From the European Vitreoretinal Society Congress in Prague … highlights from a special presentation sponsored by Alcon
Learn How Steady Advances Move 25-gauge to the Mainstream
Further progress will make even less invasive surgery possible.
BY BABAK MASHHOUR, MD
I began using 25-gauge vitreoretinal surgery 5 years ago, starting with relatively simple cases, such as macular pucker and macular hole. Since then, I am convinced that there is no reason not to use this approach in nearly 100% of cases. Compared with larger gauge surgery, entering the eye at the beginning and wound closure at the end of the procedure is more efficient with 25-g instrumentation. More importantly, patients are more comfortable and have faster visual recovery postoperatively, and induced refractive error is not an issue. A 25-g procedure is tissue-sparing in eyes with conjunctival fragility.
Technology and Technique Have Progressed
Steady advances in technology and technique have helped to move 25-g surgery into the mainstream. For example, endoillumination with xenon light probes allows excellent visibility in all cases of membrane peeling or meticulous dissection. Endoillumination probes are available in combination with other key surgical tools, including lasers, aspiration and infusion. At our center, we also take advantage of disposable forceps, scissors and complete 25-g vitrectomy packs that include what is needed for vented gas forced infusion, which gives us the ability to control IOP with the foot pedal. The efficiency of cutting and aspiration can be optimized with proper cut rate and vacuum settings, reducing traction on the vitreous base without compromising surgical time. The stiffness of the instruments has greatly improved and any flexibility can be managed with changes in patient head positioning.
Early concerns about increased risk of hypotony and endophthalmitis are proving to be unfounded as surgeons lean more toward angled wound construction.
Such advances have led me to use a 25-g system routinely in the following types of cases.
■ Macular hole. In my experience, the anatomic closure rate is approximately 99% when I perform a 25-g surgery for macular hole. The most important step is the peeling of the internal limiting membrane (Figure 1). I use disposable forceps in all cases, starting away from the hole. In addition, I create posterior vitreous detachment with the 25-g vitrectomy probe by aspirating the vitreous at the disc margin, applying tractional forces anteriorly. At the end of the procedure, I perform a complete fluid-air exchange. The vitreous cutting probe serves as an active back-flush because the port is very close to the tip.
Figure 1. This image shows internal limiting membrane peeling with GRIESHABERR® 25-g disposable forceps in an eye with a macular hole.
■ Retinal detachment. The use of wide-angle visualization in retinal detachment repair has dramatically enhanced anatomical and functional results. The 25-g approach has brought dramatic changes to this surgery. Patients have a more comfortable postoperative course and no refractive changes. In cases that also involve proliferative vitreoretinopathy, I find that disposable forceps for membrane dissection, peeling and liquid perfluorocarbon to be helpful adjuncts.
■ Proliferative diabetic retinopathy. For this indication, I perform fluid-air exchange before air-silicone exchange, so I can use either 1000 or 5000 centistoke silicone oil as an internal tamponade. Bimanual surgery is facilitated with either multiple 25-g light sources or a chandelier xenon probe, both of which facilitate suitable operating conditions.
Small-gauge Surgery is Here to Stay
The current generation of instrumentation associated with 25-g vitreoretinal surgery has made this approach the standard in my practice. Work on further advancements, such as higher-flow 25-g vitreous cutters and precise IOP monitoring, is continuing. I expect the next round of improvements to further enhance surgeon control, making it possible to achieve even less invasive surgery at smaller gauges.
Babak Mashhour, MD, practices at The Institut Mutualiste Montsouris in Paris.