and timely treatment, they can experience vision loss that may ultimately lead to permanent blindness. Although laser therapy and anti-vascular endothelial growth factor agents are widely used to treat ROP, they have limitations. Thus, it is important to identify novel therapeutics with minimal adverse effects for the treatment of ROP. To date, various pharmacologic and non-pharmacologic therapies have been assessed as treatments for ROP. In this review, the major molecular factors involved in the pathogenesis of ROP, currently offered therapies, therapies under investigation, and emerging novel therapeutics of ROP are discussed.

Cosmetic Filler Blindness: Recovery After Repeated Hyaluronidase Injections.

BACKGROUND: The rise of cosmetic injectables has involved new clinical scenarios related to complications. The scenario of hyaluronic acid (HA) aesthetic interventional-induced visual loss has become more recognized. Although this complication is rare, there can be delayed recognition and treatment, with limited opportunity to evaluate potential treatments and establish best practice guidelines. OBJECTIVES: The authors report a case of documented visual recovery with extra-orbital and intra-orbital hyaluronidase. Central retinal artery occlusion is an ischemic event requiring urgent intervention. The authors hope to assist protocols being developed for HA aesthetic interventional-induced visual loss. METHODS: Following loss of vision, 675 international units (IU) of hyaluronidase was given immediately to the injection site and extra-orbital area. Within 4 hours, 3000 IU intra-orbital and 1500 IU extra-orbital hyaluronidase were given. RESULTS: Visual loss in a 38-year-old female, following ipsilateral nasal injection of 0.15 mL of HA filler Juvéderm Voluma via the nasal tip, was documented at no perception of light with afferent pupil defect, central retinal artery occlusion, and fundoscopy showing a cherry red spot. This was associated with cerebral irritation and magnetic resonance imaging ischemia. Hyaluronidase was injected as described above. The following day, visual acuity (VA) in the affected eye recovered to 6/18 with a relative superior visual field scotoma. The VA improved to 6/6 at 1 month. CONCLUSIONS: The authors believe immediate injection followed by high dose intra-orbital and extra-orbital injection of hyaluronidase had a positive effect in this case. Recovery of vision was remarkable, from no perception of light to 6/6, documented at a tertiary referral eye hospital.

Varicella zoster virus (VZV) oculomeningoencephalomyeloradiculitis: a previously undescribed constellation.

A 53-year-old immunocompromised woman developed acute left eye blindness and paraparesis suspected to be due to neuromyelitis optica (NMO). During treatment for NMO, right eye blindness and progressive multiple cranial neuropathies developed. Cerebrospinal fluid polymerase chain reaction (PCR) revealed Varicella zoster virus (VZV). This case emphasizes the importance of considering VZV in individuals, particularly the immunocompromised, presenting with a constellation of neurological signs and symptoms, even in the absence of rash.

Outcomes of cataract surgery in eyes with diabetic macular oedema: Data from the Fight Retinal Blindness! Registry.

IMPORTANCE: There are limited data on real-world outcomes of cataract surgery in eyes receiving intravitreal treatments for diabetic macular oedema (DMO). BACKGROUND: Cataract surgery may exacerbate oedema in some eyes with DMO resulting in inferior outcomes. DESIGN: Matched, case-controlled retrospective study of observational data in routine clinical practice. PARTICIPANTS: Eyes receiving intravitreal treatments for DMO tracked in the Fight Retinal Blindness! Registry. METHODS: Eyes that underwent cataract surgery were identified and matched 1:1 with phakic controls also receiving intravitreal injections for DMO. We also assessed potential factors that were associated with better visual acuity (VA) outcomes. MAIN OUTCOME MEASURES: Change in VA 6 months after cataract surgery. RESULTS: Cataract surgery was identified in 208 eyes of 156 patients of which 147 eyes had 6 months of observations before and after surgery. The mean VA 6 months after surgery improved by 10.6 letters and was similar to their matched phakic controls (68.8 vs 69.2 letters; P = 0.8). Mean CST both 6 months before (341 µm) and after (360 µm) surgery were similar (P = 0.08). However, these eyes had thicker maculae and they received more injections than their matched phakic controls both before and after surgery. Eyes with worse VA before surgery and those that had received intravitreal treatment in the 4 weeks preceding surgery were more likely to gain vision. CONCLUSIONS AND RELEVANCE: Visual outcomes of cataract surgery in eyes receiving intravitreal therapy for DMO were reasonably better. Their maculae were thicker and required more injections in the 6 months before and after surgery than their phakic controls.

Vision treatment strategy for acute blindness in adolescent female with diffuse leptomeningeal glioneuronal tumor.

Diffuse leptomeningeal glioneuronal tumor with the first symptom of acute rapid blindness in both eyes are rare in adolescents. We present a case of an adolescent female without a history of cancer who developed a dramatic loss of vision and eventually blindness, and was diagnosed as diffuse leptomeningeal glioneuronal tumor by cerebrospinal fluid cytology and enhanced MRI. In order to save vision, under the condition of ineffective dehydration treatment, timely emergency surgery to implant Ommaya sac drainage cerebrospinal fluid. According to the pathophysiological mechanism of cerebral edema, we added Edaravone to scavenge oxygen free radicals, Alprostadil to improve microcirculation, Monosialotetrahexosylganglioside nutrient nerve, Butylphthalide to promote collateral circulation, combined with hyperbaric oxygen and acupoint injection of Anisodine. Finally, the patient's vision returned to normal. Conclusion: when dehydration treatment is ineffective, timely surgery to reduce intracranial pressure, combined with comprehensive treatment, can effectively save vision.

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.

Role of Retrobulbar Hyaluronidase in Filler-Associated Blindness: Evaluation of Fundus Perfusion and Electroretinogram Readings in an Animal Model.

PURPOSE: Hyaluronic acid gel filler-associated blindness is an uncommon but devastating complication. Hyaluronidase can potentially dissolve intravascular filler and improve perfusion; however, its role in filler-associated blindness has yet to be determined. The purpose of this study is to determine the effect of retrobulbar hyaluronidase on hyaluronic acid gel-induced ophthalmic artery occlusion in a rabbit model. METHODS: New Zealand red rabbits were used to simulate hyaluronic acid gel filler-associated vascular occlusive blindness. Ophthalmic artery occlusion and subsequent ischemia were confirmed by both retinal fundus photography and electroretinogram changes. Retrobulbar hyaluronidase 1,000 IU was injected 30 minutes after occlusion. Fundus photography and electroretinogram changes were recorded at 30, 60, 90, and 120 after administration of retrobulbar hyaluronidase. RESULTS: A total of 6 rabbits were used, for a total of 12 eyes. Four eyes were used as controls. Of the 8 experimental eyes, 2 eyes had recorded partial occlusion and 6 eyes had fully occluded ophthalmic arteries by angiographic evaluation. One of the partially occluded eyes demonstrated some improvement in perfusion 60 minutes after injection of retrobulbar hyaluronidase; however, electroretinogram readings remained flat over the 120-minute period of observation. Six eyes with completely occluded ophthalmic arteries showed no improvement in retinal perfusion with corresponding flat electroretinogram readings at 120 minutes following retrobulbar hyaluronidase injection. CONCLUSIONS: In this rabbit model, 1,000 IU of retrobulbar hyaluronidase administered 30 minutes after occlusion failed to reverse obstruction or restore function following hyaluronic acid gel occlusion of the ophthalmic artery.

Retrobulbar Injection for Hyaluronic Acid Gel Filler-Induced Blindness: A Review of Efficacy and Technique.

While blindness after hyaluronic acid gel filler injection occurs only very rarely, it represents a devastating complication for the patient and the surgeon. Retrobulbar injection with hyaluronidase is the only known potential means of reversing this adverse event. However, positive outcomes remain anecdotal. We have attempted to review the current literature regarding possible efficacy and detail the indications and technique to be utilized, if hyaluronidase retrobulbar injection is to be attempted. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Acute bilateral retinal artery occlusion causing sudden blindness in 25-year-old patient.

A 25-year-old male patient presented to the emergency department with the chief complaint of sudden blindness and was found to have suffered bilateral central retinal artery occlusion (CRAO). This process is most commonly the result of a thrombus or embolus that occludes the retinal artery, and normally presents in a single eye in patients older than 65 who are predisposed to vascular disease. Diagnosis relies most heavily upon funduscopic exam. Potential treatments involve ocular massage, acetazolamide, anterior chamber paracentesis and systemic or local fibrinolysis. Despite these interventions vision is often significantly and permanently impaired. This case underscores the importance of the emergency physician's ability to promptly perform and interpret the funduscopic exam in order to diagnose and evaluate CRAO.

Refractory Giant Cell Arteritis Complicated by Vision Loss From Optic Atrophy and Maculopathy Associated With Pachymeningitis.

BACKGROUND: We describe a 75-year-old woman who experienced vision loss in her left eye due to biopsy-proven giant cell arteritis (GCA). She subsequently developed pachymeningitis causing refractory headaches and bilateral optic neuropathy and maculopathy. METHODS: Case report with literature review. RESULTS: Eighteen months after the initial diagnosis of GCA, imaging studies in our patient demonstrated pachymeningeal enhancement, and meningeal biopsy confirmed lymphoplasmacytic tissue infiltrates with low frequencies of IgG4+ plasma cells. Laboratory investigation revealed the presence of 3 antiretinal antibodies and antimyeloperoxidase antibodies, consistent with autoimmune retinopathy. Treatment with B-cell-depleting anti-CD20 antibodies suppressed meningeal inflammation and prevented further vision loss. CONCLUSIONS: This case illustrates that bilateral vision loss and chronic headaches in patients with GCA may result from retina-directed autoimmunity and pachymeningitis.

Light Perception Vision Recovery After Treatment for Calcium Hydroxylapatite Cosmetic Filler-Induced Blindness.

A 51-year-old woman presented with no light perception vision of the right eye 12 hours after another provider injected calcium hydroxylapatite into the glabella and dorsum of the nose. Exam and fluorescein angiography demonstrated optic nerve edema and choroidal hypoperfusion consistent with ischemia of the posterior ciliary circulation. The central retinal circulation appeared intact. One thousand two hundred units of retrobulbar hyaluronidase were injected urgently in several boluses. Oral prednisone and aspirin also were administered. Ocular massage was also initiated. One day later, visual acuity improved to light perception that remained stable at 3 months. Retrobulbar hyaluronidase injection, ocular massage, prednisone, and aspirin were correlated to recovery of light perception vision in this case of calcium hydroxylapatite filler embolization to the choroidal circulation. The mechanism for the recovery of some vision and the role of hyaluronidase and other medications remain uncertain. Further research in treatments for ophthalmic complications of facial fillers is warranted.

Failure of Tafamidis to Halt Progression of Ala36Pro TTR Oculomeningovascular Amyloidosis.

Oculomeningovascular amyloidosis is a variant of transthyretin (TTR) amyloidotic polyneuropathy, which is associated with blindness and brain ischemia, microhemorrages, and siderosis due to prominent production of the abnormal TTR in the eye and in the choroid plexuses. Tafamidis is a TTR stabilizer that is orally administered and, by interfering with amyloid fibril formation and deposition, is capable of slowing progression of TTR polyneuropathy and of early-stage cardiomyopathy. However, the ocular manifestations of amyloid deposition progressed despite tafamidis therapy in Val30Met TTR amyloidosis, and the effects of tafamidis on meningovascular amyloidosis are unknown. We observed failure of tafamidis to halt progression of oculomeningovascular amyloid deposition in a patient with familial Ala36Pro TTR amyloidosis. She received molecular diagnosis at age 24 and presented at age 26 with paresthesias of the lower limbs and bowel dysfunction. Echography showed minimal amyloid opacities in the corpus vitreum. Treatment with tafamidis meglumine was started. Sixteen months later, she complained of severe headache followed by left hemiparesthesias and numbness lasting 20 minutes. Magnetic resonance imaging showed multiple focal and diffuse hemosiderin deposits compatible with microbleeds and early siderosis. Echography showed a marked increase of "vitreal opacities." Our observation confirms that tafamidis fails in halting increase of vitreal amyloid deposits and indicates that it is presumably ineffective in preventing clinical onset due to progression of meningovascular amyloidosis. These failures may be due to the incapability of tafamidis to cross the blood-retina and blood-brain barriers. Therapeutic options targeting oculomeningovascular TTR amyloidoses in humans are required.

Reversal of threatening blindness after initiation of eculizumab in Purtscher-like retinopathy secondary to atypical hemolytic uremic syndrome.

Purtscher-like retinopathy, a rare manifestation of systemic thrombotic microangiopathy, is a potentially visually debilitating condition with no effective proven treatment. Distinct pathogenic pathways have been proposed as etiological factors. We revisit the etiology of Purtscher-like retinopathy based on the rapid response and profound visual improvement after initiation of systemic intravenous eculizumab, an inhibitor of the complement cascade, in a patient with Purtscher-like retinopathy secondary to familial atypical hemolytic uremic syndrome (aHUS) due to a mutation in complement factor H. We hypothesize that the efficacy of eculizumab in this patient provides evidence for pathogenic events in the retina similar to those encountered in the renal microvasculature of aHUS patients, namely complement-mediated thromboembolization as a result of activation of the complement cascade in endothelial cells with release of tissue factor and development and amplification of a procoagulant state. To the best of our knowledge, this is the first report in the literature of eculizumab as an effective therapeutic strategy in Purtscher-like retinopathy.

Nerve growth factor improves visual loss in childhood optic gliomas: a randomized, double-blind, phase II clinical trial.

Paediatric optic pathway gliomas are low-grade brain tumours characterized by slow progression and invalidating visual loss. Presently there is no strategy to prevent visual loss in this kind of tumour. This study evaluated the effects of nerve growth factor administration in protecting visual function in patients with optic pathway glioma-related visual impairment. A prospective randomized double-blind phase II clinical trial was conducted in 18 optic pathway glioma patients, aged from 2 to 23 years, with stable disease and severe visual loss. Ten patients were randomly assigned to receive a single 10-day course of 0.5 mg murine nerve growth factor as eye drops, while eight patients received placebo. All patients were evaluated before and after treatment, testing visual acuity, visual field, visual-evoked potentials, optic coherence tomography, electroretinographic photopic negative response, and magnetic resonance imaging. Post-treatment evaluations were repeated at 15, 30, 90, and 180 days Brain magnetic resonance imaging was performed at baseline and at 180 days. Treatment with nerve growth factor led to statistically significant improvements in objective electrophysiological parameters (electroretinographic photopic negative response amplitude at 180 days and visual-evoked potentials at 30 days), which were not observed in placebo-treated patients. Furthermore, in patients in whom visual fields could still be measured, visual field worsening was only observed in placebo-treated cases, while three of four nerve growth factor-treated subjects showed significant visual field enlargement. This corresponded to improved visually guided behaviour, as reported by the patients and/or the caregivers. There was no evidence of side effects related to nerve growth factor treatment. Nerve growth factor eye drop administration appears a safe, easy and effective strategy for the treatment of visual loss associated with optic pathway gliomas.

NEOVASCULAR AGE-RELATED MACULAR DEGENERATION WITH ADVANCED VISUAL LOSS TREATED WITH ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR THERAPY: Clinical Outcome and Prognostic Indicators.

PURPOSE: To describe visual outcome and prognostic indicators in neovascular age-related macular degeneration with advanced visual loss at the initiation of anti-vascular endothelial growth factor therapy. METHODS: A retrospective chart review was performed on a consecutive series of 1,410 patients with neovascular age-related macular degeneration treated with anti-vascular endothelial growth factor therapy at the Medical College of Wisconsin. Subjects were included if at the initiation of therapy they had 20/200 or worse visual acuity (VA) with no other visually limiting eye disease and a minimum follow-up of 6 months. The change in VA at 6 months and 12 months was assessed compared with baseline. Visual improvement/worsening was defined as at least ± 0.3 logMAR (equivalent to 15 ETDRS [Early Treatment Diabetic Retinopathy Study] letters) change. Other factors for analysis included number of injections received, drug type, and various clinical and imaging findings. RESULTS: One hundred thirty-one cases met the study criteria, and 97 were followed for 12 months. Baseline VA was 1.38 logMAR (20/480 Snellen equivalent). Mean VA change (logMAR) consisted of an improvement of 0.23 (P < 0.0001) at 6 months and 0.17 (P = 0.003) at 12 months. At 12 months, VA improved in 45% and worsened in 20%. Among subjects with baseline VA worse than 20/400, VA improved in 57% and worsened in 20%. On univariate analysis at either the 6 months or 12 months follow-up, visual improvement was associated with retinal hemorrhage (P = 0.03) and subretinal fluid (P = 0.02), whereas visual worsening was associated with retinal pigment epithelial detachment (P = 0.04) and intraretinal fluid (P = 0.01). With multivariate analysis, visual improvement was predicted by both a larger number of injections received (P = 0.001) and a poorer baseline VA (P = 0.001). Injection medication type did not influence outcome. CONCLUSION: Statistically significant visual improvement was observed in association with anti-vascular endothelial growth factor therapy in patients with severe neovascular age-related macular degeneration, even in patients whose initial VA was worse than that studied in large anti-vascular endothelial growth factor clinical trials. Numerous clinically discernable or potentially modifiable factors may influence outcome in such patients.

Efficacy of Retrobulbar Hyaluronidase Injection for Vision Loss Resulting from Hyaluronic Acid Filler Embolization.

BACKGROUND: Vision loss is a rare but serious complication of facial hyaluronic acid (HA) filler injection, for which there is no proven rescue therapy. Retrobulbar hyaluronidase injection is advocated by many plastic surgeons as an emergency treatment, but has not been carefully assessed for its efficacy. OBJECTIVES: To evaluate the efficacy of retrobulbar hyaluronidase injection as a rescue treatment for vision loss caused by HA filler embolization. METHODS: Patients with vision loss caused by HA filler embolization were treated with retrobulbar hyaluronidase injection. Their visual acuity and fundoscopic images before and after treatment were analyzed for efficacy assessment. RESULTS: One patient with branch retinal artery occlusion (BRAO), one patient with posterior ischemic optic neuropathy (PION), one patient with ophthalmic artery occlusion, and one patient with both BRAO and PION were treated with one or two retrobulbar injections of 1500 or 3000 units hyaluronidase. No patients demonstrated substantial retinal artery recanalization or vision acuity improvement after treatment. CONCLUSIONS: One or two retrobulbar injections of 1500 to 3000 IU hyaluronidase are unable to recanalize retinal artery occlusion or improve the visual outcome of patients who presented with vision loss caused by HA filler embolization at least four hours after onset. LEVEL OF EVIDENCE: 4.