Relationship Between Central Corneal Thickness and Ganglionic-Inner Plexiform Cell Layer and Retinal Nerve Fibre Layer Thickness in Normal Subjects

Purpose: To determine the relationship between central corneal thickness (CCT), ganglionic cell-inner plexiform layer thickness and macular nerve fibre layer (RNFL) thickness as measured by optical coherence tomography in a cohort of healthy subjects. Methods: Sixty healthy eyes from 60 subjects were included in this study. All subjects had a standard slit-lamp examination and optical coherence tomography. Central corneal thickness was measured using the Optopol spectral domain optical coherence tomography (SD OCT) machine (version 7.2.0). A linear mixed effects model was used to assess the relationship between central corneal thickness (CCT) and ganglionic cell-inner plexiform layer thickness and macular retinal nerve fibre layer thickness (RNFL). Results: Sixty healthy eyes from 60 subjects were included in this study. The average age was 41.8 years (+/- 20.6 years). There were 22 males (37%) and 38 females (63%). The average central corneal thickness was 525.2 +/- 35.1 mu m (451-601) mu m. The average macular retinal nerve fiber layer thickness was 28.9 +/- 2.5 mu m (23-38 mu m), and the average ganglionic cell-inner plexiform layer thickness was 88.6 +/- 6.3 mu m (75-110 mu m). We found no statistically significant relationship between central corneal thickness and ganglionic cell-inner plexiform layer thickness (p=0.983) nor with macular RNFL (p=0.285). Conclusion: In this cohort of healthy subjects, there was no statistically significant relationship between central corneal thickness and ganglionic cell-inner plexiform layer thickness or with macular retinal nerve fibre layer thickness.