Antichamber Collapser

We would like to congratulate Tsuneoka and coauthors for their work to reduce the size of the incision in cataract surgery.1 Since 1998, we have been working on phakonit to facilitate removal of a cataract through a sub 1.0 mm incision.2,3 In their article, the authors mention the problem of destabilization of the anterior chamber during surgery. We had the same problem in the initial stages and solved it to a certain extent by using an 18-gauge irrigating chopper. One of us (S.A.) suggested the use of an antichamber collapser,4,5 which injects air into the infusion bottle (Figure 1). This pushes more fluid into the eye through the irrigating chopper and also prevents surge. Thus, we were able to use a 20-gauge irrigating chopper as well as solve the problem of destabilization of the anterior chamber during surgery.Figure 1.: (Agarwal) Antichamber collapser.A locally manufactured automated device, used in fish tanks to supply oxygen, is used to forcefully pump air into the irrigation bottle. This pump is available in aquarium shops. It has an electromagnetic motor that moves a lever attached to a collapsible rubber cap. There is an inlet with a valve that sucks in atmospheric air as the cap expands. On collapsing, the valve closes and the air is pushed into an intravenous (IV) line connected to the infusion bottle. The lever vibrates at a frequency of approximately 10 oscillations per second. The electromagnetic motor is weak enough to stop once the pressure in the closed system (ie, the anterior chamber) reaches about 40 mm Hg. The rubber cap ceases to expand at this pressure level. A micropore air filter is used between the air pump and the infusion bottle so the air pumped into the bottle is free of particulate matter. Two balanced salt solution (BSS®) bottles are used instead of 1. A y-shaped commercially available transurethral resection (TUR) set (Romsons, India) is used to connect the 2 BSS bottles to the irrigation tubing of the handpiece (Figure 1). The TUR set has a hard plastic end (similar to the end of the IV set), which gets connected to the irrigation tubing of the phacoemulsification handpiece. The TUR set has 3 pinch valves, 1 on each limb to prevent the backflow of BSS. One bottle is on flow at a time. As we use the continuous irrigation mode, we tend to use more than 1 bottle of BSS. It is convenient to shift from 1 bottle to another during the procedure by simply opening the pinch valve of the second bottle and shifting the air pump. A single BSS bottle connected to wide-bore tubing and the air pump would serve the same purpose. The internal diameter of the TUR set is 4.5 mm compared to 2.5 mm of the IV set routinely used. This increases the amount of fluid passing from the infusion bottle to the phacoemulsification handpiece. The bottles are kept about 65 cm above the operating field. The wide-bore tubing as well as the pressurized BSS bottle lead to increased inflow volumes of the fluid, thereby neutralizing surge and maintaining a deep anterior chamber during phakonit. With the description of this technique in 2000, another step in the quest for ultrasmall cataract surgery incisions was taken. With more improvements in phakonit technology and the commercial availability of IOLs used with ultrasmall incisions, more and more surgeons will be able to offer this technique to their patients. Amar Agarwal MD Sunita Agarwal MD Athiya Agarwal MD Vikas Lal Nishant Patel aChennai, India