March 2008

 

CATARACT/ IOL

 

Triamcinolone ... promise for cataract patients?


by Rich Daly EyeWorld Contributing Editor

   

Targeted delivery of corticosteroid sharply reduces incidence of post-op macular edema

Fluorescein angiogram of cystoid macular edema Source: Samual Masket, M.D.

This patient had severe macular edema, which cleared in 2 weeks, after subtenon injection of a corticosteroid Source: Daljit Singh, M.D.

A study of cataract surgery with intra-op intravitreal triamcinolone (IVTA) in eyes with a history of posterior uveitis found it “useful” in providing targeted delivery of corticosteroids without the risks of systemic corticosteroid prophylaxis.

The surgical approach aimed to avoid post-op exacerbation of inflammation and macular edema from cataract surgery in uveitic patients, who often develop cataracts. Although pre-op control of inflammation in such patients has shown promise, systemic corticosteroid prophylaxis is associated with significant collateral morbidity in patients with common systemic conditions such as diabetes and hypertension. The study authors sought to achieve the benefits of inflammation control through IVTA without the adverse effects of systemic therapy.

“This is an excellent idea since the intraocular cavity is accessed during the cataract procedure, so it affords a reasonable opportunity to give the steroid via the most potent route,” said John D. Sheppard, M.D., professor of ophthalmology, microbiology and immunology, and clinical director, Thomas Lee Center for Ocular Pharmacology, Eastern Virginia Medical School, Norfolk.

The study authors found their approach “markedly reduced” the incidence of post-op macular edema, and achieved post-op visual acuities in eyes with posterior uveitis similar to those in eyes without uveitis. The study was published in the July 2007 issue of Journal of Cataract and Refractive Surgery and titled “Intraoperative use of intravitreal triamcinolone in uveitic eyes having cataract surgery: pilot study.”

The results of the 19-eye study included median visual acuity of 20/40 one day after surgery, and 89% of study eyes maintained visual acuity of at least 20/40 in the two-year mean follow-up period. No patient lost acuity and no eye developed macular edema within four months of surgery. One patient developed severe intraocular inflammation after surgery, which was resolved within one week through intensive topical corticosteroid therapy.

“The major limiting factor to success after cataract surgery in uveitics is probably macular edema,” said Keith Barton, M.D., consultant ophthalmologist and glaucoma service director, Moorfields Eye Hospital, London. “The finding of a good visual result in these patients is highly significant.”

Dr. Barton performs cataract surgery on up to four patients every month with uveitis, most of whom have glaucoma. The standard approach for many British surgeons is to use systemic corticosteroid prophylaxis in these patients, but some of them will develop systemic hypertension or glucose intolerance.

Traditionally, the way to avoid post-op inflammation and cystoid macular edema in uveitic patients is a course of systemic corticosteroids, he said. An alternative approach, the use of periocular depo steroids such as Medrol (methylprednisolone, Pfizer, New York), was “helpful” but less effective. However, intravitreal triamcinolone “appears to be highly effective, avoids the systemic problems associated with corticosteroids, and offers the simplicity of one injection at the time of the cataract procedure,” Dr. Barton said.

C. Steven Foster, M.D., clinical professor of ophthalmology, Harvard Medical School, described the study authors’ approach as “reasonable” but pointed out that this approach is not without risks, including retinal detachment, glaucoma, and endophthalmitis. “If one recognizes that and is willing to accept the possibility of those as complications, then it is a perfectly reasonable approach,” Dr. Barton said.

Alternative approaches

Other treatment options in these patients include the use of intravitreal steroids and intravitreal anti-VEGF agents, said James P. Gills, M.D., professor of ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore. They are effective in suppressing and inhibiting inflammation, as well as exciting the VEGF cascade.

“This approach can be combined in many ways and used to treat the complicated cataract patient and patients with diabetes,” he said.

A combination of Kenalog (triamcinolone, Bristol-Myers Squibb, New York) without preservative plus Avastin (bevacizumab, Genentech, San Francisco) in the vitreous cavity of uveitic patients with macular edema has allowed Dr. Foster to get the uveitis under control and reduce the macular edema. This approach has proven especially useful when these patients undergo cataract surgery, which puts the patient at risk for recurrence of the macular edema, he said.

Intravitreal triamcinolone acetate, a long-held tool of retina surgeons, is probably underused by general ophthalmology, according to Dr. Gills. However, he cautioned surgeons to be aware of the differences of formulized triamcinolone acetate from preserved triamcinolone acetate.

Dr. Gills has developed a collagen insert, tested in animals, to deliver non-steroidal drugs, antibiotics and steroids in varying doses as another way to eliminate problems associated with the delivery through drops.

Several commercially available or soon-to-be-released long-term release steroid implants that provide similar results, Dr. Sheppard noted, include the Retisert (fluocinolone acetonide intravitreal implant, Bausch & Lomb, Rochester, N.Y.) and Posurdex (dexamethasone, Allergan, Irvine, Calif.). An advantage of the IVTA approach over implants is its lower cost.

IOP control findings

The study authors also found that only three eyes had raised intraocular pressure in the first post-op week after uneventful surgery. They were treated with topical antihypertensive therapy, and had normal IOPs within three months after surgery.

Dr. Foster described the IOP findings as “significant,” although puzzling, because this runs counter to another recent study in the October issue of Ophthalmology, which found IOP elevation and posterior subcapsular cataract progression occurred with greater frequency in uveitis patients receiving IVTA. “I’m not sure what to make of this,” he said.

Editors’ note: Drs. Sheppard, Foster, Barton, Dr. Gills have no financial interests related to this research.

Contact information

Barton: keith1barton@aol.com
Foster: 617-577-1370, sevans@mersi.us
Gills: 727-938-2020, jgills@stlukeseye.com
Sheppard: 757-622-2203, docshep@hotmail.com

Triamcinolone ... promise for cataract patients? Triamcinolone ... promise for cataract patients?
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