Intravitreal steriod implant helps control posterior uveitis

April 1, 2005

Baltimore—Fluocinolone acetonide intravitreal implant (Retisert, Bausch & Lomb) is an effective treatment for non-infectious posterior uveitis, but may have potential side effects, according to the interim results of a multicenter trial that Quan Dong Nguyen, MD, MSc, described during the Current Concepts in Ophthalmology meeting.

Baltimore-Fluocinolone acetonide intravitreal implant (Retisert, Bausch & Lomb) is an effective treatment for non-infectious posterior uveitis, but may have potential side effects, according to the interim results of a multicenter trial that Quan Dong Nguyen, MD, MSc, described during the Current Concepts in Ophthalmology meeting.

At 52 weeks of follow-up, the eyes with implants experienced significantly fewer recurrences in comparison with the fellow eyes, 4.3% versus 56.3%; the use of adjunctive therapies in the eyes with implants also decreased significantly. However, the steroid intravitreal implant was associated with cataract development and IOP elevation, Dr. Nguyen reported at the meeting, which was sponsored by the Johns Hopkins University School of Medicine, Baltimore, and Ophthalmology Times.

Fluocinolone acetonide has several advantages for formulation into an intravitreal implant. Due to its low solubility and high potency, it can be compacted into an extremely tiny device-the steroid implant is much smaller than the ganciclovir intravitreal implant (Vitrasert, Bausch & Lomb). In addition, fluocinolone acetonide is rapidly metabolized so that the risk of systemic exposure is reduced.

The fluocinolone acetonide intravitreal implant is designed to deliver its total dose over a period of at least 1,000 days. For the 2.0-mg implant, that translates into release of a daily dose of 1.8 to 2 µg; the release rate for the 0.5-mg implant is 0.4 to 0.5 µg per day.

The study is currently being conducted at 26 domestic centers and one site in Singapore. The enrolled patients had a mean age of 43.5 years and about three-fourths were female. Among those with bilateral diseases, the worse eye became the study eye.

Reducing steroid dependence At enrollment, 58.8% of patients were receiving systemic therapy for posterior uveitis, whereas at 52 weeks, that proportion had decreased significantly to only 11.9%.

"Systemic steroids can cause significant complications; therefore, clinicians who treat uveitis often attempt to use steroid-sparing agents (immunomodulators) to reduce the required dose of steroid to minimize its side effects," Dr. Nguyen said. Use of periocular steroid injections and topical steroid therapy also decreased significantly in the eyes with implants. During the 52 weeks prior to baseline, 70.9% of study eyes had received periocular injections compared with only 4.3% during the 52 weeks postimplantation. Topical steroid therapy was being administered in 29.1% of eyes with implants at baseline and only in 4.7% at 52 weeks. In the control eyes, the proportion of eyes needing a periocular injection increased significantly when comparing the period 52 weeks prior to study entry versus the 52 weeks thereafter, 29.5% versus 36.7%. The percentage of eyes receiving topical steroid therapy remained unchanged at 17.6%.