INTRAOCULAR FOREIGN BODY

PRESENTER DR SANIL SAWANT

MODERATOR DR DEVENDRA VENKATRAMANI

Ocular trauma constitutes one of the important cause of visual loss and subsequent disability.

Penetrating injuries are divided into various subcategories based on specific types of injuries .

Intraocular foreign bodies may complicate penetrating injury

BETTS CLASSIFICATION OF OCCULAR TRAUMA

FOREIGN BODY CLASSIFICATION

1) TOXIC Metallic

Magnetic – iron, steel, nickel Non magnetic – copper, aluminium, mercury, zinc

Non-metallic – vegetative matter

2) INERT Metallic – Gold, silver, platinum Non-metallic – Glass, carbon, stone, porcelain, plaster, rubber

MODES OF DAMAGE

Mechanical effects Introduction of infection Reaction of foreign body Post-traumatic iridocyclitis Sympathetic ophthalmitis

MECHANICAL EFFECTS

Depends on the size, velocity and type of foreign body

Foreign bodies greater than 2 mm cause extensive damage

Lesions depends upon the route of entry and the site up to which foreign body has travelled

LOCATIONS OF IOFB 1)Anterior chamber –

Usually sinks in the bottom Tiny foreign body can be visualised only on gonioscopy

2) Iris –In the stroma

3) Posterior chamber – Behind the iris after entering through pupil or making a hole in

the iris

Lens –On anterior surface or inside the lens (either an opaque tract

may be seen in lens or may become cataractous)

Vitreous cavity

Retina , choroid and sclera

Orbital cavity

INTRODUCTION OF INFECTION

Metallic foreign are usually sterile due to heat generated by them

Wood and stones carry a great chance of infection

Usually ends in endophthalmitis and panophthalmitis

REACTION OF FOREIGN BODYInorganic foreign body

No reaction by inert substances which includes glass, porcelain, gold, silver and platinum

Local irritative reaction leading to encapsulation of foreign body occurs with lead and aluminium particles .

Suppurative reaction excited by pure copper, zinc, nickel and mercury particles .

Specific reactions by iron (siderosis) and copper alloys (chalcosis)

SIDEROSIS BULBI Degenerative changes produced by an iron foreign bodyUsually occurs 2 months to 2 years of the injury MECHANISM –

The iron particle undergo electrolytic dissociation by the current of rest and its ions are disseminated throughout the eye.

These ions combine with intracellular protein and produce degenerative changes

Epithelial structures of the eye are most affected

CLINICAL MANIFESTATIONS

Anterior epithelium and capsule of lens are involved first. Rusty deposits are arranged radially in a ring; later cataract develops

Iris first stained greenish and latter on reddish brown Retinal pigmentary changes can resemble retinitis pigmentosa ERG shows progressive attenuation of b wave over timeSecondary open angle type of glaucoma due to degenerative

changes in trabecular meshwork

(reference –webeye.ophth.uiowa.edu )

CHALCOSIS

Specific changes produced by alloys of copper in the eye

IOFB with high copper content involves violent endophthalmitis often with progression to phthisis bulbi

Alloys with low copper content like brass and bronze results in chalcosis

CLINICAL MANIFESTATIONS Kayser-Fleischer ring is golden brown ring which occurs

due to deposition of copper under peripheral part of Descemet’s membrane of the cornea

Sunflower cataract produced by deposition of the capsule under posterior capsule of the lens

Brilliant golden green in colourRetina – deposition of golden plaques at the posterior

pole which reflects light with a metallic sheen Degenerative retinopathy does not develop as it is

less retinotoxic compared to iron

REACTION OF ORGANIC FOREIGN BODY

E.g. wood and other vegetative material produce proliferative reaction characterised by formation of giant cells

Caterpillar hair produces ophthalmia nodosum ,which is characterised by severe granulomatous iridocyclitis with nodule formation .

SYMPATHETIC OPHTHALMITIS Serious bilateral granulomatous panuveitis which follows penetrating ocular trauma

Injured eye is exciting eye and fellow eye is sympathizing eye .

A)Predisposing factor

Follows penetrating wound

Wounds in the ciliary region (dangerous zone ) are more prone to it

more common in children than adults

Dalen-Fuchs nodules formed due to proliferation of pigment

epithelium (of iris, ciliary body and choroid ) associated with invasion of lymphocytes and epithelioid cells

eyecalcs.com

CLINICAL PICTURE

1)Exciting ( injured eye ) –Shows clinical feature of persistent low grade plastic uveitis Ciliary congestion , lacrimation and tenderness Keratic precipitates may be present at the back of the cornea 2) Sympathizing ( sound eye ) –Usually involves 4 -8 weeks of injury in the other eye Manifest as acute iridocyclitis

TREATMENT

Prophylaxis meticulous repair of the wound using microsurgical technique

taking great care that uveal tissue is not incarcerated in the wound .

Corticosteroids (topical + sytemic), immunosuppressants

COMPLICATIONS – In Summary Rust ring on cornea at entry point Persistent inflammation Corneal defectsInfection – endophthalmitis Secondary glaucoma Lens damage –traumatic cataractsRetinal/vitreous damage Sympathetic ophthalmia

MANAGEMENT OF RETAINED IOFB

DIAGNOSIS –History – a careful history about the mode of injury may

give clue about the type of IOFBTime elapsed since injury

Ocular examination –A thorough ocular examination including slit lamp examination. Gonioscopy in select cases

SLIT LAMP PHOTOGRAPHY

Pathway of IOFB showing iris hole

Coaxial full-thickness corneal scar, iris hole, and/or lenticular opacity are highly suspicious of penetrating trauma and possible IOFB

LOCALISATION OF IOFB

X-RayPlain X rays orbit Anterio-posterior and lateral views

as most foreign bodies are opaque .

Limbal Ring Method–Obsolete Metallic ring of corneal diameter stiched at limbus and x

ray taken in three exposures one while patient looking straight , upwards and downwards .

LIMBAL RING

USG

Features of IOFB on A scan Steeply rising wide echo spike seen

The reflectivity of the spike is extremely high (100% ) which persists on low gain

Sound attenuation is very strong

Features of B scan Appears hyperechoic in contrast to clear vitreousSound attenuation is very strong . IOFB causes shadowing

of ocular and orbital structure behind it .Associated ocular damage like vitreous haemorrhage,

retinal detachment can be assessed

USG localisation can tell position of even radiolucent foreign body

B SCAN

CT SCAN-Best method of localising IOFB Axial and coronal cut of < 1.5 mm are advised

MRI Contraindicated in case of metallic foreign body

MANAGEMENT Requires immediate closure of wound and removal of

IOFB .Delay> 24 hrs produces four fold increase risk of

endophthalmitis and vision lossPrompt removal before encapsulation facilitates removal and

prevents IOFB toxicityEyes should be protected with eye shieldIV broad spectrum antibiotic Tetanus prophylaxis ( Thomson JT et al . Infectious endophthalmitis after retained IOFB . Principles and practice of vitreo retinal surgery . 1993 , 1468-1474 . )

TREATMENT

IOFB should always be removed unless inert, sterile

Foreign body in anterior chamber removed through corresponding corneal incision directed straight towards the foreign body 3 mm incision internal to limbus is taken Magnetic foreign removed with hand held magnet and

nonmagnetic foreign body picked with toothless forceps .Viscoelastic protects delicate structures

Foreign body entangled in iris tissue –Sector iridectomy of part containing magnetic and non

magnetic foreign body .Foreign body in lens

Lens extraction with IOL implant Forceps removal with a pars plana vitrectomy –

Use of intraocular magnet or forceps, via sclerotomy or limbal route in aphakes

PROGNOSIS Depends on

Initial BCVA Time of surgery Initially attached retina Scleral entry site Presence of afferent pupillary defect Mechanism of injury Vitreous hemorrhage

(Akesbi J et al . IOFB of posterior segment : retrospective analysis and management of 57 cases . J Fr Ophtalmol 2011 Nov ;34 (9) 634- 640 .

CASE

42 /M came with c/o DOV , pain ,redness in LE since one day

H /O foreign body (steel) particle entry in LE one day back

BCVA RE: 6/9, LE: HM

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