Automatic assessment of time-resolved OCT images for selective retina therapy

Abstract

Purpose In recent years, selective retina laser treatment (SRT), a sub-threshold therapy method, avoids widespread damage to all retinal layers by targeting only a few. While these methods facilitate faster healing, their lack of visual feedback during treatment represents a considerable shortcoming as induced lesions remain invisible with conventional imaging and make clinical use challenging. To overcome this, we present a new strategy to provide location-specific and contact-free automatic feedback of SRT laser applications.Methods We leverage time-resolved optical coherence tomography (OCT) to provide informative feedback to clinicians on outcomes of location-specific treatment. By coupling an OCT system to SRT treatment laser, we visualize structural changes in the retinal layers as they occur via time-resolved depth images. We then propose a novel strategy for automatic assessment of such time-resolved OCT images. To achieve this, we introduce novel image features for this task that when combined with standard machine learning classifiers yield excellent treatment outcome classification capabilities.Results Our approach was evaluated on both ex vivo porcine eyes and human patients in a clinical setting, yielding performances above 95 % accuracy for predicting patient treatment outcomes. In addition, we show that accurate outcomes for human patients can be estimated even when our method is trained using only ex vivo porcine data.Conclusion The proposed technique presents a much needed strategy toward noninvasive, safe, reliable, and repeatable SRT applications. These results are encouraging for the broader use of new treatment options for neovascularization-based retinal pathologies.

Selective retina therapy: toward an optically controlled automatic dosing

“…There are different optical [21][22][23][24] and acoustical 25 techniques to detect microbubbles as indicators of RPE cell damage. One approach is based on the evaluation of pressure waves emitted during the formation and dynamics of microbubbles.…”

“…Another experimental approach is based on an evaluation of bubble-related tissue displacement through optical coherence tomography. 23,24 A further experimental optical approach makes use of the evaluation of the backscattered light of a scanned laser beam. In this case, an increase in backscattered treatment light, induced by additional Mie-scatterers (microbubbles), is detected.…”

Selective retina therapy monitoring by speckle variance optical coherence tomography for dosimetry control

“…Optical coherence tomography (OCT), which can provide depth-resolved imaging, was also applied for the SRT monitoring. [15][16][17][18][19] The treatments are considered successful when OCT signal variations, i.e., intensity decrease, are detected, and the results show good agreement with the evaluation of lesions by FFA.…”

Selective Retina Therapy

“…As assumed, features found within the first 100 ms after exposure deliver the highest yield, while later portions of the signal between 100 and 300 ms after the exposure pulse continuously lose their relation to the distortion. Such automated analysis boosts prediction to success rates from initial ~60% beyond 90% when targeting for 95% specificity [93].…”