SN6 SHORT NOTE 5M ★ High-yield

Describe traumatic cataract with the effects of retained intraocular foreign bodies.

Ophthalmology · 3rd Professional

A blunt (concussion) injury may damage the lens without rupturing the capsule, and the resulting changes are among the most characteristic in ophthalmology

Finding	Description
Vossius ring	A circular imprint of pigment from the posterior pupillary border stamped onto the anterior lens capsule at the moment of impact. It is harmless and gradually absorbs, but it is permanent evidence that a blunt injury occurred — which may matter medicolegally, and which should prompt a search for other concussion damage
Rosette (flower-shaped) cataract	The classical concussion cataract: feathery, radiating, petal-like opacities along the suture lines, giving a flower or star shape. Usually posterior subcapsular. May appear early (within days) and progress, or late (months to years afterwards), and the late form may be missed as a cause. It is essentially pathognomonic of concussion
Subluxation or dislocation	From zonular rupture, giving phacodonesis and iridodonesis
Other concussion damage to look for	Corneal abrasion and oedema; hyphaema; traumatic mydriasis and iridodialysis; angle recession with late glaucoma; commotio retinae (BERLIN oedema); choroidal rupture; retinal dialysis and detachment; and optic nerve avulsion

The lens changes are rarely the whole story, and a concussion injury requires a complete examination including gonioscopy for angle recession and a dilated fundus examination with indentation for retinal dialysis. Angle recession glaucoma may appear decades later, so these patients need lifelong pressure monitoring, and should be told so

Assessment — a careful history of the mechanism, and specifically whether there was hammering, grinding or an explosion, which raises the question of an intraocular foreign body; visual acuity in both eyes recorded at presentation; a search for a wound and a SEIDEL test; assessment of the anterior chamber depth, pupil shape and lens position; and, where a foreign body is possible, orbital CT — and never MRI if the material may be metallic
Timing of surgery — the wound is repaired first and primarily; the lens may be removed at the same sitting if it is disrupted and swelling, or as a secondary procedure once the eye has settled, which often gives a better view and a more predictable lens power. Urgent removal is indicated where there is lens-induced glaucoma, severe uveitis, or extruded cortex in the anterior chamber
Surgical considerations — the capsule may be torn unpredictably, zonules may be absent, and vitreous may be present; so anterior vitrectomy, capsular tension rings and alternative lens fixation must be available. Biometry is difficult and lens power calculation less reliable

All questions in The Lens and Cataract