Vitreo-retinal societies have embarking new technologies in the name of progress which begins as mystic concept to something revolutionising in the surgical filed. After Oshima introduced 27G vitrectomy, it underwent staged adaptation in the background of standard 23G vitrectomy technique since 2010.
The advantage of smaller scleral incision (0.4mm compared to 0.5mm of 25G), non-leaking wounds and greater manoeuvrability close to retina kept it in the frontier compared to 23/25G systems. The sphere of influence that is the volume of fluid and vitreous movement around the cutter is so small (because of small cutter port size 0.066m2) that, it allows working very close to retina as in peripheral base shave and in narrow compartments like in diabetic vitrectomies.
Introduction of twin duty cycle cutters with improved duty cycle increased the cutting efficiency of 27G system. Adding to that, high flow cannulas instead of regular infusion lines have overcome problem of reduced fluid flow. Thus the cutting efficiency and surgical time is near equal to conventional 25G system.
Newer adaptations like shortening length of cutter shaft from 32mm to 25mm, addition of supporting sleeves in the proximal end made these instruments sturdy and less malleable. Cutter ports close to the tip and bevelled tip designs further enhanced its efficiency and safety.
As other accessories are in the streamline of improvisation, 27G system use garned wider acceptability of its use starting from simple ERM removal surgeries to surgeries involving complex retinal detachments. Though staged adaptation and learning curve slows its universal acceptance, very promising results and technological improvements would very soon place this emerging ray into conventional standard approach.
Nagesha C K. MS, FMRF
Dept of Vitreo-Retinal services
B W Lions Superspeciality Eye Hospital