Abstract:AIM:To investigate the influence of myopia on peripapillary retinal nerve fiber layer thickness(RNFLT)using Cirrus optical coherence tomography(OCT)in myopic juveniles aged 12-18 years.
METHODS: Cross-sectional observational study. High-definition(HD), spectral-domain Cirrus OCT(Cirrus HD-OCT; Carl Zeiss, Dublin, CA)was used to analyze RNFLT in 145 healthy juveniles(145 eyes). The data for left eye were selected for analysis. The magnification effect was adjusted by the modified axial length method. The subjects were divided into four groups by spherical equivalent(SE): normal group(52 eyes, -0.25-+0.25D), low myopia group(60 eyes, -0.5--3.0D), moderate myopia group(25 eyes, -3.25--6.0D)and high myopia group(8 eyes,-6.25--12.0D). The correlations between RNFLT and axial length(AL)or SE was tested with linear regression analysis.
RESULTS: The older the age, the longer the eye axis length, the higher the degree of myopia. Comparison of adjusted RNFLT among the four groups: after adjustment, the average RNFLT of the low myopia group and the moderate myopia group were thicker than those of the normal control group(P<0.05). The adjusted RNFLT of temporal quadrant in the moderate myopia group and the high myopia group were significantly thicker than those in the normal group and the low myopia group, as well as the adjusted RNFLT of nasal quadrant in the low, moderate myopia group were significantly thicker compared with those in the normal group(P<0.05). There were statistically significant difference of adjusted RNFLT at 1-4 o'clock, 6 o'clock, 7 o'clock and 9 o'clock among multiple groups(P<0.05). The adjusted values of RNFLT at 1-4 o'clock all showed positively correlated with AL(r=0.220, 0.259, 0.356, 0.237, 0.335, all P<0.01)and negatively correlated with SE(r=-0.386, -0.276,-0.307, -0.254, -0.260, all P<0.01); The adjusted RNFLT at 6, 7 o'clock showed negatively correlated with AL(r=-0.296,-0.327, all P<0.01)and positively correlated with SE(r=0.245,0.295, all P<0.05).
CONCLUSION: Teenagers' eyeballs are still in the shaping stage. When judging RNFLT in myopic juveniles, effects of ocular magnification effect, AL and SE should be considered. When adjusted temporal RNFLT at 1-4 o'clock are thinner than normal, glaucoma should be considered.