Conversion from phaco to ECCE is still important to learn

The procedure may still be required in cases of traumatic cataract or posterior capsule tears, so surgeons should be prepared for it.

ByMichela Cimberle

MILAN – Conversion from phaco to extracapsular cataract extraction is a rare occurrence today. However, some cases of intraoperative complications may still require it, and surgeons should not be exempt from knowing and mastering this technique, according to a panel of surgeons discussing this topic during the Satelcataract meeting here.

All panelists agreed that in the hands of experienced surgeons, phacoemulsification is safely carried out from beginning to end in even the most com plicated cataract cases. Among the cases they treated, conversions amounted to less than one in a thousand.

“Even hard, brunescent cataract or adverse events like intraoperative miosis are no longer a problem. Only inexperienced surgeons, when they realize that ultrasound time is running beyond the threshold of safety, convert to ECCE for that reason,” said Maurizio Zanini, MD, chairman of the roundtable.

However, some cases of traumatic cataract may still be at risk with phaco.

“If at any time the surgeon feels that the capsular support is too weak to stand the vibration and the pressure of phaco, then it is better to convert to ECCE,” he said.

Also, in case of subluxated nucleus, a manual removal may sometimes be necessary to prevent nucleus loss in the vitreous. Tears in the posterior capsule, or a posterior extension of the capsulorrhexis, may also require conversion in some cases.

“A key factor is the presence of vitreous in the anterior chamber, which usually indicates that the tear is large and there is a poor vitreous support. This is a potentially highly dangerous situation, which may favor conversion to ECCE. Other factors to be considered are the hardness of the nucleus, the size of the pupil and the ability to maintain a deep, easily accessible anterior chamber,” he said.

Enlarging the incision

A crucial step in the conversion to ECCE is enlargement of the incision, which must be carried out with extreme care to prevent postoperative astigmatism.

“I perform the phaco incision temporally in clear cornea, or in near-clear cornea,” said Alessandro Pezzola, MD. “If I have to convert to ECCE, I enlarge it to the appropriate size, keeping the blade on the horizontal plane. At the end of the procedure I suture it, keeping the limits of the phaco tunnel as alignment marks, to minimize surgically induced astigmatism.”

Carlo Vanetti, MD, presented a different approach.

“I suture the clear cornea incision and start ECCE, performing a new peritomy with vertical incision. This produces less astigmatism than an enlarged incision in clear cornea,” he said.

“I also prefer the near-clear or clear cornea incision, but in a few cases in the past I had to convert from a sclerocorneal tunnel, which I did by enlarging the incision on both sides,” said Khiun Tjia, MD. “In all cases, the most important thing is to make a large incision, larger than you may think, and use a good knife. I prefer a vertical widening for better control of wound closure and astigmatism.”

Secure the nucleus

If a posterior capsule tear has occurred or the capsulorrhexis has extended posteriorly, the first step is to immediately secure the nucleus with a dispersive viscoelastic to prevent nuclear fragments from dropping into the vitreous cavity, according to Dr. Tjia.

“Inject the viscoelastic underneath the nucleus to support it and lift it up from the capsular break. A Sheets glide can then be used to secure it further,” he said.

“If the situation is critical, you can also implant two 27-gauge, 25-mm long needles under the nucleus,” Dr. Vanetti added.

If the nucleus drops into the vitreous cavity, specialized help from a vitreoretinal surgeon may be necessary, according to Erik L. Mertens, MD.

“If there’s just cortex material dropping into the vitreous, you can deal with it by performing an anterior vitrectomy. In most cases, you can clear the vitreous from the cortical fragments by applying some vacuum, or manually by using a hook or a spatula. However, if the nucleus drops, I would just suture the wound and send the patient to a vitreoretinal surgeon,” he said.

Sometimes, small cortical fragments are naturally reabsorbed. According to Dr. Zanini, observation is sufficient, and local steroids may be administered if inflammation develops.

“Nucleus loss, on the other hand, requires pars plana vitrectomy combined with perfluorocarbon liquids injection and fragmatome. If you don’t have enough experience to perform it, refer the patient to a specialist. The operation should be performed within 15 days,” he said.

IOL implantation

All panelists agreed that, after conversion to ECCE, the IOL can be placed in the bag if there are small or no capsular tears. In case of small tears with escaping edges or large tears with capsular support, a sulcus fixation is preferable.

“If there’s no capsular support, you can adopt either scleral fixation or iris fixation with McCannel suture technique,” Dr. Zanini said. “A three-piece acrylic IOL is the best option with capsular tears. Remember to insert and rotate the IOL away from the area of the tear, with the long axis crossing the meridian of the posterior tear.”

For Your Information:

Maurizio Zanini, MD, can be reached at Centro Salus, Via Saffi 4/h, 40131 Bologna, Italy; +(39) 05-155-5311; fax: +(39) 05-152-4486; e-mail: salus@eyeproject.com.

Carlo Vanetti, MD, can be reached at Via Ripamonti 1, 20136 Milan, Italy; +(39) 02-5830-5550; fax: +(39) 02-5830-5535; e-mail: vanetti@dada.it.

Alessandro Pezzola, MD, can be reached at Via San Bartolomeo 15, 25128 Brescia, Italy; +(39) 03-0370-0138; fax: +(39) 03-0370-1393; e-mail: alpez@libero.it.

Erik L. Mertens, MD, can be reached at Kapelstraat 8, B2660 Hoboken, Belgium; +(32) 3-828-2949; fax: +(32) 3-820-8891; e-mail: e.mertens@skynet.be.

Khiun Tjia, MD, can be reached at Isala Klinieken, Locatie Weezenlanden, Groot Weezenlanden 20, 8011 JW Zwolle, The Netherlands; +(31) 38-424-2980; fax: +(31) 38-424-3334; e-mail: ktjia@isala.nl.