AIM: To study the thickness of peripapillary retinal nerve fibre layer and morphological changes of optic disc in myopic subjects using optical coherence tomography(OCT).

METHODS:Prospective study. A total of 61 myopic subjects(95 eyes)with a mean age of 27.76±7.05 years and 15 controls(30 eyes)with a mean age of 28.33±3.08 years were included. All subjects underwent standard comprehensive refraction(SE), axial length(AL), intraocular pressure(IOP), dilated fundus examination,, and OCT. Based on SE, myopic subjects were divided into three groups: 14 eyes in the moderate to low myopia group(-3D≤SE<-6D), 56 eyes in the high myopia group(-6D≤SE≤-9D), and 25 eyes in the ultra-high myopia group(SE> -9D). The mean retinal nerve fiber layer thickness of the optic disc and the nerve fiber layer thickness of the four quadrants were analyzed, as well as the peripapillary atrophy area(PPA), optic disc ovality index(OI), and horizontal optic disc tilt(HOT).

RESULTS:The thickness of nerve fiber layer in each quadrant was significantly different among the four groups(P<0.01). The mean thickness of nerve fiber layer, the thickness of superior nerve fiber layer and the thickness of nasal nerve fiber layer were significantly higher in the control group than in the three myopic groups(all P<0.05). The thickness of temporal nerve fiber layer in the control group was significantly lower than that in the high myopia group and the super high myopia group(P<0.001, P=0.002), and also significantly lower in the moderate and low myopia group than that in the super high myopia group(P=0.043); the PPA of the four groups was statistically different(P<0.001), in which the super high myopia group and the high myopia group was significantly greater than that in the low myopia group and the control group(P<0.01); the HOT of the four groups was statistically different(P=0.020), in which the high myopia group and the super high myopia group was significantly higher than that in the control group(P<0.001, P<0.001). The nerve fiber layer thickness in the upper and lower quadrants was negatively correlated with OI, HOT, and PPA(all P<0.05), while the nerve fiber layer thickness in the temporal side was positively correlated with OI, HOT, and PPA(all P<0.05).

CONCLUSION: Mean and superior and inferior nerve fiber layer thickness was thinner in myopic patients, with temporal thickening and no change in the nasal side. The tilt of optic disc and the area of peripapillary atrophy were increased in high myopia, which were closely related to the thickness of nerve fiber layer.