November 2007

 

COVER FEATURE

 

ocular trauma

Treating ocular injuries


by Michelle Dalton EyeWorld Contributing Editor

 

 

Example of a corneal laceration with iris prolapse

Example of iridodialysis with dislocated traumatic cataract Source: Emory University/Grady Hospital

Knife wound that penetrated the globe Source: Emory University/Grady Hospital

Whether open or closed globe injuries, careful treatment of trauma injuries can help improve visual acuity prognosis

There are an estimated 2.4 million eye injuries a year — 90% that are preventable. In the U.S. alone, eye trauma costs amount to about $300 million annually. Injury is the leading cause of eye-related hospital admissions, according to the American Medical Association. The National Research Council adds that eye injury is “probably the most under-recognized major health problem facing the nation today.” A majority of all eye injuries occur in people under 30 years of age, and trauma is the most common cause of enucleation in children older than 3, the American Society of Ocular Trauma notes.

Visual outcomes can vary from full recovery to complete blindness (with or without enucleation). In the U.S., about 40,000 eye injuries result in permanent visual impairment. Eye injury is the leading cause of monocular blindness in the U.S., and is second only to cataract as the most common cause of visual impairment.1 In the past 50 years, however, advances in both anterior and posterior segment surgery have improved surgical management of eye injuries as well. Animal model studies have helped ophthalmologists understand that a predictable series of events tends to occur following injury as the eye attempts to heal itself.2 “Outside the U.S., in the developed countries, the figures are very similar,” said Ferenc Kuhn, M.D., PhD., associate professor of ophthalmology, University of Alabama at Birmingham, and professor, University of Pecs, Hungary. Dr. Kuhn is also the co-developer of the Birmingham Eye Trauma Terminology System (BETTS). Recommendations on how to treat open globe injuries had been based largely on retrospective reviews before the 1990s, when the U.S. Eye Injury Registry was developed.

First things first

“The nomenclature is important,” said Geoffrey Broocker, M.D., endowed professor of ophthalmology at Emory University, and chief of service of ophthalmology at Grady Hospital, Atlanta. “But more important is the history of the patient upon presentation.” “Is it a blunt injury? Penetrating? Perforating? If we’re going to treat the problem, we have to know the extent of the injury and if there’s a possibility of an intraocular foreign body. Is there a chance for developing endophthalmitis? We can glean important tips from the patient’s history if the latter two are a possibility,” said Jonathan Sears, M.D., head of the department of vitreoretinal disease at the Cleveland Clinic, Ohio. Francis Mah, M.D., co-medical director, the Charles T. Campbell Ophthalmic Microbiology Laboratory, University of Pittsburgh School of Medicine, Pa., agreed. When someone presents with a projectile injury, immediately take an X-ray and CT scan, and “if you don’t see anything, you need to do an MRI. If it’s a metallic foreign body, get it out of the eye as quickly as possible.” Dr. Mah said when the injury involves the lid and lacrimal system, “I pretty much leave it to a lacrimal specialist and call in an oculoplastics specialist. You want to keep saline on there to keep the eye moist, but you also need to ensure it’s repaired in the first 12 hours.”

Orbital injuries are most likely caused by motor vehicle accidents, altercations and sports, said Andrew R. Harrison, M.D., director, ophthalmic plastic and orbital surgery, University of Minnesota. “It depends on the demographics, though,” he said. “In children, one of the more common causes is dog bites.” First and foremost, he said, is to ensure the patient is stable from a medical standpoint, and then ensure the eye is okay. “That entails ensuring the eye is clear with no injury to the globe. You shouldn’t try to fix the lid until the eye is in tact,” he said. Once the eye has been stabilized, the surgeon needs to determine if there is eyelid or lacrimal system damage, he said. “If it’s a horizontal laceration across the eyelid, it should be something an ER doc could sew up. But if the injury goes through the lid margin, it needs careful layered closure of the eyelid or there could be cosmetic and/or functional problems like a notch in the margin. The lacrimal system also needs to be evaluated in all lacerations involving the medial eyelid. Most common is damage to the canniculus. This can occur with a shearing injury of the lateral eyelid which causes a tear at the canaliculus because it’s the weakest area of the eyelid.”

Treatment options

Getting a true patient history is extremely important, Dr. Broocker said. In cases of chemical injury, knowing if the chemical was alkali or acid may change treatment.

“The punishment needs to fit the crime, so to speak,” Dr. Broocker said. “The history we get, especially with children, is sometimes unrelated to what’s going on. Be very careful about what you hear and what you see when you’re taking patient history.”

Fixing the globe takes precedence over any other injury the eye has sustained, Dr. Mah said. “If there’s a large subconjunctival hemorrhage, we want to get a scan. If the pupil is irregular, that’s got to be a concern. We’d rather do an exploratory surgery and find there is no open globe than not go in and find out 2 to 3 days later there is an open globe,” he said. For eyelid trauma, Dr. Harrison usually implants a silicone stent if there is a lacrimal system injury to keep the system patent as it heals.

“There are several options for stenting the lacrimal system. If it’s a simple laceration through one canniculus, right at the proximal part of the canaliculus, those can be repaired in a minor procedure room. I’ll often implant a MiniMonoka (FCI Ophthalmics, Pembroke, Mass.) if the laceration is proximal,” he said. Bicannicular repair tends to involve a silicone stent through the upper and lower cannicula systems, he added.

“The hardest part is finding the distal cut end,” he said. One of his pearls is to put fluorescein stain in Healon (sodium hyaluronate, Advanced Medical Optics, Santa Ana, Calif.) and inject that concoction through the uninjured canaliculus and see where it exits in the deep part of the wound. “I use that mixture especially if the laceration is close to the lacrimal sac,” he said. Once any lacerations are closed, “be they corneal, corneoscleral or scleral, and intraocular pressure is normal, the eye is watertight and the wound is no longer leaking, the next decision is whether the patient needs local antibiotics or systemic or both,” Dr. Sears said. “If the laceration is only anterior—that is anterior to the limbus—we’ll use topical antibiotics, probably a single dose IV antibiotic in the OR and double check the patient has an up-to-date tetanus shot. As an added precaution, we may use oral gatifloxacin, but it’s expensive to administer,” he said. In posterior lacerations that involve the vitreous, Dr. Sears will prescribe intravitreal Vancocin (vancomycin, Eli Lilly, Indianapolis, Ind.) at 1 mg/0.1 mL or ceftazadime at 2 mg/0.1 mL. “We’ll also use antifungals if the history indicates the need,” he said. He recommended anyone who treats trauma immediately refer to a vitreoretinal specialist to rule out traumatic endophthalmitis, retinal detachment, vitreoretinal incarceration, choroidal rupture or submacular hemorrhage.

“A peaked pupil can happen even in closed globe trauma when the clot pulls the pupil towards the clot,” Dr. Broocker said. “IOP is one area to look at, and has to be measured with caution in open globe injuries or there’s a risk of extruding the ocular contents.”

If there’s a scleral rupture at the rectal muscle insertions, “you may not see it directly because of overlying subconjunctival hemorrhage,” Dr. Broocker said. “Subconjunctival hemorrhage is not a sign of the severity of the disease, though. However, if a lot of blood is causing the conjunctiva to billow out, that’s more consistent with an open globe or orbital trauma.”

Managing patient expectations One goal of the Ocular Trauma Classification System categorizes injured eyes by four parameters (type, grade, pupil and zone), with scores from 1-5 assigned. Based on the initial visual acuity and the presence of certain variables, such as rupture or retinal detachment, the Ocular Trauma Score (OTS) has been developed to offer an objective, numerical estimate of what a patient’s final vision is expected to be. “We try not to give patients false hope,” Dr. Broocker said. “Rather than use the OTS to say there’s a zero chance of visual recovery, we’ll say the visual prognosis is not good. “Even with large globe wounds, primary repair is usually recommended. The use of postoperative topical corticosteroids to reduce inflammation and timely enucleation of the severely injured and NLP [no light perception] eyes can significantly reduce the risk of sympathetic ophthalmia.”

Dr. Mah agreed, saying “pre-op vision is probably a prognostic indicator of post-op vision. If the patient presents with poor vision, our prognosis is guarded. Second, it’s the timing of the surgeries. We can fix open globes immediately or wait 12-24 hours and that doesn’t really change the prognosis.”

In Dr. Mah’s experience, matching up the angle is necessary in an irregular tear, making sure it’s watertight or negative. “You don’t want to pull tight on tissue unless you have to. Star-like corneal/scleral lacerations are the most difficult to close. If the injury affects the uveal issue, we’ll cut it off instead of putting it back,” he said. He reserves lensectomy for instances of open capsule or repair-induced cataract. “I prefer to wait and get accurate measurements and keratometry. If you have a significant amount of inflammation, we’ll take the lens out but leave the patient aphakic, take As and Ks and insert a lens later,” Dr. Mah said. “The blood vessels inside the eye are used to an environment with an elevated pressure on top of the atmospheric, and every injury increases blood flow to the eye. The risk of one of those vessels spontaneously rupturing in the context of an open globe injury is always there. If such an expulsive hemorrhage happens, you can lose the eye in 2 to 3 seconds. Expulsed in just a few seconds,” Dr. Kuhn said. “Any object that enters the eye may be infected, which represents the second greatest risk of an injury. That’s a little easier to treat, depending on bacteria and other factors. If the injury is closed globe, though, there’s time to evaluate and manage the injury. With an open globe trauma, everything is a little more acute. The main management question is should you do a staged approach, close the globe and then do everything else a few days later, or a primary comprehensive reconstruction. This and many questions must be answered by the ophthalmologist based on the case itself and on knowing his own capabilities. Does he have experience and equipment to fairly treat the injury?” Dr. Kuhn said.

Secondary glaucoma

Secondary glaucoma is one of the most neglected areas of eye injury treatment, Dr. Kuhn said. “I think the figures are extremely underestimated at 4%. I always teach my fellows and colleagues to pay attention to infection, inflammation, IOP. If you’re able to control all three you’re much better off. IOP must be monitored closely and long term and treated just as aggressively as it would be without the history of open globe or closed globe trauma,” he said.

Hyphema is also a concern, he said. “Hemorrhage in front of the eye is not a big deal by itself, but it is if the patient has sickle cell disease. There’s an increased chance of re-bleeding. The risk of corneal blood staining is also real. Be very careful with patients who have hyphema and high IOP,” he said.

Ongoing studies

The USEIR is currently evaluating a new treatment method for perforating, posterior rupture, and deep-impact intraocular foreign body (IOFB) injuries. The prospective international trial—believed to be the first of its kind in ocular trauma—will compare the results of the new treatment method with those published in the literature. The new method focuses on prophylactic chorioretinectomy around the exit/rupture wound/intraocular foreign body impact site to prevent retinal incarceration and to remove the intravitreal blood and disrupt the intravitreal tract in a perforating of IOFB injury. The protocol states the steps must be taken within the first 100 hours after injury. The trial will study perforating injuries (corneal or scleral entrance wound with a scleral exit wound), foreign body injuries that impact deeper than the retina (choroidal or choroidoscleral involvement), and ruptures with scleral extension posterior to extraocular muscle insertion. For more information or to participate in the trial, visit the USEIR Web site at www.useironline.org.

Community education is still needed, Dr. Kuhn said.

“Prevention is the most important aspect of eye injury management and that comes from common sense,” he said. “Any trauma prevented is better than any trauma that is treated.”

Editor’s note: None of the physicians interviewed have any financial interest in the products discussed.

Contact:

Broocker: 404-778-4530; geoffrey.broocker@emory.edu

Harrison: 612-625-4400; harri060@umn.edu

Kuhn: 205-933-0064; fkuhn@mindspring.com

Mah: 412-647[-2214; mahfs@upmc.com

Sears: 216-444-8157; searsj@ccf.org

References:

1 McGwin G, Hall TA, Xie A, Owsley C. Trends in eye injury in the United States, 1992-2001. Invest Ophthalmol Vis Sci. 2006;47:521-7.

2 Castellarin AA, Pieramici DJ. Open Globe Management. Compr Ophthalmol Update. 2007;8:111-124.

Overview of USEIR

The USEIR (www.useironline.org) was formed in late 1988 in recognition of the lack of a national eye injury epidemiologic data. The registry is based in Birmingham, Ala., under the direction of founders Robert Morris, M.D., and C. Douglas Witherspoon, M.D.

By May 1991: • More than 2,600 reports of serious eye injury • 2,000 reports of final outcome

Today: • Database includes injuries from individual ophthalmologists and institutions and eye hospitals • Has documented more than 15,000 seriously injured eyes

Treating ocular injuries Treating ocular injuries
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