Research Digest

Investigating New Uses for Bevacizumab

Researchers at the Medical University of Vienna evaluating bevacizumab (Avastin, Genentech) for treatment of persistent macular edema secondary to branch retinal vein occlusion (BRVO) or central retinal vein occlusion (CRVO) found that while it was safe and effective, its benefits were short term and recurrence rates were high.¹

Twenty-nine eyes were included in the 12-month prospective clinical trial, with 21 cases showing macular edema secondary to BRVO and 8 macular edema secondary to CRVO. Eyes received three initial intravitreal bevacizumab injections of 1 mg at a monthly interval, with monthly follow-up visits. Retreatment was based on central retinal thickness (CRT) as determined by optical coherence tomography. If continuous injections were indicated up to month 6, the dose was increased to 2.5 mg.

Patients were required to have a baseline CRT of at least 250 μm and no neovascularization. Complete evaluations of all eyes were performed at baseline, day 1, day 7, month 1, and at monthly intervals during follow up.

Examinations included best-corrected visual acuity testing using ETDRS charts at 2 m, slit lamp and fundus examination including tonometry, standardized optical coherence tomography imaging and color fundus photography. In addition, fluorescein angiography was performed at baseline and at 3-month intervals to identify the presence of BRVO/CRVO, active extravasation and the extent of retinal non-perfusion.

Baseline mean ETDRS visual acuity was 50 letters (range: three letters to 78); baseline mean 1 mm CRT was 558 (range 353-928) μm, as measured by OCT. At the 6 months follow up evaluation, the mean BCVA had increased to 65 letters, and mean central retinal thickness had decreased to 382 μm. After 12 months, patients in the CRVO group showed an increase in BCVA of 7 letters, a change the researchers called not statistically significant.

In the BRVO group, mean best-corrected acuity increased by 18 letters. CRT decreased significantly in both groups — by 268 μm in the CRVO group, and 214 μm in the BRVO group.

Additionally, no severe ocular or systemic adverse events were reported after 12 months of follow up. While these results were promising, the researchers point out that macular edema did not resolve completely in 86.2% of patients after three initial injections and that the retreatment rate was high, with a mean of eight out of 13 possible injections over the course of 1 year. OM

Reference

1. Prager F, Michels S, Kriechbaum K, et al. Intravitreal bevacizumab for macular edema secondary to retinal vein occlusion: 12-month results of a prospective clinical trial. Brit J Oph. 2009;93:452-456.

Anterior Lamellar Keratoplasty Outcomes at ASCRS

A review of 2 retrospective studies that compared surgical outcomes between anterior lamellar keratoplasty (ALK) and penetrating keratoplasty show ALK gaining ground as an alternative to PK, according to Tan.¹

A retrospective case study of optical keratoplasties comparing visual outcomes, complications and graft failure rates in 206 cases of manual predescemetic deep ALK (DALKm), big bubble descemetic DALK (DALKa) and PK showed statistically significant improvement in best-corrected visual outcomes in DALKa vs. DALKm or PK. Both DALK groups showed less major complications with regards to allograft rejection, postoperative glaucoma and cataract than did PK.

A retrospective comparative study of ALK and PK for severe, acute infectious keratitis in 126 eyes demonstrated that ALK was a viable alternative to PK for equivalent eradication of infection, improved clear graft survival and better visual outcomes. Though therapeutic success was not statistically significant between the two procedures, half of the cases of recurrence of infection in the PK eyes resulted in secondary endophthalmitis with poor outcomes, including evisceration. ALK eyes showed a mean improvement of 7.25 Snellen lines, with PK eyes showing improvement of 4.76 lines. One-year graft survival was 0% for ALK and 78% in PK eyes. OM

Reference

1. Tan DTH. Lamellar Surgery — Anterior Lamellar Keratoplasty: Outcomes. Presented at: The 2009 American Society of Cataract and Refractive Surgery Annual Meeting. San Francisco. April 3, 2209.