Ganglion Cell-Inner Plexiform Layer and Peripapillary Retinal Nerve Fiber Layer Thicknesses in Age-Related Macular...

To investigate changes of inner retinal layers and optic nerve head (ONH) in patients with dry age-related macular degeneration (AMD) and demonstrate the pattern of these changes.

A total of 76 eyes classified as having dry AMD and 76 control eyes were included. Ophthalmologic evaluations included best-corrected visual acuity (BCVA) assessment, spectral-domain optical coherence tomography (SD-OCT), and Humphrey visual field (VF) test. The drusen area and volume were determined using the automated algorithm of the SD-OCT software. Macular ganglion cell-inner plexiform layer (mGCIPL) and peripapillary retinal nerve fiber layer (pRNFL) thicknesses and ONH parameters, as well as VF parameters, were compared between groups.

Macular GCIPL thickness was significantly lower in eyes with AMD than in controls (73.83 ± 7.13 vs. 82.00 ± 4.85 μm; P < 0.001), and mGCIPL thinning was observed in a ring-shaped pattern around the fovea. The pRNFL thickness was also significantly lower in eyes with AMD than in controls (88.69 ± 6.93 vs. 93.96 ± 8.33 μm; P < 0.001), but no significant difference in ONH parameters was found. An inverse correlation between drusen area and average mGCIPL thickness was found (r = -0.3253; P = 0.0064). Best-corrected visual acuity and VF parameters were worse in AMD eyes than in controls. The pattern of VF defects was mostly consistent with foveal or parafoveal scotoma.

In eyes with dry AMD, mGCIPL and pRNFL thicknesses were lower than measurements in control eyes, and the average mGCIPL thickness was negatively correlated with the drusen area. However, the pattern of these changes differed from glaucomatous abnormalities.