4 treatment strategies for managing retinal vein occlusions

Philadelphia-Although much progress has been made in treating retinal vein occlusions, much still needs to be done.

Julia Haller, MD, described the four-step, evidence-based approach that she uses to treat these patients:

Step 1: History and medical evaluation

This step includes assessing the patients for hypertension, diabetes, and glaucoma, plus completing a medical workup.

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“I tell patients that there is good evidence that a complete history and a medical evaluation are going to be important,” said Dr. Haller, an ophthalmologist-in-chief and The William Tasman, MD, Endowed Chair in Ophthalmology, Wills Eye Hospital, and professor and chair of ophthalmology, Jefferson Medical College, Thomas Jefferson University, Philadelphia.

“Diagnosing and treating risk factors for vein occlusion can be very important for a patient’s health,” she explained.

Step 2: Ocular evaluation

Good evidence shows that a complete ocular evaluation can impact the treatment decisions in terms of detecting macular edema, evaluating retinal nonperfusion, and possibly modifying treatment in patients with risk factors for development of cataract or glaucoma after steroid treatment, she noted.

Step 3: Formulation of a treatment plan

The first decision the ophthalmologist must make is determining whether to treat or observe the patient based on clinical trial evidence.

“We know that many trials [randomly assign] patients to early treatment, such as in the dexamethasone study [Ozurdex, Allergan] compared with following the patients for 6 months and delaying treatment,” she explained. “We know that in the patients [randomly assigned] to delayed treatment, the vision never caught up with the vision in the patients who were treated early.”

Duration of the macular edema and regression analysis showed that for every 2-month increase in the presence of macular edema at baseline, the odds of a 15-letter gain at day 98 decreased by 12% and further decreased by 17% at day 180, she noted.

In the ranibizumab (Lucentis, Genentech) for branch and central retinal vein occlusion (BRVO and CRVO), trials, the patients randomly assigned to delayed treatment also had vision that never caught up to the patients who were randomly assigned to early treatment.

Likewise, in patients with BRVO and CRVO in the aflibercept (Eylea, Regeneron) studies, those receiving delayed treatment at 6 months never caught up to those treated early.

“If we are going to treat, we recommend treating early,” Dr. Haller said.

In patients with BRVO, there is also a question about administering laser or intravitreal drug injections. The evidence-based data for making this decision is drawn partly from the Ranibizumab for Branch Vein Occlusion Study in which patients could receive laser treatment after a 3-month delay. The study determined that the vision in eyes treated later with laser never caught up with those treated with the intravitreal ranibizumab injections.

Likewise, in the aflibercept study, patients who received intravitreal aflibercept injections immediately were compared with those who received early grid laser applications. In the eyes treated with laser, the vision never caught up with those treated with the eyes that received intravitreal injections.

Once early drug therapy is chosen, the next decision concerns the specific drug choice.

“Our decision boils down to an anti-vascular endothelial growth factor (VEGF) drug or a steroid,” she said.

The choice is a risk-benefit analysis because there is no head-to-head, level-one analysis on which to base the choice of drug, Dr. Haller explained.

The Diabetic Retinopathy Clinical Research Network evaluated the use of laser with triamcinolone compared with laser with ranibizumab in patients with diabetic macular edema, she explained. At 2 years, the patients without cataract did well with either treatment. However, this evidence is unavailable for patients with vein occlusions, she observed.

Steroids are not used as an initial therapy. However, they can be considered in patients with a severe occlusion or used as a second agent or later on in treatment-especially in cases with an IOL and no evidence of a steroid response.

“Usually, and almost always in phakic eyes and in those in which the IOP is a consideration, treatment begins with administration of an anti-VEGF drug,” she said. However, the choice of the specific anti-VEGF drug is not supported by comparative evidence from a head-to-head trial for vein occlusion.

“The evidence we tell patients is that the best efficacy and risks are probably comparable and the patients may make the decision based on other factors such as FDA-approval status; the drug source, that is, their feelings about compounding pharmacies; finances, and the convenience and duration of the treatment,” Dr. Haller explained.

Step 4: Prognosis and expectations

Dr. Haller explains to patients that their vision is likely to improve.

“There is good evidence to support this,” she said.

She also explains that vein occlusions are chronic conditions and patients should be prepared for lengthy treatments.

“For the other prognostic and expectations factors, evidence-based data are lacking,” Dr. Haller said. “Patients are told that they will likely receive monthly treatments at least initially. However, there is no way to know how long that will continue.”

Evidence also has shown that there is a decreased need for monthly injections after 4 to 6 months of monthly injections.

“In the aflibercept trial, after 6 months, there was a decrease in the number of injections to 2.5 to three injections,” Dr. Haller said.

Patients are also informed that vision can continue to improve even in eyes with nonperfusion as seen in the Copernicus and Galileo studies.

“However, patients may need to be patient,” she explained. “There is still hope even weeks after treatment that there will be additional gains of three or more lines of vision. Physicians should also explain that in cases in which there is an initial response to a drug that wears off or patients are refractory to treatment that switching to another drug can often achieve drying of the macular edema and improved vision.”

Concerning her four-step approach to treatment, Dr. Haller summarized, “There is good evidence. However, a great deal of work still needs to be done.”