A systematic review was recently conducted by Wu and colleagues examining the risk of blindness associated with platelet-rich plasma (PRP) injection. In dermatology, PRP is used more commonly now than 5 years ago to promote hair growth with injections on the scalp, as an adjunct to microneedling procedures, and sometimes – in a similar way to facial fillers – to improve volume loss, and skin tone and texture (particularly to the tear trough region).
Total unilateral blindness occurred in all cases. In one of the seven reported cases, the patient experienced recovery of vision after 3 months, but with some residual deficits noted on the ophthalmologist examination. In this case, the patient was evaluated and treated by an ophthalmologist within 3 hours of symptom onset.
Dr. Naissan O. Wesley
In addition, four cases were reported from Venezuela, one from the United States, one from the United Kingdom, and one from Malaysia. Similar to reports of blindness with facial fillers, the most common injection site reported with this adverse effect was the glabella (five cases);
Other reports involved injections of the forehead (two), followed by the nasolabial fold (one), lateral canthus (one), and temporomandibular joint (one). Two of the seven patients received injections at more than one site, resulting in the total number of injections reported (10) being higher than the number of patients.
The risk of blindness is inherent with deep injection into a vessel that anastomoses with the blood supply to the eye. No mention was made as to whether PRP or platelet-rich fibrin was used. Other details are lacking from the original articles as to injection technique and whether or not cannula injection was used. No treatment was attempted in four of seven cases.
As plasma is native to the arteries and dissolves in the blood stream naturally, the mechanism as to why retinal artery occlusion or blindness would occur is not completely clear. One theory is that it is volume related and results from the speed of injection, causing a large rapid bolus that temporarily occludes or compresses an involved vessel.
Another theory is that damage to the vessel results from the injection itself or injection technique, leading to a clotting cascade and clot of the involved vessel with subsequent retrograde flow or blockade of the retinal artery. But if this were the case, we would expect to hear about more cases of clots leading to vascular occlusion or skin necrosis, which does not typically occur or we do not hear about.
Details about proper collection materials and technique or mixing with some other materials are also unknown in these cases, thus leaving the possibility that a more occlusive material may have been injected, as opposed to the fluid-like composition of the typical PRP preparation.With regards to risk with scalp PRP injection, the frontal scalp does receive blood supply from the supratrochlear artery that anastomoses with the angular artery of the face – both of which anastomose with the retinal artery (where occlusion would occur via back flow). The scalp tributaries are small and far enough away from the retina at that point that risk of back flow the to retinal artery should be minimal. Additionally, no reports of vascular occlusion from PRP scalp injection leading to skin necrosis have ever been reported. Of note, this is also not a risk that has been reported with the use of PRP with microneedling procedures, where PRP is placed on top of the skin before, during and after microneedling.
Anything that occludes the blood supply to the eye, whether it be fat, filler, or PRP, has an inherent risk of blindness. As there is no reversal agent or designated treatment for PRP occlusion, care must be taken to minimize risk, including awareness of anatomy and avoidance of injection into high risk areas, and cannula use where appropriate. Gentle, slow, low-volume administration, and when possible, use of a retrograde injection technique, may also be helpful.
Dr. Wesley and Lily Talakoub, MD, are cocontributors to this column. Dr. Wesley practices dermatology in Beverly Hills, Calif. Dr. Talakoub is in private practice in McLean, Va. This month’s column is by Dr. Wesley. Write to them at dermnews@mdedge.com. They had no relevant disclosures.