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Manual prechop allows cataract removal through relatively small incision
With prechop manual phacofragmentation, less anterior chamber manipulation is required than with other nonphaco techniques.
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CHANTABURI, Thailand — A manual method of cataract extraction can provide visual recovery results comparable to phacoemulsification, according to two surgeons in practice here.
Cheocharn Wiriyaluppa, MD, and Pipat Kongsap, MD, the ophthalmologists at Prapokklao Hospital here, are the developers of a technique they call prechop manual phacofragmentation (prechop MPF).
They told Ocular Surgery News they feel phaco is a better procedure. However, prechop MPF does not require expensive instrumentation and provides rapid visual recovery similar to phaco. This can be a particular benefit for surgeons in developing countries or in cases where a phaco system is disabled, they said.
In a study of the technique, the main complication was postop corneal edema, which was controlled using topical steroids. they said patients had an average 0.5 D to 1 D of surgically induced astigmatism postop.
Prechop MPF could also remove cataracts of grade 4+ nuclear hardness, although it can be difficult to divide the nucleus in these very hard cataracts. Zonular dialysis may take place, they said.
Surgical technique
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In 2000, Drs. Wiriyaluppa and Kongsap developed prechop MPF after learning the prechop method described by Takayuki Akahoshi, MD. The phacofragmentation method is a combination of prechop phaco and the mininuc procedure described by Michael Blumenthal, MD, which they had been using since 1994, they said.
According to the study, published in the Asian Journal of Ophthalmology, the technique divides the nucleus into fragments before they are removed through a 5-mm to 6-mm temporal clear corneal incision. A 15° stab knife is used to create a paracentesis at the 1 o’clock and 5 o’clock positions and at the 7 o’clock and 11 o’clock positions. A 3-mm keratome is then used to make a temporal clear corneal incision.
After injecting viscoelastic, a large capsulorrhexis is made, followed by hydrodissection and hydrodelineation and reinjection of viscoelastic to stabilize the anterior chamber.
A Sinskey hook is passed through one of the side-port incisions and placed under the anterior capsule to stabilize the nucleus. Prechop forceps (Khosla Surgical Industries, Mumbai, India) are inserted through the clear corneal incision into the nuclear core, and slowly opened to split the nucleus.
The corneal wound is then enlarged to 5 mm or 6 mm, and viscoelastic is again injected into the anterior chamber. A spatula is used to help prolapse the nuclear fragments into the anterior chamber.
“Gentle pressure on the posterior lip of the wound with 0.12-mm corneal forceps will tip the lens fragment to become engaged within the wound. A Sinskey hook is then reinserted above and toward the center of the fragment to draw it out,” the authors reported.
Drs. Wiriyaluppa and Kongsap said care is needed when splitting the nucleus in the bag, as the instrument can cause zonular dialysis.
“Prolapsed fragments in the anterior chamber can cause trauma to the endothelium. Thus, a viscoelastic agent should be injected,” they said.
An anterior chamber maintainer is inserted and advanced until the tip is visible in the anterior chamber. The epinucleus and lens cortex are then removed using a single lumen cortex aspirator through the side-port incision before an IOL is inserted, and the wound is closed using a 10-0 nylon suture.
Study
Between April 2000 and July 2001, Drs. Wiriyaluppa and Kongsap and colleagues performed 145 surgeries using this method.
No serious complications were experienced. There were five cases of posterior capsular rupture; two during removal of the nucleus, two during removal of the epinucleus and one during IOL implantation. In all cases a posterior chamber IOL was implanted in the sulcus.
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The authors note that all complications were experienced by the first 40 patients operated on using this technique.
A clear cornea was evident 1 day postop in 127 of the 145 eyes (87.5%). Minimal early postop corneal edema was seen in 18 eyes (12.4%), all of which responded well to topical steroids after a few days.
According to the study authors, the average operation time lasted between 15 and 25 minutes. Also, they said, prechop MPF required less manipulation of the anterior chamber than other nonphaco cataract extraction techniques, such as the sandwich technique or phacotrisection. There was also a decreased rate of transient corneal edema: 12.4% in prechop MPF, compared to 38% for the sandwich technique and 54% for phacotrisection in published studies.
At 1 week follow-up, 121 eyes (83.45%) achieved best corrected visual acuity of 20/40 or better.
For Your Information:Reference:
- Cheocharn Wiriyaluppa, MD, and Pipat Kongsap, MD, can be reached at the Department of Ophthalmology, Prapokklao Hospital, Chantaburi 22000, Thailand; (66) 39-324-975; fax: (66) 39-324-861; e-mail: pkongsap@yahoo.com; cheocharn_w@hotmail.com.
- Wiriyaluppa C, Kongsap P. Prechop manual phacofragmentation: Cataract surgery without a phacoemulsification machine. Asian J Ophthalmol. 2002;4:7-9.