The Analysis of Retinal Nerve Fiber Layer in Amblyopia Using Spectral Domain Optical Coherence Tomography

PURPOSE: To determine whether retinal nerve fiber layer (RNFL) thickness and optic nerve head parameters differ in the amblyopic and normal fellow eyes of hyperopic anisometropic amblyopic patients using spectral domain optical coherence tomography (SD-OCT). METHODS: This study included 30 patients with hyperopic anisometropic amblyopia; patient eyes were divided into 30 anisometropic amblyopic eyes and 30 normal fellow eyes. RNFL thickness, disc area, rim area, average cup-to-disc ratio, and cup volume were obtained using SD-OCT. Axial length was obtained using the IOL Master®, and the interocular differences between group were analyzed. RESULTS: Nasal quadrant RNFL thickness of amblyopic eyes was significantly thicker than that of normal fellow eyes in amblyopic patients (p = 0.010). Among optic nerve parameters, cup volume of amblyopic eyes was significantly smaller than that of normal fellow eyes (p = 0.021). No significant relationship between refractive error and RNFL thickness was observed, and a significant positive linear relationship was observed between neural rim area and RNFL thickness (rho = 0.426, p = 0.005). CONCLUSIONS: SD-OCT analysis of hyperopic anisometropic amblyopic eyes demonstrated a significant increase in nasal RNFL thickness compared to fellow non-amblyopic eyes. No optic nerve head parameters except cup volume showed significant change.

Tomographic characteristics of optic nerve head on Heidelberg retina tomograph Ⅲ in healthy Chinese subjects / 中华实验眼科杂志

Background Normal adult optic disc rim width follows inferior ≥ superior ≥ nasal ≥ temporal (ISNT) rule.Analysis of the optic disc structural parameters with Heidelberg retina tomograph (HRT) can understand whether ISNT principle is suitable to other optic disc structure parameters.Objective This study was to investigate the characteristics of optic nerve head structure parameters in normal Chinese adults.Methods The parents of twins who participated Guangzhou Twin Eye Study were enrolled in Zhongshan Ophthalmic Center from 2006 June to 2011 August.All subjects received the routine eye examinations,including visual acuity,slit lamp microscope,direct ophthalmoscope examination,auto-refraction examination and HRT Ⅲ examination.All data from the right eyes were collected and analyzed.HRT values from different quadrants of optical nerve head were compared with one-way analysis of variance,and the multiple comparison between quadrants was carried out by Bonferroni test.The differences of optical nerve head parameters in different gender were analyzed using independent sample t test and Bland-Altman test.Results In this study,1672 eyes of 1672 subjects were included,with the 759 male and 913 female persons and average age of (41.8±5.3)years.No significant differences were seen in the disc area (DA)between the superior and inferior,as well as the nasal and temporal quadrants among the subjects (P＞0.05).In addition,there were not significantly different in the rim area (RA) between the superior and nasal disc as well as the rim volume (RV) among the inferior,superior and nasal disc (P＞O.05).However,significant differences were found in the cup area (CA),cup/disk area ratio (C/DAR),cup volume (CV),mean cupdepth (MCD),maximum cup depth (MxCD),height variation contour (HVC),cup shape measure (CSM),mean retinal nerve fiber layer thickness (mRNFLT) and retinal nerve fiber layer cross section area (RNFLcsa) among the different quadrants (P＜0.001).The local differences from only DA and RA complied with an ordination of the ISNT rule.The values of DA,CA,C/DAR,CV,MCD,MxCD from male individuals were higher,but those of the RV,HVC,mRNFLT RNFLcsa were lower in comparison with female individuals.Nevertheless,all the differences were ＜ 0.1 with a maximal mean difference in DA and CA (both 0.07 mm2).Conclusions The optical nerve head configurations measured by HRT have different distributing characteristics in four quadrants in normal adults.Most parameters show the higher values in the inferior and superior than those in nasal and temporal of disc,but DA and RA meet ISNT rule.The differences of most parameters between male and female subjects can be ignored.

Analysis of RNFL Thickness and Optic Nerve Head Measured with OCT in Children

PURPOSE: To analyze peripapillary retinal nerve fiber layer (RNFL) thickness and optic nerve head (ONH) parameters with regard to age in children by using optical coherence tomography (OCT). METHODS: We analyzed RNFL thickness and ONH parameters by using Stratus OCT Model 3000 (Zeiss-Humphrey) in two-hundred eyes of 100 children ranging in age from 5 to 14 years, with 5 males and 5 females for each age. RESULTS: The RNFL thicknesses for 100 children (200 eyes) in total were as follows: Mean 104.67+/-9.07 micrometer, superior 131.84+/-18.71 micrometer, temporal 78.49+/-12.91 micrometer, nasal 73.85+/-14.26 micrometer, and Inferior 133.87+/-18.58 micrometer. The parameters of ONH for 100 children (200 eyes) in total were as follows: optic disc area 2.80+/-0.21 mm2, rim area 1.85+/-0.28 mm2, cup to disc area ratio 0.34+/-0.08, horizontal cup to disc diameter ratio 0.47+/-0.11, and vertical cup to disc diameter ratio 0.49+/-0.11. In analyzed RNFL thickness and ONH according to age, there was a significant negative correlation among mean RNFL, inferior RNFL, and age (r=-0.258, p=0.000, r=-0.464, p=0.000). There was a significant positive correlation between nasal RNFL and age (r=0.135, p=0.028). There was a significant positive correlation between disc area and age (r=0.528, p=0.000). There was a significant negative correlation among the cup to disc area ratio, the horizontal cup to disc diameter ratio, the vertical cup to disc diameter ratio, and age (r=-0.170, p=0.008, r=-0.266, p=0.000, r=-0.155, p=0.014). CONCLUSIONS: OCT can be used to measure RNFL thickness and ONH parameters in children. Age had an effect on RNFL thickness and ONH parameters in children.

Influence of Diabetes Mellitus on the Morphometric Analysis of the Optic Nerve Head

To evaluate the influence of diabetes mellitus (DM)on the optic nerve head topographic parameters, each group of 101 patients with open-angle glaucoma (OAG)and 91 control subjects was divided into two subgroups according to the presence or absence of DM.We compared the optic nerve head topographic parameters among groups using Topographic Scanning System (TopSSTM software version 2.2, LDT, Inc., U.S.A.);53 nonglaucomatous eyes without DM (normal group), 38 nonglaucomatous eyes with DM, 67 OAG eyes without DM, and 34 OAG eyes with DM. In the group with OAG without DM, mean contour depth, cup shape, neuroretinal rim area (NRRA), NRRA/disc area were significantly smaller but, effective area and cup/disc area were signifcantly larger than normal group (p<0.05, Student t-test).In nonglaucomatous group, the presence of diabetes showed statistically significant decrease in mean contour depth, cup shape, NRRA, NRRA/disc area ratio (p<0.05).It also showed increase in effective area and cup/disc ratio (p<0.05).These changes were similar to those reported for glaucomatous optic nerve damage.In the group with OAG, the presence of diabetes did not show statistically significant differences in the optic nerve head topographic parameters. In this study, we tried to measure the diabetic changes of the optic nerve head quantitatively using the confocal scanning laser ophthalmoscope (TopSSTM). These results suggest that the diabetic changes should be considered in the evaluation of the optic nerve head parameters for the screening or early diagnosis of open-angle glaucoma when using TopSSTM.