Minimising Risks of Hyaluronic Acid Embolic Visual Loss

A research team of 22 prominent medical and nursing practitioners (15 from across Australia, as well as international experts from the USA, Germany, New Zealand, South Africa, Taiwan and India) has just published a major paper in Aesthetic Surgery Journal (official publication of the American Society of Aesthetic Plastic Surgery) titled ‘A Consensus on Minimizing the Risk of Hyaluronic Acid Embolic Visual Loss and Suggestions for Immediate Bedside Management’.

While hyaluronic acid (HA) fillers have a satisfactory safety profile, adverse reactions do occur – and on rare occasions intravascular injection may lead to blindness.

Currently there is no internationally recognised consensus on either the prevention or management of blindness from HA filler. The research team’s objective was to “give guidance on how to minimise the risk and optimise the management of this rare but catastrophic adverse reaction”.

To that end, a multinational group of experts in cosmetic injectables from multiple disciplines convened to review current best practice and develop updated consensus recommendations for prevention and bedside intervention if visual loss occurs after cosmetic injection of HA filler.

The group provided specific recommendations focusing on the consenting process, prevention and early management of visual impairment related to intravascular HA filler injection.

7 key ‘consensus questions’

Following a review of current research and expert observations, the team agreed on 4 preliminary issues:

  • A column of filler is probably required to induce embolic visual loss from hyaluronic acid injection.
  • The degree of visual loss may relate to the volume injected, its cohesivity, particle size and vessels affected.
  • The exact embolised vessels within the orbital system will dictate the clinical pattern.
  • Cerebral infarction may occur in 25% of patients with embolic visual loss.

A consensus meeting was held in September 2018 in Melbourne, where 7 prepared questions were introduced to the group. Options were then put to the group for a vote, allowing development of a consensus statement when greater than 75% agreement was reached. (Anything less than 75% agreement was not deemed to be a consensus.)

After the consensus statements were finalised, 5 ophthalmologists and 2 interventional radiologists were consulted regarding their opinion on the outcomes of the meeting and the consensus statements. These opinions were taken back to the group for discussion and further refinements were made, although none of the consensus statements were substantively altered and no agreements affected.

Q1: Should the Consenting Document Given to a Prospective Patient Include a Discussion About the Possibility of Visual Loss?

The group considered the consent document should ideally state:

  • There is a small but definite risk that injection of fillers may injure a facial blood vessel.
  • Most times this just produces bruising and is not overly significant.
  • However, rarely the filler will enter a blood vessel and produce an event that may result in skin and tissue loss if not treated urgently.
  • Very rarely, estimated at 0.001% (less than 1 in 100,000 injection syringes used), blindness has occurred from filler being injected in a vessel, which may be irreversible.
  • Also, very rarely there may be a risk of stroke from an injection into a vessel.
  • If the practitioner notices problems (of blindness or pending tissue necrosis) at the time of the procedure or subsequent to the procedure, it is essential that they are allowed to dissolve this material or take other remedial measures and the patient should consent to this approach prior to the procedure.

Q2: What Preventive Strategies Should be Undertaken by the Practitioner to Decrease the Incidence of Post-Filler Visual Loss?

The group discussed strategies which may be employed on a regular basis that may lessen risk and determined 9 consensus points:

  • Understand the safest depth of injection in any given area.
  • Inject VERY slowly and with low extrusion pressure.
  • Cannulae are considered by many to be a safer alternative to needles in certain areas including the brow, lateral and anterior cheek. They are not considered safer for nasal injection. Smaller gauge cannulae (less than 25 gauge) may behave somewhat like needles in terms of their ability to pierce blood vessels.
  • Consider using local anesthetic with epinephrine at cannula entry points and within the injection field to constrict local vessels. When using local anesthetic with epinephrine, it may be worthwhile observing the patient after injection to ensure the vasoconstrictive effect resolves, to avoid confusion with intravascular injection of filler.
  • Consider directing the needle/cannula perpendicular to primary axial vessels in the anatomical region to reduce the likelihood of vessel cannulation.
  • Micro-boluses should be injected in small aliquots (<0.1ml).
  • Move the needle in the chosen plane at all times when delivering microboluses, even if only in small amplitude movements.
  • Consider ensuring the direction of injection is away from the eye in higher risk areas such as nose, glabella and nasolabial fold.
  • There is currently no evidence to support aspiration as a safety measure.

Q3: Are There Areas of Increased Risk That Require More Training and More Supervision?

The group discussed whether to grade ‘regions of concern’ by risk, and advise the required level of access to medical care?

This was predicated on two facets of practice – the amount of teaching and experience of the practitioner and the ready access to medical care if required.

Immediate issues included:

  • Should teaching and learning deal with regions of least risk first, moving on to more difficult regions as experience and knowledge increases?
  • Are there regions that should not be treated without medical clinic status and/or access to medical assistance?

The group divided regions into 4 grades, dependent on risk associated with these principles.

Grade 1: Regions of lower risk and should only be treated:

  • By those with adequate training
  • Utilising up-to-date knowledge of regional anatomy and safest practice
  • In a clinical setting
  • Jawline and marionette, lateral cheek (lateral to a vertical line through the lateral canthus), sub-malar, preauricular, chin augmentation.


Grade 2:Regions of moderate risk and should only be treated:

  • By those with adequate training
  • Utilising up-to-date knowledge of regional anatomy and safest practice
  • In a clinical setting
  • Lips, perioral region, anterior cheek (between a vertical line through the lateral canthus and the mid pupillary line) Lips and the perioral area are considered high incidence areas for intravascular injection and embolism, but only moderate likelihood of visual loss.

Grade 3: Regions of high risk and should only be treated:

  • By those with adequate training
  • Utilising up-to-date knowledge of regional anatomy and safest practice
  • In a clinical setting with rapid access available to medical personnel if required
  • Temples, nasolabial folds, tear troughs, peri-orbital, medial cheek (between the mid pupillary line and the side of the nose)

Grade 4: Regions of greatest risk of serious intravascular injection that may lead to visual embolic events and should only be treated:

  • By those with extensive experience
  • Comprehensive training
  • Utilising up-to-date knowledge of regional anatomy and safest practice
  • In a medical clinic
  • Glabella, nose, forehead

Q4: What Should Be Documented at the Bedside if Visual Loss is Suspected or Apparent?

The group agreed this is a true vascular emergency and, as with a cardiac or neurological vascular occlusion, it should be treated as such. The priority should be urgent referral to expert care, with additional actions suggested:

  • Seek help from ‘in clinic’ colleagues and aim to transfer the patient at the earliest opportunity to external personnel such as an emergency physician from a specialist eye hospital with experience in treating this or similar conditions, or otherwise an experienced ophthalmologist
  • Document the time of the beginning of the vascular event
  • Document visual deficit if able to assess. This step should not cause delay in transfer
  • If assessing visual loss ask the patient to read text, assess number of fingers held up in front of the affected eye, and if unable to do that, assess detection of hand movement.
  • One eye should be assessed at a time
  • Assess pupillary reactions, eye movements
  • Questioning should assess history of migraines if not ascertained beforehand
  • Providing it does not delay transfer, basic neurological assessment should be completed, including speech, hand, arm, and leg movements and level of consciousness
  • Assess any associated cutaneous signs of impending skin necrosis
  • Take photographs if time permits or a short video, possibly via a phone or tablet, if this is the most expeditious method

Q5: If Hyaluronic Acid was the Substance Being Used, What Role Does Hyaluronidase Have in the Management of the Visual Loss?

The group discussed the issue: what should every clinic know about hyaluronidase and what should they be expected to do with this agent?

Hyaluronidase was only considered useful if hyaluronic acid filler was known to be the cause of the visual loss. It was stressed that the person available with the highest level of expertise “should be handling this stage of treatment” and any treatment should not delay appropriate transfer.

Treatment should be extremely timely as time to reverse the blindness is short. There is very limited evidence to support intervention but supratrochlear, supraorbital and dorsal nasal vascular access treatments and retrobulbar injections have had some limited success.

The group agreed:

  • Every clinic must have hyaluronidase available for immediate use in case of any intravascular event
  • Every clinician using hyaluronic acid filler must have reconstituted or be able to reconstitute hyaluronidase
  • In Australia and New Zealand, the hyaluronidase Hyalase (SanofiAventis Australia Pty Ltd) is available as 1,500 units as a powder for reconstitution. We recommend a minimum of 7,500 units in total should be available ‘on site’ – and even more than this may be required in certain circumstances.
  • In the case of visual impairment, high dose (1500 units in 2 ml xylocaine 1%) hyaluronidase should be injected where the hyaluranon filler was placed and any other areas demonstrating signs of impending skin necrosis.
  • Injection of high dose hyaluronidase (1500 units in 2 ml xylocaine 1%) should be performed at the supraorbital margin specifically in the location of the supratrochlear artery (14mm from mid line beneath the medial brow creases) and/or supraorbital notch or foramen (25mm from midline) or targeting other branches of the ophthalmic arterial system if the practitioner feels comfortable with this technique.
  • Peribulbar or retrobulbar injections should only be performed if the operator has expertise in this injection technique and feels confident in the diagnosis.

Q6: Should the Clinic Anti-coagulate the Patient at the Bedside With Aspirin or Other Agents?

It was agreed unanimously that there is little evidence for anti-coagulating patients at the bedside. As this is initially a non-thrombotic occlusion it is not advised.

Q7: Should the Clinic Attempt Manoeuvres to Decrease Intraocular Pressure at the Bedside or During Transport?

It has been suggested that the practitioner and patient may try to decrease intraocular pressure by the following means:

  • Ocular massage
  • Re-breathing in a paper bag or Carbogen (95% O2, 5% CO2)
  • Timolol 0.5% drops (1-2 drops each eye)
  • Sublingual glycerol trinitrate

The majority of ophthalmologists (4/5) asked post-meeting felt the above manoeuvres, especially closed eye massaging, were worthwhile trying but unlikely to be successful.

As a result:

  • Attempts to decrease intraocular pressure were felt to have low levels of evidence
  • The consensus group did not reach agreement on the value of these manoeuvres
  • However, the group did not recommend against attempts to decrease intraocular pressure at the bedside

9 Major Conclusions

The major conclusions of this consensus group were:

1: The patient should be adequately consented for the possibility of visual impairment and cerebrovascular accident – and should also agree to remedial measures in the event of these adverse events.

2: Safety measures should be employed in all patients, including:

  • understanding the injection anatomy in any given area
  • injecting slowly with low extrusion pressure
  • cannulae are safer in some areas but not all areas
  • one should consider local anaesthetic with epinephrine at cannula entrance points
  • the injection instrument should be directed across axial vessels
  • micro boluses (<0.1ml) should be used
  • the instrument should be continually moving, even in small amplitude movements in the chosen plane
  • the instrument should be injected in a direction away from the eye when possible.

3: There is currently no evidence to support aspiration as a safety measure and the consensus was against relying on this manoeuvre.

4: It is possible to grade regions according to risk and the clinical environment in which these injections should be delivered. The forehead, nose, and glabella were considered those that should only be delivered by those with extensive experience, comprehensive training, up-to-date training in anatomy and safest practice, and delivered in a medical clinic where help may be readily available.

5: If visual loss is suspected this should be documented, as should cutaneous and neurological involvement.

6: All clinics should be equipped with hyaluronidase – and know how to use this for cutaneous involvement and attempt injection at the suspected injection point of filler as well as supratrochlear and/or supraorbital regions.

7: Retrobulbar and peribulbar hyaluronidase should be attempted only by those experience in this technique.

8: Anti-coagulation should not be performed at the bedside.

9: The consensus group could not agree on the effectiveness of manoeuvres to decrease intraocular pressure and took no stance on these.

Aesthetic Medical Practitioner magazine asked half a dozen members of the research team for their responses to these important questions:

QUESTION 1. Why did this group of concerned doctors think it both important and timely to cooperate in producing this report?

QUESTION 2. What do you see as the most important messages (in terms of patient safety) for both fellow medicos and the public at large to prioritise from your work?


Dr Sean Arendse is an Emergency Physician at Melbourne’s Alfred Hospital

 Q1:Injectors know adverse reactions do occur; and rarely intra-vascular injection of hyaluronic acid filler may lead to blindness –a catastrophic complication not only for the patient but also the practitioner. A multinational group of 22 experts in cosmetic injectables was assembled by Professor Greg Goodman at a consensus meeting to review the current ‘best practice’ and formulate updated consensus recommendations for prevention and early management of visual impairment related to intra-vascular hyaluronic acid filler injection.

Q2:The Paper can be summarised into 7 key recommendations:

  • We should consent patients for the small but definite risk that fillers may cause visual impairment; and the patient should also agree to immediate treatment should this occur.
  • We should all have an intimate knowledge of the injecting anatomy, and also safety measures to reduce the risk of an adverse vascular event –such as injecting slowly and continually moving our injection instrument.
  • Not to rely on aspiration.
  • That areas of the face can be graded with regards to risk –Glabella, forehead and nose being the highest risk areas.
  • If visual disturbance does occur, there is a minimum standard for documentation and examination.
  • All clinics should stock Hyaluronidase –and know how to use it.
  • And retrobulbar injection of Hyaluronidase should only be attempted by those experienced in this technique.


Dr Greg Goodman is an Adjunct Associate Professor at Melbourne’s Monash University and Chief of Surgery at Victoria’s Skin and Cancer Foundation

Q1: Although rare, visual loss from injectable fillers is a devastating event, especially in the life of the patient but also for the practitioner. It is something the patient needs to be aware of as a rare consequence. It is not completely preventable, but there are measures a clinician can adopt that will limit the risk of this occurrence. These are outlined in the article. There are also measures we do not believe help, which are commonplace beliefs among clinicians that we have attempted to dispel. We also wanted to outline what the consensus group thought was appropriate and less appropriate management at the bedside, if this was to happen. 

Q2: Be aware this is a material, albeit rare, risk. We believe the risk sits at about 1 in 100,000 injection syringes used. Practice injection as though this is always a possibility. We want all practitioners to have or gain a knowledge, not only of facial anatomy but also of ‘injection anatomy’ –understanding what is under the skin at every point they are injecting and on what plane of tissue the structures lie.

We also think there are areas of much higher risk than others. We suggest people learn to inject the safest areas first, and then move progressively on to more challenging regions once they have developed competence and increased knowledge. There are regions such as the forehead, nose and glabella that demand the highest knowledge and should be performed only in medical clinics, where immediate help may be at hand.

We need all clinics to understand the antidote to hyaluronic acid (hyaluronidase) and its appropriate use in patients –and to have this agent on hand, and be able to reconstitute and use this appropriately.


Dr David Kosenko is an aesthetic physician in private practice at Mt Eliza in Victoria

Q1: Patient safety and well-being are of utmost importance to doctors and provide one of the pillars central to the philosophy of medical practice. All doctors, irrespective of speciality or craft group, have this in common –and producing a consensus statement allows for the development of recommendations based on the expertise of doctors with diverse experience and differing knowledge. The collaboration seemed particularly timely, given reports of visual loss following injection with hyaluronic acid fillers.

The question was straight forward: Can we give guidance to minimise the risk and optimise the management of this catastrophic adverse reaction?The aim was to increase public awareness and provide guidance to practitioners using hyaluronic acid ,with the goal of increasing patient safety and improving outcomes.

Q2: For the public, it is important to be afforded the opportunity to give ‘informed consent’. This includes being made aware of rare complications that may affect an individual’s decision to undergo a particular treatment; in this case, hyaluronic acid fillers. A patient also needs to be made aware of how a complication may need to be treated – and consent to any potential treatment prior to undergoing the procedure. It is important that a patient recognises there is no ‘safe’ area in the face to treat; only areas that are considered ‘safer’ than others, with regard to the risk of visual loss. They need to understand there are other factors that need to be considered, such as: the experience of the practitioner performing the procedure; the setting in which the procedure is carried out (eg. is it a clinical setting?); and the availability of medical personnel who have the ability to manage a complication, such as visual loss, immediately should it occur.

For practitioners performing hyaluronic acid filler injections –irrespective of whether they are doctors or not –an understanding of what constitutes ‘full informed consent’ is vital. The injector needs an understanding of the factors that influence risk of visual loss, including: injecting technique; risk of  ‘cannula-versus-needle’; and the regions that have been associated with higher risk of visual loss. They need to have an intimate knowledge of vascular anatomy and understand its potential for variability from person-to-person. The practitioner performing hyaluronic acid filler injections needs to be appropriately trained and experienced to treat the various areas of the face. Lastly, they need to be able: to recognise the signs if a visual complication occurs; know how to asses and document its onset, progression and severity; be able to institute appropriate ‘first aid’ treatment with hyaluronidase; and arrange timely transfer for ongoing management. Referral should be made to a facility with a knowledge and understanding of this rare, but devastating, complication and its management.

Finally, the public, doctors and nurse injectors need to recognise that while hyaluronic acid filler procedures are generally safe, they are not without risk. They are medical procedures and should not be trivialised.


Dr Steven Liew is a plastic surgeon in private practice in Sydney 

Q1: The consensus was undertaken to provide the latest thinking for injectors on the issue of blindness associated with dermal filler. While risk of blindness is extremely rare –especially in Australian-New Zealand due to the overall  high standard of the injectors here –this can potentially still happen. As such, our main aim is to provide guidelines on the safest way of minimising the risk – that is, to inject very slowly in the correct anatomical plane, constantly moving the tip of the needle in the same plane.

Q2: Facial injectables are a medical procedure. They are extremely safe in experienced hands. However complications can still occur –and patients need to be aware of the risks. For medicos, we know there are areas considered higher risks than others; each injector should restrict their injection to their ‘scope of practice’ and not take unnecessary risks on their patients in areas they are not trained in.


Dr Michael Molton is an aesthetic physician in private practice in Adelaide 

Q1: There are a lot of varying suggestions published from a number of small groups, and sometimes individuals, about how to minimise risk of serious complications of hyaluronic acid dermal fillers. We needed to establish where the highest-to-lowest risk areas of the face were, and what protocol doctors might follow in the event of a complication such as vision loss.

Q2: Once we collected the data, it was clear patient safety relied heavily on which areas of the face required higher levels of experience, training and technique. The consensus was that people with low experience and anatomical knowledge should consider some areas of the face very carefully before proceeding, or avoid these areas completely. The paper aims to assist injectors with a framework for this type of decision making.



Dr Mark Magnusson is Associate Professor of Plastic Surgery at Queensland’s Griffith University

Q1: The consensus group was formed from representatives of the major craft groups involved in administration of cosmetic injectables to Australian patients – including plastic surgeons, dermatologists, GPs and nurses. This year we saw the first reported case of the devastating complication of filler-induced blindness associated with injectable fillers in Australia. On a deeper dive into the numbers, three cases have been treated by ophthalmologists in Australia and New Zealand. This data was reported at the recent Aesthetics 2019 conference in Sydney, in the same session where we released findings of our recently published consensus paper which discussed how this occurs, the relevant anatomy, safer methods of injecting and management of this problem.

There have been a number of consensus papers on treatment of filler-induced blindness, but none have addressed the issue of pre-treatment consent or suggested preventative measures –which is what we set out to do. The paper is specifically aimed at providing guidelines to practitioners working in this field and is open access for free download from the Aesthetic Surgery Journal. The aim is to improve the safety and management of our patients.

Part of the consensus document assessed what level of experience and what clinical setting was required for the injection of different anatomical locations on the face, relative to the risk of major complications in different areas. Injection locations relative to the risk for intravascular injection that may lead to effects on vision were graded into four categories. (See underQ3: Are There Areas of Increased Risk That Require More Training and More Supervision?’in accompanying Main Story.)

Q2: There are several important messages for practitionersworking in this field which includes nurses, GPs, dentists, plastic surgeons, ophthalmic surgeons and dermatologists:

  • Filler induced blindness is a very rare problem – estimated at less than one in 100,000 –but with devastating consequences.
  • This complication requires a bolus of filler to be injected into the blood vessels with sufficient force to travel against the prevailing blood flow and in sufficient volume to reach the back of the eye; consequently all our injectable techniques need to be minimising the likelihood that this can occur.
  • There are principles for safe injection that apply to all areas, not just these zones; but the consequences of this complication exceed all others associated with injectable fillers. These principles are:
    • An understanding of the safest depth of injection in any given area, according to anatomy in that location
    • Inject slowly with low extrusion forces
    • Inject microboluses in small amounts
    • Continual small amplitude movements during injection –consider directing the needle/cannula perpendicular to the primary axial vessels in the region being treated to reduce the likelihood of cannula puncture
    • Consider injecting away from the eye in higher risk zones
  • There is currently no evidence to support aspiration as a safety measure – and our consensus was against relying on this manoeuvre.
  • The danger areas associated with the highest incidence of this problem are the nose, glabella (eyebrows) and forehead.
  • These danger zones should only be managed by those with extensive experience, comprehensive training, up-to-date understanding of the anatomy and safest practice.
  • These areas should be treated in a medical practice, rather than less well equipped clinical settings.
  • The medication which dissolves hyaluronic acid fillers is hyaluronidase. This medication should be available in all clinics –and staff should understand its use.
  • All patients should be consented for a intra-vascular injection of dermal fillers that could result in impending skin necrosis or filler induced blindness.

For the public at large:

  • The injection of fillers for cosmetic reasons is common and has a very acceptable safety record –but it is a medical procedure with the potential for complications, which can be very significant in rare instances.
  • Filler-induced blindness is the most catastrophic possibility, but it is a very rare problem (estimated at less than one occurrence for every 100,000 syringes of dermal filler injected).
  • There are facial regions that are more complex and have higher risk. These areas require different levels of practitioner experience and training –and different clinical environments to maximise safety. It is your ‘right to know’ the experience of your injector and that they have bona fide qualifications.
  • The highest risk areas are injections into the nose, brow and forehead. These areas should only be injected in a medical clinic setting, by extensively trained and highly experienced practitioners.