Thickness of the Macula, Retinal Nerve Fiber Layer, and Ganglion Cell-inner Plexiform Layer in the Macular Hole: The Repeatability Study of Spectral-domain Optical Coherence Tomography

Purpose: We measured the thicknesses of the ganglion cell and inner plexiform layer (GCIPL), the macula, and the retinal nerve fiber layer (RNFL) using spectral-domain optical coherence tomography in patients with idiopathic macula holes to analyze the repeatability of these measurements and compare them with those of the fellow eye. Methods: We evaluated 85 patients who visited our retinal clinic. The patients were divided into two groups according to their macular hole size: group A had a size of $<400{\mu}m$, while group B had a size of ${\geq}400{\mu}m$. Repeatability was determined by comparing the thicknesses of the GCIPL, macula, and RNFL with those of the normal fellow eye. Results: The average central macular thickness in patients with macular holes was significantly thicker than that in the normal fellow eye ($343.8{\pm}78.6$ vs. $252.6{\pm}62.3{\mu}m$, p < 0.001). The average thickness of the GCIPL in patients with macular holes was significantly thinner than that in the normal fellow eye ($56.1{\pm}23.4$ vs. $77.1{\pm}12.8{\mu}m$, p < 0.001). There was no significant difference in the average RNFL thickness between eyes with macular holes and fellow eyes ($92.4{\pm}10.0$ vs. $95.5{\pm}10.7{\mu}m$, p = 0.070). There were also no significant differences in the thicknesses of the GCIPL and RNFL among the two groups (p = 0.786 and p = 0.516). The intraclass correlation coefficients for the macula and RNFL were 0.994 and 0.974, respectively, in patients with macular holes, while that for the GCIPL was 0.700. Conclusions: Macular contour change with macular hole results in low repeatability and a tendency of thinner measurement regarding GCIPL thickness determined via spectral-domain optical coherence tomography. The impact of changes in the macular shape caused by macular holes should be taken into consideration when measuring the GCIPL thickness in patients with various eye diseases such as glaucoma and in those with neuro-ophthalmic disorders.