Download - Intra ocular foreign body
Dr. Gauree GattaniDNB 1st yr
40% of open globe injuries- at least 1 IOFB Majority at Workplace Young males (economic + personal hazard) Visual prognosis best when: IOFB removal during initial wound repair Good pre-op vision
Important things: History Detailed ocular examination Appr anciliary testing Timely management
Visual loss may occur due to:
Mechanical effect
▪ Retinal detachment
▪ Ciliary body dysfunction
Introduction of infection
▪ Endophthalmitis
Ocular metallosis
▪ Siderosis
▪ Chalcosis
IOFB is defined as an intraocular retained unintentional projectile.
Etiology: Hammering metal or stone
Machine tools
Gun firing, explosions
Assault, RTA
Lawn mower, broomstick
Insect stings
IOFB
Metallic
Magnetic Fe, steel
Non – magnetic
Inert Au, Ag, Pt
IrritativeCu, Pb, Hg, Zn,
Al, brass
Non – metallic
Non- organic
Irritative Spore, talc
InertSand, coal, gun powder, glass,
quartz
Organic
AnimalCilia, catterpillar
hair
Vegetable Cotton, Wood
Activity/ tool being used during injury Type and mechanism of injury Rural setting organic IOFB fungal
infections Time since injury
Importance of early exam (media clarity)
Corneal haze, vitritis, vitreous haemorrhage
Capsule formation
Corneal entry wound – easily seen Fine linear corneal scars – easily missed Size of corneal wound< FB Localized corneal haze at 6’o clock FB in
AC Large wound
Large FB
Orbital FB (double perforation)
No IOFB
Corneal entry wound
Iris hole
Relation with corneal wound
Hidden by arcus
Iris heterochromia
Iron FB
FB track Lens opacity
rapidly becomes total
Intactness of PC
Vitreous clear+ lens injury + intact PC FB in AC
Rarely, through zonules
Fall at the bottom of AC
Very small FB may get embedded in angle
Get embedded in Iris
Glass IOFB in AC Small FB in
angle –gonioscopy
FB in ciliarybody area
Most important: Thorough IO asap !! Location of FB in clear media by scleral
indentation Delayed exam capsule formation FB
may be missed Iron FB on retina for long localized
siderosis bulbi Large glass FBs in peripheral opaque
(h’rrhagic) vitreous missed
Vitreous track formed by blood Intraretinal haemorrhage May riochet so inf periphery should be
examined if FB not at site of haemorrhage Double perforation FB in ocular coats or
orbit
Berman’s locator: Detecting range of metallic FB (10x) & non
metallic FB (1-2x)
Non metallic FB can be detected only if >3mm Roper-Hall locators: A.k.a electroacoustic FB detector
Metallic FB – continuous
Non metallic FB – intermittent Carnay’s locator Ophthalmometalloscope of Hale
Only FB ≥ 0.5 mm diameter All metals except aluminium Demonstration of FB:
True lateral: affected side towards the film
PA view: face against the film,
Nose & chin in contact with film,
tube centred in middle of orbit
Direct Methods
Methods depending on rotational movements of the eye
Methods on geometric projection
Bone free methods
Stereoscopic methods
Methods based on delineation of globe
2 exposures: PA and Lateral views FB is located in relation to marker bearing a
known relation to the globe Limitations:
Errors due to movement of marker
Limited use in severely damaged eyes
Assumes axial length of eye = 24mm
Head & X-ray remain fixed Several exposures with eye in different gazes 3 exposures in lateral view with eye looking
up, straight and down Position of FB calculated w.r.t centre of
rotation Limitations:
No true centre of rotation
Eye assumed to be 24mm
Mackinzie Davidson
• Eye & head remain fixed
• 2 X-rays are taken with 2 metal detectors in known position
Sweet’s method
Dixon’s method
Two x-rays are positioned at 2 fixed angles with markers attached to the globe in different positions
FB is calc w.r.t displacement of its shadow from radio opaque marker
Using radio opaque dye:
Thorotrast, lipoidol, diodrast in Tenon’s space
Limitations
Air embolism if air is used
Tissue reaction to eye
Stallard and SomersetMetallic ring (11-14mm) sutured
to limbus
PA and lateral view
• Radio opaque markers in all 4 quadrants
Comberg’smethod
• Lens held in place with partial vacuum
Worst Covac
method
Usually high echogenicity Dense white spots on gray scale display;
persist at low gain Reverberating echoes may be seen Metal and Stones : High echo Wood and veg matter : intermediate echo Glass : High echo only when US beam strikes
perpendicularly Look for CD, RD, VD ; vitreous incarceration
in post coat of eye double perforation
Very large FBs: shadowing Linear glass FBs: low echoes FB in eye wall : ? Closer to vitreous or sclera Very ant FBs, FBs entrapped in dense vitreous
hemorrhage : missed Integrity of coats of eyeball : cant be assessed d/t
shadowing by FB Air bubble in vitreous cavity: can mimic IOFB (high
echo) Multiple / irregular FBS : bizarre patterns Organic matter : diff to detect Generally USG overestimates the size of Fb
50 Hz probe (high resolution, low penetrance) For FBs in anterior segment C/I in open globe injury or precariously
approximated wound Caterpillar hair can only be detected only by
UBM
Non-invasive, no need of radio-opaque marker
Localization of FB is better in vitreous and coats
Associated damage orbital bones and brain can be evaluated
Multiple FBs can be identified 100% sensitivity for FB>0.06 cu mm Small IOFBs- high reso overlapping slices Wood FBs not imaged
Not indicated in detection of IOFBs Damage to intraocular structures Plastic or wooden FBs
Extensive vitreous exudation: FB may be hidden in the peripheral opaque vitreous
Aggressive vitrectomy: Can increase retinal tears
Selective debulking in suspected areas Magnetic FBs: intraocular magnet
Fast capsule formation Hides true colours of FB Magnetic FB : may show movement with
magnets Careful incision of the capsule should expose
the internal end of FB
Placement of external magnet over the site of scleral perforation
Exit aided by enlarging scleral wound
CT, USG may not delineate it clearly Site of posterior perforation may be covered
by clot/ fibrosis depending on duration best to plug the sclerotomies& explre orbit in corresponding quadrant
Extraocular portion covered by fibrous capsule Careful dissection aided by disinserstion of EOM can expose FB
Figure 1. Preoperative axial CT with metal intraocular foreign body.
Figure 2. View of sutured entry wound and band.
Figure 3. Intraoperative view of the IOFB, local retinal detachment, and retinal whitening.
Figure 4. Intraocular foreign body attached to intraocular magnet.
Figure 5. Large retinal break after removing intraocular foreign body.
Figure 6. Intraocular foreign body after removal.
20-year-old male sustained an intraocular foreign body (IOFB) in his left eye by hitting a hammer against a large metallic object. He presented to the emergency room 1 day after the injury. On examination, his visual acuity was 20/200, and a large nasal conjunctival hemorrhage was observed with hypotony and clear cornea and lens. On indirect funduscopy, a metallic intraocular foreign body was observed stuck in the inferior retina at the equator with a local retinal detachment, whitening of the retina around its edges, and a mild vitreous hemorrhage. The intraocular foreign body was demonstrated on orbital CT (Figure 1). An exploration revealed a 4 mm entry wound, extending posteriorly from the limbus at the nasal side. The wound was sutured with Vicryl 7/0 suture, an encircling #41 solid silicone band was placed (Figure 2), and a pars plana vitrectomy was performed during the primary procedure. The intraocular foreign body was released from its adhesions to the retina (Figure 3) and removed with a magnet (Figure 4) through a previously prepared sclerotomy, revealing a large retinal tear (Figure 5). The intraocular foreign body outside the eye is shown in Figure 6.
Figure 1. Preoperative axial CT with metal intraocular foreign body. Figure 2. View of sutured entry wound and band. Figure 3. Intraoperative view of the IOFB, local retinal detachment, and retinal whitening. Figure 4. Intraocular foreign body attached to intraocular magnet. Figure 5. Large retinal break after removing intraocular foreign body. Figure 6. Intraocular foreign body after removal.
Several attempts to remove the posterior cortical vitreous failed and were abandoned because they seemed to increase the area of the detachment. The retina was flattened with perfluoro-octane, and laser was performed around the large retinal tear and also 360° in the periphery. The eye was filled with silicone oil. Vitreous samples were sent for culture and came back negative. We did not inject intravitreal antibiotics, but intravenous antibiotics (vancomycin and ceftazidime) were given for 5 days. Three weeks later, a recurrent inferior detachment was observed with elevation of the anterior edge of the tear. A second operation was performed, and this time the posterior cortical vitreous was easily removed (Figure 7), the retina was flattened, and the eye was filled again with silicone oil. Four months later, the silicone oil was removed, and 1 year following the injury, the patient underwent cataract extraction and IOL implantation. The final visual acuity was 20/100 following this last operation.
Figure 7. Detaching the posterior cortical vitreous after staining with triamcinoloneacetonide.
Several questions arise from this case. Was a lensectomy indicated followed by a thorough peripheral vitrectomy with indentation during the primary procedure? What should have been the extent of the primary procedure? Should we have deferred the vitrectomy with the IOFB removal in order to facilitate PCV removal? Was placing a buckle necessary, and should an intraocular lens implantation have been performed during the primary procedure if the lens had been removed? Should we have tried harder to remove the PCV? Were intravitreal antibiotics or steroids indicated? Could we have used gas instead of silicone oil? What is the best broad-spectrum coverage with systemic antibiotics? Despite the fact that ocular injury with IOFBs is not rare, and the literature is abundant with relevant series and reports, there are still many open issues, as illustrated by this case, and the purpose of this review is to systematically address them.