Focus on retinal disease with Sebastian Woolf

Q: What are currently the major controversies regarding the treatment of retinal disease? There are currently two major controversies in the treatment of macular disease and both involve intravitreal anti-VEGF therapy. First is the question of whether it is better to treat AMD with ranibizumab, an approved drug, or bevacizumab, a less rigorously tested off-label drug which must be repackaged for intravitreal use. The CATT study showed that the two agents have a very similar efficacy but there is still some question about whether they are equally safe, and this is where much of the controversy lies. Bevacizumab is much cheaper than ranibizumab but it hasn't been tested like an approved drug and there may be safety issues which will only come out after larger studies. The CATT study showed some differences but it was not powered to show differences in safety so those may have been chance findings. We also do not know if bevacizumab will have the same efficacy as ranibizumab at two years, so we'll have to wait for the two-year results.

The other question regarding anti-VEGF therapy is in the treatment of diabetes. Do we still need to perform macular photocoagulation, which has been the standard of care for many years? There are some who feel that there is still a place for macular photocoagulation in focal macular oedema, and there are others who think that anti-VEGF therapy is the major breakthrough and that laser photocoagulation is no longer needed. If we look at the data, anti-VEGF therapy is yielding better visual outcomes than laser photocoagulation in all studies. But there are some specialists who maintain that the differences are not so big in their hands. Therefore, it may be that you have to be very experienced in macular photocoagulation to get the same results with the techniques as you do with anti-VEGF therapy.

Q: New diagnostic technologies have become available in recent years, how are these effecting your treatment decision?

We have had spectral domain OCT in our hands for three years. It's a relatively new diagnostic tool, and it has dramatically improved our abilities to diagnose and follow-up patients with macular oedema. It really enables us to detect small amounts of intra- or subretinal fluid which is very important for treatment decisions if we have active disease in AMD. That is how we know when to re-inject these patients. I think nowadays most people use OCT as their primary tool for follow-up of patients and for making decisions. Fluorescein angiography has become much less important and this holds true not only for AMD but also for diabetic macular oedema, central vein occlusion oedema and all vascular oedemas.

Q: Do you think retinal physicians need to take a closer look at safety issues in medical retina, as regards endophthalmitis, for example?

There is an issue if we use bevacizumab if we use repackaged injections and there has been a series of outbreaks of endophthalmitis following the use of bevacizumab repackaged at compounding pharmacies. This is a real issue for using bevacizumab; we need to have quality control and we need to have better standardisation of the aliquotation of the drug. Otherwise, with respect to endophthalmitis, the risk is very low. On the other hand if we think of safety for systemic disease like cardiovascular disease or stroke it probably would be good to have more detailed data.

Q: In the CATT study there were six cases of endophthalmitis among 1,200 patients during the first year of treatment, two of which occurred in patients receiving ranibizumab. Is an incidence of one in three hundred patients still fairly high?

I think this may be due to a difference in health systems. In Europe the incidence of endophthalmitis has been much lower in all studies than in the US, which may be connected to the fact that there are more strict rules in how to do the injections.

Q: Do you think ophthalmologists who are not retinal specialists should receive additional training before practising medical retina?

These injections put patients at risk and ophthalmologists need training in how to perform and monitor their effects. They at least must be able to do a thorough examination and be able to perform and read OCT and understand fluorescein angiography. I think these are the minimal requirements for general ophthalmologists going into the field of intravitreal injections.

Q: The 2012 EURETINA Meeting will be held in combination with the ESCRS meeting. What do you think are some of the areas in which the two specialties could benefit from closer cooperation and collaboration?

Nowadays quite a few patients undergo a combination of anterior and posterior segment surgery and some anterior segment surgeons are handling the anterior complications from surgery of the posterior pole. A closer exchange of ideas will help us to improve combined surgery and a close relationship between the two specialties is very important in the assessment of the patients receiving treatments like steroids for the posterior segment, which may cause problems like glaucoma and cataract.