Abstract
Purpose :
Anti-vascular endothelial growth factor (VEGF) is the first line of treatment for diabetic macula edema (DME). Previous retinal function studies using full-field or multifocal electroretinography have investigated late effects of anti-VEGF treatment on retina. The aim of this study is to follow full-field electroretinography (ffERG) changes for the first 6 months of anti-VEGF treatment using portable ffERG system.
Methods :
In this prospective pilot study, eyes with diabetic macula edema and either severe NPDR or PDR have been included. Inclusion criteria were treatment naïve patients with no prior ocular surgery willing to participate in study. All patients received 3 injections in the initial loading phase with 3 months follow up and injection if needed. The retinal function has been assessed at baseline and months 1, 2, and at the last follow up - 6 months after the first injection with the full Field Flash ERG (RETeval® ERG). We measured 16Td and 32Td flash stimulus for both a- and b-wave amplitudes and implicit times. Other collected data included best-corrected visual acuity (BCVA) and spectral-domain optical coherence tomography (OCT) at every visit.
Results :
Eleven eyes of 7 patients with a mean age of 54 years (range 42-67) have been included in the analysis. Patients have received on average 4 injections in the study period. The mean BCVA improved significantly from 0.41±0.34 to 0.27±0.29 logMar (p=0.014). The central retinal thickness improved from 415±151microns to 333±105 microns, which was not statistically significant (p=0.1). The implicit time at 32Td flash intensity significantly prolonged from 32.08±3.68ms to 33.48±3.05ms (p=0.04)(Figure 1). There was a moderate correlation between the BCVA gain and the implicit time at baseline of r=0.63. The amplitudes remained unchanged and stable during the observation. In the majority of patients, the implicit time prolonged after the first injection and then slightly recovered or remained stable at the new level over the course of the following 5 months.
Conclusions :
The best corrected visual acuity improved significantly as a result of the anti-VEGF intravitreal treatment. The implicit time significantly prolonged after the first injection followed by stabilization with time. This might be a manifestation of an increased cell stress after the initiation of treatment to which the eye adapts over the course of the treatment.
This is a 2021 ARVO Annual Meeting abstract.