SCORE study needs optometrist participation

Issue: August 2005

ByMichael S. Ip, MD

The Standard Care vs. Corticosteroid for Retinal Vein Occlusion (SCORE) study is a National Eye Institute-sponsored multicenter, randomized, controlled clinical trial that seeks to better define the efficacy and safety of intravitreal triamcinolone injections in the management of macular edema associated with both central retinal vein occlusion (CRVO) and branch retinal vein occlusion (BRVO). The SCORE study began enrolling patients in November 2004. It includes more than 80 clinical centers and plans to enroll more than 1,200 patients with CRVO or BRVO. The help of optometrists is needed in this effort.

Expected follow-up for the SCORE study is 3 years, and patients will be eligible for repeat treatment based on pre-specified, protocol-defined retreatment criteria. Based on results from a number of reports to date, eye care practitioners are very excited about the potential of intravitreal triamcinolone as a new therapy for macular edema. However, there is a need to temper this enthusiasm because of its side effects and the short-term follow-up that is a limitation of many of the prior reports describing its use.

With the long-term efficacy and safety of intravitreal triamcinolone currently unknown, clinicians need to await the results of these randomized controlled trials before we can tell our patients with any certainty whether or not they will benefit in the long-run from treatment with these steroid injections.

History of intravitreal triamcinolone

Intravitreal triamcinolone was first used about 25 years ago as an adjunct to improve the outcome of retinal detachment surgery by reducing the rate of proliferative vitreoretinopathy. Basic science studies performed at that time revealed no evidence that triamcinolone itself or the vehicle in the commercially available preparation posed retinal or other ocular toxicity.

Subsequently, intravitreal triamcinolone was investigated in a variety of other indications. In the 1990s, researchers in Australia began to evaluate it for the treatment of eyes with age-related macular degeneration, while in the United States, significant interest did not emerge until the latter part of that decade. More recently, studies have been undertaken to investigate eyes with macular edema associated with CRVO and BRVO.

The experience in treating macular edema due to CRVO and BRVO showed promising efficacy with respect to anatomical and functional outcomes in many patients. In many cases, macular edema was reduced or resolved as evaluated by clinical exam or optical coherence tomography. Additionally, some patients experienced significant improvement in visual acuity.

The vision benefits noted are particularly exciting, as no treatment for macular edema associated with either CRVO or BRVO is able to achieve such results. While laser photocoagulation offers a reasonable treatment for some patients with BRVO, its primary goal is to stabilize vision, and only uncommonly do patients achieve any significant gains, whereas for CRVO, there is no known treatment for macular edema.

Safety issues

The good news from these prior reports, however, is tempered by safety issues. Problems with steroid-related toxicity are common, including intraocular pressure elevation and cataract. Moreover, the intravitreal method of delivery posed injection-related risks of vitreous hemorrhage, retinal detachment and infectious endophthalmitis. In addition, the commercially available preparation of triamcinolone was found to be associated with the development of a sterile inflammatory reaction in some eyes.

The reason some patients develop a sterile inflammatory reaction is unknown. It may be due to an endotoxin or one of the preservatives in the Kenalog (triamcinolone acetonide, Bristol-Myers Squibb) formulation, but it is a concern, because the inflammatory reaction is sometimes difficult to distinguish from an infectious etiology. In light of this inflammatory risk, the SCORE study is being conducted using a novel formulation of triamcinolone being manufactured by Allergan. This preparation will be preservative-free, so it is expected to be more “ocular friendly.”

Being left at the crossroad of having to weigh the benefit of a treatment for macular edema with the unique potential for improving visual acuity against its known short-term risks and unknown long-term safety profile, the only option left for the eye care community is to further evaluate intravitreal triamcinolone in a prospective, multicenter, randomized, controlled clinical trial such as the SCORE study.

In addition to helping us sort out whether the long-term efficacy outcomes associated with intravitreal triamcinolone are superior to our current standard of care, these trials will help us determine if maintenance treatment is something we want to continue. From anecdotal experience, we know that macular edema recurs within 4 to 8 months after the steroid injections, so we anticipate that multiple treatments will be needed. With re-injections, however, we expect there will also be an increasing rate of complications.

Optometry’s help is needed

As a result of the large sample size of the SCORE study (1,200 patients), the NEI has funded the study to enroll patients from many clinical sites. However, the ophthalmology community cannot do it alone, and we need the help of the optometric community to identify eligible patients and refer such patients to one of the 90 clinical centers across the United States that are certified to enroll patients in the SCORE study. It is hoped that with the full support of both ophthalmologists and optometrists the study will be fully recruited in an expeditious fashion.

Optometrists can help by informing and educating patients about the study. It is a public health problem, and optometrists can get involved by helping to spearhead the process of patient education. Optometrists are often the first to see patients with visual acuity loss due to retinal vein occlusion, and referrals to clinical centers certified to enroll patients in the SCORE study are important to help the study recruit in a timely fashion.

By completing patient recruitment and follow-up in the SCORE study, the eye care profession may have a new weapon in the armamentarium against the devastating vision loss experienced by many patients with CRVO and BRVO. The primary inclusion and exclusion criteria are listed in the table above. For additional information concerning the SCORE Study or to locate a SCORE Study site near you, please e-mail score@emmes.com.

For Your Information:

Michael S. Ip, MD, is associate professor at the University of Wisconsin. He can be reached at the Fundus Photograph Reading Center, Park West One, 406 Science Drive, Ste. 400, Madison, WI 53711-1068; (608) 263-2853; fax: (608) 262-1899; e-mail: msip@wisc.edu. Dr. Ip has no direct financial interest in the products mentioned in this article, nor is he a paid consultant for any companies mentioned.