Traumatic cataracts occur secondary to blunt or penetrating ocular trauma. Infrared energy (glass-blower's cataract), electric shock, and ionizing radiation are other rare causes of traumatic cataracts.[1]
Cataracts caused by blunt trauma classically form stellate- or rosette-shaped posterior axial opacities that may be stable or progressive, whereas penetrating trauma with disruption of the lens capsule forms cortical changes that may remain focal if small or may progress rapidly to total cortical opacification. Shah et al found that traumatic cataracts without globe rupture generally have a better prognosis for visual recovery after surgery, at least in children.[2]
Note the images below.
View Image | Classic rosette-shaped cataract in a 36-year-old man, 4 weeks after blunt ocular injury. |
View Image | Same cataract as seen in previous image, viewed by retroillumination. |
See What the Eyes Tell You: 16 Abnormalities of the Lens, a Critical Images slideshow, to help recognize lens abnormalities that are clues to various conditions and diseases.
Lens dislocation and subluxation are commonly found in conjunction with traumatic cataract. Other associated complications include phacolytic, phacomorphic, pupillary block, and angle-recession glaucoma; phacoanaphylactic uveitis; retinal detachment; choroidal rupture; hyphema; retrobulbar hemorrhage; traumatic optic neuropathy; and globe rupture.[3, 4, 5]
Traumatic cataract can present many medical and surgical challenges to the ophthalmologist. Careful examination and a management plan can simplify these difficult cases and provide the best possible outcome.[5, 6]
Blunt trauma is responsible for coup and contrecoup ocular injury. Coup is the mechanism of direct impact. It is responsible for Vossius ring (imprinted iris pigment) sometimes found on the anterior lens capsule following blunt injury. Contrecoup refers to distant injury caused by shockwaves traveling along the line of concussion.[7]
When the anterior surface of the eye is struck bluntly, there is a rapid anterior-posterior shortening accompanied by equatorial expansion. This equatorial stretching can disrupt the lens capsule, zonules, or both. Combination of coup, contrecoup, and equatorial expansion is responsible for formation of traumatic cataract following blunt ocular injury.[8, 9, 10]
Penetrating trauma that directly compromises the lens capsule leads to cortical opacification at the site of injury. If the rent is sufficiently large, the entire lens rapidly opacifies, but when small, cortical cataract can seal itself off and remain localized.
United States
Approximately 2.5 million eye injuries occur annually in the United States. It is estimated that approximately 4-5% of a comprehensive ophthalmologist's patients are seen secondary to ocular injury. Traumatic cataract may present as acute, subacute, or late sequela of ocular trauma.
Trauma is the leading cause of monocular blindness in people younger than 45 years. Annually, approximately 50,000 people are left unable to read newsprint as a result of ocular trauma. Only 85% patients who experience anterior segment injury reach a final visual acuity of 20/40 or better, whereas only 40% patients with posterior segment injury reach this level.[8, 9]
The male-to-female ratio in cases of ocular trauma is 4:1.
Work- and sports-related eye injuries most commonly occur in children and young adults. Between 1985-1991, a National Eye Trauma System study reported a median age of 28 years in 648 assault-related cases.
Protective eyewear is important in high-risk activities to avoid injury. For patient education resources, see the Eye & Vision Center as well as Cataracts.
Note the following:
Complete ophthalmic examination (defer in case of globe compromise), to include the following:
Lens dislocation and subluxation are commonly found in conjunction with traumatic cataract.[4]
Other associated complications include the following: phacolytic, phacomorphic, pupillary block, and angle-recession glaucoma; phacoanaphylactic uveitis; retinal detachment; choroidal rupture; hyphema; retrobulbar hemorrhage; traumatic optic neuropathy; and globe rupture.[5]
Perform the following:
Tabatabaei et al showed that 20-MHz ultrasound (Eye Cubed) was both more sensitive and more specific than anterior-segment optical coherence tomography (OCT; Visante model 1000) and Scheimpflug imaging (Pentacam) in detecting posterior capsular rupture prior to surgery in patients with traumatic cataract.[13]
If glaucoma is a problem, control intraocular pressure with standard medications. Add corticosteroids if lens particles are the cause or if iritis is present.
For focal cataract, observation is warranted if the cataract is outside the visual axis. Miotic therapy may be of benefit if the cataract is close to the visual axis.
In some cases of lens subluxation, miotics may correct monocular diplopia. Mydriatics may allow for vision around the lens with aphakic correction.
Planning the surgical approach is of the utmost importance in cases of traumatic cataract. Preoperative capsular integrity and zonular stability should be surmised.
In cases of posterior dislocation without glaucoma, inflammation, or visual obstruction, surgery may be avoided.
Indications for surgery include the following:
Standard phacoemulsification may be performed if the lens capsule is intact and sufficient zonular support remains.
Intracapsular cataract extraction is required in cases of anterior dislocation or extreme zonular instability. Anterior dislocation of the lens into the anterior chamber requires emergency surgery for its removal, as it can cause pupillary block glaucoma.
Shah et al demonstrated that, as part of the primary procedure for traumatic cataract, posterior capsulectomy and anterior vitrectomy improve visual outcomes.[14] According to Trivedi and Wilson, primary posterior capsulectomy and vitrectomy should be considered irrespective of age in children undergoing surgery for traumatic cataract.[15]
Pars plana lensectomy and vitrectomy may be best in cases of posterior capsular rupture, posterior dislocation, or extreme zonular instability.
Automated irrigation/aspiration can be used in patients younger than 35 years.
Lens implantation[16] is as follows:
Vitreoretinal consultation is necessary if a pars plana approach is mandated and the surgeon is untrained in posterior segment surgery.
Protective eyewear should be worn when participating in any high-risk activities. Most serious eye trauma can be avoided if proper eye and face protectors are used.