Q2 LONG ANSWER 10M ★ High-yield

Describe the effects of blunt ocular trauma.

Ophthalmology · 3rd Professional

Mechanism and Anterior Segment Injury

Blunt (contusion) injury is a closed globe injury in which the eyewall remains intact.
The globe is compressed along its anteroposterior axis and expands equatorially, so damage occurs both at the site of impact and at points remote from it — the COUP and contrecoup effect.
The classical mechanisms in India — a fist, a cricket or tennis ball, a shuttlecock (which fits the orbital rim exactly and transmits force directly to the globe), a stone, a stick, a bungee cord, a champagne cork, an airbag and a road traffic injury

Posterior Segment Injury

Injury	Features
Commotio retinae (BERLIN oedema)	Grey-white opacification of the retina at the site of impact from photoreceptor outer segment disruption — it is not true oedema. At the macula it gives a pseudo-cherry-red spot. resolves in 3 to 4 weeks with good recovery, but may leave permanent pigmentary change and reduced acuity
Choroidal rupture	A break in BRUCH membrane, choriocapillaris and pigment epithelium. Characteristically a crescentic, yellowish-white streak concentric with the optic disc and temporal to it. Vision is lost if it crosses the fovea; and there is a late risk of choroidal neovascularisation at its margin.
Traumatic macular hole	May occur immediately; some close spontaneously, so a period of observation precedes surgery
Retinal dialysis	Disinsertion of the retina at the ora serrata, characteristically inferotemporal and superonasal. It causes a slowly progressive detachment which often presents late, months after a forgotten injury in a young person — so any young patient with a detachment should be asked about past trauma
Retinal tears and detachment	Giant tears and horseshoe tears at the vitreous base
Vitreous haemorrhage	Obscures the fundus; requires B-scan to exclude a detachment, repeated while the media remain opaque
Purtscher retinopathy	After severe compression injury to the chest or head, or long bone fracture: multiple cotton-wool spots and superficial haemorrhages around the disc, from complement-mediated leucoembolisation. No specific treatment
Scleral rupture (occult)	May be hidden beneath intact conjunctiva. Suspect it with hypotony, a deep anterior chamber, 360-degree bullous subconjunctival haemorrhage, reduced motility and poor vision

Management and Applied Aspects

Management is directed at the specific injuries found, but several principles apply generally:
A cycloplegic and topical steroid for traumatic iritis; and topical antibiotic where the epithelium is breached
Monitor the intraocular pressure, which may be raised (from hyphaema, inflammation, angle recession or lens subluxation) or low (from cyclodialysis or an occult rupture)
A dilated, indented peripheral retinal examination is mandatory once the globe is confirmed intact and the media allow — and repeated at 2 to 4 weeks, since tears and dialysis may be missed or may develop later
Warn the patient of the symptoms of retinal detachment before discharge, and give a route back
Arrange lifelong annual pressure monitoring after angle recession, and record the gonioscopic findings by quadrant so that a future clinician can interpret them
Review for late complications — cataract, which may appear years later; glaucoma; choroidal neovascularisation at a rupture; and detachment
The globe compresses front to back and expands at the equator.
A shuttlecock fits the orbital rim exactly and transmits its force directly to the globe.
Iridodialysis gives a D-shaped pupil and a second pseudopupil, with monocular diplopia and glare
Compare the ciliary body band with the fellow eye; angle recession is recognised by asymmetry rather than by absolute width
Recession beyond 180 degrees carries the glaucoma risk, so the extent should be recorded quadrant by quadrant
Cyclodialysis causes hypotony and maculopathy, and is the mirror image of angle recession in its effect on pressure
A Vossius ring is harmless but permanent evidence that a blunt injury occurred.
A rosette cataract may appear years later, so a late cataract in a young person should prompt a question about past injury
Commotio retinae is photoreceptor disruption, not oedema, despite the name Berlin oedema, and resolves in three to four weeks

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