This refers to a group of complications that occur after hyaluronic acid filler (filler injection) or autologous fat injection around the eye socket. As cosmetic medicine has become more common, filler injections into the eyelids, under-brow area, tear trough, and nasal bridge have become widespread, and reports of ophthalmic complications are increasing worldwide.
The most serious complication is vision loss caused by retrograde embolism into the ophthalmic or retinal artery system, and once it occurs, it is often irreversible1). A review of the worldwide literature has reported hundreds of cases of filler-related vision loss, with injection into the glabella and nasal bridge cited most often as the cause1).
Ophthalmologists need to be familiar with the pathophysiology, diagnosis, and emergency management of these complications so they can handle not only complications after ophthalmic surgery but also consultations from cosmetic medicine providers and emergency visits.
Although extremely rare, if hyaluronic acid or fat is pushed backward by the pressure of the injection and embolizes the retinal artery, it can cause irreversible vision loss. Injections into the glabella and nasal root are especially high risk. A review of the world literature found multiple reports of vision loss after periorbital filler injections, and once it occurs, it often leads to permanent blindness. For hyaluronic acid, there are case reports of recovery with early hyaluronidase treatment, but delayed treatment greatly worsens the prognosis.
Complications after filler and fat injection are classified into three categories according to mechanism and severity2).
| Category | Main complications | Severity |
|---|---|---|
| Vascular embolic | Central retinal artery occlusion (CRAO), orbital artery embolism, cerebral infarction | Most severe (often irreversible) |
| Local complications | Hematoma, infection, cellulitis, skin necrosis, granuloma, Tyndall effect | Moderate (recoverable with early treatment) |
| Eyelid-specific | Eyelid edema, ptosis, conjunctival edema, and filler migration into the anterior chamber | Mild to moderate |
Retrograde embolism occurs when the filler injection pressure exceeds arterial pressure. Symptoms immediately after injection are characteristic.
Central retinal artery occlusion (CRAO)
The filler flows backward into the ophthalmic artery and central retinal artery, causing occlusion. Sudden loss of vision in one eye (no light perception to severe vision loss) is the main symptom. Fundus findings include a cherry-red spot, retinal pallor, and arterial occlusion. Retinal ischemia is irreversible, and visual recovery is extremely difficult, especially with emboli other than hyaluronic acid (fat or permanent fillers).
Orbital artery embolism
Causes impaired blood flow to the eye and optic nerve. The main symptoms are eye pain, proptosis, and decreased vision, and optic nerve ischemia (findings similar to anterior ischemic optic neuropathy) may occur.
Cerebral infarction
The most severe complication, caused by retrograde embolism into the internal carotid artery system, leading to cerebral ischemia3). If altered consciousness, hemiparesis, or aphasia occur in addition to eye symptoms, an immediate neurology consult is required.
Hematoma and subcutaneous bleeding
Needle injury to blood vessels can cause a hematoma in the eyelid or around the eye. Mild cases are naturally absorbed, but larger hematomas may require compression.
Infection and cellulitis
Cellulitis can develop from infection at the filler injection site. Redness, warmth, pain, and abscess formation are signs, and early treatment with antibiotics is important.
Skin necrosis
If local ischemia caused by vascular embolism persists, necrosis can occur in the skin and subcutaneous tissue. It is common between the eyebrows and at the nasal root, and may appear within a few hours after filler injection as pale skin, pain, and reticular skin mottling.
Granuloma (filler lump, hard nodule)
As a foreign-body reaction to the filler material, a hard lump or granuloma forms at the injection site. It may also appear later.
Tyndall effect
This occurs when hyaluronic acid is injected too superficially. It is an optical phenomenon in which the injection site appears bluish-green because hyaluronic acid scatters visible light. It is especially noticeable in the thin skin around the eye.
Eyelid edema and ptosis
Eyelid edema and ptosis can occur because of mechanical pressure from the filler or an inflammatory reaction. Most cases are temporary, but if they persist, hyaluronidase injection or surgical treatment may be needed.
Conjunctival edema
Conjunctival edema (swelling of the conjunctiva) can occur due to increased intraorbital pressure or impaired lymph flow.
Filler migration into the anterior chamber
Although extremely rare, there have been reports of filler migrating into the anterior chamber. There is a risk of endophthalmitis and corneal endothelial damage, and urgent ophthalmic care is required.
Periorbital filler injections are rapidly becoming more common in aesthetic medicine, but accurate epidemiologic data on the incidence of blindness caused by vascular embolism are limited. In pooled surveys from multiple practitioners and facilities, vision loss from filler injections overall is reported at less than about 0.001%, but it has drawn attention because it can be irreversible once it occurs5).
The most common anatomical high-risk sites are the glabella and nasal root, followed by the nasal dorsum, brow, and forehead1). In these areas, the supratrochlear and dorsal nasal arteries run as terminal branches of the ophthalmic artery, providing an anatomical basis for retrograde embolization from filler to reach the ophthalmic arterial system directly.
Injection into the tear trough (lower eyelid) and under the brow (upper eyelid) is also increasing, and these sites also carry a risk of embolism via the palpebral and dorsal nasal arteries. As procedure frequency increases, reports of ocular complications from injections in areas other than the periorbital region (the nose and forehead) are also increasing2).
In diagnosing complications after filler or fat injection, promptly recognizing vascular embolism is critical to visual prognosis.
| Examination | Purpose | Main findings |
|---|---|---|
| Fundus examination | Confirmation of retinal artery occlusion | cherry-red spot, retinal pallor, and interrupted arterial flow |
| Fluorescein fundus angiography | Evaluation of retinal perfusion impairment | Delayed filling, nonperfusion areas, and prolonged arteriovenous transit time |
| Orbital CT/MRI | Confirmation of filler distribution and hematoma assessment | Identification of filler material, soft tissue edema, and hematoma |
Key points for early recognition of vascular embolism
If the following symptoms appear immediately after injection (within seconds to minutes), strongly suspect vascular embolism and move to emergency treatment at once.
Fundus examination
In central retinal artery occlusion, a cherry-red spot (a red spot in the macula) and milky cloudiness and pallor of the surrounding retina are characteristic. Arterial cutoff and interrupted blood flow (“cattle truck sign”) are also seen. Differentiation from optic nerve ischemia is also made based on the presence or absence of optic disc edema and pallor.
Imaging tests
Orbital CT/MRI is useful for confirming the distribution of the filler and evaluating hematoma and infection. Hyaluronic acid generally appears isoattenuating to low attenuating on CT. After fat injection, it may be difficult to distinguish it from adipose tissue. If cerebral infarction is suspected, add head MRI (DWI).
Differential diagnosis
A sudden drop in vision immediately after injection may indicate a vascular embolism. Tell the person performing the procedure right away, and if it was a hyaluronic acid filler, emergency hyaluronidase injection is needed. At the same time, an urgent eye examination is essential. Because even a delay of minutes can greatly affect the visual prognosis, do not choose to observe and wait on your own. If brain symptoms (altered consciousness or hemiplegia) are present, call an ambulance.
Response to hyaluronic acid filler embolism
Emergency hyaluronidase injection: Perform immediately if embolism is suspected
Injection site: Subcutaneous tissue around the embolism and the orbit (retrobulbar injection if needed)
Additional measures: Lower intraocular pressure (eye massage, intravenous acetazolamide) and anterior chamber paracentesis
Possibility of vision recovery: Reports of recovery with early treatment4)
Response to autologous fat injection embolism
No specific antidote: Hyaluronidase is ineffective
Symptomatic treatment only: Lower intraocular pressure, vasodilators, and oxygen therapy
Visual prognosis: Irreversible in many cases, and recovery is extremely difficult
Watch for neurological complications: If neurological symptoms appear, urgently consult neurology
Hyaluronidase is the only specific agent that enzymatically breaks down hyaluronic acid4). If embolization is suspected, perform it promptly without delay.
Principles of administration
Emergency management of retinal artery occlusion
In parallel with hyaluronidase administration, promptly carry out the following procedures.
Hyaluronidase is ineffective for autologous fat, and there is no specific antidote. Only symptomatic treatment is used, including the eye-pressure-lowering, vasodilatory, and oxygen therapies above. The prognosis is often poor. If a brain complication is suspected, an urgent neurology consultation is needed.
Infection and cellulitis
Start broad-spectrum antibiotics (oral or intravenous) promptly. In severe cases, consider hospital care and surgical drainage. If a hyaluronic acid filler is the source of infection, hyaluronidase can be used to help break it down and drain it.
Hematoma
The basic approach is observation with compression and cooling. If a large hematoma or optic nerve compression is suspected, perform puncture and drainage.
Granuloma (filler mass)
Try to reduce it with local steroid injection (triamcinolone acetonide injection). If there is no improvement, consider surgical removal. Hyaluronidase injection may be effective for hyaluronic acid granulomas.
Tyndall effect
Improvement can be achieved by injecting hyaluronidase to break down and remove the hyaluronic acid. Consulting the practitioner and prompt treatment are effective for improving discoloration.
Eyelid edema and ptosis
Temporary cases often improve with observation. If it persists, consider hyaluronidase injection for hyaluronic acid, or surgical treatment for fat or other materials.
Both carry a risk of vascular embolism. However, hyaluronic acid has a degrading enzyme called hyaluronidase, and if an embolism occurs, emergency administration may make vision recovery possible. Autologous fat has no specific way to break it down, and if an embolism occurs, recovery of vision is considered extremely difficult. From the standpoint of what can be done in an emergency, hyaluronic acid fillers have an advantage in safety over autologous fat.
To prevent complications related to filler injection, the practitioner needs to master the following anatomical knowledge and safe techniques2,5).
The glabella and nasal root are the highest-risk areas. In this region, the supratrochlear artery (a terminal branch of the ophthalmic artery) runs superficially, and there are dense direct anastomoses with the ophthalmic arterial system. When filler injection pressure exceeds arterial pressure (about 60–90 mmHg systolic blood pressure), retrograde embolism is more likely to occur.
Priority order of high-risk areas:
Use of a blunt cannula
Compared with a sharp injection needle, a cannula has a lower risk of accidental intravascular injection. Because it is flexible, it is less likely to pierce the vessel wall and advances by pushing aside the vessel lumen. Use of a cannula is especially recommended in danger areas such as the glabella and around the eyes5).
Low-pressure, small-volume injection
Rapid injection under high pressure increases the risk of retrograde embolization. The basic approach is slow, low-pressure injection and divided administration in small amounts.
Aspiration test
Before injection, negative pressure is applied to check for blood reflux. However, the positive rate is low, and even a negative result does not completely guarantee safety.
Filler selection
Hyaluronic acid fillers can be broken down with hyaluronidase, and from the standpoint of emergency management, they are preferable to autologous fat and permanent fillers.
Hyaluronidase on hand
The clinic should keep hyaluronidase on hand and be ready to give it in an emergency.
The following risks should be explained to patients.
Low-pressure injection, an aspiration test (checking for blood return), and the use of a blunt cannula are recommended. Extra caution is required in anatomically high-risk areas (the glabella, nasal root, and nasal dorsum). Keeping hyaluronidase on hand is also an important safety measure, and a system should be in place so it can be given quickly if embolization occurs. When choosing a filler, hyaluronic acid is considered preferable to autologous fat or permanent fillers because it can be managed in an emergency.
When the pressure during filler injection exceeds the local arterial pressure, the filler material flows backward into the vessel lumen. After the injection pressure is released, blood flow resumes and carries the embolic material distally (toward the ophthalmic and cerebral arteries). This embolization is completed through a two-step process of backward flow followed by forward flow3).
The supratrochlear artery distributed in the glabellar and nasal root region is a terminal branch of the ophthalmic artery. If injected filler flows backward and ascends the supratrochlear artery, it can reach the main trunk of the ophthalmic artery and then enter the central retinal artery and orbital artery. In the glabella and nasal bridge, multiple terminal arteries form a dense network of anastomoses, creating anatomic conditions that make it easy for filler to spread into the ophthalmic artery system.
The ophthalmic artery is the first branch of the internal carotid artery and divides within the orbit into the central retinal artery, ciliary arteries, artery of the optic nerve sheath, and others. All of these can be targets of retrograde embolization.
| Item | Hyaluronic acid filler | Autologous fat |
|---|---|---|
| Embolic mechanism | Retrograde (supratrochlear artery → ophthalmic artery → central retinal artery) | Same as the left |
| Breakdown of the substance | Enzymatic breakdown is possible with hyaluronidase | Enzymatic breakdown is not possible |
| Emergency treatment | Emergency hyaluronidase injection is effective | Symptomatic treatment only |
| Possibility of vision recovery | Reported with early intervention4) | Extremely difficult |
| Local dissolution | Possible (including granuloma) | Impossible |
Hyaluronic acid is a type of glycosaminoglycan in the body and is hydrolyzed by hyaluronidase. Hyaluronic acid used as a filler is further cross-linked, so it is designed to break down more slowly in the body, but high-dose hyaluronidase can speed its breakdown. If an embolism occurs, hyaluronidase is injected into the injection site, retrobulbar space, and surrounding tissue to try to break down the filler and restore blood flow4).
Autologous fat involves transplanting lipoaspirate (suctioned fat) and, histologically, contains adipocytes, stromal vascular fraction (SVF), and extracellular matrix. There is no specific drug that can break it down enzymatically, so emboli after injection can only be removed physically. Fat emboli tend to form stable masses within the vessel lumen and are often difficult to clear.
In central retinal artery occlusion, there is a limited time before retinal ischemia becomes irreversible. Animal data suggest that blood flow restored within 240 minutes may allow some functional recovery, but clinically, the earlier the treatment, the better the prognosis. Early administration of hyaluronidase (as soon as possible after onset, at least within 90 to 120 minutes) increases the chance of visual recovery4).
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Cho KH, Dalla Pozza E, Toth G, et al. Vascular complications after filler injection: a systematic review. Aesthet Surg J. 2021;41:NP1204-NP1218.
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DeLorenzi C. New High Dose Pulsed Hyaluronidase Protocol for Hyaluronic Acid Filler Vascular Adverse Events. Aesthetic surgery journal. 2017;37(7):814-825. doi:10.1093/asj/sjw251. PMID:28333326.
Goodman GJ, Roberts S, Callan P. Experience and Management of Intravascular Injection with Facial Fillers: Results of a Multinational Survey of Experienced Injectors. Aesthetic plastic surgery. 2016;40(4):549-55. doi:10.1007/s00266-016-0658-1. PMID:27286849.
