Abstract
Purpose: :
This study was performed to evaluate the macular and peripapillary retinal nerve fiber layer (RNFL) thicknesses, as measured by optical coherence tomography (OCT), and to evaluate thier association with glaucomatous visual field change.
Methods: :
A total of 190 eyes from 116 subjects were classified into six groups: 40 normal eyes, 30 ocular hypertension eyes, 30 pre-perimetric glaucoma eyes and 90 open angle glaucoma eyes (30 early defect eyes, 30 moderate defect eyes and 30 severe defect eyes, as determined by the severity of the visual field defect). We measured the macular and peripapillary RNFL thicknesses by OCT and we performed visual field tests via Humphrey’s automated perimetry.
Results: :
In the six groups, the macular thickness showed a significant difference in all areas of the macula except the fovea (p<0.01), and the peripapillary RNFL thickness also showed a significant difference in all areas (p<0.001). Further, there was a significant decrease of both the macular (p<0.05) and peripapillary RNFL thickness (p<0.001) in the open angle glaucoma group compared with the normal group (p<0.05). There were a significant positive relationship between the mean deviation (MD) and all areas of the peripapillary RNFL thickness (R=0.554, p<0.001), between the MD and all areas of the macular thickness except the fovea (p<0.05), and there were a positive relationship between the MD and the mean peripapillary RNFL thickness (R=0.513, p<0.001) and between the MD and the mean macular thickness (R=0.513, p<0.001). The mean macular thickness was significantly thinner as the mean peripapillary RNFL thickness became thinner (R=0.495, p<0.001). The inner ring (p<0.026) and outer ring (p<0.001) of macular thickness and peripapillary RNFL thickness (<0.001) were significantly decreased in the lower half as compared with the upper half in 20 eyes that showed upper visual field defect only.
Conclusions: :
The macular and peripapillary RNFL thicknesses, as measured by OCT, were significantly decreased and this showed a significant association with the visual field change in open angle glaucoma patients. Accordingly, the macular thickness may also be an important clue, along with the peripapillary RNFL thickness, for making the diagnosis of open angle glaucoma.
Keywords: nerve fiber layer • visual fields • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)