DME DEVELOPMENTS

Advanced imaging techniques allied to potent new anti-VEGF and steroid therapies have radically transformed the prognosis and management of patients with diabetic macular oedema and other debilitating retinal diseases over the past decade, according to Francesco Bandello MD, FEBO. “We are living in exciting times for retinal experts. We have new diagnostic tools and new therapeutic options where we are able to modify the management of many retinal diseases. The prognosis of diabetic retinopathy has really improved thanks to the progress made in recent years, which is good news for us as retinal specialists but more importantly for our patients who are suffering the effects of DME,” he told delegates attending the 13th EURETINA Congress in Hamburg.

In a broad overview of recent developments in the diagnosis and treatment of DME, Dr Bandello noted that the disease remains the leading cause of visual impairment in people with diabetes mellitus. “If untreated, more than 50 per cent of patients lose more than two lines of visual acuity in two years. DME affects the working-age population, thereby imposing a significant burden both on society and the individual,” he said.

While imaging modalities have improved greatly over the past decade, DME imaging must always be correlated to visual function, Dr Bandello said. “No examination alone can tell us everything about the prognosis and management of DME. While we have seen a major improvement in the quality of morphological information that we can obtain from our instruments, we still need more precise, functional information to be able to bridge the gap which exists sometimes between what the patient is experiencing and what we are seeing on our images,” he said.

Imaging modalities such as fluorescein angiography, spectral domain optical coherence tomography (OCT), retromode imaging, fundus autofluorescence, adaptive optics and microperimetry are now available to help clinicians in the diagnosis and management of DME, said Dr Bandello. While fluorescein angiography alone is not sufficient for DME diagnosis, it is nevertheless useful for providing a qualitative assessment of vascular leakage.

“It helps in identifying treatable vascular lesions and is essential for assessing the presence of the foveal avascular zone (FAZ) associated with poor prognosis. It also gives us valuable information on the capillary network or to understand why we may have a drop in visual acuity in cases where there is no obvious explanation based on fundus imaging,” he said. The real game-changer for DME management in clinical practice, however, has been undoubtedly the progress made in OCT, said Dr Bandello.

“Nothing else has been able to modify the day-to-day management of patients like OCT. The combination of potent intravitreal therapies and a non-invasive diagnostic tool that is reliable and gives good results in terms of the quantification of lesions has made a huge difference to our understanding and management of DME,” he said. With OCT now being used routinely in clinical practice, hard data is emerging to guide clinicians in their management of patients. “We now know that around 60 per cent of patients with foveal thickening and intraretinal optical reflectivity on OCT have focal leakage on fluorescein angiography. But more than 90 per cent of patients with diffuse cystoid leakage exhibit foveal thickening with decreased optical reflectivity on OCT,” he said. OCT is also helpful in quantifying changes over time and assessing the presence of intraretinal and subretinal fluid, added Dr Bandello.

“This is useful for charting the natural history of the disease, as well as response to treatment and retreatment evaluation. We tried unsuccessfully for a long time to do the same thing with fluorescein angiography for leakage, whereas OCT enables us to objectively evaluate different treatment effects. This explains why it is being so widely used now in clinical trials,” he said. With so many imaging options available to clinicians, Dr Bandello advised drawing on as many different modalities as possible in order to build up the most complete picture possible of the disease.

“I think it is important to consider all these diagnostic tools together in order to be able to classify our patients in a better way. I am always repeating that the old definition of clinically significant DME based on topography of lesions may not be the best way of classifying our patients. We should try to use the different options available to us in order to interpret each single clinical case and be able to attribute different treatment options based on that information,” he said. With a variety of treatment options now available for DME, Dr Bandello said that his group has created a treatment algorithm to help guide the treatment for each patient.

“For vasogenic DME we perform laser treatment and then only in cases where we have no response we use anti-VEGF drugs or steroids. In non-vasogenic oedema we start with anti-VEGF and steroids and use laser afterwards in cases where it is possible to obtain a thin retina after the injections. This means that you perform the laser treatment using less energy for better results. For tractional DME, we usually advocate surgery plus steroids or anti-VEGF injections,” he said.