27.1 Introduction

The merits of a closed chamber infusion system that helps to maintain the tonicity of the globe throughout the intraocular surgery cannot be understated. Maintenance of a deep anterior chamber (AC) is a prerequisite for safe, smooth performance of an intraocular surgery as it prevents inadvertent and harmful touch to the corneal endothelium and also to various other structures. For the same reason, sodium hyaluronate was introduced and it served as a major breakthrough for all anterior segment intraocular surgeries. ^{1 , 2 , 3} Although the use of viscoelastic cannot be understated, its role in the maintenance of an AC in corneal surgeries is not a prudent idea, more so with endothelial keratoplasty procedures.

Blumenthal devised a simple and practical method for maintaining the AC with a device that he called as the anterior chamber maintainer (ACM) that was made from a 21-G scalp vein (“butterfly”) set. Since the introduction of an ACM, there have been various modifications to the ACM so as to suit the surgical condition of the eye (▶Video 27.1, ▶Video 27.2, and ▶Video 27.3).

27.2 Concept

Fluid is the natural milieu of the eye and constant fluid infusion inside the eye helps to maintain the globe and prevent it from collapsing. Anterior segment surgeons most commonly employ ACM. The advantage with the use of ACM is that it is simple to use, as it needs only a paracentesis incision to set the ACM in place. However, the disadvantage is that the paracentesis incision has to be of an exact size or else forceful introduction can lead to Descemet’s membrane detachment, whereas with a slightly larger width of paracentesis incision, the ACM can get extruded from the eye leading to sudden globe collapse.

Posterior segment surgeons primarily employ trocar infusion at pars plana site and it has an inherent advantage of being self-retaining. Initially, the authors published the technique of using routine trocars employed as ACM for fluid infusion wherein the trocars were inserted at a distance of 0.5 mm from the limbus (▶Fig. 27.1, ▶Fig. 27.2, and ▶Fig. 27.3). ⁴ The disadvantage in using the routine trocars was that the surgeon had to be very careful while introducing it or else there was a possibility of injuring the corneal endothelium with the tip of the trocar blade.

Hence, a special trocar for ACM was designed and it was labeled as trocar ACM (▶Fig. 27.4a). The newly designed trocar ACM has a shorter blade and has an aluminum dusting on its shaft that prevents its slippage from the scleral wall.