Abstract
Purpose: :
To compare the diagnostic ability to detect glaucomatous changes between the macular ganglion cell complex (GCC) and peripapillary retinal nerve fiber layer (RNFL) thickness in highly myopic patients using Fourier-Domain optical coherence tomography (OCT).
Methods: :
Participants, consecutively enrolled from January 2009 to June 2009, underwent Stratus OCT (fast RNFL scan, Carl Zeiss Meditec, Dublin, CA) and RTVue OCT (ONH scan and GCC scan, Optovue Inc, Fremont, CA) during the same visit. Axial length was measured using partial laser interferometry, and noncycloplegic refraction was measured using an autorefractor and then further refined subjectively. The relationship between demographic variables and OCT parameters was evaluated using multiple linear regression analysis in normal controls. Area under the receiver operator characteristic (AUROC) curves were generated to assess the ability of each parameter to detect glaucomatous changes.
Results: :
Seventy-three normal controls and 77 glaucoma patients were included. Participants were categorized as 105 non-high myopes (Spherical equivalent [SE] >-6.0 diopters) and 45 high myopes (SE ≤ -6.0 diopters). The GCC thickness showed a strong correlation with RNFL thickness using both Stratus and RTVue OCT (correlation coefficient = 0.741 and 0.763, p < 0.001 and p < 0.001, respectively) in all participants. The axial length showed a significant relationship with average RNFL thickness using both Stratus and RTVue OCT (p = 0.050 and 0.040, respectively), but was not associated with the average GCC thickness (p = 0.836). Although the difference did not reach statistical significance, the ability to detect glaucomatous changes in the highly myopic group by examining the average GCC thickness (AUROC, GCC; 0.933) was higher than when examining RNFL thickness from either type of OCT (AUROC, Stratus RNFL; 0.857, RTVue RNFL; 0.857).
Conclusions: :
The ability to diagnose glaucoma with macular GCC thickness was comparable to that with peripapillary RNFL thickness in high-myopia patients. As macular GCC thickness is less affected by axial length than peripapillary RNFL thickness, macular GCC thickness measurements may be a good alternative or a complimentary measurement to RNFL thickness assessment in the clinical evaluation of glaucoma in patients with high myopia.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • myopia