Trauma |
11 |
|
11.1Penetrating Eye Injury by Metal Intraocular Foreign Bodies (IOFB)
DVD
Video 16 IOFB
Penetrating eye injuries should be treated by experienced surgeons. These cases are associated with a high complication rate and a guarded prognosis, and the initial surgical intervention is of vital importance. There has been a long debate about the timing and the extent of the initial surgical intervention. In essence, one school recommends a two-step approach with an initial primary closure of the wounds and a secondary delayed intervention to remove the IOFB. The idea behind this is that initial closure can be performed almost anywhere in any setting, the more extensive surgery is then carried out in a planned fashion by an experienced surgeon with all necessary equipment available, preferably several days after the injury when all haemorrhages have settled and a PVD has occurred. Another school recommends extensive surgery to treat the injury as early as possible. The idea behind this approach is that the risk for developing severe PVR rises in cases that are not treated at an early stage, and only early and extensive surgery will prevent this.
Instruments
1.4-port trocar
2.Endo Magnet
3.Endodiathermy
4.Crocodile forceps or diamond-dust-coated foreign body forceps
Tamponade
Intraoperative: PFCL
Postoperatively: 1,000 cSt silicone oil
U. Spandau, H. Heimann, Practical Handbook for Small-Gauge Vitrectomy, |
161 |
DOI 10.1007/ 978-3-642-23294-7_11, © Springer-Verlag Berlin Heidelberg 2012 |
|
162 |
11 Trauma |
|
|
Individual steps
1. 4-port system
2. Opening of the conjunctiva at the superotemporal sclerotomy
3.Vitrectomy, PVD
4.Exposure of IOFB
5. Extraction of IOFB through the enlarged superotemporal sclerotomy
6. 1-mm retinectomy around the impact site and diathermy of the exposed choroid
7.Apply laser at the impact site
8.Tamponade: Silicone oil
1.4-port system
2.Opening of the conjunctiva at the superotemporal sclerotomy
We use the 4-port trocar system. Superotemporally, you should open the conjunctiva in the area of the sclerotomy in order to enlarge the sclerotomy when the foreign body is extracted.
3. Vitrectomy, PVD
It is very important to induce a posterior vitreous detachment; otherwise, there is an increased risk of PVR. Since a metallic IOFB induces a posterior vitreous detachment itself due to its toxic effect, some surgeons prefer to operate a few weeks after the trauma (see above). As it can be difÞcult to determine a posterior vitreous detachment in young eyes, you may use dyes such as triamcinolone or trypan blue. This procedure applies to metallic IOFB only. Organic IOFB should be operated immediately, as the endophthalmitis risk is high.
4. Exposure of IOFB
One has to resist the urge to remove the IOFB as soon as you can see it. An extensive vitrectomy should be performed Þrst and, in particular, around the IOFB. Only remove the IOFB when no more vitreous is attached or surrounding it and no vitreous is on the way towards the sclerotomy through which it will be removed. If the IOFB is stuck in the choroid and sclera, you may apply laser around it in order to lower the intraocular haemorrhage that will occur when you pull the IOFB out of the sclera.
5. Extraction of IOFB through the enlarged superotemporal sclerotomy
The foreign body can be extracted with the forceps (crocodile or diamond dusted) or the Endo Magnet. Before extraction of the foreign body, inject a PFCL bubble to protect the macula and enlarge the sclerotomy sufÞciently.
6. 1-mm retinectomy around the impact site and diathermy of the exposed choroid
After successful extraction of the IOFB, a 1 mm retinectomy is performed around the impact site. You should also cauterize the underlying choroid. This is thought to reduce the rate of postoperative PVR. First, cauterize the retina 1 mm distant from the edge of the impact, then cut the retina with the 23-gauge retinectomy scissors or