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.