Damage to the ganglion cell-inner plexiform layer (GC-IPL) may portend the onset of numerous neurological and systemic diseases, according to research. Studies connect Alzheimer’s disease, Parkinson disease and glaucoma to thinning GC-IPL, making it one of the earlier biomarkers for disease progression.^1-3 Now that this layer can be effectively imaged with OCT technologies, new research is offering a hint toward which patients might benefit from GC-IPLs imaging.⁴

Highly myopic eyes have thinner GC-IPL and a significantly greater reduction in GC-IPL over the course of three years when compared with normal eyes, according to a Korean research team.⁵ The prospective observational study also found that the reduction rate of the GC-IPL thickness was greater in patients older than 50.5

The researchers looked at two groups of patients: a high myopia group with an axial length greater than or equal to 26mm and a control group with normal axial lengths. Both groups were then subdivided by age: those in the their 20s, 30s, 40s and 50s. After the initial visit, GC-IPL thicknesses were measured three more times with at least a one-year interval between examinations using spectral domain OCT.⁵

The average GC-IPL thickness at the first visit was 78.50µm for the high myopia group—significantly thinner than the 84.29µm in the control. The rate of GC-IPL reduction changed significantly over time. Individuals in the high myopia group in their 50s, 40s, 30s and 20s showed thinning of −0.81µm/year, -0.51µm/year, -0.28µm/year and -0.12µm/year, respectively. The controls also experienced this increasing thinning with age, coming in at -0.31µm/year, -0.25µm/year, -0.12µm/year and -0.02µm/year, among the same respective age groups.⁵