Subspecialty News
Eye Injuries Take
a Toll in Iraq
But High-Performance Goggles Are Saving Sight.
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An Army Ranger wears his
Wiley X SG-1 protective eyewear. |
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With insurgents relying on weapons such as mortars and roadside bombs that spray multiple fragments over a wide area, eye injuries to U.S. forces in Iraq have become an increasing concern. In fact, a senior military ophthalmologist says the percentage of U.S. troops sustaining combat-related eye damage in Iraq was, until recently, higher than in any previous conflict.
Fortunately, the protective eyewear available to American soldiers and Marines has been greatly upgraded in recent years and is helping to reduce eye injuries.
Military doctors and ophthalmologists serving in Iraq had been reporting that approximately 10% of all American troops they've treated for battle-related wounds had some form of eye damage, almost always associated with other blast injuries. It's a figure that Col. Thomas Ward, MD, consultant to the U.S. surgeon general in ophthalmology, said that he accepted. However, Col. Ward says that after commanders mandated that protective eyewear be worn in potentially dangerous situations the percentage of wounded soldiers with eye injuries dropped to about 6%.
WHAT DOCTORS ARE TREATING
Maj. Michael Cohen, DO, an Army doctor who recently served in Iraq, says explosives are the major source of eye damage.
"Typically the injuries are related to rockets, mortars, or improvised explosive devices (IEDs), says Maj. Cohen. The injuries are caused by shrapnel and dirt, a lot of penetrating trauma. Probably the most common battle eye injury is a corneal foreign body/corneal abrasion. I have seen lots of casualties with metal or debris embedded in the cornea that is not easily removed. Quite frequently these are associated with a traumatic iritis, likely from the impact of the blast/injury. Anterior chamber hyphemas occur in about 10% of the traumatic eye injuries. Lots of lid lacerations as well. We also saw about 1 or 2 orbital fractures per month."
Regarding nonhostile eye injuries, Maj. Cohen says corneal abrasions and traumatic iritis top the list.
"There is so much dust and dirt around that small foreign bodies are common, which in turn cause mild abrasions," he notes.
Capt. Kerry E. Hunt, MD, specialty leader in ophthalmology at the National Naval Medical Center in Bethesda, Md., leads a team that treats Marines and Navy personnel whose eye injuries are serious enough to require further attention in the United States.
He says battle-related injuries include blunt and penetrating trauma, with the biggest threat coming from explosions that send up multiple, small, high-speed fragments involving large areas of the body.
"The head and neck and extremities aren't as easy to protect as the torso," says Capt. Hunt, "so we are seeing a number of injuries to those parts of the body. There have been a large number of ocular injuries including penetrating foreign bodies (sometimes multiple), choroidal ruptures, vitreous hemorrhages, eyelid injuries, and bony injuries involving the orbits. Our vitreoretinal and oculoplastic specialists have been the most busy."
DEVELOPING "EYE ARMOR"
Given these assessments, it's clear that protective eyewear, or "eye armor," can play a key role in reducing the number and severity of combat-related eye injuries.
About 4 years ago, the Army Rangers began working with Wiley X Eyewear of Livermore, Calif., to develop a versatile type of protective eyewear that wasn't bulky and that could be worn in multiple situations, including jumping out of airplanes.
The result was the SG-1, a multifunctional antiballistic eyewear "system" with antifog and antiscratch shatterproof polycarbonate lenses. The SG-1 easily converts from a low-profile goggle to a stylish sunglass. Not only did the SG-1 exceed military standards for high-impact fragmentation protection, it also had a look that appealed to the soldiers.
Once the Rangers adopted the Wiley X SG-1, other elite military units such as the Navy SEALs and Army Special Forces also made it standard issue.
With the endorsement of those elite units, the military began to order the SG-1 in the hundreds of thousands, making it the soldier's choice.
OXiGENE Expands Ophthalmic R&D Program
One Target: Myopic Macular Degeneration.
OXiGENE, a Massachusetts-based drug development company specializing in small-molecule therapeutics for the treatment of cancer and eye diseases, has expanded its research and development program in ophthalmology. This effort is being largely funded by $24.2 million the company raised from the sale of stock in 2004.
OXiGENE, which already has a small phase 1/2 trial under way for wet AMD, recently announced the initiation of a phase 2 study of its lead compound, Combretastatin A4 Prodrug (CA4P) in patients with myopic macular degeneration (MMD). CA4P is categorized as a vascular targeting agent that disrupts unwanted abnormal blood vessels. CA4P is derived from a natural compound, the bark of the South African bush willow tree, and has been synthesized and patented. It's called a vascular targeting agent because it targets the endothelial cells that line blood vessel walls and changes their shape from flat to round, thereby blocking blood flow.
The company decided to broaden its ophthalmic program after a patient afflicted with MMD showed dramatic improvement after being treated with CA4P.
The 35-year-old man had 20/50 vision in the study eye with active leakage in both eyes prior to treatment with CA4P. After treatment with systemically delivered CA4P, the patient's vision had been restored to 20/20 with significantly reduced leakage in each eye.
The MMD phase 2 trial is an open-label, dose-ranging, international multicenter study to assess the safety and efficacy of CA4P in the treatment of this disease, which is estimated to afflict approximately 300,000 people worldwide, with a high incidence rate in Asia. The company will be enrolling patients with active CNV associated with MMD. Patient progress will be monitored by visual acuity, fluorescein angiography, and optical coherence tomography.
"At this time, we are unaware of any other investigational compounds being studied in MMD," notes Fred Driscoll, OXiGENE CEO.
OXiGENE has begun studying multiple ways to deliver CA4P directly to the eye, with the ultimate goal of avoiding systemic exposure to CA4P.
In Brief
Macugen reimbursement. Eyetech Pharmaceuticals, Inc. said the Centers for Medicare & Medicaid Services has posted, effective Jan. 1, that the Medicare Part B allowable for pegaptanib sodium injection (Macugen) is 106% of Average Sales Price, or $1054.70 per injection. Macugen was approved by the FDA on Dec. 17 for use in the treatment of wet AMD. Eyetech and Pfizer launched Macugen on Jan. 20, with Eyetech estimating 2005 Macugen revenues between $125 and $140 million.
New DME treatment. Alimera Sciences Inc., an emerging ophthalmic pharmaceutical company, and Control Delivery Systems Inc. (CDS), a developer of innovative drug delivery systems for the eye, have announced a worldwide agreement to codevelop and market a new pharmacologic treatment indicated for diabetic macular edema (DME).
Alimera Sciences and CDS are in discussions with the FDA to initiate clinical trials to determine the effectiveness of injecting an implantable form of CDS' technology into the vitreous of the eye to treat DME. The miniscule implant is small enough to be injected into the eye via a 25-gauge needle and is expected to provide delivery of drug to the back of the eye for up to 3 years.
Retaane reflux controlled. Alcon, Inc., reported the results of a clinical pharmacokinetic study evaluating the effectiveness of a counter-pressure device (CPD) it developed to control reflux during the administration of anecortave acetate for depot suspension (Retaane 15 mg) by posterior juxtascleral depot (PJD). The study demonstrated that the CPD was effective in controlling drug reflux in 100% of the study participants. Reflux, or drug leakage, was cited as a key factor in the disappointing results from a Retaane clinical trial for the treatment of wet AMD.
TTT study subset results. Iridex Corporation reported a significant clinical benefit in a subset of patients with wet AMD who were treated with the transpupillary thermotherapy (TTT) laser protocol when compared with the sham-treated control group in the TTT4CNV clinical trial. The results showed that in patients with baseline visual acuity of 20/100 or worse, 22% of treated eyes improved vision by 1 or more lines compared with none of the eyes in the untreated control group. Furthermore, at 18 months, there was a 2-line benefit in preserving vision in this subgroup when compared with sham-treated eyes. Specifically, TTT treated eyes on average lost 2 lines of visual acuity while sham-treated eyes lost 4 lines.
To our readers: The staff of Retinal Physician regrets the production quality of the Photo of the Month appearing in the January/February 2005 issue on pages 72 and 73. Due to a production error, the fundus photograph and OCT scans were not depicted in a manner that accurately reflected the clarity and quality of the images.
Additionally, the diagnosis was incorrectly stated as choroidal osteoma and should have been retinal astrocytic hamartoma.