OPESAVER— Super Irrigation System · In: Fine IH (ed). Phacoemulsiﬁcation: New Technology and Clinical Application. Thorofare, NJ: Slack; 1996:83– 100. 3. Okamoto T. Anterior

Techniques in Ophthalmology 3(4):000–000, 2005 � 2005 Lippincott Williams & Wilkins, Philadelphia

OPESAVER— Super Irrigation SystemMakoto Kishimoto, MDDokkyo University School of MedicineKishimoto Eye ClinicMoriyama CityShiga, Japan

n ABSTRACT

OPESERVER reduces the surge phenomenon duringultrasonic phacoemulsification. It is composed of aY-shaped joint (connecting the irrigation tube to theultrasonic handpiece) to which a silicone tube (3.5 mmin internal diameter, 5 mm in outer diameter, and 2 m inlength) is connected. The opposite end of the siliconetube is closed. Making use of the spontaneous compres-sion and inflation, which take place to make the anteriorchamber pressure equal to the air pressure within thesilicon tube, OPESERVER instantaneously releases theirrigation fluid (entering the silicon tube) into the anteriorchamber, thus allowing avoidance of surge and stabiliza-tion of the anterior chamber. If OPESERVER is used, sta-bility of the anterior chamber is remarkably improvedeven when cataract surgery is performed with the irriga-tion fluid bottle set at a height 30 to 40 cm lower thanusual, thus contributing to improving the safety of sur-gery and promoting postoperative patient recovery. Be-cause the use of OPESERVER involves only a simplechange in the pattern of the irrigation side, it can be usedin combination with existing methods for manipulationon the aspiration side, and there is no restriction on thetype of the apparatus used for aspiration.

n HISTORICAL PERSPECTIVE

For the purpose of performing the phacoemulsification(ultrasonic cataract operation) safely without placing ex-cessive burden on a patient,1 the top priority that shouldbe considered is prevention of surge phenomenon. Thesurgical efficiency (of operation) is reduced, resultingin larger burden on the patients if the prevention

(inhibition) depends on the aspiration side.2–6 The me-chanical solution for the prevention (inhibition) is almostimpossible at present because the duration up to the onsetof surge phenomenon is as short as 0.15 second. It is justconceivable for the surgeons to make the irrigation bottleheight being lower (that the irrigation bottle height7 mustbe lowered) because the intraocular pressure during theoperation should be maintained as close to the normallevel as possible. When I tried and sought the methodsto stabilize the anterior chamber effectively, the air en-tered the anterior chamber and formed bubbles duringthe operation. When we inserted I/A, the bubbles becamesmaller due to the irrigation pressure. When the foot pedalwas returned to the zero position to stop the irrigation, thebubbles became larger again. Every surgeon who con-ducted cataract surgery may have had such experience.This led to the development of OPESAVER.8,9

n TECHNIQUE

OPESAVER consists of a silicone tube (internal diameter3.5 mm, external diameter 5 mm, length 2 m; F F1ig. 1). One

FIGURE 1. OPESAVER.

Address correspondence and reprint requests to Makoto Kishimoto,Dokkyo University School of Medicine, Kishimoto Eye Clinic 1-10-8Moriyama, Moriyama City, Shiga 524-0022, Japan (e-mail: [email protected]).

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end of the tube is closed (FF2 ig. 2) and the other end isattached to a Y-shaped joint (FF3 ig. 3). An irrigation tubeis connected to the female end of this Y-shaped joint(FF4 ig. 4) and the male end is connected to the femaleend of phaco or ultrasonic (US) handpiece (FF5 ig. 5).

To understand the system of OPESAVER, we shouldknow the mechanism of the surge phenomenon. To de-termine the variables of the anterior chamber pressureduring the operation, we analyzed them by attaching anelectronic tonometer to a simulated anterior chamber andusing a device that can transform the electric signals ofthe tonometer into a graph in real time on the PC (FF6 ig. 6).FF7 igure 7 shows the internal pressure of anterior cham-ber in a graph. ‘‘A’’ refers to the condition in which thephaco tip (ultrasonic tip) opens and is released for aspi-ration. When the phaco tip (nose of ultrasonic tip) isoccluded by the nucleus at ‘‘a,’’ the intraocular pres-sure increases. The bottle height corresponds to the

intraocular pressure at ‘‘B.’’ The higher the bottle israised, the higher the intraocular pressure becomes. Ifthe bottle height is 120 cm, the intraocular pressure at‘‘B’’ becomes 111 mm Hg, whereas that at ‘‘f’’ and‘‘g’’ reaches to 160 mm Hg, 10 times higher than the nor-mal intraocular pressure. This sharp increase in intraoc-ular pressure is attributable to the moment of inertia bywhich the irrigation keeps flowing. When aspiration flowcomes into the phaco tip (ultrasonic tip is released) at‘‘b,’’ the intraocular pressure goes down sharply as in‘‘C.’’ Though the surge phenomenon has yet to be clearlydefined, the author would like to define such plunge (b–e)as the surge phenomenon. In this graph, 0 mm Hg in thebroken line is against the atmospheric pressure but thebroken line should go up further in the case of actualeyeball because the balance in the posterior capsule ismaintained by the vitreous pressure and anterior chamberpressure. When the phaco tip opens again, the condi-tion returns to ‘‘D,’’ which is the same as ‘‘A’’ in thebeginning.

FIGURE 2. One end of the tube is closed and the other endis attached to a Y-shaped joint (Fig. 3). An irrigation tube isconnected to the female end of this Y-shaped joint (Fig. 4)and the male end is connected to the female end of phacoor ultrasonic (US) handpiece (Fig. 5).AU1

FIGURE 3. Y-shaped joint.

FIGURE 4. Connection of irrigation tube.

FIGURE 5. Connection of handpiece.



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FIGURE 6. Mock-up anterior chamber pressure measure-ment system.

FIGURE 7. Change in anterior chamber pressure.

FIGURE 8. Difference by the height of the bottle.

FIGURE 9. (A) When the irrigation fluid flows into the an-terior chamber under normal conditions, aspiration occurson the corresponding side without resistance. (B)When thenucleus occludes the end of the ultrasonic tip, the pressurechanges. (C) When the nucleus is crushed, aspirationresumes.



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Though plural causes are intricately involved, thecauses of surge phenomenon are roughly classified intoa sharp increase in the aspiration flow volume and a short-age of irrigation volume. For example, the irrigation bot-tle is raised sometimes to prevent the surge phenomenon.However, as shown in FF8 igure 8, marked changes still oc-cur in the internal pressure of anterior chamber becausethe elevation of bottle neither reduces the plunge in the

surge phenomenon nor increases the irrigation volume atthe onset of surge. Because irrigation occurs as a free fallfrom the irrigation bottle, the acceleration rate is alwaysthe same so long as the operation is performed on theearth. It takes about 0.5 second for the irrigation volumeto reach from zero to the maximum. However, the surgephenomenon that lasts for about 0.15 second is alreadycompleted before the lapse of 0.5 second. The higherthe bottle is raised, the larger the changes in the intraoc-ular (internal) pressure of anterior chamber.2

On the other hand, when OPESAVER is used, the airin A–B (F F9ig. 9A) is slightly compressed while the irriga-tion fluid flows into the anterior chamber and the aspira-tion flows without resistance. When phaco tip (the noseof ultrasonic tip) is occluded by the nucleus, the pressureof irrigation fluid attributable to the irrigation bottle isapplied inside the anterior chamber and the air in A–Bis further compressed to make the pressure closer tothe level in the anterior chamber as much as possible.As a result, a small change occurs as shown in A–C(Fig. 9B) and irrigation fluid flows into the connectiontube in an amount (B–C) corresponding to the decreasein the air. Because the pressure in the anterior chamber

FIGURE 10. Condition in the surgery.AU2

FIGURE 11. (A) Normal. (B) OPESAVER attachment.

FIGURE 12. (A) Eyes show clear on postoperative dayone. (B) Eyes show clear on postoperative day one.



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sharply goes down when the nucleus is fragmented andaspired, the air in A–C inflates to become A–B (Fig. 9C)to bring the pressure closer to the level in the anteriorchamber as much as possible. The irrigation fluid thatis pushed back flows into the anterior chamber to main-tain the stability. To sum up, OPESAVER maintains thestability in the anterior chamber by supplementing theirrigation volume that is required to maintain the normaland constant level. Because the pressure in the tube isalways higher than the atmospheric pressure, no back-flow of air occurs. Furthermore, considering that thepressure has nothing to do with the direction and posi-tion of the tube, a surgeon can arrange the tube freely soas not to hamper the surgical procedure (FF10 ig. 10).

To determine the changes in the anterior chamberpressure, we compared them by attaching the electronictonometer to a simulated anterior chamber and trans-formed the electric signals of tonometer into a graphin real time on a PC.

The combination of a small tip and Sovereign(Advanced Medical Optics, Inc., manufactured by AMO,Inc.) was investigated. The aspiration pressure was setat 500 mm Hg, irrigation volume at 30 ml and bottleheight at 60 cm (the nose of ultrasonic tip was regardedas 0 cm). The occlusion and release of nucleus were sim-ulated by the open/close of aspiration tube.

The condition by normal tube and that by OPESAVERare shown in FF11 igure 11A and Figure 11B, respectively.As shown in these figures, there is a definite difference.

n DISCUSSION

As described above, the use of OPESAVER enables saferoperation because the device keeps the anterior chambermore stable even if the bottle is lowered from the normalposition by 30 to 40 cm. Because the anterior chamberpressure during the operation is lower and there are fewerchanges in the pressure, the phacoemulsification process(nuclear processing) becomes smoother, and the ultra-sonic time and irrigation fluid volume are reduced. Asa result, the burden on the eyeball is also reduced. Fur-thermore, the inflammation on the post-operation day 1 isdecreased and the cornea remains clearer (FF12 igs. 12A and12B). Therefore, favorable post operation recovery isexpected.

n REFERENCES

1. Oki K. Measuring rectilinear flow within the anterior cham-ber in phacoemulsification procedures. J Cataract RefractSurg. 2004;30:1759–1767.

2. Mackool RJ. Storz Premiere/MicroSeal system description.In: Fine IH (ed). Phacoemulsification: New Technologyand Clinical Application. Thorofare, NJ: Slack; 1996:83–100.

3. Okamoto T. Anterior chamber stability not improved bybypass flow of aspiration bypass system. Atarashii Ganka(Journal of the Eye). 1999;16:1567–1571.

4. Chang DF. High-vacuum bimanual phaco attainablewith STAAR’s Cruise Control. Ocular Surgery News2003;3.

5. Wilbrandt HR. Evaluation of intraocular pressure fluctua-tions with differing phacoemulsification approaches.J Cataract Refract Surg. 1993;19:223–231.

6. Wilbrandt HR. Comparative analysis of the fluidics of theAMO Prestige, Alcon Legacy, and Storz Premier phacoe-mulsification systems. J Cataract Refract Surg. 1997;23:766–780.

7. Alm A. Ocular circulation. In: Hart WM (ed). Adler’s Phys-iology of the Eye. St. Louis: Mosby Year Book; 1992:212–216.

8. Kishimoto M. Air cushion tube system. Jpn J OphthalmicSurg. 2001;14:549–552.

9. Kishimoto M. OPESAVER help maintain chamber stabilityduring phaco. Ocular Surgery News 2005;23(2).

Due to the nature of free fall, setting the irrigatingsolution bottle in a high position causes a burden tothe eyeball and does not result in the fundamentalresolution to avoid surge phenomenon.

Although OPESAVER is a very simple structure, itcan correspond to the pressure change within theanterior chamber before it is complicated, b AU3ecauseit is controlling with telescopic of the air that wascompressed.

As for OPESAVER, there is no influence to theaspiration side, due to connection on the irrigationside.

The anterior chamber was stabilizing even whenthe bottle of irrigating solution is set at 35 cm highin the cataract operation by SOVEREIGN, whichconnected OPESAVER.



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Documents

OPESAVER— Super Irrigation System · In: Fine IH (ed). Phacoemulsiﬁcation: New Technology and Clinical Application. Thorofare, NJ: Slack; 1996:83– 100. 3. Okamoto T. Anterior