Abstract
Purpose: :
To assess the peripapillary retinal nerve fiber layer (RNFL) thickness in non-glaucomatous young Korean subjects with myopia as measured by time domain (TD) and spectral domain (SD) optical coherence tomography (OCT), and to evaluate the relationship between RNFL measurements and ocular biometric variables including the optic disc measurements by confocal scanning laser ophthalmoscopy (CSLO) and the degree of myopia.
Methods: :
This prospective study included 115 eyes of 64 healthy subjects, which were grouped into two groups: 64 low-to-moderate myopia (-0D < spherical equivalent (SE) < 6.0D) and 51 high myopia (SE ≥ -6.0D). RNFL thickness was measured using the TD OCT (Stratus OCT) and the SD OCT (Spectral OCT/SLO). Optic disc variables were measured using the CSLO (HRT III), and axial length using the laser interferometer (IOL Master). Global and sectoral RNFL thickness was compared between the groups for both OCTs. Associations between RNFL thickness and ocular variables were sought by linear regression.
Results: :
RNFL measurements in myopes were well correlated between TD and SD OCT for all global and sectoral areas. Both OCTs revealed that global and sectoral RNFL thickness was significantly lower in high myopes than in low-to-moderate myopes (p<0.05) except for temporal sectors in which RNFL thickness is higher in high myopes than in low-to-moderate myopes. SD OCT showed better performance in discriminating normal eyes as "normal" based on normative database. The axial length and SE were significantly associated with global RNFL thickness measured by both OCTs (p<0.01). Optic disc area measured by CSLO had no associations with RNFL thickness measured by both OCTs.
Conclusions: :
As demonstrated by TD and SD OCTs, high myopic eyes had a different RNFL thickness distribution when compared with low-to-moderate myopic eyes. Axial and refractive myopia seemed to affect the RNFL thickness measured by both OCTs in healthy myopic eyes, while optic disc area measured by CSLO did not.
Keywords: myopia • imaging/image analysis: clinical