Intracameral injection of triamcinolone is very useful for "staining" vitreous that has prolapsed into the anterior segment to enable vitrectomy. Safety is favorable, but there are some issues to consider.
Atlanta-Intracameral injection of triamcinolone is a safe, highly effective, and very useful technique for aiding visualization of prolapsed vitreous within the anterior segment, said Michael E. Snyder, MD, at the annual meeting of the American Academy of Ophthalmology. During the "Spotlight on Cataract Surgery Symposium," which focused on management of complications, Dr. Snyder, Cincinnati Eye Institute, provided a historical perspective on intraocular triamcinolone use; discussed the practical issues of why, what, and how; and reviewed possible safety concerns.
Intraocular injection of triamcinolone acetonide for a therapeutic indication first was described almost 30 years ago. In 2000, Gholam Peyman, MD, reported on the use of triamcinolone as an aid for training vitreoretinal surgery fellows in posterior vitrectomy, and the technique was first adopted for use in anterior vitrectomy by Dr. Snyder's colleague at the Cincinnati Eye Institute, Scott E. Burk, MD, PhD.
The indications for intracameral triamcinolone are either to enhance visualization of vitreous that is known to be present in the anterior segment or to assess if vitreous has surreptitiously prolapsed into the anterior segment during complicated surgery.
Until recently, intraocular use of triamcinolone was all off-label and performed using either a commercially available preparation (Kenalog, Bristol Myers Squibb) or one that was prepared by a compounding pharmacy.
In December 2007, the FDA approved the first ophthalmic preparation of triamcinolone acetonide (Triesence, Alcon Laboratories), eliminating issues associated with off-label product use.
"The approved ophthalmic preparation of triamcinolone is a preservative-free suspension," Dr. Snyder said. "It has been rigorously studied, and we know the vehicle is safe. The potential for vehicle-related toxicity using other formulations is an open question."
Another advantage of the ophthalmic product is that it can be injected safely and directly without any additional preparation. In contrast, it has been recommended that the commercially available non-ophthalmic preparation be "washed" to remove the benzyl alcohol preservative.
The technique involves trapping the triamcinolone particles in a filter, rinsing with balanced salt solution (BSS), and then resuspending the washed particles in BSS for instillation. Dr. Snyder recommended diluting the ophthalmic product 1:10 with BSS rather than using it full strength, however.
He presented a video to demonstrate that use of the diluted preparation provides much better visualization because there is less excess triamcinolone.
"After the full-strength material is injected and irrigation is begun, the anterior segment looks like a snowstorm because of the swirling particles of free triamcinolone," he said. "We don't get these kinds of snowstorms in Cincinnati. Instead, we tend to get light snowfalls that appear similar to the anterior segment when using diluted triamcinolone."
Aside from the vehicle-related toxicity concerns using off-label triamcinolone, other risks of the procedure include steroid-responsive glaucoma and pseudoendophthalmitis, he said.
"Elevation in IOP can occur with any use of steroids and should be watched for," Dr. Snyder said. "In fact, it can be fairly common in this setting considering that the eyes where triamcinolone is being used are often [undergoing] complex procedures and may particularly involve trauma cases that are already at greater risk for elevated IOP.
"Cataract is also always a risk with steroids, but [it is] not relevant in this setting since the cataract either has been removed already or will be removed in the same anterior segment surgical procedure," he added.
Recognizing pseudoendophthalmitis (triamcinolone in the vitreous cavity) and differentiating it from infection is a potential challenge that surgeons interested in using intracameral triamcinolone should address by spending some time with a vitreoretinal colleague.
Cataract surgeons should find out when procedures using intravitreal triamcinolone are scheduled, Dr. Snyder suggested, so that they can observe and familiarize themselves with the appearance of the material in the vitreous by looking into the eye with an indirect ophthalmoscope at the end of the case.