13 Sep Blindness from Dermal Filler Injections
Screenshot of CNA’s headline on the recent case of blindness caused by filler injections in Singapore.
A non-reversible dermal filler containing PDLLA , is in the headlines in Singapore recently for the wrong reasons. According to The Straits Times in September 2023, a patient who had this filler in injected in Singapore went blind.
Update April 2025: A case of blindness has been reported by a patient who underwent filler injections with a similar product in Korea.
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This unfortunate news of filler complications will undoubtedly cast fears on aesthetic treatments in Singapore. Granted, all aesthetic treatments and surgeries have inherent risks. Doctors have to minimise these risks as much as possible to protect the safety of their patients undergoing filler injections through a combination of filler choices, injection techniques and knowledge of anatomy.
Some fillers can potentially be more dangerous than other fillers. Here’s a scientific review of how dermal fillers can cause blindness.
What is PDLLA?
PDLLA refers to Poly-D, L-lactic acid (PDLLA). PDLLA are long chains consisting of lactic acid. Lactic acid is naturally found in human bodies; our muscles form lactic acid as a byproduct after exercise. Lactic acid can also be synthesised in a laboratory1. Lactic acid exists in two forms (enantiomers): L- and D-lactic acid. Both of them can form poly-D, lactic acid (PDLA); poly-L, lactic acid (PLLA); and a mix of both called poly D, L, lactic acid (PDLLA)1.
How do PDLA fillers work?
PLA fillers are thought to increase collagen levels by a foreign body reaction2. Essentially, these PLA filters are foreign to the human body, so the body initiates an immune reaction to break down the PLA filler. This immune reaction also causes inflammation, which also increases the activity of the collagen building cells (fibroblasts); thereby increasing the amount of collagen fibres2,3.
The presence of PLA particles act as a stimulant for fibroblast production and collagen Synthesis3. As PLA particles gradually break down, the stimulus for fibroblast and collagen production also dissipates3. Hence, AestheFill and Sculptra are also known as bio-stimulatory fillers.
Specific to PDLLA fillers, animal studies have shown that PDLLA fillers also enhance collagen synthesis between the PDLLA particles4,5.
How are PDLLA or PL fillers different from traditional hyaluronic acid fillers?
Traditional dermal fillers containing hyaluronic acid are commonly used in Singapore and globally to replenish volume loss in hollow areas of the face (e.g. temples, cheeks); lift the face and reduce laugh lines; and sculpt the face (e.g. lips, nose). The volume gained from hyaluronic acid fillers is almost entirely dependent on the amount of dermal fillers injected. Due to hyaluronic acid’s humectant properties, this type of filler may cause temporary swelling initially. Some types of hyaluronic acid fillers have been found to also cause neocollagenesis5.
Related blogposts:
Everything You Need to Know About Hyaluronic Acid
Temple Fillers for Hollow Temples
Things You Need to Know About Nose Fillers
PDLLA is a material that is used for creating medical devices that degrade over months such as dental implants7. PDLLA fillers dual effects of increasing volume; and also inducing collagen production over time.
How long do the results of PDLLA fillers last?
The results of PDLLA fillers last for about 2 years.
What happens to PDLLA fillers in the human body after injections?
PDLLA fillers get broken down into carbon dioxide and water; and these are removed by the body’s vessels8.
Blood supply compromise by fillers can be due to dermal fillers directly occluding the artery; or indirectly by compressing the vessel. Image credit: Sito et al13.
Are PDLLA fillers safe as dermal fillers?
Update October 2023: Singapore’s Health Science Authority (HSA) has concluded its investigation into this case of blindness from a particular brand of PDLLAfiller injections. Due to HSA regulations I am unable to disclose the name of the brand; but news articles have already disclosed the brand name The report by HSA stated that the cause of blindness was due to occlusion of blood vessels near to the site of injection. The full report is available here.
Prior to this unfortunate case of blindness that occurred in Singapore after PDLLA filler injection, there has already been one reported case of blindness from the same PDLLA product in Taiwan9. Also reported in 2023, this patient’s vision loss occurred because the PDLLA filler blocked the retinal artery, the blood vessel that supplies the eye9. After 2 months of treatment, her vision returned but it was not completely restored9.
Other published studies on PDLLA fillers have shown that such bio-stimulatory fillers were not inferior compared to hyaluronic acid fillers10,11. The reported side effects in these studies were temporary; and consisted of bruising, vesicles and nodules. There were no serious complications such as blindness in these studies on PDLLA fillers.
As with all dermal fillers, PDLLA fillers can also cause vessel occlusion and damage to the affected tissues9,13 One of the most adverse outcomes with PDLLA fillers, as illustrated above, is blindness.
Why does blindness happen after PDLLA fillers?
There are several factors that can contribute to blindness with filler injections, such as rate and volume of filler injected, and choice of dermal filler material12,13.
When complications like blindness occur after dermal filler injections through direct blocking the blood vessel; or indirectly by pressing on the blood vessel13. Prompt early intervention can influence the outcome13. Hyaluronic acid fillers remain the only dermal filler that can be dissolved quickly by an enzyme called hyaluronidase. Hyaluronidase breaks down the hyaluronic acid vessel to unblock the affected blood vessel14-16.
Related blogposts:
How to Dissolve & Remove Fillers with Hyaluronidase
Telltale Signs of Too Much Filler Injections
PDLLA fillers do not have an effective antidote that can reverse the procedure of dermal filler injections. Because hyaluronic acid fillers can be treated with hyaluronidase, some papers argue that hyaluronic acid fillers are the safest for dermal filler injections16,17.
Conclusion: Why I don’t do PDLLA fillers in my clinic in Singapore
In summary, PDLLA fillers add volume and stimulates collagen formation, hence it is also known as a collagen bio-stimulator filler. PDLLA is a type of material used for surgical implants; and it stimulates the body to cause inflammation and build collagen.
All dermal fillers can potentially block blood vessels; and the consequences can be devastating as illustrated. Because of this inherent risk of dermal fillers, I do not offer PDLLA fillers in my clinic in Singapore. In my opinion, the safety of patients should be prioritised over trends and novel treatments which may not be safer than conventional treatments, especially when there are alternatives that are safer and just as effective.
Complications can and will happen; and to me as a doctor, it’s crucial that steps are taken by the injector to minimise risks of any complication happening. When there are fillers that can be reversed in events of complications, why would I choose PDLLA fillersfor my patients?
I hope you have found this review on PDLLA fillers useful. If you follow me on Instagram, you might realise that I have a conservative approach to dermal fillers- always choosing a less is more approach with natural looking outcomes over over-filled, pillow faces. I’ve also turned patients’ requests down when I do not think that their choices are safe or will give satisfactory outcomes. Ultimately, your outcomes with dermal filler injections, both good and bad, are very dependent on your doctor, so be sure to convey your expectations to your physician.
References:
1. Compositions of injectable poly‐d, l‐lactic acid and injectable poly‐l‐lactic acid. Chen et al. Clin Exp Dermatol. 2020 Apr; 45(3): 347–348.
2. Sculptra: a stimulatory filler. Lacombe. Facial Plast Surg. 2009 May;25(2):95-9.
3. Sculptra: the new three-dimensional filler. Sherman. Clin Plast Surg. 2006 Oct;33(4):539-50.
4. Efficacy and safety of poly-D, L-lactic acid micro-spheres as subdermal fillers in animals. Lin et al. Plast. Aesthet. Res. 2019;6:16.
5. Biostimulatory effects of polydioxanone, poly-d, l lactic acid, and polycaprolactone fillers in mouse model. Kwon et al. J Cosmet Dermatol. 2019 Aug;18(4):1002-1008.
6. Hyaluronic Acid Filler Injection for Localized Scleroderma – Case Report and Review of Literature on Filler Injections for Localized Scleroderma. Sharad. Clin Cosmet Investig Dermatol. 2022; 15: 1627–1637.
7. The Use of Poly-d,l-lactic Acid (PDLLA) Devices for Bone Augmentation Techniques: A Systematic Review. Annunziata et al. Molecules. 2017 Dec; 22(12): 2214.
8. High-Frequency Ultrasound for Long-term Safety Assessment of Poly-L-Lactic Acid Facial Filler.Li et al. Dermatol. Surg. 2022;48:1071.
9. Multiple branch retinal artery occlusions following the new facial cosmetic filler (Poly-D, L-lactic Acid) injection a case report. Wang et al. BMC Ophthalmol. 2023; 23: 86.
10. Efficacy and safety of injection with poly-L-lactic acid compared with hyaluronic acid for correction of nasolabial fold: A randomized, evaluator-blinded, comparative study. Hyun et al. Exp. Dermatol. 2015;40:129–135.
11. Long-term (24-Month) safety evaluation of poly-DL-lactic acid filler injection for the nasolabial fold: A multicenter, open, randomized, evaluator-blind, active-controlled design. No et al. Plast. Reconstr. Surg. 2015;135:1074e–1075e.
12. Management of a Vascular Occlusion Associated with Cosmetic Injections. King et al. J Clin Aesthet Dermatol. 2020 Jan; 13(1): E53–E58.
13. Vascular Complications after Facial Filler Injection: A Literature Review and Meta-analysis. Sito et al.J Clin Aesthet Dermatol. 2019 Jun; 12(6): E65–E72.
14. Vascular complications of hyaluronic acid fillers and the role of hyaluronidase in management. Kim et al. .J Plast Reconstr Aesthetic Surg. 2011;64(12):1590–1595.
15. The role of hyaluronidase in the treatment of complications from hyaluronic acid dermal fillers. Cavallini et al. Aesthet Surg J. 2013;33(8):1167–1174.
16. Hyaluronidase: from clinical applications to molecular and cellular mechanisms. Buhren et al. Eur J Med Res. 2016;21(1):5.
17. Injected hyaluronidase reduces restylane-mediated cutaneous augmentation. Vartanian et al. Arch Facial Plast Surg. 2005;7(4):231–237.
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