Longitudinal changes in the ganglion cell-inner plexiform layer thickness of age-related macular degeneration.

Abstract

To determine longitudinal changes of the ganglion cell-inner plexiform layer (GC-IPL) thickness in patients with non-exudative age-related macular degeneration (AMD) without other ophthalmic disease. Thirty-three eyes of 33 patients with early and intermediate non-exudative AMD (non-exudative AMD group) and 33 normal control eyes were followed for 2years, and GC-IPL thickness was measured by spectral domain optical coherence tomography at 1-year intervals. The mean rate of GC-IPL reduction was estimated using a linear mixed model and compared between two groups. The mean age of patients in the non-exudative AMD group and control groups were 68.82±6.81years and 67.73±5.87years, respectively (p=0.488). The mean GC-IPL thickness at the first visit was 76.61±16.33μm in the non-exudative AMD and 81.76±3.69μm in control group (p=0.387), and these values significantly decreased over time, with an average reduction rate of average GC-IPL -0.86μm/year in the non-exudative AMD group and -0.32μm/year in the control group. The difference between two groups was statistically significant (p<0.001), and there was also a significant interaction between group and duration in linear mixed models in mean GC-IPL thickness (p=0.001). The reduction rate of the GC-IPL thickness was greater in non-exudative AMD eyes, even at relatively early stages of the disease. Physicians should maintain awareness of the presence of non-exudative AMD in various cases of ophthalmic diseases where GC-IPL thickness evaluation is necessary.