Abstract
Purpose:
The number of intraocular injections being performed is constantly increasing due to the use of new anti-VEGF drugs for the treatment of AMD and other retinal diseases. However, due to the absence of a specific injector, these are largely carried out with a standard insulin syringe using a two-handed procedure. The purpose of our work was to develop a new type of injector which could be operated with one hand and which facilitated the accurate positioning of the needle for a smoother, faster and safer procedure.
Methods:
The design process was carried out with the solid edge 3D software (Siemens®). The brief was that the device should be held between the thumb and fingers of one hand leaving the index finger free to operate the plunger. Several requirements were set and evaluated: i) Ease of injection, ii) The possible injection of small volumes (0.01-0.3ml), iii) Plunger displacement with the index finger of same hand, iv) Guide tool for the precise location of the injection site (3.5mm from the limbus), v) Needle penetration limited to 3mm. For comparative purposes, 10 injections were performed in an ex-vivo model with both standard insulin syringes and our device. Procedure time and accuracy were measured.
Results:
Needle insertion time was 10 ± 2 with the insulin syringe and 3 ± 1 seconds with the one handed injector (P<0.01). Total time required for intraocular injection was 20 ± 3 seconds with the insulin syringe and 9±1 seconds with the injector. Our device permitted the surgeon to perform the injection with the thumb and two fingers of one hand, leaving the ring and little fingers free to be placed over the periocular structures for maximum control of the location and depth of the needle during the procedure. In all cases the accuracy and control of the location of the injection, the depth of penetration of the needle and the operation of the plunger was better with the one handed injector.
Conclusions:
An innovative single-handed injector that improves the intraocular injection procedure has successfully been developed. This device allows a smoother and faster injection procedure in which the risks associated with the movement of the eye by the patient are reduced. Compared with the currently used tool, the single-handed injector offers superior accuracy and safety.
Keywords: 762 vitreoretinal surgery •
688 retina