Is Avastin the new laser for diabetic macular edema?

19 11 2009

In the June 2009 issue of Ophthalmology Soheilian et al, out of Tehran, published an important paper comparing intravitreal bevacizumab (IVB) alone or in combination with triamcinolone (+IVTA) to macular photocoagulation for treatment of diabetic macular edema.  They randomized a total of 150 eyes with clinically significant macular edema (CSME) into three treatment groups, and followed them for up to 36 weeks (which is about 9 months).   If CSME persisted at 12 week (3 mo) intervals, the eye were retreated with the same intervention.  Their study showed that intravitreal bevacizumab yielded better visual acuity results at 36 weeks than did laser treatment.  Specifically, vision improved by > 2 Snellen lines of acuity in 37% of the IVB group, 25% of the IVB+IVTA group, and 15% of the laser group.  On the other hand, retreatment was required in 28%, 20% and 6% of the three groups respectively.  IVB improves vision more, but needs to be used more often.

One of the things that the study did not do, was differentiate the patients with CSME into those with cystic edema and those with non-cystic edema.  My hunch is that we would find that in the group with cystic edema, the difference between the effectiveness in bevacizumab and laser would be even greater.  Will bevacizumab become a replacement for laser in treating CSME?  It’s too soon to say.  My hope is that the Sohelian et al will continue to follow these patients and report on results as they reach the 1 year and 2 year marks.

In clinical practice, this paper seems to support what many of us are currently doing:  using bevacizumab as first line treatment for diabetic macular edema to decrease the edema and improve the vision, and following it up with laser treatment for long term control.  I’d like to see a study that looks at this situation.  I use the sequential approach with greatest success in patients with massive or cystic macular edema.

Here is the abstract:

Ophthalmology. 2009 Jun;116(6):1142-50. Epub 2009 Apr 19.

Randomized trial of intravitreal bevacizumab alone or combined with triamcinolone versus macular photocoagulation in diabetic macular edema.

Soheilian MRamezani AObudi ABijanzadeh BSalehipour MYaseri MAhmadieh HDehghan MHAzarmina MMoradian SPeyman GA.

Ophthalmology Department, Labbafinejad Medical Center, Shaheed Beheshti Medical University, Tehran, Iran.

PURPOSE: To compare the results of intravitreal bevacizumab (IVB) injection alone or in combination with intravitreal triamcinolone acetonide (IVT) versus macular laser photocoagulation (MPC) as a primary treatment of diabetic macular edema (DME). DESIGN: Randomized 3-arm clinical trial. PARTICIPANTS: A total of 150 eyes of 129 patients with clinically significant DME and no previous treatment.

METHODS: The eyes were randomly assigned to 1 of the 3 study arms: the IVB group, patients who received 1.25 mg IVB (50 eyes); the IVB/IVT group, patients who received 1.25 mg of IVB and 2 mg of IVT (50 eyes); and the MPC group, patients who underwent focal or modified grid laser (50 eyes). Retreatment was performed at 12-week intervals whenever indicated. MAIN OUTCOME MEASURES: Change in best-corrected visual acuity (VA) at week 24.

RESULTS: VA changes among the groups were statistically significant at 6 (P<0.001) and 24 (P = 0.012) weeks. The significant treatment effect was demonstrated in the IVB group at all follow-up visits and in the IVB/IVT group at 6 and 12 weeks. VA changes +/- standard deviation at 36 weeks were -0.28+/-0.25, -0.04+/-0.33, and +0.01+/-0.27 logarithm of minimum angle of resolution in the IVB, IVB/IVT, and MPC groups, respectively (P = 0.053). Significant central macular thickness (CMT) reduction was observed in all groups only up to 6 weeks; however, CMT changes were not significant among the groups in all visits. Overall, retreatment was required for 27 eyes up to 36 weeks (14 in the IVB group, 10 in the IVB/IVT group, and 3 in the MPC group). In the IVB group, in which a greater VA improvement was observed, only 1 injection was required in 72% of the cases. VA improvement >2 Snellen lines at 36 weeks was detected in 37%, 25%, and 14.8% of patients in the IVB, IVB/IVT, and MPC groups, respectively.

CONCLUSIONS: Intravitreal bevacizumab injection in patients with DME yielded a better visual outcome at 24 weeks compared with macular photocoagulation. A change in CMT beyond the 6-week time point that corresponded to the vision change was not detected. No adjunctive effect of IVT was demonstrated.




One response

13 10 2010

Reading these have given me a wider outlook on the topic. I hope there is more to come. Many thanks …

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