A NEWTROCAR CANNULA SYSTEM FOR MICRO INCISION VITREOUS SURGERY

摘要

Vitreous surgery became a reality in 1971 when Robert Machemer, described pars plana vitrectomy. Pars Plana Vitrectomy involves making openings in the sclera (white of the eye), going behind the human lens and operating with certain handheld instruments on Vitreous Gel and Retina. Till year 2000 the openings used were of 20 Gauge size ( 0.90mm or 0.03575inch). In 2002, Eugene de Juan, introduced 25-Gauge (0.51mm or 0.02025inch) sutureless vitrectomy. In 2005 Claus Eckardt, developed a similar technique, but with 23G (0.641mm or 0.0252inch) instrumentation. This has become popular and is becoming the current preferred technique worldwide. The key to both 23 and 25 gauges MIVS is the nearly self-sealing incision in the sclera. This opening in the sclera is made with specially designed trocar-cannula blade system. Previously these trocar- cannula system followed a two step technique which was popularized by DORC ( Dutch Ophthalmic Research Center International BV, Netherlands) or a single step technique as popularized by ALCON Laboratories, Fort Worth /Texas. Most surgeons now prefer the single step technique for MIVS. Most of the Trocar cannula systems available in the market are disposable and are supplied as a set of three Trocar-cannula. The Alcon Labs has stopped marketing it's Trocar-cannula as a stand alone pack, but is available as a comprehensive Total plus Pack that costs about Rs 16,000.Other companies supplying single step Trocar-Cannula systems bill it at Rs 3500 onwards. I have attached Photo of the most commonly available single step Trocar-cannula in the market (Fig A)