Assessing the Effect of Central Subfield Thickness and Volatility on Visual Acuity in nAMD Clinical Trials
In Fort Lauderdale, Florida, Justis P. Ehlers, MD, presented a lecture titled “The Impact of Compartmental Exudative Volatility on Visual Acuity and Ellipsoid Zone Integrity in Neovascular AMD”.
I am therefore pleased to share today some of the results of our research. As many of you know, a lot of work has recently been done on the impact of central subfield thickness, volatility, and overall impact on visual acuity in clinical trials on the Wet AMD.
One of the big questions that remains is: what drives this volatility in retinal thickness changes, and do these changes actually lead to significant anatomical sequelae that we can understand and strive to minimizing as clinicians?
For this study what we did is we looked at the phase 3 Hawk clinical trial, we are able to use machine learning, augmented multi-layer segmentation, as well as feature extraction to extract specific fluid compartments, including intraretinal fluid and subretinal fluid, as well as subretinal material.
With this, we are able to look at volatility from week 12, after the loading phase, until the end of the first year, and assess the impact of high volatility in each of these compartments on visual acuity results and anatomical sequelae.
What we found was that each of these compartments intraretinal fluid, subretinal fluid, as well as subretinal material all had a negative impact on visual acuity if they were in the high volatility group , while the eyes of the low volatility group continued to improve vision. overtime. When we looked at anatomical sequelae, we found that the subretinal fluid compartment was the primary driver of negative anatomical findings, specifically increased subretinal fibrosis and subretinal material, as well as a poor maintenance of the integrity of the ellipsoid zone.
Interestingly, this goes a bit against what we know in terms of subretinal fluid. We’ve seen in the past that this may be linked to better overall visual acuity at specific times, but what it shows is that the potentially overall activity and volatility of this compartment is an important discriminator between eyes who can tolerate subretinal fluid well, this static, versus really minimizing this subretinal fluid which can be volatile and dynamic. So overall there is still work to be done in this area. This is truly an exciting opportunity given the new advanced image analysis techniques available to us, and we are excited to share it here at Retina World Congress.