The retinal nerve fiber layer in normal and glaucomatous eyes. II. Correlations

The retinal nerve fiber layer is different in normal and glaucomatous eyes. We correlated semi-quantitative data of the retinal nerve fiber layer of 398 eyes with chronic primary open-angle glaucoma and of 234 normal eyes with the intra- and parapapillary morphometric signs and with the perimetric indices. The three parameters "sequence of the fundus sectors concerning the best visibility of the retinal nerve fiber bundles", "visibility of the nerve fiber bundles", and "localized defects" were significantly (p less than 0.001) correlated to 1) area of the neuroretinal rim as a whole and in four different optic disc sectors, 2) neuroretinal rim width determined every 30 degrees, 3) optic cup area, diameters and form, 4) horizontal and vertical cup/disc ratios and the quotient of the horizontal to vertical cup/disc ratio, 5) area and width of zone "Alpha", zone "Beta", and the total parapapillary chorio-retinal atrophy, 6) diameter of the retinal vessels, 7) grade of a "tesselated fundus", and 8) the visual field loss. If only the inferior temporal and the superior temporal sectors were considered, the retinal nerve fiber bundles were less visible in that sector with the largest notch in the neuroretinal rim, the smaller neuroretinal rim area and width, the thinner retinal vessels, and the larger zone "Alpha", zone "Beta", and total parapapillary chorio-retinal atrophy. The glaucomatous changes in the retinal nerve fiber layer are correlated in time and location with the intra- and parapapillary and the perimetric alterations. Evaluation of the retinal nerve fiber layer is a useful method to detect a glaucomatous optic nerve damage.(ABSTRACT TRUNCATED AT 250 WORDS)     

Preperimetric glaucoma assessment with scanning laser polarimetry (GDx VCC): analysis of retinal nerve fiber layer by sectors

PURPOSE: To evaluate the capability of the GDx VCC nerve fiber analyzer to detect preperimetric glaucoma across 12 retinal nerve fiber layer (RNFL) peripapillary sectors. METHODS: Data were obtained in a cross-sectional, hospital clinic-based study; 699 eyes from 699 glaucoma suspects were enrolled in this protocol. All subjects underwent ophthalmologic examination, static automated perimetry [Humphrey 24-2 Swedish interactive threshold algorithm (SITA) Standard], optic nerve stereoscopic photographs, red-free digital RNFL photographs and GDx VCC examination. Group S included 283 normal eyes and 39 preperimetric glaucoma eyes with RNFL superior or diffuse defects in the fiber layer photographs. Group I included 324 normal subjects and 24 with preperimetric glaucoma eyes with RNFL inferior or diffuse defects in fiber layer photographs. RESULTS: Mean values of the area under the curve (AUC) for receiver operating characteristic analysis for inferior average (Inf Avg), temporal-superior-nasal-inferior temporal average (TSNIT Avg), superior average (Sup Avg), and the nerve fiber indicator were significantly less in the eyes with RNFL defects than the control group compared with the AUC for thickness at hour 12 and at hour 6 calculated from the RNFL sector density. The AUC for receiver operating characteristic analysis of the new parameters improved by 12% with respect to the best GDx VCC standard values. CONCLUSIONS: Our results confirm that the 12 sector divisions of the GDx VCC have better diagnostic reliability in preperimetric glaucoma, and are able to improve the discrimination capability between normal and early damaged RNFLs.     

Parapapillary retinal vessel diameter in normal and glaucoma eyes. I. Morphometric data

The retinal blood vessels serve for nutrition of the retinal ganglion cells and their axons. This study was undertaken to evaluate the vessel diameter in normal and glaucoma eyes. The calibers of the superior temporal and inferior temporal retinal artery and vein were measured at the optic disc border and at a distance of 2 mm from the optic disc center; 473 eyes of 281 patients suffering from chronic primary open-angle glaucoma and 275 eyes of 173 normal subjects were examined. Fifteen-degree, color stereo optic disc photographs were used. In the normal eyes the inferior temporal vessels were significantly larger than the superior temporal vessels. This corresponds with: (1) the configuration of the normal neuroretinal rim, which is significantly broader in the inferior disc region than in the superior disc area; (2) the visibility of the retinal nerve fibers, which are better detectable in the inferior temporal area than in the superior temporal one; and (3) the foveola location 0.53 +/- 0.34 mm inferior to the optic disc center. The retinal vessel diameter was independent of the patients' age and optic disc and parapapillary chorioretinal atrophy size. In the glaucoma group the vessel caliber was significantly smaller than in the normal eyes. The differences were more marked for the arteries and the inferior temporal vessels, respectively. The vessel diameters decreased significantly with increasing glaucoma stage independently of the patients' age. The parapapillary retinal vessel diameter may reflect the need of vascular supply in the corresponding superficial retinal area. It may be correlated with the local ganglion cell density and retinal nerve fiber layer thickness.     

Parapapillary retinal vessel diameter in normal and glaucoma eyes. II. Correlations

The juxtapapillary diameters of the superior temporal and inferior temporal retinal artery and vein have been shown to be significantly smaller in glaucomatous eyes than in normal eyes. They had been measured in 473 eyes of 281 patients with chronic primary open-angle glaucoma and in 275 eyes of 173 normal subjects. In the current study the vessel diameters were correlated with intra- and parapapillary morphometric data and visual field indices. Only one eye per patient and subject was taken for statistical analysis. The retinal vessel calibers were significantly (P less than 0.001) correlated with: (1) the area of the neuroretinal rim as a whole and in four different optic disc sectors; (2) the rim width determined every 30 degrees; (3) the optic cup area and diameters; (4) the horizontal and vertical cup/disc ratios and (5) the quotient of them; (6) the retinal nerve fiber layer score; (7) the area of the parapapillary chorioretinal atrophy; and (8) the visual field indices. In the same eye the vessel caliber was smaller in that sector where the neuroretinal rim loss was highest and the retinal fiber layer score lowest. In intraindividual comparison the vessels were smaller in that eye with less neuroretinal rim tissue and lower nerve fiber layer score. No significant correlations were found with the form of the optic disc, the area of the peripapillary scleral ring, side, sex and refraction. The correlation coefficients were not significantly different when the control group was matched for age. The parapapillary retinal vessel diameter decreases with advancing glaucomatous optic nerve damage. It is correlated with morphometric intra- and parapapillary glaucomatous changes and perimetric defects.     

Structural measurements and vessel density of spectral-domain optic coherence tomography in early, moderate, and severe primary angle-closure glaucoma

AIM: To compare the macular ganglion cell-inner plexiform layer (GCIPL) thickness, retinal nerve fiber layer (RNFL) thickness, optic nerve head (ONH) parameters, and retinal vessel density (VD) measured by spectral-domain optical coherence tomography (SD-OCT) and analyze the correlations between them in the early, moderate, severe primary angle-closure glaucoma (PACG) and normal eyes. METHODS: Totally 70 PACG eyes and 20 normal eyes were recruited for this retrospective analysis. PACG eyes were further separated into early, moderate, or severe PACG eyes using the Enhanced Glaucoma Staging System (GSS2). The GCIPL thickness, RNFL thickness, ONH parameters, and retinal VD were measured by SD-OCT, differences among the groups and correlations within the same group were calculated. RESULTS: The inferior and superotemporal sectors of the GCIPL thickness, rim area of ONH, average and inferior sector of the retinal VD were significantly reduced (all P<0.05) in the early PACG eyes compared to the normal and the optic disc area, cup to disc ratio (C/D), and cup volume were significantly higher (all P<0.05); but the RNFL was not significant changes in early and moderate PACG. In severe group, the GCIPL and RNFL thickness were obvious thinning with retinal VD were decreasing as well as C/D and cup volume increasing than other three groups (all P<0.01). In the early PACG subgroup, there were significant positive correlations between retinal VD and GCIPL thickness (except superonasal and inferonasal sectors, r=0.573 to 0.641, all P<0.05), superior sectors of RNFL thickness (r=0.055, P=0.049). More obvious significant positive correlations were existed in moderate PACG eyes between retinal VD and superior sectors of RNFL thickness (r=0.650, P=0.022), and temporal sectors of RNFL thickness (r=0.740, P=0.006). In the severe PACG eyes, neither GCIPL nor RNFL thickness was associated with retinal VD. CONCLUSION: The ONH damage and retinal VD loss appears earlier than RNFL thickness loss in PACG eyes. As the PACG disease progressed from the early to the moderate stage, the correlations between the retinal VD and RNFL thickness increases.     

Parapapillary retinal vessel caliber. II. Caliber reduction in eyes with glaucoma (a papillometric study of 309 eyes with chronic simple glaucoma compared with 264 normal eyes)

The diameter of the temporal superior or inferior artery and vein was measured at the optic disk border and 2 mm from the disk center in 309 nonselected eyes with chronic primary open-angle glaucoma. The values obtained were compared with those of 264 nonselected normal eyes. The calibers of both vessels were significantly larger in the normal eyes than in the glaucomatous ones (p = 0.000 or p less than 0.01; Wilcoxon-Mann-Whitney test). Their diameters diminished significantly (p less than 0.001) with decreasing width and area of the neuroretinal rim as a whole and when divided into different optic disk sectors, and with increasing optic cup area, horizontal and vertical cup/disk ratios, area of the subtotal to total parapapillary choriopigmentepithelioretinal atrophy, perimetric loss, and glaucoma stage. Thus, the caliber of the parapapillary retinal vessels decreases significantly with increasing glaucomatous optic nerve damage.     

Visibility of the normal retinal nerve fiber layer correlated with rim width and vessel caliber

Since the distribution of the retinal nerve fiber layer (RNFL) is not regular, this study was performed to evaluate the normal regional variation in its ophthalmoscopic appearance. Wide-angle red-free photographs of the RNFL and color stereo optic disc slides of 195 normal eyes of 119 subjects were morphometrically examined. The RNFL was most visible in the temporal inferior sector, with the neuroretinal rim being correspondingly broadest (P < 0.001) and the diameter of the corresponding retinal artery the widest; these parameters were found to diminish appreciably in the temporal superior sector, the nasal superior sector, and the nasal inferior sector in this order. The visibility of the RNFL in a particular region therefore correlates positively with the rim width and retinal artery caliber in that region, the RNFL being most detectable in the temporal inferior part of the fundus. This may be important in the evaluation of eyes with optic nerve damage.This study was supported by funds from Deutsche Forschungsgemeinschaft (Klinische Forschergruppe Glaukome, DFG Na 55/6-1/Jo) Parts of the study were presented at the Annual Meeting of the Association for Research in Vision and Ophthalmology (ARVO), held in Sarasota, May 1992.     

Retinal nerve fiber layer thickness in human eyes

· Background: A study was carried out to measure the thickness of the retinal nerve fiber layer (RNFL) at the optic disc border. · Methods: RNFL thickness at the optic disc border was histomorphometrically measured on histological sections of 22 human eyes with normal optic nerves and 21 human eyes with absolute secondary angle-closure glaucoma. For three eyes with normal optic nerves, serial sections through the whole optic disc area were available. · Results: In the eyes with normal optic nerves, the RNFL at the optic disc border showed a double hump configuration with the highest mean thickness in the inferior quadrant (mean ± S.D: 266±64 μm), followed by the superior quadrant (240±57 μm), the nasal quadrant (220±70 μm), and finally the temporal quadrant (170±58 μm). In the three globes with serial sections, RNFL was thickest at the inferior disc pole (397±58 μm), followed by the superior disc pole (313±38 μm), the nasal disc pole (165±19 μm), and finally the temporal disc pole (131±15 μm). In the eyes with absolute glaucoma, mean thickness of the remainder of the RNFL was 40±18 μm with no marked differences between the disc regions. · Conclusions: In normal eyes, the RNFL shows a double hump configuration with its thinnest part at the temporal disc pole, followed by the nasal disc pole and the superior disc pole. RNFL is thickest at the inferior disc pole. In glaucomatous optic neuropathy, the inner limiting membrane moves backward about 60–100 μm at the temporal disc border, and more than 200 μm at the inferior and superior disc poles. Received: 24 July 1998 Revised version received: 29 September 1998 Accepted: 22 October 1998     

Polarimetric measurement of retinal nerve fiber layer thickness in glaucoma diagnosis

PURPOSE: To evaluate reliability and diagnostic value of polarimetric measurements of the retinal nerve fiber layer (RNFL) thickness in the diagnosis of glaucoma. METHODS: The study included 81 eyes with perimetric glaucoma with glaucomatous changes of the optic disc and visual field defects; 52 eyes with preperimetric glaucoma with glaucomatous optic disc abnormalities and normal achromatic visual fields; and 70 normal eyes. For determination of reliability, four examiners repeated polarimetric measurements five times in ten normal subjects. RESULTS: The polarimetric variables were significantly correlated with increasing mean visual field defect and decreasing neuroretinal rim area. In correlation analyses with visual field defects, correlation coefficients were highest for the variable "superior/nasal ratio" and "the Number," a variable calculated by the neural network of the device. In correlations with neuroretinal rim area, correlation coefficients were highest for measurements of the inferior nerve fiber layer thickness. The preperimetric glaucoma group and the control group differed significantly in the variables "superior/nasal ratio" and "the Number" and, to a smaller degree, in the variables "superior/temporal ratio" and "superior/inferior ratio." The Number variable had a sensitivity of 82% and 58% at a predefined specificity of 80% in separating perimetric glaucoma patients and preperimetric glaucoma patients, respectively, from control subjects. Reproducibility of the polarimetric measurements ranged between 70% and 89%. CONCLUSION: Polarimetric measurements of the RNFL thickness can detect glaucomatous optic nerve damage in patients with visual field loss, and in some patients with preperimetric glaucomatous optic nerve damage. Considering the fast performance, easy handling, and low maintenance costs, RNFL polarimetry may be helpful in glaucoma diagnosis.     

Comparison of retinal nerve fiber layer thickness and optic disk algorithms with optical coherence tomography to detect glaucoma

PURPOSE: To compare the performance of the retinal nerve fiber layer (RNFL) thickness and optic disk algorithms as determined by optical coherence tomography to detect glaucoma. DESIGN: Observational cross-sectional study. METHODS: setting: Academic tertiary-care center. study population: One eye from 42 control subjects and 65 patients with open-angle glaucoma with visual acuity of > or =20/40, and no other ocular pathologic condition. observation procedures: Two optical coherence tomography algorithms were used: "fast RNFL thickness" and "fast optic disk." main outcome measures: Area under the receiver operating characteristic curves and sensitivities at fixed specificities were used. Discriminating ability of the average RNFL thickness and RNFL thickness in clock-hour sectors and quadrants was compared with the parameters that were derived from the fast optic disk algorithm. Classification and regression trees were used to determine the best combination of parameters for the detection of glaucoma. RESULTS: The average visual field mean deviation (+/-SD) was 0.0 +/- 1.3 and -5.3 +/- 5.0 dB in the control and glaucoma groups, respectively. The RNFL thickness at the 7 o'clock sector, inferior quadrant, and the vertical C/D ratio had the highest area under the receiver operating characteristic curves (0.93 +/- 0.02, 0.92 +/- 0.03, and 0.90 +/- 0.03, respectively). At 90% specificity, the best sensitivities (+/-SE) from each algorithm were 86% +/- 3% for RNFL thickness at the 7 o'clock sector and 79% +/- 4% for horizontal integrated rim width (estimated rim area). The combination of inferior quadrant RNFL thickness and vertical C/D ratio achieved the best classification (misclassification rate, 6.2%). CONCLUSION: The fast optic disk algorithm performs as well as the fast RNFL thickness algorithm for discrimination of glaucoma from normal eyes. A combination of the two algorithms may provide enhanced diagnostic performance.     

Comparisons of ganglion cell-inner plexiform layer loss patterns and its diagnostic performance between normal tension glaucoma and primary open angle glaucoma: a detailed, severity-based study

AIM: To evaluate the patterns of macular ganglion cell-inner plexiform layer (GCIPL) loss in normal tension glaucoma (NTG) and primary open angle glaucoma (POAG) in a detailed, disease severity-matched way; and to assess the diagnostic capabilities of GCIPL thickness parameters in discriminating NTG or POAG from normal subjects. METHODS: A total of 157 eyes of 157 subjects, including 57 normal eyes, 51 eyes with POAG and 49 eyes with NTG were enrolled and strictly matched in age, refraction, and disease severity between POAG and NTG groups. The average, minimum, superotemporal, superior, superonasal, inferonasal, inferior, and inferotemporal GCIPL thickness, and the average, superior, temporal, inferior, and nasal retinal nerve fiber layer (RNFL) thickness were obtained by Cirrus optical coherence tomography (OCT). The diagnostic capabilities of OCT parameters were assessed by area under receiver operating characteristic (AUROC) curves. RESULTS: Among all the OCT thickness parameters, no statistical significant difference between NTG group and POAG group was found (all P>0.05). In discriminating NTG or POAG from normal subjects, the average and inferior RNFL thickness, and the minimum GCIPL thickness had better diagnostic capabilities. There was no significant difference in AUROC curve between the best GCIPL thickness parameter (minimum GCIPL) and the best RNFL thickness parameter in discriminating NTG (inferior RNFL; P=0.076) and indiscriminating POAG (average RNFL; P=0.913) from normal eyes. CONCLUSION: Localized GCIPL loss, especially in the inferior and inferotemporal sectors, is more common in NTG than in POAG. Among all the GCIPL thickness parameters, the minimum GCIPL thickness has the best diagnostic performance in differentiating NTG or POAG from normal subjects, which is comparable to that of the average and inferior RNFL thickness.     

Ophthalmoscopic appearance of the normal optic nerve head in rhesus monkeys

PURPOSE: To evaluate the ophthalmoscopic appearance of the normal optic disc, parapapillary region, and retinal nerve fiber layer in rhesus monkeys. METHODS: Color stereo fundus photographs of 17 normal eyes of 17 rhesus monkeys aged between 13 and 23 years were morphometrically evaluated. RESULTS: The neuroretinal rim was significantly (P: < 0.008) broadest in the inferior disc region followed by the superior disc region, the nasal region, and the temporal region. Retinal nerve fiber layer visibility was significantly highest in the inferior temporal fundus region followed by the superior temporal fundus region, the superior nasal fundus region, and the inferior nasal fundus region. It decreased significantly (P: < 0.001) with increasing age. The retinal arterioles were significantly (P: < 0.01) wider in the inferior temporal and superior temporal fundus regions than in the superior nasal and inferior nasal fundus regions. The alpha zone of parapapillary atrophy (14/17 or 82.4%) occurred significantly (P: < 0.001) more often than the beta zone (2/17 or 11.8%). In 15 eyes (88. 2%), the foveola was located inferior to a horizontal line drawn through the center of the optic disc. Neuroretinal rim shape and area and size of alpha and beta zones of parapapillary atrophy were independent of age. CONCLUSIONS: As in humans, in normal rhesus monkeys the neuroretinal rim has a typical physiologic configuration that spatially correlates with the retinal arteriole diameter, retinal nerve fiber layer visibility, and position of the foveola inferior to the center of the optic disc. Neuroretinal rim shape is independent of age. Retinal nerve fiber layer visibility decreases significantly with increasing age. These findings may be useful for the early detection and differentiation of experimental optic nerve damage in rhesus monkeys.     

Parapapillary chorioretinal atrophy in normal and glaucoma eyes. I. Morphometric data

Glaucomatous optic nerve damage is associated with alterations of the intra- and parapapillary optic disc area. We measured and compared the parapapillary region in 582 eyes of 321 patients suffering from chronic primary open-angle glaucoma and in 390 eyes of 231 normal subjects. Only one randomly assessed eye per patient and subject was taken for statistical analysis. Highly mopic eyes with a myopic refractive error of more than -8.00 diopters had been excluded. The parapapillary chorioretinal atrophy was divided into a peripheral zone "Alpha" with irregular hyper- and hypopigmentation, and a more central zone "Beta" characterized by whitish colour, visible large choroidal vessels and visible sclera. In the normal eyes both zones were significantly (P less than 0.001) largest and most common in the temporal horizontal sector, followed by the inferior temporal sector, the superior temporal sector and finally the nasal sector. In the glaucoma group both zones were significantly larger (P less than 0.0001; Mann-Whitney test) and more frequent than in the normal eyes (0.40 +/- 0.32 mm2 versus 0.65 +/- 0.49 mm2 for zone Alpha, 0.13 +/- 0.42 mm2 versus 0.79 +/- 1.17 mm2 for zone Beta). The differences were significant also for the earliest glaucoma stage of this study. They were most marked for the nasal parapapillary sector. Significant differences (P less than 0.001) between the normal group and the earliest glaucoma stage were: zone Alpha larger than 0.20 mm2 or broader than 0.20 mm in the temporal horizontal sector, total area of zone Alpha larger than 0.30 mm2, occurrence of zone Alpha in the nasal sector, and occurrence of zone Beta anywhere.     

Retinal nerve fiber layer thickness in the fellow eyes of normal-tension glaucoma patients with unilateral visual field defect

PURPOSE: To quantitatively evaluate retinal nerve fiber layer (RNFL) thickness in the fellow eyes of normal-tension glaucoma (NTG) patients with unilateral visual field defect. DESIGN: Observational case-control study. METHODS: Twenty-nine NTG patients with unilateral visual field defect were enrolled in this study. All 29 fellow eyes showed normal visual field. Thirty-one normal eyes of 31 subjects served as controls. The RNFL thickness around the optic disk was determined using Fast RNFL thickness (3.4) of optical coherence tomography. Average and segmental (4 quadrants and 12 clock- hours) RNFL thickness measurements were compared among the three groups. RESULTS: RNFL thicknesses were significantly different among the three groups in the average, superior quadrant (11 and 12 clock-hour segments), and inferior quadrant (6 clock-hour segment) (P = .00, one-way ANOVA and Tukey's tests). CONCLUSIONS: RNFL thickness reductions are already present in the fellow eyes of NTG patients with unilateral visual field defect.     

青光眼视网膜神经纤维层的数码摄影及模糊影像的图像处理

目的 视网膜神经纤维层（ｒｅｔｉｎａｌ ｎｅｒｖｅ ｆｉｂｅｒ ｌａｙｅｒ,ＲＮＦＬ）的检测是青光眼早期诊断的重要手段,但照片冲洗难度大,部分患者难以显示清晰的ＲＮＦＬ图像,为些进行ＲＮＦＬ的数码摄影及模糊影像图像处理的研究。方法 采用Ｎｉｋｏｎ眼底摄像机,连接高分辨Ｋｏｄａｋ数码摄像机。图像处理采用Ｐｈｏｔｏｓｈｏｐ软件。对首都医科大学附属北京同仁医院眼科１０５例青光眼患者,３２例白内障患者,２     

合并高度近视的原发性开角型青光眼视野分析(英文)

目的:探讨合并高度近视和非高度近视的原发性开角型青光眼早期视野改变特点及其与视网膜神经纤维层缺损的关系。方法:利用Humphrey750型计算机自动视野计对17例(21眼)合并高度近视的POAG和16例(17眼)非高度近视的POAG及20例(25眼)单纯高度近视以及17例(19眼)正常组进行静态中心阈值视野检查,利用OCT进行视盘周围RNFL厚度检查。比较正常组、合并高度近视POAG组、非高度近视POAG组、单纯高度近视组视野缺损的总偏差概率图;比较正常组、合并高度近视的POAG组、非高度近视的POAG组以及单纯高度近视组的MD值、PSD值、上方、下方、鼻侧、颞侧平均光敏感度;比较正常组、合并高度近视的POAG组、非高度近视的POAG组以及单纯高度近视组的平均、上方、下方、鼻侧、颞侧RNFL厚度;分别分析合并高度近视的POAG组、非高度近视的POAG组以及单纯高度近视组各组内上方、下方、鼻侧、颞侧各象限RNFL厚度与视野对应部位的缺损之间的关系以及各组视野特点。结果:合并高度近视的早期POAG患者在总偏差概率图中多表现为普遍敏感性降低,而在模式偏差概率图则更多表现出POAG早期视野缺损;平均缺损值显著高于其它各组。合并高度近视的POAG患者无论平均光敏感度还是MD、PSD值均与其他三组有显著差异(P<0.05);单纯高度近视组与非高度近视的POAG组的各象限平均光敏感度的差异均有显著性(P<0.05)。合并高度近视的POAG组较非高度近视的POAG组以及单纯高度近视组RNFL厚度明显变薄;此三组较正常组RNFL厚度变薄;单纯高度近视组与非高度近视的POAG组的平均RNFL厚度及各象限RNFL厚度的差异均有显著性(P<0.05);各组四个象限RNFL厚度与视野对应部位的缺损相关。结论:在进行合并高度近视的POAG视野结果判定时要依靠模式偏差概率图,其特点是伴有生理盲点扩大和外移。OCT能够反映合并高度近视的POAG的RNFL厚度的改变,及RNFL厚度与视野缺损的相关性有助于在合并高度近视POAG中的临床诊断。     

Early detection of thinning of retinal nerve fiber layer in glaucomatous eyes by optical coherence tomography 3000: analysis of retinal nerve fiber layer corresponding to the preserved hemivisual field

The retinal nerve fiber layer (RNFL) thickness was measured with the optical coherence tomography using version 3.0 software (OCT3000) in 153 eyes of 153 normal subjects. The mean of the average RNFL thickness over the entire 360 degrees in the control group was 92.5 +/- 12.9 microm which was significantly thinner than the normative data of 95.9 +/- 11.4 microm included with the OCT3000 (p < 0.01). The RNFL thickness decreased with increasing age (p < 0.01, r = -0.395). The RNFL thickness was also measured in 53 eyes of 53 patients with glaucoma whose superior (13 eyes) or inferior (40 eyes) perimetric hemifields were normal. Only the RNFL thickness corresponding to the preserved perimetric hemifields were measured by OCT3000 and scanning laser ophthalmoscopy (SLO). The RNFL thickness in the superior and inferior 30 degrees sectors, the maximum and average RNFL thickness in the superior (S(max) and S(avg)), and inferior quadrants (I(max) and I(avg)) were analyzed.The S(max), S(avg), I(max), I(avg), and the RNFL thickness in the superior (p < 0.05), superotemporal and inferotemporal sectors (p < 0.01) in the glaucoma patients without a nerve fiber layer defect (SLO) were significantly thinner than in the control subjects in same age. OCT3000 measurements showed that the RNFL thickness in glaucomatous eyes with normal perimetric visual fields and SLO was significantly thinner than the RNFL thickness in normal eyes.     

Localised wedge shaped defects of the retinal nerve fibre layer in glaucoma.

Glaucoma can be associated with a diffuse or localised loss of the retinal nerve fibre layer (RNFL). This study evaluated the wedge shaped localised RNFL defects. Red free wide angle RNFL photographs of 421 patients with glaucoma and 193 normal subjects were examined. Localised RNFL defects were described for one eye of the normal group and for 20% of the patients with glaucoma. They were usually located in the inferior temporal and superior temporal fundus regions. Within the glaucoma group, localised RNFL defects occurred most often (p < 0.05) in normal pressure glaucoma, followed by primary open angle glaucoma, and finally secondary open angle glaucoma. They were positively associated with disc haemorrhages. The localised RNFL defects had a high specificity to indicate optic nerve damage. The nerve fibre layer defects occurring more likely in mild rather than advanced glaucoma, they were helpful in the diagnosis of early glaucoma. The association between localised RNFL defects and disc haemorrhages and the varying frequency of localised RNFL defects in different types of glaucoma may be important diagnostically and pathogenetically.     

Application of optical coherence tomography in glaucoma suspect eyes

Purpose: The aim of the study was to compare the optical coherence tomography (OCT) parameters of the optic nerve head (ONH) and retinal nerve fibre layer (RNFL) and to identify which measurements are best able to differentiate between normal and glaucoma suspect eyes. Methods: The study included 27 eyes with ocular hypertension (OHT), 33 eyes with pre‐perimetric glaucoma (PG), 30 perimetrically unaffected eyes of patients with glaucoma in the fellow eye (FE) and 58 eyes of age‐matched normal volunteers. All subjects underwent a complete eye examination with standard automated perimetry, optic disc photography and OCT imaging. Peripapillary ‘fast RNFL thickness scans’ and ‘fast optic disc scans’ were performed with time‐domain OCT. The ONH and RNFL parameters were compared among the four study groups. The ONH and RNFL parameters were examined alone and then combined via four linear discriminant functions (LDF): LDF 1, the optimal combination of ONH parameters; LDF 2, the optimal combination of RNFL parameters; LDF 3, the optimal combination of both ONH and RNFL parameters; and LDF 4, the optimal combination of the best 11 parameters. The areas under the receiver operating curves (AUC) and the sensitivity at fixed specificity of at least 80 and 95 per cent were calculated for single parameters and LDF combinations and then compared. The best 11 parameters were selected based on their AUC values. Results: Comparative analysis of OCT parameters revealed statistically significant differences in all seven ONH parameters in both PG and FE groups (and only in one ONH measurement in the ocular hypertensive group) when compared with normal eyes. Most of the RNFL parameters demonstrated statistically significant differences in all of the study groups when compared with the control group. The max‐min parameter (0.835), inferior quadrant (0.833) and average RNFL thickness (0.829) obtained the highest AUC values in the whole glaucoma suspect group. The rim area had the best diagnostic accuracy among the ONH parameters (AUC = 0.817). The AUC values of the four LDF were: 0.825 (LDF 1), 0.882 (LDF 2), 0.902 (LDF 3) and 0.888 (LDF 4). Statistically significant differences were found between the AUC values of the single best ONH and RNFL parameters and LDF 3 and LDF 4. Conclusions: In the present study, RNFL parameters presented with better discriminatory abilities than ONH parameters in the OHT and FE groups. The ONH parameters demonstrated better diagnostic precision in differentiating between PG and normal eyes. The average RNFL thickness, max–min parameter and inferior quadrant RNFL thickness had the best abilities among single OCT measurements for discriminating between glaucoma suspect (including all ocular hypertensive, PG and FE eyes) and normal eyes. The combination of RNFL parameters only or both ONH and RNFL parameters, using linear discriminant analysis, provided the best classification results, improving the diagnostic accuracy of the instrument.     

Retinal nerve fiber layer and macular inner retina measurements by spectral domain optical coherence tomograph in Indian eyes with early glaucoma

Purpose

To compare the diagnostic abilities of peripapillary retinal nerve fiber layer (RNFL) and macular inner retina (MIR) measurements by spectral domain optical coherence tomography (SD–OCT) in Indian eyes early glaucoma.

Methods

In an observational, cross-sectional study, 125 eyes of 64 normal subjects and 91 eyes of 59 early glaucoma patients underwent RNFL and MIR imaging with SD–OCT. Glaucomatous eyes had characteristic optic nerve and RNFL abnormalities and correlating visual field defects and a mean deviation of better than or equal to -6 dB on standard automated perimetry. Areas under the receiver operating characteristic curves (AUC), sensitivities at a fixed specificity and likelihood ratios (LRs) were estimated for all RNFL and MIR parameters.

Results

The AUCs for the RNFL parameters ranged from 0.537 for the temporal quadrant thickness to 0.821 for the inferior quadrant RNFL thickness. AUCs for the MIR parameters ranged from 0.603 for the superior minus inferior MIR thickness average to 0.908 for ganglion cell complex focal loss volume (GCC–FLV). AUC for the best MIR parameter (GCC–FLV) was significantly better (P<0.001) than that of the best RNFL parameter (inferior quadrant thickness). The sensitivities of these parameters at high specificity of 95%, however, were comparable (52.7% vs58.2%). Evaluation of the LRs showed that outside normal limits results of most of the RNFL and MIR parameters were associated with large effects on the post-test probability of disease.

Conclusion

MIR parameters with RTVue SD–OCT were as good as the RNFL parameters to detect early glaucoma.