Identifying the Retinal Layers Linked to Human Contrast Sensitivity Via Deep Learning

Abstract

Purpose Luminance contrast is the fundamental building block of human spatial vision. Therefore contrast sensitivity, the reciprocal of contrast threshold required for target detection, has been a barometer of human visual function. Although retinal ganglion cells (RGCs) are known to be involved in contrast coding, it still remains unknown whether the retinal layers containing RGCs are linked to a person's contrast sensitivity (e.g., Pelli-Robson contrast sensitivity) and, if so, to what extent the retinal layers are related to behavioral contrast sensitivity. Thus the current study aims to identify the retinal layers and features critical for predicting a person's contrast sensitivity via deep learning. Methods Data were collected from 225 subjects including individuals with either glaucoma, age-related macular degeneration, or normal vision. A deep convolutional neural network trained to predict a person's Pelli-Robson contrast sensitivity from structural retinal images measured with optical coherence tomography was used. Then, activation maps that represent the critical features learned by the network for the output prediction were computed. Results The thickness of both ganglion cell and inner plexiform layers, reflecting RGC counts, were found to be significantly correlated with contrast sensitivity ( r = 0.26 ∼ 0.58 , Ps < 0.001 for different eccentricities). Importantly, the results showed that retinal layers containing RGCs were the critical features the network uses to predict a person's contrast sensitivity (an average R 2 = 0.36 ± 0.10). Conclusions The findings confirmed the structure and function relationship for contrast sensitivity while highlighting the role of RGC density for human contrast sensitivity.

Foveal crowding appears to be robust to normal aging and glaucoma unlike parafoveal and peripheral crowding

“…However, accumulating evidence has shown substantial structural damage (i.e. degeneration of ganglion cell bodies and their axonal and dendritic structures) and functional deficits in the central vision of patients with glaucoma ( Anctil & Anderson, 1984 ; Elze et al, 2015 ; Glen et al, 2012 ; Hood, 2017 ; Hood et al, 2012 ; Hood et al, 2013 ; Hood et al, 2014 ; Kwon et al, 2017 ; Medeiros et al, 2013 ; Ramulu et al, 2013 ; Roux-Sibilon et al, 2018 ; Shamsi, Liu, Owsley, et al, 2022 ; Stievenard et al, 2021 ; D. L. Wang et al, 2015 ; Min Wang et al, 2009 ; Mengyu Wang, Tichelaar, Pasquale, Shen, Boland, Wellik, De Moraes, Myers, Ramulu, Kwon, Saeedi, Wang, Baniasadi, Li, Bex, & Elze, 2020 ). More relevantly, increased parafoveal and peripheral crowding have been observed even in relatively mild and moderate glaucoma ( Ogata et al, 2019 ; Shamsi, Liu, & Kwon, 2022 ).…”

“…Despite the conventional view that the central vision remains intact until the end stages of glaucoma, recent neuroanatomic and behavioral evidence support the presence of glaucomatous damage in the central vision ( Anctil & Anderson, 1984 ; Chien, Liu, Girkin, & Kwon, 2017 ; Elze, Pasquale, Shen, Chen, Wiggs, & Bex, 2015 ; Glen, Crabb, Smith, Burton, & Garway-Heath, 2012 ; Hood, 2017 ; Hood, Raza, de Moraes, Johnson, Liebmann, & Ritch, 2012 ; Hood, Raza, de Moraes, Liebmann, & Ritch, 2013 ; Hood, Slobodnick, Raza, de Moraes, Teng, & Ritch, 2014 ; Kwon, Liu, Patel, & Girkin, 2017 ; Medeiros, Lisboa, Weinreb, Liebmann, Girkin, & Zangwill, 2013 ; Ramulu, Swenor, Jefferys, Friedman, & Rubin, 2013 ; Roux-Sibilon, Rutgé, Aptel, Attye, Guyader, Boucart, Chiquet, & Peyrin, 2018 ; Shamsi, Liu, Owsley, & Kwon, 2022 ; Stievenard, Rouland, Peyrin, Warniez, & Boucart, 2021 ; Wang, Raza, de Moraes, Chen, Alhadeff, Jarukatsetphorn, Ritch, & Hood, 2015 ; Wang, Hood, Cho, Ghadiali, De Moraes, Zhang, Ritch, & Liebmann, 2009 ). Specifically, a number of retinal imaging studies have shown significant thinning of the retinal nerve fiber layer (RNFL) and the retinal ganglion cell plus inner plexiform layer (RGC+) even in the macular region of glaucomatous eyes ( Hood et al, 2012 ; Hood et al, 2013 ; Hood et al, 2014 ; Shamsi, Liu, Owsley, et al, 2022 ; D. L. Wang et al, 2015 ). It has been reported that such macular damage occurs in up to 80% of patients with mild glaucoma ( Blumberg, Liebmann, Hirji, & Hood, 2019 ; Hood et al, 2014 ).…”

Contrast Sensitivity Deficits and Its Structural Correlates in Fuchs Uveitis Syndrome

“…Wai et al showed that eyes with macular disease and good VA have significantly reduced CSF compared with healthy control eyes ( 45 ), and they thought CSF may be able to explain some subjective visual complaints and patients' bad visual experiences while visual acuity may not. Shamsi et al have even put forward the idea that the visual acuity and contrast sensitivity in the foveal region were dissociative ( 46 ). Our study has demonstrated the above-mentioned ideas.…”

“…Wang found that the retinal inner layer is associated with reduced contrast sensitivity in retinal vein occlusion ( 47 ). Shamsi et al found that 36% of the variance in the contrast sensitivity could be explained by the retinal structure in patients with glaucoma, age-related macular degeneration, and normal people ( 46 ). In our study, we identified structural changes in the fundus of the eyes of patients with FUS via VD, but no significant correlation was observed between VDs and contrast sensitivity.…”

“…There is also another possibility that the retinal region of VDs that leads to visual impairment in FUS does not match the 3 mm × 3 mm macular region that was focused on in our study. It was reported that the thickness of the ganglion cell layer plus the inner plexiform layer within the retinal region between 1 and 2 mm eccentricities was highly correlated with contrast sensitivity ( 46 ). Therefore, in our future research, we can explore the correlation between different regions and layers of the retina and contrast sensitivity.…”