The global injectable market is predicted to more than double in the next decade. One reason for this popularity is because they are seen as ‘non-invasive’, alluding to the minimal disruption to tissue when performed competently instead of opting for surgery.
However, whilst the popularity of dermal filler treatments are enjoying an almost exponential increase, so are reports of complications. Although rare, complications from dermal fillers can be devastating.
The most serious complications are vascular. Vascular occlusions (blockages) can lead to necrosis (tissue death), scarring and, even more seriously, blindness. Indeed, dermal fillers have already led to 98 reported cases of blindness world wide.
In a recent literature review (Beleznay et al, 2015), Hyaluronic Acid (HA)was the second most common type of filler associated with ocular complications, after autologous (your own) fat injections. HA is the most frequently used soft tissue filler in cosmetic practice.
Out of 98 cases of vision complications from dermal fillers, 65 led to unilateral vision loss, and only two cases of vision loss were reversible. Injection sites at highest risk were the glabella (frown area), nose, forehead and nasolabial fold.
How can dermal filler injections cause blindness?
The basic mechanism of filler induced blindness is central retinal artery occlusion. (ie the artery behind the eye gets blocked.) If the tip of the needle penetrates the vessel, leading to an intravascular injection, and too much pressure is applied to the plunger when injecting, the arterial pressure can be overwhelmed and retrograde movement of HA into the more proximal arterial network can occur. Eventual filler embolisation into the central retinal artery will deprive the retina of oxygen and lead to blindness.
How can an injector avoid causing blindness with dermal fillers?
1. The only way to avoid arteries is to know where they are, so advance facial anatomical knowledge is imperative. Clinicians delivering dermal filler injections must have an in-depth, working knowledge of vascular anatomy.
2. The Clinician Injects slowly and incrementally. In many cases of retinal vascular necrosis, filler was injected with too much pressure.
3. The Clinician Injects to the correct depth and plane, taking into account the relevant anatomy of the skin, muscle, vessels and fascia.
4. Unfortunately,even with all of the above, no procedure is immune to error.
Therefore its imperative that the injector has an emergency management strategy in place and be able to refer the patient immediately to an ophthalmologist within the limited window of opportunity to reverse the effect – after complete central retinal artery occlusion, the retinal survival time is 60-90 minutes. Although a quick intra-occular injection hyaluronidase (an enzyme that dissolves Hyaloronic Acid filler ) has been successful in dissolving the filler and preventing permanent blindness, there is no agreed method for reversing central retinal artery occlusion from fillers. Fortunately there has only been 2 cases of blindness caused by fillers in Australia. However,it is 2 too many. Sadly, with the dermal filler market proliferating the risks of complications will also increase.