Metabolic monitoring of transcorneal electrical stimulation in retinitis pigmentosa

Optical coherence tomography angiography findings in patients undergoing transcorneal electrical stimulation for treating retinitis pigmentosa

“…These structural changes seem to be not as dynamic as the retinal vessel oxygen metabolism [3]. Furthermore, our findings are compatible with preliminary data showing that TES does not have a significant effect on the diameter of large peripapillary vessels [3]. Our study confirms that also the microvascular changes in the different retinal layers seem to follow the same mechanism and thus remain unaffected despite ongoing TES treatment.…”

“…With few exceptions such as gene therapy for RPE65associated retinal dystrophy, TES is currently the only evidence-based and clinically available method to slow down disease progression in RP [1,2]. A recent study suggested retinal vessel oximetry to possibly serve as a sensitive monitoring method for TES therapy [3]. However, since these devices are preserved to specialised ophthalmology centres, we aimed to investigate whether OCTA might also show changes that are attributed to TES treatment.…”

“…The grey points indicate outliers Table 4 Results of peripapillary microvasculature analysis such as the capillary perfusion density (CPD) and the capillary flux index (CFI) of the peripapillary nerve fibre layer microvasculature in eyes of patients suffering from retinitis pigmentosa undergoing TES treatment as mean ± standard deviation (SD) for all subsections of the grid shown in Fig 2 and proximal intraretinal pigment migration followed by inner retinal atrophy, neuronal or glial migration, and neurovascular remodelling [32]. These structural changes seem to be not as dynamic as the retinal vessel oxygen metabolism [3]. Furthermore, our findings are compatible with preliminary data showing that TES does not have a significant effect on the diameter of large peripapillary vessels [3].…”

“…The pathophysiological mechanisms are not fully understood. However, it is likely that the stimulation induces the release of neurotrophic factors that improve the remaining retinal cells' survival [2][3][4][5][6][7][8][9]. A more detailed explanation is given in the TES pivotal trial and in the TES study presenting 1-year results [1,2].…”

“…In order to evaluate the therapeutic TES response in RP patients in a short-lasting, non-invasive, contact-free, and patient-friendly way, a recent study has shown that retinal vessel oximetry (RO) might be superior over full-field electroretinography (ffERG) or visual field (VF) as outcome measurement [1][2][3]. However, since RO devices so far are mainly used in a scientific context and thus are mostly preserved to specialised ophthalmology centres, further monitoring methods that are short-lasting, non-invasive, contact-free, and patient-friendly and have a better availability in daily clinical practice are needed.…”