2020–2021 BCSC Basic and Clinical Science Course™
11 Lens and Cataract
Chapter 5: Pathology
Traumatic lens damage may be caused by mechanical injury and by physical forces such as radiation, chemicals, and electrical current.
Blunt injury to the eye can sometimes cause a ring of pigment (known as a Vossius ring) from the pupillary ruff to be imprinted on the anterior surface of the lens. Although a Vossius ring is visually insignificant and gradually resolves with time, its presence indicates prior blunt trauma, and it may be associated with other ocular injuries, including damage to angle structures.
A blunt, nonperforating injury may cause lens opacification either as an acute event or as a late sequela. A contusion cataract may involve the entire lens or only a portion of the lens. Often, the initial manifestation of a contusion cataract is a stellate or rosette-shaped opacification (rosette cataract), usually axial in location, that involves the posterior lens capsule (Fig 5-12). In some cases, blunt trauma causes both dislocation and cataract formation (Fig 5-13). In rare cases, mild contusion cataracts can improve spontaneously.
Figure 5-12 Slit-lamp retroillumination of a stellate lens opacity following contusion.
Figure 5-13 Cataractous lens has partially dislocated into anterior chamber following blunt trauma.
(Courtesy of James Gilman, CRA, FOPS.)
Shah M, Shah S, Upadhyay P, Agrawal R. Controversies in traumatic cataract classification and management: a review. Can J Ophthalmol. 2013;48(4):251–258.
Smith MP, Colyer MA, Weichel ED, Stutzman RD. Traumatic cataracts secondary to combat ocular trauma. J Cataract Refract Surg. 2015;41(8):1693–1698.
Dislocation and subluxation
During a blunt injury to the eye, rapid expansion of the globe in an equatorial plane immediately follows compression. This rapid equatorial expansion can disrupt the zonular fibers, causing dislocation or subluxation of the lens. The lens may be dislocated in any direction, including posteriorly into the vitreous cavity or anteriorly into the anterior chamber.
Symptoms and signs of traumatic lens subluxation include fluctuation of vision, impaired accommodation, monocular diplopia, and high astigmatism. Often, iridodonesis or phacodonesis is present. Retroillumination of the lens at the slit lamp through a dilated pupil may reveal the zonular disruption.
Irvine JA, Smith RE. Lens injuries. In: Shingleton BJ, Hersh PS, Kenyon KR, eds. Eye Trauma. Mosby; 1991:126–135.
Excerpted from BCSC 2020-2021 series: Section 11 - Lens and Cataract. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.