Removal Of IntraOcular Foreign Body

IOFB should always be removed, except when it is
inert and probably sterile or when little damage has
been done to the vision and the process of removal
may be risky and destroy sight (e.g., minute FB in the
retina).
Removal of magnetic IOFB is easier than the removal
of non-magnetic FB. Usually a hand-held
electromagnet (Fig. 17.13) is used for the removal of
magnetic foreign body. Method of removal depends
upon the site (location) of the IOFB as follows:
1. Foreign body in the anterior chamber. It is
removed through a corresponding corneal incision
directed straight towards the foreign body. It should
be 3 mm internal to the limbus and in the quadrant of
the cornea lying over the foreign body (Fig. 17.14).
Magnetic foreign body is removed with a handheld
magnet. It may come out with a gush of
aqueous.
Non-magnetic foreign body is picked up with
toothless forceps.
2. Foreign body entangled in the iris tissue
(magnetic as well as non-magnetic) is removed by
performing sector iridectomy of the part containing
foreign body.
usually difficult for intralenticular foreign bodies.
Therefore, magnetic foreign body should also be
treated as non-magnetic foreign body. An
extracapsular cataract extraction (ECCE) with
intraocular lens implantation should be performed.
The foreign body may be evacuated itself along with
the lens matter or may be removed with the help of
forceps.
4. Foreign body in the vitreous and the retina is
removed by the posterior route as follows:
i. Magnetic removal. This technique is used to
remove a magnetic foreign body that can be well
localized and removed safely with a powerful magnet
without causing much damage to the intraocular
structures.
An intravitreal foreign body is preferably
removed through a pars plana sclerotomy (5 mm
from the limbus) (Fig 17.15A). At the site chosen
for incision, conjunctiva is reflected and the
incision is given in the sclera concentric to the
limbus. A preplaced suture is passed and lips of
the wound are retracted. A nick is given in the
underlying pars plana part of the ciliary body. And
the foreign body is removed with the help of a
powerful hand-held electromagnet. Preplaced
suture is tied to close the scleral wound.
Conjunctiva is stitched with one or two
interrupted sutures.
For an intraretinal foreign body, the site of
incision should be as close to the foreign body
as possible (Fig. 17.15 position ‘B’). A trapdoor
scleral flap is created, the choroidal bed is treated
with diathermy, choroid is incised and foreign
body is removed with either forceps or external
magnet.
ii. Forceps removal with pars plana vitrectomy. This
technique is used to remove all non-magnetic foreign
bodies and those magnetic foreign bodies that can
not be safely removed with a magnet. In this
technique, the foreign body is removed with vitreous
forceps after performing three-pore pars plana
vitrectomy under direct visualization using an
operating microscope