Advantages:

To improve certain vitreo-retinal instruments to enhance the accesses to posterior pole and avoid complications during macular surgery in highly myopic eyes.

Methods:

Modified double bent aspiration 23-gauge cannula with 30.00 mm working part was used during pars plana vitrectomy in highly myopic eyes. The aspiration of residual PFCL or BSS with modified cannula was performed under visual control using different kinds of viewing systems: OFFISSE (Topcon), BIOM (Oculus), EIBOS (Moller-Wedel) and RESIGHT 500 (Carl Zeiss Meditec). PFCL-silicon oil exchange was performed in 12 eyes and fluid-air/gas exchange was performed in 10 eyes with high myopia with mean AXL=32,47 mm (range 28,25-36,5mm). The cannula was bent in two different locations and the angle was 135 and 150 degree with the working distance of 30.00 mm from the last bending to the end of the tip. Cannula was introduced into vitreous cavity and placed above optic disc and macular area. In all cases aspiration of PFCL and fluid underwent without any complications.

Effectiveness / Safety:

The most important advantage achieved was the extension of the distance between the surgeon’s finger holding the base of the cannula and the distant lens of the viewing system, which was provided by double bending of the cannula. Thanks to the new cannula design surgeon could easily position the instrument under the sharper angle in regards to the viewing system visual axis and easily reach the posterior pole and macula without contact with the distant lens and its displacement. Another advantage achieved is the length of the working part of the cannula (30.00 mm) that makes the surgery of the posterior pole easier.

Take home message:

The use of modified double bent cannula in eyes with long axial length allows more comfortable work for the surgeon and reduces time of the procedure. Additionally, same design may be applied to other instruments for macular surgery done in highly myopic eyes.