Table 1. Advantages and disadvantages of conventional sutured 20-gauge pars plana vitrectomy vs narrow-gauge transconjunctival systems with cannulated sclerotomies^{101, 135, 136, 138, 163, 164, 165, 166, 167}.

	Advantages	Disadvantages
20-Gauge	More rigid instruments. Availability of angulated scissors. Greater potential illumination. Higher achievable flow rates. Less prone to clogging with dense material.	Sutures needed to close conjunctiva and sclerostomies with postoperative surface discomfort and irritation. Higher rate of sclerostomy-related retinal breaks. Requirement for plugs to close sclerostomies when instruments removed from eye. Reduced globe stability with higher potential for surge.
Narrow-gauge	Less conjunctival disruption and faster surface recovery with less postoperative discomfort. Quick entry and exit from the eye. Less potential for entry site trauma and lower incidence of entry site-associated retinal breaks. Lower flow rates with narrower field flow effects and less retinal traction. Smaller cutter port size with more precise end cutting ability. Valved sclerostomies eliminate unwanted sclerostomy leakage.	Postoperative hypotony with sclerostomy leak in some cases. Change in technique needed to use instruments Lower achievable flow rates. Occasional requirement to open conjunctiva and enlarge sclerostomy to introduce larger instruments. Lower infusion flow rates with higher resistance.