Evaluation of Blunt and Sharp Needle Tips in Correction of the Tear Trough Deformity

Goals/Purpose:

Correction of a tear trough deformity is a common concern treated by aesthetic surgeons.  While no-injectable product is FDA approved for use in this area, various facial fillers have been advocated for periorbital rejuvenation.  Injection of the tear-trough has raised concern from safety standpoint because of its anatomic location near the eye. Many surgeons use blunt cannula tips to reduce risk of intravascular and periorbital injection of filler.  An anatomic study using fresh frozen cadavers was designed to look at the differences between blunt and sharp needle injection of the tear trough.

Methods/Technique:

8 fresh frozen cadaver heads were obtained and 16 hemifacial tear troughs underwent injection.  Hyaluronic acid facial filler was mixed with 0.1cc of methylene blue in 1cc syringes.  Using a discontinuous serial threading injection method, approximately O.4cc of filler was injected to the tear trough area placing the catheter tip along the infraorbital rim in the supraperiosteal plane.  The left side was injected using a blunted 30-gauge cannula and the right was injected using a sharp 30-gauge needle.  After injection a detailed anatomic dissection was performed on all heads.

Results/Complications:

The tear trough in all cases was visibly altered after injection prior to dissection.Anatomical dissection was able to expose the orbital septum to the infraorbital rim.  In all 16 hemifacial sections the periobita was intact with no staining of the infraorbital fat pads and the methylene blue stained filler was found long the rim both deep and within oribicularis occuli in all circumstances.

Conclusion:

Use of Blunt or Sharp needles did not violate the orbital septum or infraorbital fat pads during tear trough dissection using commonly used injection techniques.  This would advocate the sharp needles are equally safe as far as anatomic plane violation.  This study does not determine the risk of intravascular injection and retinal or ocular thrombosis.