Consider type of injury when treating a traumatic cataract

Extent and type of trauma should dictate the best surgical approach to addressing ocular damage.

Uday Devgan

“You can’t undo trauma,” said my professor of trauma surgery when I was a medical student at Los Angeles County-USC Medical Center. After seeing countless gunshot or stab wounds and blunt trauma from car crashes, I knew that he was right. This is especially true in the eye, where the delicate ocular structures are particularly vulnerable to damage from trauma. Among the most common injuries is the traumatic cataract.

What is the extent of the trauma?

In assessing a patient with acute ocular trauma in an emergency setting, the first step is to evaluate the patient systemically for evidence of other injury that may be life-threatening. While this is typically done by the emergency medicine department of the hospital, patients with severe ocular trauma may have also suffered head trauma, such as an intracranial bleed or traumatic brain injury. If you are certain that only the eye is involved, the extent of the ocular trauma must be determined.

In acute injuries, the visual acuity and the pupillary function — including relative afferent pupillary defect testing — of both eyes should be performed first. Both eyes should be examined carefully for signs such as a peaked pupil, iris/uveal prolapse, a collapsed anterior chamber, ocular hypotony, diffuse bloody chemosis or vitreous hemorrhage, which may indicate a ruptured globe. Usually, open globe injuries are primarily repaired within 12 to 24 hours of the trauma. If the globe is intact, then it can be medically managed while waiting for the inflammation, hyphema or other conditions to resolve. The anterior and posterior segments can then be examined in detail to determine the extent of the injury.

A small penetrating foreign body pierced the cornea, damaged the iris, distorted the pupil, ruptured the anterior lens capsule, induced a cataract and ended up embedded in the lens nucleus.

A blunt force injury caused 300° of zonular loss, a subluxated white cataract and vitreous prolapse into the anterior segment. The posterior segment suffered a perimacular choroidal rupture but no retinal detachment. Images: Devgan U

Patients may present with a traumatic cataract and a rapid decrease in vision weeks, months or even years after the initial trauma. They may have other ocular conditions due to the trauma, such as angle recession glaucoma or choroidal rupture. Penetrating ocular injury may induce a cataract by puncturing the lens capsule, and the eye may still contain this intraocular foreign body. Blunt ocular injury can cause a diffuse cataract with a higher chance for zonular loss.

What is the best approach?

If blunt trauma has caused a large degree of zonular loss with subluxation of the cataract and vitreous prolapse into the anterior segment, the best approach may be via the pars plana. Referral to a retina colleague for a proper pars plana vitrectomy and lensectomy may be better than an anterior segment fishing approach. Triamcinolone can be injected into the anterior segment to stain and assess the extent of the prolapsed vitreous. Once the cataract and vitreous are removed, the patient can be scheduled for a future operation to implant a secondary IOL. This secondary IOL can be angle-supported in the anterior chamber, iris-sutured in the posterior chamber, or scleral-fixated in the posterior chamber.

For penetrating injuries in which there is zonular integrity, the cataract can be removed via a traditional clear corneal or scleral incision. The anterior lens capsule is likely to be compromised, so small incisions and a retentive viscoelastic should be used to keep the anterior chamber pressurized. Although a capsulorrhexis is preferable, the extent of the capsular damage may necessitate using a can-opener capsulotomy technique. The eye must be examined and imaged to locate any potential intraocular foreign bodies that may cause infection and pose a toxic risk to the eye.

What are the other issues?

Intraoperatively, these patients often have iris and pupillary injuries that may require iris retraction devices or iridoplasty in order to improve exposure for the surgery. If a continuous curvilinear capsulorrhexis can be accomplished, a capsular tension ring may help to address mild to moderate degrees of zonular loss. In cases of more significant zonular weakness, the Cionni ring, a capsular tension ring with eyelets, facilitates suture fixation.

The penetrating corneal injuries may have induced irregular astigmatism, which makes measurement of the corneal power more difficult. This may result in less accurate IOL calculations, but the measurements from the other eye can be used for comparison and a somewhat myopic refractive goal can be selected. With an irregular capsulorrhexis, a three-piece IOL offers the most flexibility for placement because it can be implanted in the capsular bag, in the ciliary sulcus or via a suturing technique.

The posterior segment or optic nerve may have sustained damage, which could limit visual function. The patient also may have a lifetime risk of sympathetic ophthalmia, which could affect either eye.

Although my professor was right to say, “You can’t undo trauma,” when it comes to traumatic cataracts, there is usually a way to surgically address much of the ocular damage. We can’t make the vision perfect, but we can almost certainly improve it.

• Uday Devgan, MD, FACS, is in private practice at Devgan Eye in Los Angeles, chief of ophthalmology at Olive View UCLA Medical Center and an associate clinical professor at the UCLA School of Medicine. Dr. Devgan can be reached at 11600 Wilshire Blvd., Suite 200, Los Angeles, CA 90025; 800-337-1969; fax: 310-388-3028, e-mail: devgan@gmail.com; Web site: www.UdayDevgan.com. Dr. Devgan has no disclosures related to this article.