Abstract
Purpose :
Glaucoma has been associated with retinal ganglion cell (RGC) damage and their dysfunction, as well as with thinning of the inner retinal thickness layers; but to the best of our knowledge, no such data is available regarding the involvement of the photoreceptor thickness layer, especially in glaucoma suscepts (GS). The aim is to evaluate the relationships between steady state pattern electroretinogram (ssPERG) with inner and outer retinal layer thicknesses in GS.
Methods :
Forty eyes from twenty glaucoma suspects were enrolled in this cross-sectional study conducted at Manhattan Eye Ear Throat Hospital. Subjects underwent comprehensive eye examination, as well as Humphrey visual fields, SD-OCT thickness measurements, and ssPERG testing. Spearman, Pearson, and partial correlation analyses were used.
Results :
Spearman’s rho analysis showed PERG parameters were significantly correlated with almost all the sectorial retinal thickness measurements (rs > 0.352, p < 0.03). As expected, Pearson correlation analysis revealed significant associations between all PERG parameters and the ganglion cell layer (GCL) (r > 0.352, p < 0.041) and inner plexiform layer (IPL) (r > 0.356, p < 0.039) thicknesses independently. Additionally, partial correlation showed that Magnitude (Mag) and MagnitudeD (MagD) PERG parameters were significantly and negatively correlated with foveolar outer nuclear layer (ONL) (r = -0.572, p = 0.004). No other associations between PERG parameters and parafoveal ONL and outer plexiform layer (OPL) were found.
Conclusions :
In GS, retinal ganglion cell (RGC) dysfunction, assessed by means of PERG testing, was associated with not only thinning of the ganglion cell layer and inner plexiform layers independently, but also with simultaneous swelling of the foveolar outer nuclear layer demonstrating a possible combined and simultaneous glaucomatous morphological change to the photoreceptors (cone swelling, infiltration of glial cells, and increased extracellular matrix deposition) as well as to the RGCs (reductions in the size of cells, axons, and dendritic tree, apoptosis). More studies are needed to investigate the electrophysiology of the retinal neuronal pathway in glaucoma as well as to determine the possible breakdown of the neurovascular coupling in GS.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.