Prechop Manual Phacofragmentation: Cataract Surgery without a Phacoemulsification Machine

C Wiriyaluppa, P Kongsap
Department of Ophthalmology, Prapokklao Hospital, Chantaburi, Thailand

In this cataract extraction technique, the nucleus is manually split into 2 fragments by prechopper forceps and the fragments removed through a 5.5 to 6.5 mm temporal clear corneal incision. After capsulorrhexis, hydrodissection, hydrodelineation, and surface cortex aspiration, a prechopper forceps is gently passed into the centre of the nucleus core and the nucleus is fragmented into 2 pieces. Each piece is prolapsed into the anterior chamber and extracted with 0.12 corneal forceps and a Sinsky hook via a small incision. This method of cataract removal was performed for 145 consecutive patients, among whom there were 5 posterior capsule ruptures, but no serious complications occurred. Postoperative best corrected visual acuity was better than 20/40 for 80% of patients.

Key Words: Cataract extraction, Corneal incision, Phacoemulsification

Asian Journal of Ophthalmology 2002;4(4):7-9.


Introduction


Phacoemulsification prechop is a technique described by Akahoshi,¹ in which lens nucleus is divided into 4 pieces by the phacoemulsification prechopper or Akahoshi's forceps. Each fragment is then emulsified by the phacoemulsification machine.

Phacoemulsification allows the surgeon to work with small incisions but this technique requires expensive, complex equipment, which is an obstacle in many regions.^2,3 During the 1980s, manual cataract fragmentation techniques began to appear as alternatives to phacoemulsification. These small incision procedures are associated with a short learning curve and involve a relatively small financial outlay.⁴

In this article, a technique that divides the nucleus into 2 fragments prior to manual removal through the temporal clear corneal incision is described. This prechop manual phacofragmentation (prechop MPF) procedure is easy, economical, and has a good visual outcome. The procedure is performed without a phacoemulsification machine but achieves a similar outcome.


Surgical Technique


After administration of retrobulbar anaesthesia, 2 paracenteses, at the 1 and 5 o'clock positions in the left eye and the 7 and 11 o'clock positions in the right eye, are made with a 15° stab knife, followed by a temporal clear corneal incision using a 3 mm keratome. A large capsulorrhexis is performed after injection of a viscoelastic substance. Hydrodissection followed by hydrodelineation are performed until the the 'golden ring' is present. Viscoelastic is then reinjected for optimal visualisation and stability of the anterior chamber. For the left eye, the Sinsky hook is passed through 1 side port and placed at the 9 o'clock position under the anterior capsule to stabilise the nucleus. The prechop forceps (Khosla Surgical Industries PVT Ltd, Mumbai, India) is inserted through the corneal wound at the 3 o'clock position and gently passed into the centre of the nucleus core. Slowly opening the forceps will easily split the nucleus split into 2 pieces. However, if the nucleus does not split, a second insertion may be made until the division of the nucleus occurs (Figure 1).

Figure 1. The Sinsky hook is passed through 1side port of the left eye and was placed at the 9 o'clock position under the anterior capsule. The prechopper forceps are gently inserted into the nucleus core and slowly opened.

The corneal incision is then enlarged to 5 to 6 mm with a 3.2 mm disposable keratome. After the viscoelastic agent is injected, the first fragment is prolapsed into the anterior chamber with the help of a spatula and is set on its end facing the internal opening of the incision (Figure 2). Gentle pressure on the posterior lip of the wound with 0.12 corneal forceps will tip the lens fragment to become engaged within the wound. A Sinsky hook is then reinserted above and towards the centre of the fragment to draw it out (Figure 3). The remaining fragment is removed using the same technique.

Figure 2. The nuclear fragment is prolapsed into the anterior chamber with the help of a spatula.	Figure 3. The nuclear fragment is removed through the corneal incision using 0.12 corneal forceps and a Sinsky hook.

An anterior chamber maintainer (ACM) is now gently inserted into 1 of the side port incisions and firmly advanced until the tip is visible in the anterior chamber.⁵ The epinucleus and lens cortex are flushed out by gentle pressure on the sclera posterior to the incision. The residual cortex is removed through the side port incisions by a single lumen cortex aspirator. A 5.5 mm polymethyl methacrylate posterior chamber intraocular lens (IOL) is implanted in the capsular bag and the wound is closed with one 10.0 nylon suture.

Outcomes

From April 2000 to July 2001, 145 cataract extractions were performed at Prapokklao Hospital in Thailand using this method. The average operation time was 15 to 25 minutes. Posterior capsule rupture occurred during removal of the nucleus in 2 eyes, during removal of the epinucleus in 2 eyes, and during implantation of the IOL in 1 eye. In all cases of capsule rupture, a posterior chamber IOL was implanted in the sulcus. There were no serious complications during the operation. Clear cornea was observed on the first postoperative day in 127 eyes and minimal early postoperative corneal oedema occurred in 18 eyes (12.41%), which responded well to topical steroid administration within a few days. Best corrected visual acuity (BCVA) of 20/40 or better was achieved for 121 eyes (83.45%) at the end of the first postoperative week.

Discussion

Phacoemulsification has become the surgery of choice for cataract extraction. However, this procedure requires costly instrumentation and is associated with a relatively long learning curve. Many manual small incision techniques have been developed to achieve the same benefit as those of small incision phacoemulsification, including the mininuc, sandwich, phacosection, phacotrisection, and quarters extraction techniques.^2,6-8

In the prechop MPF technique, the nucleus is divided into 2 pieces in the capsular bag. Each piece is prolapsed in the anterior chamber and extracted through a relatively small incision, using inexpensive instrumentation. During cataract extraction, the critical step in endothelial safety is at the point of fragmentation. With this technique, fragmentation is in-the-bag, while with the sandwich and phacosection techniques, fragmentation occurs in the anterior chamber. This technique requires less anterior chamber manipulation than other techniques. Compared with the sandwich technique (38.0%)7 and the phacotrisction technique (54.0%),⁹ prechop MPF resulted in a decreased incidence of postoperative transient corneal oedema (12.4%). In addition, use of viscoelastic and progression along the learning curve can lower the incidence of endothelial related complications. Of 18 patients with postoperative corneal oedema, 13 (72.22%) were among the first 40 patients and only 5 cases occurred among the remaining patients (27.78%). In addition, all intraoperative complications occurred among the first 40 patients.

Prechop MPF does not require expensive instrumentation, and visual recovery is as rapid as that after phacoemulsification. Since prechop MPF can be entirely manual, it is well suited to areas in which the likelihood of finding advanced instrumentation is low. However, this technique is contraindicated for patients with a large nucleus or subluxated lens. Further improvements for optimal surgery are required.

References

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