8.2Dropped Nucleus

A PPV due to a dropped nucleus can be performed by a beginner if the lens material is soft. If the lens is hard, the surgery becomes exponentially more difÞcult. In this case, the surgery should be performed by an advanced vitreoretinal surgeon due to the high complication proÞle (injury of the retina and choroid). There is a signiÞcant rate of post-operative retinal detachments after these complications of cataract surgery. The surgery should take place under general anaesthesia; however, if an experienced surgeon is called to a cataract surgery going wrong in the neighbouring theatre, it may be best to Þnish the surgery under local anaesthesia if this is sufÞcient for the expected length of the procedure.

DVD

Video 12a, b Extraction of dropped nucleus with fragmatome or with ICCE

Assess pre-operatively whether or not the anterior capsule is intact. If the anterior capsule is intact, implant a 3-piece IOL in the sulcus. If it is not intact, you can implant a sclera-Þxated, or even easier an iris-Þxated IOL.

You need a combined phaco/PPV set and also:

Instruments

1.4-port trocar (1 × 20-gauge sclerotomy)

2.120D lens

3.Fragmatome (20-gauge or 23-gauge)

Tamponade

Intra-operative: PFCL

Post-operative: None

Individual steps

1. 4-port system (superotemporal: 20-gauge sclerotomy without trocar) 2. Anterior vitrectomy via pars plana

3. Removal of residual cortex from the lens capsule via paracentesis

4.Core vitrectomy

5.PFCL bubble as macular protection

6.PhacoemulsiÞcation of the nucleus with fragmatome and ßuid needle

7.Implantation of an IOL

8.Removal of PFCL

1. 4-port trocar (1 × 20-gauge sclerotomy)

We use a 4-port vitrectomy because we work bimanually in step 6. Superotemporally we open up the conjunctiva in the area of the sclerotomy, perform a 20-gauge sclerotomy and insert no trocar.

2. Anterior vitrectomy via pars plana

3. Removal of residual cortex from the lens capsule via paracentesis

Fig. 8.11 Dropped nucleus. Depending on how hard the nucleus is, you can remove it with the fragmatome or extract it in toto with SICS technique

Fig. 8.12 Injection of PFCL to lift the nucleus and protect the macula

Method 1 (Luxation and extraction of the nucleus in the anterior chamber)

Phacoemulsification: Perform a core vitrectomy, induce a PVD, inject PFCL up to the sclerotomies, the nucleus is then pushed up to the level of the pupil. Then, inject viscoelastic into the anterior chamber and luxate the dislocated nucleus into the anterior chamber with a 23-gauge membrane pic from the pars plana and a pushpull from the paracentesis. Now inject viscoelastic above the lens to protect the endothelium. Then emulsify the nucleus with a normal phaco handpiece. The disadvantage of this method is that the phacoemulsiÞcation disintegrates the nucleus into small pieces that can slide away on the PFCL bubble in the retinal periphery and must be retrieved from there. The viscoelastic in the pupil can help to hold the lens fragments in the anterior chamber. The second disadvantage is an injury of the endothelium with the phaco energy, which may result in a decompensated cornea if you have a hard lens and a less advanced phaco handpiece.

SICS technique: If the nucleus is too hard for the phaco (Fig. 8.11), you can extract the nucleus faster and with a lower risk of complications in toto (Figs. 8.12Ð8.15).

Fig. 8.16 This dropped nucleus is removed with the fragmatome. First PFCL is injected in order to protect the macula

Fig. 8.17 The dropped nucleus is lifted bimanually with the ßuid needle into the centre of the vitreous cavity and removed with the Fragmatome. The Fragmatome is difÞcult to handle because the lens fragments tend to jump away from the Fragmatome tip. This procedure is safer performed bimanually because monomanually, the lens fragments have to be aspirated with the Fragmatome from the retina, which may cause iatrogenic breaks

I recommend the so-called SICS technique (small-incision cataract surgery), which is a modiÞed form of ECCE. In short: 6Ð8-mm-wide frown incision, 5Ð6-mm capsulorhexis, mobilisation of the nucleus, injection of viscoelastics below and above the nucleus and Þnally extraction of the nucleus with loop, Þshhook or viscoelastics. The incision need not be sutured.

Method 2 (Extraction of the nucleus in the vitreous cavity)

Instill a small PFCL bubble so that the macula is protected from the nucleus. Verify or induce and complete a PVD before you inject PFCL. Soft lens material can be removed Þrst with the vitreous cutter (approximately 400 cuts/min). For hard lens fragments, you can use the ßuid needle in your left hand and the fragmatome in the right hand. Aspirate the lens fragments with the ßuid needle and emulsify them in the central vitreous cavity with the fragmatome. This procedure is performed repeatedly until all the lens fragments are removed (Figs. 8.16Ð8.18).