The contour of the juxtapapillary nerve fiber layer in glaucoma

Reliable structural markers for early glaucomatous optic nerve damage would facilitate the diagnosis of glaucoma at an early stage, possibly before visual field loss occurs. Computerized image analyses were used to develop and analyze new structural parameters for glaucomatous optic nerve damage. Multiple measurements of relative juxtapapillary nerve fiber layer height were made in glaucoma patients (n = 112), patients suspected of having glaucoma (n = 87), and in age-matched normal control subjects (n = 53). The average relative nerve fiber layer (NFL) height differed in glaucoma patients and normal subjects by 70 microns, but differences exceeded 100 microns at the superior and inferior poles of the disc. Mean values for "glaucoma suspects" were intermediate between those for the normal subjects and glaucoma groups. The ability of summary statistics of relative NFL height measurements to discriminate between normal and glaucomatous eyes was superior to that of the standard disc parameters cup-disc ratio, disc rim area, and cup volume. Measurements of relative NFL height correlated with indices of visual field loss; the strongest correlations occurred for measurements at the superior and inferior poles. Measurements of juxtapapillary NFL height may prove useful to detect glaucomatous optic nerve damage at an early stage and to accurately recognize progressive nerve damage over time.     

Reproducibility of topographic measurements of the normal and glaucomatous optic nerve head with the laser tomographic scanner

We acquired five independent topographic images of the optic nerve head of eight normal eyes and eight eyes with primary open-angle glaucoma with a laser tomographic scanner. Each image had a field of view of 15 x 15 degrees with a resolution of 256 x 256 pixels. The pixel size was approximately 15 x 15 microns. The value of a pixel of a topographic image represented the height at this position. The mean height and the standard deviation over the five topographic images were calculated for each of the 65,536 pixel positions. The standard deviation of a single height measurement in normal eyes was 38.7 microns (range, 23.4 to 62.2 microns) for areas in the peripapillary retina and 42.6 microns (range, 24.4 to 53.7 microns) for measurements within the optic nerve head area. In glaucomatous eyes, the standard deviation was 41.2 microns (range, 23.2 to 59.6 microns) in the peripapillary retina and 49.4 microns (range, 28.1 to 72.8 microns) within the optic nerve head. There was no significant difference between the standard deviation of a single height measurement in normal and glaucomatous eyes (P = .34 within the optic nerve head area; P = .57 on peripapillary retina). No correlation was found between standard deviation of the measurements and pupil size or age of the subject.     

Regional and long-term variability of fundus measurements made with computer-image analysis

We studied the variability of optic disk and peripapillary nerve fiber layer surface contour measurements made by use of computer-image analysis. Six hundred twenty-five measurements of surface contour were made on each eye by use of simultaneous stereoscopic videography. Regional differences in short-term measurement variability were studied in 12 eyes (six normal and six glaucomatous), each imaged nine times over several days. The widths of the 95% confidence interval for the measurements averaged 82 microns for the juxta-papillary surface and 132 microns for the disk surface. Measurements of peripapillary surface contour were significantly less variable than were measurements of the disk surface (P = .000). The greatest variability was detected along large blood vessels and at steep contours. Long-term variability was studied in a separate group of 30 clinically stable patients with glaucoma, each imaged three to six times over a period of more than one year. The widths of the 95% confidence intervals were 132 microns for the peripapillary surface and 217 microns for the disk surface. The long-term variability was significantly greater than the short-term variability (P = .000). The peripapillary nerve fiber layer surface, located away from the margins of large vessels, may provide the most dependable measurements of contour. These estimates of long-term variability of optic disk and peripapillary contour measurements provide clinically relevant confidence intervals with which to detect progressive glaucomatous nerve fiber damage.     

New findings in the evaluation of the optic disc in glaucoma diagnosis

PURPOSE OF REVIEW: Ophthalmoscopical evaluation of the optic disc is a feasible and largely accessible method to diagnose glaucoma. Many qualitative parameters have been described in glaucomatous optic neuropathy. Considering individual variations in the details of topography or tissue components damaged by the glaucomatous process, however, adequate identification of glaucomatous optic disc signs requires training and experience. Without adequate guidelines of optic disc examination, the physician may miss important aspects that could lead to adequate diagnosis or identification of progression in a patient with established glaucoma. This paper presents a systematic approach for the examination of the optic disc and retinal nerve fiber layer to aid the detection of glaucoma. RECENT FINDINGS: Optic disc qualitative parameters are better than quantitative parameters in separating glaucomatous from normal eyes. The sequential evaluation of optic disc size, neuroretinal rim size and shape, retinal nerve fiber layer, presence of peripapillary atrophy, and presence of retinal or optic disc hemorrhages enhances the ability to detect glaucomatous damage and its progression. SUMMARY: Ophthalmologists should be familiar with glaucomatous optic disc signs that can be identified during clinical examination. A simple systematic approach may allow improved diagnosis and management of glaucoma.     

Vessel density in OCT angiography permits differentiation between normal and glaucomatous optic nerve heads

AIM: To evaluate whether optical coherence tomography angiography (OCTA) can detect altered vessel density (VD) at the optic nerve head (ONH) in glaucoma patients. Special attention is paid to the accuracy of the OCTA technique for distinguishing healthy from glaucomatous eyes. METHODS: A total of 171 eyes were examined by the OCTA system AngioVue? (Optovue): 97 eyes diagnosed with glaucoma and 74 healthy control eyes. The papillary and peripapillary VD was measured. Furthermore, the VD was correlated with different structural and functional measurements. In order to test the accuracy of differentiation between eyes with and without glaucoma, we calculated the receiver operating characteristic curve (ROC) and the area under the curve (AUC). RESULTS: The papillary and peripapillary VD in glaucomatous eyes was significantly lower than in healthy eyes (P<0.05). The VD of the nasal peripapillary sector was significantly lower than in the other sectors. The further the disease had progressed [measured by determining the thickness of the ganglion cell complex (GCC) and the retinal nerve fiber layer (RNFL)] the greater the VD reduction. The AUC discriminated well between glaucomatous and normal eyes (consensus classifier 94.2%). CONCLUSION: OCTA allows non-invasive quantification of the peripapillary and papillary VD, which is significantly reduced in glaucomatous eyes and accurately distinguishes between healthy and diseased eyes. OCTA expands the spectrum of procedures for detecting and monitoring glaucoma.     

Optic disc histomorphometry in normal eyes and eyes with secondary angle-closure glaucoma

The intrapapillary region of the optic disc shows ophthalmoscopical changes in glaucoma. In search of a histological correlate, this region was examined histomorphometrically in serial sections of 21 human eyes with secondary angle-closure glaucoma and 28 control eyes with malignant choroidal melanoma. The lamina cribosa was significantly (P less than 0.05) thinner, the optic cup deeper and wider, the peripapillary scleral ring finer, and the corpora amylacea count was lower in glaucoma eyes than in control eyes with normal optic nerves. There was no significant difference in optic disc diameter. The decrease in lamina cribrosa thickness may be one of several factors leading to glaucomatous optic nerve fiber loss. Due to a decrease in the relative height the inner limiting membrane should not be taken as the reference level for optic-cup-depth measurement. A high corpora amylacea count may point to a normal optic nerve fiber population.     

Study of the optic papilla and nerve fiber layer in glaucoma]

BACKGROUND: For diagnosis and follow-up of glaucoma an exact evaluation of the optic nerve disc and the nerve fiber layer is necessary. METHODS: The slit-lamp evaluation of the optic nerve disc and nerve fiber layer is presented as well as the evaluation with the Nerve Fiber Analyzer and the Heidelberg Retina Tomograph. RESULTS: Signs of a glaucomatous optic disc include a difference of more than 0.2 in the vertical cup to disc (CD) ratio between the eyes, a vertical CD ratio exceeding more than 0.1 the horizontal, larger CD ratios in small optic discs, notching of the neuroretinal rim, an enlarged zone beta of parapapillary chorioretinal atrophy, and peripapillary hemorrhages. Atrophy of the nerve fiber layer may be localized or diffuse. Both types of atrophy may be present at the same time. CONCLUSIONS: Knowledge of all signs of the glaucomatous optic disc and forms of nerve fiber layer atrophy allows an earlier diagnosis of glaucoma and an earlier recognition of progression.     

Clinical implications of peripapillary atrophy in glaucoma

PURPOSE OF REVIEW: To elucidate peripapillary atrophy in glaucomatous optic neuropathy; its ranking in the morphologic diagnosis of the glaucoma, and its value for the differentiation of various types of chronic open-angle glaucoma, for the separation of glaucomatous eyes from nonglaucomatous eyes, and for the detection of progression of glaucoma. RECENT FINDINGS: Recent studies showed an association of peripapillary atrophy with glaucoma and the eventual development of glaucomatous disc hemorrhages independent of a small neuroretinal rim area, and an association between increasing peripapillary atrophy and progressive glaucoma. A ranking of optic disc parameters to detect glaucomatous damage revealed that the alpha and beta zones of peripapillary atrophy, compared with neuroretinal rim parameters, are less useful. Pseudoexfoliation syndrome without glaucoma is not a risk factor for peripapillary atrophy. In arteritic anterior ischemic optic neuropathy, peripapillary atrophy does not enlarge. Peripapillary atrophy does not differ markedly between Europeans and South Indians. In contrast to the position of the central retinal vessel trunk, the presence and position of cilioretinal arteries do not markedly influence the progression of peripapillary atrophy in glaucoma. SUMMARY: Peripapillary chorioretinal atrophy is one among several morphologic variables to detect glaucomatous abnormalities. Ranking optic disc variables for the detection of glaucomatous optic nerve damage, peripapillary atrophy is a variable of second order. It is useful for the differentiation of various types of chronic open-angle glaucomas. In contrast to glaucomatous eyes, eyes with nonglaucomatous optic nerve atrophy, including eyes after arteritic anterior ischemic optic neuropathy, do not show an enlarged peripapillary atrophy.     

3-dimensional topographic analysis of the papilla as a component of glaucoma diagnosis]

Three-dimensional topography of the optic nerve head can be objectively described by means of quantitative parameter values. Owing to interindividual variability in the disc configuration, new structural variables, such as the relative height of the peripapillary retinal nerve fiber layer in stereo-videography and height variations in the contour line along the disc border in laser scanning tomography, have been shown to differentiate normal optic discs and optic nerve heads with pathological alterations better than standard volumetric data. Using laser scanning tomography, the effect of age on the parameter values of disc area, rim area and the ratio of the cup-to-disc area was evaluated in 61 healthy subjects (age 14 to 77) who had normal visual fields on computerized static perimetry. The rim area decreased with age (rs = -0.26, P < 0.05); the ratio of the cup area to disc area increased (rs = 0.25; P < 0.05). No relationship was found between patient age and disc area (Spearman correlation). Although the coefficients of correlation are rather small, they may reflect the physiological age-related decline in axonal count. The high resolution of strictly confocal laser scanning microscopy allows for visualization of nerve fiber bundle defects underneath a surface of regular reflectivity. The existence of such hidden nerve fiber bundle defects has been postulated before on the basis of experimental studies and may be an early morphological sign of glaucomatous damage.     

Measurements of peripapillary nerve fiber layer contour in glaucoma

We developed a method to quantify the surface contour of the peripapillary nerve fiber layer from simultaneous stereoscopic videographic images. Parameters that describe this contour are defined and compared to standard optic nerve structural parameters (cup/disk ratio, disk rim area, cup volume) in three age-matched groups of patients: 52 normal controls, 79 glaucoma suspects, and 101 glaucoma patients. Greater discriminatory information was obtained from the measurements from the superior and inferior quadrants than from the measurements from the temporal and nasal quadrants. This approach helps identify new structural markers that may more closely reflect the number of ganglion cell axons in the optic nerve. Such measurements made longitudinally in living eyes will provide valuable information about the relative rates of ganglion cell death in aging and in glaucoma.     

视网膜神经纤维层定量测定在青光眼方面的应用

青光眼的主要病理过程是视网膜节细胞轴突（即视神经纤维）的丢失，故测量视网膜神经纤维层（ｒｅｔｉｎａｌｎｅｒｖｅｆｉｂｅｒｌａｙｅｒ，ＲＮＦＬ）来确定轴突丢失的程度在青光眼的早期诊断和治疗上具有非常重要的意义。近年来，计算机图像分析技术应用于眼科，它能对ＲＮＦＬ作出客观的量化检测。该文综述有关文献，就ＲＮＦＬ定量测定方法的原理，以及它们在青光眼ＲＮＦＬ损害检测方面的应用情况作一介绍。     

Videographic measurements of optic nerve topography in glaucoma

Topographic measurements of the optic nerve head were made with computerized videographic image analysis (Rodenstock Analyzer) in one eye each of 36 normal controls, 41 glaucoma suspects and 46 glaucoma patients matched for age. Glaucoma suspects had elevated intraocular pressures and normal visual fields in both eyes. Glaucoma patients had typical visual field defects. Disc measurements were corrected for the optical dimensions of individual eyes. One-way analysis of variance revealed statistically significant differences among the diagnostic groups for cup-disc ratio (P = 0.0006), disc rim area (P less than 0.0001) and cup volume (P = 0.0001). Mean (+/- SEM) disc rim area was 1.14 +/- 0.04 mm2 for controls, 1.10 +/- 0.04 mm2 for glaucoma suspects and 0.87 +/- 0.05 mm2 for glaucoma patients. Mean (+/- SEM) optic nerve cup volume was 0.35 +/- 0.02 mm3 for controls, 0.44 +/- 0.04 mm3 for glaucoma suspects and 0.60 +/- 0.05 mm3 for glaucoma patients. Planimetric measurements of disc rim area were made from manual tracings of stereoscopic disc photographs of the same eyes. There was a statistically significant correlation between the computerized videographic measurements and the manual photographic measurements of disc rim area (r = 0.73, P less than 0.0001). The broad range of values for these optic nerve structural parameters in normal eyes and their overlap with values in glaucomatous eyes prevents their use to reliably predict which patients are normal and which have glaucomatous visual field loss. New parameters are required to fully describe the depth information generated with new quantitative techniques.     

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.     

Nerve fiber layer assessment with scanning laser polarimetry in glaucoma patients and glaucoma suspects.

PURPOSE: To investigate whether scanning laser polarimeter can differentiate glaucoma and suspected glaucoma patients from normals. METHODS: Polarimetric measurements were obtained using the nerve fiber analyzer (NFA)-I from 80 eyes of patients with glaucoma with mostly moderate glaucomatous optic nerve damage (37 eyes with primary open angle glaucoma, 21 with normal tension glaucoma, 17 with pseudoexfoliative glaucoma, 3 with angle closure glaucoma, and 2 with juvenile glaucoma), 53 eyes of patients suspected of glaucoma based on disc appearance, and from age-matched healthy volunteers as control groups. Ratios (superior/nasal, inferior/nasal, superior/inferior) were used for assessing nerve fiber layer (NFL) thickness. Student's t-test and linear regression analysis were used for statistical analysis. RESULTS: Both the glaucoma patients and glaucoma suspects had significantly lower NFL ratios (mean S/N 2.34 +/- 0.47, I/N 2.46 +/- 0.52, S/I 0.94 +/- 0.18) than the control groups (respectively 2.88 +/- 0.48, 2.88 +/- 0.48, 1.00 +/- 0.13) (p<0.05). There was an ample overlap between the patient groups and the normals. The superior and inferior NFL ratios in glaucoma patients gradually decreased as the mean defect in visual field increased (linear regression analysis, p<0.05). CONCLUSIONS: The NFL of glaucomatous eyes and eyes suspected of glaucoma based on disc appearance was significantly less thick than normals. NFA-I detects pathological abnormalities in some patients with glaucomatous optic nerve damage and normal visual fields as measured by conventional achromatic computerized perimetry. NFA-I, however, is unable to distinguish these patients from normals, at least using these parameters, because of the considerable overlap.     

频域OCT视盘形态及神经纤维层厚度参数在青光眼诊断中的作用μ

背景青光眼是一种可引起视神经结构改变,继而导致不可逆视功能损害的一类疾病。光学相干断层扫描（OCT）通过对视盘形态以及神经纤维层的检测,有助于青光眼的早期诊断。目的探讨频域OCT视盘形态及神经纤维层厚度各参数在青光眼诊断中的作用。方法非干预性、横断面研究。应用频域RTVue OCT测量62例正常人和67例青光眼患者的视盘参数,以及视网膜各区域的神经纤维层厚度。用受试者工作特性曲线下面积（ROC）评价OCT每个检测参数区分正常眼与青光眼的能力大小。结果各型青光眼组患者的年龄明显大于正常组,各型青光眼组视野平均缺损（MD）和视野模式标准化差（PSD）值均明显大于正常组,差异均有统计学意义（P〈0．01）。正常组、青光眼组、开角型青光眼组和闭角型青光眼组间视盘面积的总体差异均无统计学意义（P=0．101、0．741、0．652）;正常人平均视网膜神经纤维层厚度为（109．758±9．095）μm,青光眼患者为（79．539±18．986）μm,明显低于正常人（P〈0．01）。在视盘周围8个神经纤维层区域中,正常人最厚的区域在颞下方和颞上方,分别为（150．109±18．007）μm和（146．105±15．529）μm,而青光眼患者最厚处在颞上方和颞下方,分别为（104．354±27．641）μm和（102．436±32．243）μm,但均较正常参数减小。正常人和青光眼患者鼻侧和颞侧视网膜神经纤维层厚度均较薄。视盘参数中,各型青光眼诊断效能最高的是盘沿容积和垂直杯盘比,二者的ROC值在总青光眼患者中分别为0．850和0．840,其特异性在80％时的敏感性分别为73．1％和76．1％,在开角型青光眼患者中分别为0．841和0．849,其特异性在80％时的敏感性分别为73．0％和81．1％,在闭角型青光眼患者中分别为0．862和0．830,其特异性在80％时的敏感性分别为73．3％和70．O％。视网膜神经纤维层厚度各参数中,诊断效能最高的是平均神经纤维层厚度,其ROC值在总青光眼、开角型青光眼、闭角型青光眼中分别为0．925、0．910和0．942,其特异性在80％时的敏感性分别为89．6％、89．2％和90．0％。视盘周围8个神经纤维层区域中,诊断效能最高的是IT区域,诊断效能最低的是TU和TL区域。结论RTVueOCT具有很好地区别正常人和青光眼患者的能力,在青光眼诊断方面是一个较实用的工具。     

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.     

应用SD-OCT纵向比较正常人群和青光眼进展及非进展人群的RNFL厚度

目的：应用频域光学相干断层扫描（ spectral－domain optical coherence tomography ,SD－OCT）纵向比较正常人群、青光眼进展及非进展人群的视网膜神经纤维层（ retinal nerve fiber layer ,RNFL）厚度。方法：应用SD－OCT对36例POAG患者和24例正常人监测RNFL厚度。受试者行视盘OCT、眼底照相及视野检查,每6mo一次,随访2a,至少有4次可信的OCT检查结果。根据视野及眼底照相结果将POAG患者划分为进展组和非进展组。分析各组RNFL厚度变化差异,同视野参数变化值做相关性分析。结果：平均随访2．1±0．3 a。17例被确定为POAG进展组。POAG进展组平均RNFL厚度损失速率明显高于POAG非进展组（2．46μm／a vs 1．21μm／a,P＜0．001）。下方RNFL厚度变化同视野平均偏差（ mean deviation ,MD）变化相关性最佳（r＝0．423,P＝0．03）。结论：应用SD－OCT纵向监测RNFL厚度, POAG进展者RNFL厚度丢失速率明显增高,下方RNFL厚度参数变化可能在监测中意义较大。     

Imagings of glaucoma: characteristics of ocular configurations and automated diagnosis

Glaucoma is characterized by the coexistence of structural changes in the fundus and the corresponding functional abnormalities. The advances in imaging devices that reveal structural changes in glaucoma should facilitate reliable diagnosis of early or preperimetric glaucoma and a proper evaluation of glaucoma progression. Moreover, the increase in our knowledge of structural changes in glaucoma will provide a better platform for investigating up to now unknown glaucoma etiologies. In this review, we summarize a series of our clinical investigations of glaucoma imaging technologies. The diagnostic performance of Heidelberg Retina Tomograph (HRT) II and the characteristics of the HRT II parameters in high myopia were studied with population-based data to provide data for nerve head configuration; the correlation of parameters determined by planimetry of optic disc stereophotography with the results of the HRT II was evaluated; optic disc parameters were determined based on spectral-domain optical coherence tomography (SD-OCT); and optic disc configurations were evaluated in eyes with peripapillary atrophy and eyes with superior segmental optic nerve hypoplasia. Peripapillary retinal nerve fiber layer (RNFL) thickness was determined with SD-OCT in normal Japanese eyes; and the diagnostic performance of RNFL thickness was studied. The characteristics of each layer, including retinal nerve fiber layer, ganglion cell layer, and each complex layer in the macular area, and their correlation with the stages of glaucoma were evaluated. Finally, imaging of the anterior chamber angle using ultrasound biomicroscopy (UBM) were studied about the distribution of the UBM parameters in a Japanese population and the factors relating to the presence of peripheral anterior synechia in narrow angle eyes.     

Peripapillary atrophy in unilateral capsular glaucoma

Pairwise comparisons of peripapillary crescents and haloes were performed for 56 eyes of 28 patients with early or moderate unilateral capsular glaucoma and no signs of exfoliation in the contralateral eye. The eyes differed highly significantly in rim area, rim/disc area ratio, cup area, and cup volume. They did not differ in disc areas, scleral ring areas, or size of peripapillary crescents. In the nonglaucomatous and glaucomatous eyes a significant correlation existed between the intraocular pressure (IOP) and the area of peripapillary atrophy. The area of peripapillary atrophy was significantly correlated with the damage to the glaucomatous optic nerve head. We concluded that the area of peripapillary atrophy is largely an inborn feature, and that nerve fiber loss can occur without differences in the peripapillary tissues. Nevertheless, an IOP-induced change in the retinal pigment epithelium cannot be ruled out.     

The diagnostic value of optic nerve imaging in early glaucoma

In the last decade, new imaging techniques have been added to conventional fundus photography and have been evaluated for use in early glaucoma. They all measure the loss of neuroretinal rim or retinal nerve fiber layer as a correlate to glaucomatous ganglion cell and axon loss. The value of optic disc photography, planimetry, laser scanning tomography, laser scanning polarimetry, and optical coherence tomography for the diagnosis of glaucomatous eyes in a preperimetric or early perimetric stage is analyzed on the basis of sensitivity, specificity, and receiver operating characteristics (ROC) curves. It becomes clear that all these techniques allow a more or less semi-automated evaluation of the optic disc and retinal nerve fiber layer but still have their limitations in the diagnosis of a very early, preperimetric stage of the glaucoma disease.