A comparative study of optic nerve head in low- and high-tension glaucomas

The disc and rim areas in 15 eyes from 15 selected low-tension glaucoma (LTG) patients were compared with those in 15 eyes from 15 selected high-tension glaucoma (HTG) patients. In all patients, visual field defects (VFD) were at an early stage (mean deviation > – 5 dB, program 30-2 of Humphrey Visual Field Analyzer, STATPAC) and were confined to either the upper or lower hemifield. There were no significant differences in the degree of VFD between LTG and HTG, and the peak intraocular pressure averaged 18.9 and 29.2 mmHg for LTG and HTG eyes, respectively. The disc and rim areas were determined from stereoscopic disc photographs using the method of Littmann. The half rim area corresponding to the upper or lower hemifield without VFD was significantly smaller for LTG than HTG (LTG 0.26 ± 0.08 mm², HTG 0.31 ± 0.08 mm², mean ± SID, n= 15, P < 0.005). The rim area corresponding to the upper or lower hemifield with VFD was also significantly smaller for LTG than HTG (LTG 0.19 ± 0.08 mm² HTG 0.24 ± 0.08 mm², P < 0.01). On the other hand, there was no significant difference in the disc area between LTG and HTG (LTG 1.96 ± 0.57 mm², HTG 2.03 ± 0.45 mm², P > 0.4). It was suggested that the differences in rim area were already present prior to the manifestation of the VFD.Correspondence to: M. Araie     

Association between localized visual field losses and thickness deviation of the nerve fiber layer in glaucoma

PURPOSE: To perform a correlation between morphology and function by studying local perimetric field losses and thickness reduction of the nerve layer in corresponding areas. METHOD: Forty-seven patients with "preperimetric" open-angle glaucoma, 95 patients with "perimetric" open-angle glaucoma, and 75 control subjects had perimetric (Octopus) and polarimetric measurements. Criteria for exclusion: optic discs larger than 4 mm, media opacities, polarimetric hourglass pattern in the macular image. Thickness values of the retinal nerve fiber layer were determined in 14 upper and 14 lower sectors (10 degrees each) as well as nasally and temporally (40 degrees each) as provided from the GDx (software version 4000). The healthy control subjects served to determine age-corrected thickness deviation in all sectors. Analyses were calculated in eight nerve fiber bundle related areas. Due to non-linear relationships between perimetric defects and corresponding thickness deviation non-parametric tests were used. RESULTS: Localized visual field defects in the present perimetric patients were highest in upper and lower visual field areas abutting the nasal meridian. Thickness loss of nerve fiber layer however was highest in more circumferential upper and lower nerve fiber bundles. Correlations between local mean defects and deviation of the retinal nerve fiber layer thickness from normals showed a clear association for corresponding areas. The correlation coefficients were significant (P < 0.01) for all arcuate superior and inferior visual field zones except horizontally and not for the area of the lower nasal step. CONCLUSION: The present correspondence map indicates that focal perimetric defects can be identified best polarimetrically if they occur in the arcuate bundles of the visual field. A lack of correspondence was observed in the area of the papillo-macular bundle.     

Frequency doubling technology perimetry in open-angle glaucoma eyes with hemifield visual field damage: comparison of high-tension and normal-tension groups

PURPOSE: To evaluate the performance of frequency doubling technology (FDT) perimetry in open-angle glaucoma eyes with hemifield visual field damage and to compare it between open-angle glaucoma with high pressure [high-tension glaucoma (HTG)] and those with normal pressure [normal-tension glaucoma (NTG)] groups. METHODS: FDT perimetry with the N-30 full threshold protocol and standard automated perimetry (SAP) using the Humphrey Field Analyzer with the 30-2 full threshold protocol were performed in 20 eyes of 20 HTG patients and 36 eyes of 36 NTG patients with visual field damage confirmed with SAP in only one hemifield. RESULTS: There was no significant difference in demographics, the Heidelberg Retina Tomography indices, and the Humphrey Field Analyzer indices between HTG and NTG groups. Regarding the FDT perimetry results, mean deviation in the global field (P=0.009) and mean sensitivity in the SAP-spared (P=0.001) and SAP-impaired (P=0.011) hemifields were lower; the numbers of FDT abnormal test points (probability of abnormality <5%) in the SAP-spared hemifield were significantly greater (P=0.005) in HTG than in NTG groups. Eyes in which FDT results of the SAP-spared hemifield were judged as abnormal was more frequent in HTG groups (P=0.007). CONCLUSIONS: The performance of FDT perimetry to detect early or preperimetric glaucomatous functional changes should be different between HTG and NTG eyes.     

Relationship between short-wavelength automatic perimetry and Heidelberg retina tomograph parameters in eyes with ocular hypertension

AIM:To compare and correlate optic nerve head parameters obtained byHeidelberg retina tomograph (HRT) with short-wavelength automatic perimetry (SWAP) indices in eyes with ocular hypertension (OHT).METHODS: One hundred and forty-six patients with OHT included in the present study. All subjects had reliable SWAP and HRT measurements performed within a 2wk period. The eyes were classified as normal/abnormal according to visual field criteria and Moorfields regression analysis (MRA). Correlations between visual field indices and HRT parameters were analyzed using Pearson correlation coefficient (r).RESULTS:Twenty-nine eyes (19.9%) had SWAP defects. Twenty-nine eyes (19.9%) were classified as abnormal according to global MRA. Six eyes (4.1%) had abnormal global MRA and SWAP defects. The k statistic is 0.116 (P=0.12) indicating a very poor agreement between the methods. No statistical significant correlation between HRT and SWAP parameters was detected.CONCLUSION:SWAP defects may coexist with abnormalities of optic disc detected by HRT in eyes with OHT. In most eyes, however, the two methods detect different glaucoma properties.     

Correlation of structure and function in glaucoma. Quantitative measurements of disc and field

The relationship between quantitative structural measurements of the optic nerve head and quantitative measurements of the visual field in glaucoma was studied. Computerized videographic image analysis (Rodenstock Analyzer) was used to obtain cup-disc ratio, disc rim area, and cup volume in 50 glaucoma suspects and 37 glaucoma patients. The visual field indices, mean defect and loss standard deviation, were calculated from Octopus Program 32. There were statistically significant linear correlations between each of the optic nerve structural parameters and visual field mean defect and loss standard deviation. The strongest correlation was between disc rim area and visual field mean defect (r = -0.49), which are both global measures of glaucomatous damage. The correlations were not strong enough to readily allow the recognition of early nerve damage by the parameters analyzed thus far. Closer correlations may be evident if structural parameters can be found that more accurately reflect the number of surviving axons in the optic nerve head.     

Comparison of retinal nerve-fiber layer in high- and normal-tension glaucoma

In all, 20 eyes of 20 normal-tension glaucoma (NTG) patients and 20 eyes of high-tension glaucoma (HTG) patients matched for similar visual field defects underwent retinal nerve-fiber-layer (RNFL) analysis using a computerized digital-image analysis system. Subjects with NTG showed more localized RNFL loss than diffuse loss as compared with HTG patients. The results support the hypothesis that there may be different mechanisms of damage in glaucoma. Offprint requests to: Y. YamazakiThis study was supported by Grant-in-Aid for Scientific Research 02857249 from the Ministry of Education, Science, and Culture of Japan     

Measuring the optic papilla with planimetry and the optic nerve head analyzer in glaucoma and suspected glaucoma. II. Correlations of the results of both methods with changes in the visual field, studied with the Octopus automatic perimeter

Sixty-seven optic nerve heads of 40 patients with proven or suspected glaucoma were measured by planimetry and with the Rodenstock Optic Nerve Head Analyser (ONHA). The results were compared to visual field indices obtained with the Octopus program G-1. Good correlation of the results obtained by the two measurement procedures has been shown (Stürmer et al. 1989), between values for the disk area, the excavation area, and the cup/disk ratio. However, there is only weak correlation of values for the neuroretinal rim. The planimetrically measured neuroretinal rim area in the total population examined proved to be significantly correlated only with the visual field index for mean retinal sensitivity (MS; r2 = 0.106; P = 0.007) and short-term fluctuations (SF; r2 = 0.066; P = 0.036). After division of the population examined into different diagnostic groups, further statistically significant correlations between optic nerve head parameters and the various visual field indices were shown; here, the cup/disk ratio of both measurement procedures in two subgroups showed the best correlation with the visual field indices MS and mean defect (MD). Neither in the total population nor in any of the subgroups was a statistically significant correlation found between the volume of the excavation and one of the visual field indices. Comparing only the data for the temporal quadrant of the optic nerve head with the visual field did not improve the correlations. The best, i.e. highly significant, correlations were between optic nerve head parameters and the age of the patient. The correlation factors are much lower than other published data. A variety of factors could be responsible for these weak correlations: different optic nerve head configurations on the one hand, and localized or diffuse visual field defects on the other. In unselected cases it appears impossible to predict the visual field of a given optic nerve head. Both methods are suitable for follow-up, but not all anatomical configuration of the optic nerve head permit this.     

Fluorescein fundus angiography of optic nerve head in primary open angle glaucoma and low tension glaucoma]

Fluorescein fundus angiography was performed at angle of 20 degrees in the 58 low tension glaucoma (LTG) eyes (30 cases) and 77 primary open angle glaucoma (POAG) eyes (41 cases) and the relation of the optic nerve head fluorescein changes to visual field disturbances (stage classification of Kosaki) was compared between POAG and LTG groups. The filling defect of fluorescein in the deep area and the decrease in number of superficial capillaries were observed in the optic nerve head. The filling defect area of fluorescein in the optic nerve head corresponding to Bjerrum scotoma was recognized even in the mild visual field disturbance cases of both LTG and POAG. The following findings were noted in both LTG and POAG cases; expansion of the filling defect area and the decrease in number of superficial capillaries in the same area with progression of visual field disturbances. Filling defect area of fluorescein of the optic nerve head accorded with visual field disturbance area in 19 LTG eyes (32.8%) and 61 POAG eyes (79.2%). On the contrary, the filling defect area of the optic nerve head was wider than the visual disturbance area in 37 LTG eyes (63.8%) and 16 POAG eyes (20.8%). These findings suggest that blood circulatory disorders of the optic nerve head occurred earlier in LTG than in POAG and that the development of LTG might be closely associated with the blood circulatory disorders.     

Correlation between intraocular pressure level and optic disc changes in high-tension glaucoma suspects

PURPOSE: To assess the correlation between intraocular pressure (IOP) and future optic disc changes in eyes of patients suspected of having high-tension glaucoma and to determine the target pressure in eyes of patients suspected of having high-tension glaucoma. DESIGN: Prospective, comparative, observational case series. PARTICIPANTS: Fifty-seven eyes of 57 patients suspected of having high-tension glaucoma selected from 226 consecutive patients with glaucoma or suspected glaucoma. INTERVENTION: The status of the optic disc and visual fields was evaluated during an initial examination by confocal laser ophthalmoscopy and automatic perimetry, respectively. Fifty-seven eyes were followed up for at least 2.5 years and then underwent a final examination. IOP was measured every 3 months. MAIN OUTCOME MEASURES: The correlation between changes in optic disc status and IOP control during follow-up was determined. Changes in the optic disc were evaluated by using the percentage change in total contour area, neuroretinal rim area, and cup-to-disc ratio. The control IOPs were evaluated on the basis of the percentage of time during which IOP was <18 mmHg (%<18 mmHg control) and <21 mmHg (%<21 mmHg control) during follow-up in each eye. The correlation between visual field changes and IOP control was also analyzed. RESULTS: Results from 48 (84.2%) of 57 participants were included. Patients were followed up for a mean 4.4 years. The %<21 mmHg control was significantly correlated with changes in neuroretinal rim area (r = 0.40; P = 0.0055) and in cup-to-disc ratio (r = -0.40; P = 0.0051) by linear regression analysis. The correlations were also significant if the difference in the length of follow-up was adjusted by multivariate regression analysis. There was no significant correlation between %<18 mmHg control and changes in disc parameters. Seven (14.6%) of 48 eyes had glaucomatous visual field defects at the final examination. The %<21 mmHg control was significantly lower in eyes with visual field changes compared with eyes with no changes (P = 0.0153; unpaired t test). In contrast, %<18 mmHg control was not significantly different between eyes with and without visual field changes (P = 0.3886). CONCLUSIONS: The IOP level correlates with topographic changes in the optic disc in eyes of patients suspected of having high-tension glaucoma. The target pressure for such eyes may need to be between 18 and 21 mmHg, and <18 mmHg is a safe target level in the treatment of patients suspected of having high-tension glaucoma to delay topographic optic disc changes.     

青光眼阈值视野缺损的计分方法评价

目的：评价青光眼视野缺损计分方法的有效性和可靠性。方法：采用AGIS(Advanced Glaucoma Intervention Study)研究组推荐的计分方法并稍加改动对9l例(91眼)青光眼患者的视野进行计分，分析视野缺损计分值与C／D比、平均缺损(mean defect，MD)值及缺失方差（loss variance，LV)值的关系和相关性。结果：视野缺损计分值越大，C／D比、MD值及LV值亦越大，视野缺损计分值与C／D比呈明显的正相关（r=0．8712)，其相关系数大于MD值和LV值与C，D比的相关系数。结论：视野缺损计分法较视野指数能更准确地反映青光眼视神经损害情况，能对青光眼视野损害的程度进行量化表达。     

Ability of a confocal scanning laser ophthalmoscope (TopSS) to detect early glaucomatous visual field defect

AIMS: To evaluate the ability of the confocal scanning laser ophthalmoscope (TopSS) to detect early glaucomatous visual field defect using our unique discriminant criteria. METHODS: The optic discs of 110 eyes of normal Korean subjects were examined and normal values for each variable were obtained according to the size of the optic disc. The five most sensitive optic disc variables for discriminating glaucoma were then applied to one eye of 80 Korean subjects with primary open angle glaucoma or normal tension glaucoma. Only eyes with an optic disc size of 2.0-3.0 mm(2) and a contour tilt of less than 3 degrees were included. These variables were used to develop unique discriminant criteria for detecting early glaucomatous visual field defect and their sensitivity and specificity were calculated in three groups of patients with visual field loss. RESULTS: The five most sensitive variables were half the depth area, cup/disc (C/D) ratio, total area of the neuroretinal rim (NRR), volume above, and localised thinning of the NRR. The following criteria were used to diagnose glaucoma: (1) total area of the NRR decreased and one of the other four variables abnormal, and (2) total area of the NRR normal, localised thinning of the NRR, and one of the other three variables abnormal. The sensitivity of these criteria was 89.7% in patients with a mildly impaired visual field and 100% in those with a moderately or severely impaired visual field; the specificity was 89.1%. CONCLUSIONS: The discriminant criteria used had high sensitivity and specificity in the diagnosis of glaucoma and the TopSS can be useful in the early detection of changes in the glaucomatous optic disc.     

Visualising structural and functional characteristics distinguishing between newly diagnosed high-tension and low-tension glaucoma patients

Purpose

To determine whether there are quantifiable structural or functional differences that can distinguish between high-tension glaucoma (HTG; intraocular pressure [IOP] > 21 mm Hg) and low-tension glaucoma (LTG; IOP ≤ 21 mm Hg) at diagnosis.

Method

This was a retrospective, cross-sectional study. Clinical results of one eye from 90 newly diagnosed HTG and 319 newly diagnosed LTG patients (117 with very-low-tension glaucoma [vLTG; ≤15 mm Hg] and 202 with middling LTG [mLTG; >15 mm Hg, ≤21 mm Hg]) were extracted, which included relevant demographic covariates of glaucoma, quantitative optical coherence tomography (including the optic nerve head, retinal nerve fibre layer and ganglion cell-inner plexiform layer) measurements and standard automated perimetry global metrics. We used binary logistic regression analysis to identify statistically significant clinical parameters distinguishing between phenotypic groups for inclusion in principal component (PC) (factor) analysis (PCA). The separability between each centroid for each cohort was calculated using the Euclidean distance (d(x,y)).

Results

The binary logistic regression comparing HTG and all LTG identified eight statistically significant clinical parameters. Subsequent PCA results included three PCs with an eigenvalue >1. PCs 1 and 2 accounted for 21.2% and 20.2% of the model, respectively, with a d(x,y) = 0.468, indicating low separability between HTG and LTG. The analysis comparing vLTG, mLTG and HTG identified 15 significant clinical parameters, which were subsequently grouped into five PCs. PCs 1 and 2 accounted for 24.1% and 17.8%, respectively. The largest separation was observed between vLTG and HTG (d(x,y) = 0.581), followed by vLTG and mLTG (d(x,y) = 0.435) and lastly mLTG and HTG (d(x,y) = 0.210).

Conclusion

Conventional quantitative structural or functional parameters could not distinguish between pressure-defined glaucoma phenotypes at the point of diagnosis and are therefore not contributory to separating cohorts. The overlap in findings highlights the heterogeneity of the primary open-angle glaucoma clinical presentations among pressure-defined groups at the cohort level.     

Retinal nerve fiber layer measures in high- and normal-tension glaucoma.

PURPOSE: To use optical coherence tomography (OCT) to investigate the qualitative and quantitative differences in the defects of the retinal nerve fiber layer (RNFL) in subjects with high tension primary open angle glaucoma and subjects with normal tension glaucoma. METHODS: RNFL was assessed with OCT in 21 eyes with high-tension glaucoma (HTG) and 20 eyes with normal-tension glaucoma (NTG). Regression analyses were performed to investigate the interaction of disease group and location for localized RNFL loss, and to predict diffuse and localized RNFL loss as a function of age, mean defect, spherical equivalent, disease group, and location. Local RNFL thicknesses for superior clock-hour regions were estimated after adjustment for the thicknesses of symmetrically opposed locations. RESULTS: There were no differences in mean age, visual field defect mean deviation, and refractive error between subjects in HTG and NTG groups. Diffuse RNFL thickness was not significantly different between the two groups [mean RNFL for NTG > HTG by 3.48 mum, 95% confidence interval (CI) -3.9 to 10.9 microm, p = 0.092]. There was no significant interaction of group and location for localized RNFL loss (p = 0.916). Local RNFL thickness at superior regions was not significantly different in the two groups, after adjustment for RNFL thickness at corresponding inferior locations (mean RNFL for NTG > HTG by 6.30 microm, 95% CI -1.08 to 13.7 microm, p = 0.34). RNFL thickness decreased, on average (1.88 microm/dB mean deviation, 95% CI 1.21 to 2.55 microm, p < 0.0001) and locally (1.37 microm/dB mean deviation, 95% CI 0.79 to 1.96 microm, p < 0.0001), with increasing severity of glaucoma. CONCLUSION: There is no difference in the spatial pattern of RNFL defects, as assessed by the OCT, between HTG and NTG.     

正常眼压性青光眼与高眼压性青光眼视神经图像分析的对比研究

目的 探讨正常眼压性青光眼 (normal-tension glaucoma, NTG)与高眼压性青光眼(high-tension glaucoma, HTG)视盘和视神经纤维层(retinal nerve fiber layer, RNFL)损害的差异。 方法 选择具有青光眼性视神经损害或RNFL缺损、相应的视野缺损的青光眼患者,NTG至少2次24 h眼压曲线和多次眼压测量均≤21 mm Hg(1 mm Hg =0.133 kPa)，HTG的眼压至少2次测量≥25 mm Hg。患者进行详细的眼科检查，同时用扫描激光偏振仪(scanning laser polarimetry, SLP)、光学相干断层扫描（optical coherence tomography, OCT）和海德堡视网膜成像仪(Heidelberg retinal tomography, HRT)定量测定视盘形态和RNFL厚度。比较两组视盘总体和相同象限测量参数。 结果 30例 NTG和 19例 HTG (共49只眼)患者的平均年龄分别为(59.6±8.6)岁(39～71岁)和(59.2±12.3)岁(36～75岁)。两组间视野缺损的平均偏差(mean deviation, MD)差异不显著(P＞0.05)。HRT测量的视盘 C/D面积比，除鼻侧象限外,NTG者视盘总体和上、下、颞侧3个象限均显著大于HTG者(P＜0.05 ),而盘缘面积小于HTG者(P＜0.05)；两组间其他视盘参数差异不显著。3种激光扫描技术所测定的总体和象限RNFL厚度，两组间差异不显著。 结论 NTG趋向大 C/D面积比和窄盘缘面积。RNFL缺损的形态分布须更精细和节段性分析。 (中华眼底病杂志, 2002, 18: 109-112)     

Progressive visual field defects from experimental glaucoma: measurements with white and colored stimuli.

PURPOSE: Our purpose was to study the effects of using monochromatic test stimuli to measure the relative rate of progression of visual field defects caused by experimental glaucoma. METHODS: Visual field measurements were obtained by static perimetry from trained macaque monkeys with laser-induced, unilateral glaucoma. The visual field defects were assessed by perimetric (global) indices derived from comparisons of experimental visual fields to the expected normal fields of monkeys. Three types of perimetry stimuli were used, the conventional white Goldmann III and two monochromatic (460 and 620 nm) Goldmann V test stimuli. The relationships between field defects with white and monochromatic stimuli were investigated by linear regression of the Z-scores for the perimetric indices. RESULTS: The correlations between the mean deviation global indices for chromatic vs. white stimuli were high (r > 0.9) and linear throughout the period of progression of field defects. The slopes of the regression lines typically were greater than unity, indicating that statistical significance was higher for visual field defects measured with chromatic stimuli than with white light stimuli. The higher significance level for defects measured with chromatic stimuli was not explained by a difference in visual thresholds, because the thresholds with chromatic and white light were highly correlated across the full range of visual field defects, from initial-onset to end-state. This result also suggests that the early detection of glaucomatous visual defects with monochromatic stimuli does not reflect a selective loss of retinal ganglion cells. CONCLUSIONS: Although these experiments do not suggest an alternative neural mechanism for the clinical utility of perimetry with chromatic light for the early detection of glaucoma, it is very likely that the combinations of neural and/or analytical factors that explain the utility of perimetry with chromatic stimuli will also provide an explanation for the higher sensitivities in identifying early glaucoma reported for other prototype stimuli.     

Is the nasal optic disc sector important for morphometric glaucoma diagnosis?

BACKGROUND/AIM: Since the central retinal vessel trunk usually located in the nasal optic disc sector can render difficult the delineation of the neuroretinal rim and optic disc, the aim of this study was to evaluate whether the nasal region of the optic nerve head is important, or can be left out, for the morphometric glaucoma diagnosis. METHODS: The clinical observational study included 1337 patients with primary or secondary open angle glaucoma and 649 normal subjects. The glaucoma group was divided into 1187 patients with glaucomatous visual field defects ("perimetric glaucoma"), and into 150 patients with optic nerve head changes and normal visual fields ("preperimetric glaucoma"). Colour stereo optic disc photographs were morphometrically evaluated. RESULTS: Highest diagnostic power for the separation between the normal group and the perimetric glaucoma group, and for the differentiation between the normal group and the preperimetric glaucoma group, had the sum of inferotemporal rim area plus superotemporal rim area, the sum of inferotemporal rim area plus superotemporal rim area plus temporal rim area, and the inferotemporal rim area as single parameter. The lowest diagnostic precision had the nasal rim area as single parameter or in combination with rim measurements in other disc sectors. CONCLUSION: Excluding the nasal optic disc sector does not markedly decrease the diagnostic power of morphometric optic disc analysis in glaucoma diagnosis. It may have importance for an automated computerised morphometric detection of glaucomatous optic nerve damage.     

Anisometropia and degree of optic nerve damage in chronic open-angle glaucoma

PURPOSE: To address the question of whether the refractive error plays a role in the amount of optic nerve damage in glaucoma, we intraindividually compared inter-eye differences in refractive error with inter-eye differences in parameters indicating the degree of glaucomatous optic nerve damage, and we interindividually correlated refractive error with neuroretinal rim area and visual field loss.DESIGN: Comparative clinical observational study.METHODS: This comparative clinical observational study was conducted in a university eye hospital. The study included 1,444 eyes of 876 patients with primary or secondary chronic open-angle glaucoma. Patients with a highly myopic refractive error (> or = -8 diopters) were excluded, owing to differences in the anatomy of the optic nerve head. Color stereo optic disk photographs were taken and morphometrically evaluated. The main outcome measures were refractive error, neuroretinal rim area, horizontal and vertical cup/disk diameter ratios, and visual field loss.RESULTS: In an interindividual statistical analysis, area of neuroretinal rim, horizontal and vertical cup/disk diameter ratios, and mean visual field loss were not significantly (P >.10) correlated with refractive error. In an intraindividual comparison, inter-eye differences in refractive error were not significantly (P >.05) correlated with inter-eye differences in neuroretinal rim area and mean visual field defect. The eye with the more myopic refractive error and the contralateral eye with the less myopic refractive error did not vary significantly in neuroretinal rim area and mean visual field defect.CONCLUSIONS: For nonhighly myopic (< -8 diopters) patients with primary or secondary chronic open-angle glaucoma, the refractive error may not play a major role for the amount of glaucomatous optic neuropathy. For nonhighly myopic (< -8 diopters) patients with primary or secondary chronic open-angle glaucoma, myopia may not be an important risk factor for glaucoma.     

Parapapillary region in normal and glaucoma eyes. II. Correlation of planimetric findings to intrapapillary, perimetry and general data

The planimetric values of the parapapillary region in 312 unselected eyes with chronic primary open-angle glaucoma and 125 normal eyes of an age-/and refraction-matched control group were correlated to the intrapapillary, perimetric, and general data of these eyes. High myopics (less than -8.00 D) and "ocular hypertensives" were excluded. Zone "Alpha" and "Beta" incipient to advanced or subtotal to total parapapillary chorio-pigmentepithelioretinal atrophy) were significantly correlated (p less than 0.001) to: 1) area and width of the neuroretinal rim as a whole and in four different optic disk sectors; 2) cup area; 3) horizontal and vertical c/d ratios; 4) glaucoma stage; 5) age, and 6) refraction. Zone "Beta" was additionally correlated to the perimetric indices. Its correlation coefficients were generally higher than those of zone "Alpha." Sex and side showed no significant relationships. Divided into four different radial sectors, both zones "Alpha" and "Beta" were significantly larger (p less than 0.001) the smaller the neuroretinal rim area (intrapapillary) in the same sector was. Additionally, zone "Beta" was significantly (p less than 0.001) most often largest in the sector where the rim area was smallest. Thus, besides the temporal there was also a spatial correlation between the intrapapillary and parapapillary glaucomatous alterations. "Conus pigmentosus" and the peripapillary scleral rim showed no significant glaucoma-associated correlations and are thus without importance for quantified optic disk evaluation in glaucoma. Zones "Alpha" and "Beta", as regions of early to advanced of subtotal to total parapapillary, chorio-pigmentepithelioretinal atrophy, are not only chronologically but also spatially correlated to intrapapillary glaucomatous changes and are important in optic disk evaluation in glaucoma.     

Fluorescein filling defects of the optic nerve head in normal tension glaucoma, primary open-angle glaucoma, ocular hypertension and healthy controls

BACKGROUND: To evaluate fluorescein filling defects of the optic nerve head in normal tension glaucoma (NTG), primary open-angle glaucoma (POAG), ocular hypertension (OHT) and controls. METHODS: Forty patients with NTG (mean age 55 +/- 10 years), 40 patients with POAG (mean age 55 +/- 11 years), 40 patients with OHT (mean age 53 +/- 13 years), and 40 age-matched controls (mean age 54 +/- 11 years) were included in a prospective study. Video fluorescein angiograms were performed by means of a scanning laser ophthalmoscope. The extent of absolute filling defects of the optic nerve head was assessed (as a percentage of the disc area) using digital image analysis. Visual fields were tested by automatic static perimetry (Humphrey Field Analyzer, programme 24-2). RESULTS: Absolute filling defects were significantly larger in patients with NTG (12.2 +/- 15.5%) and POAG (12.9 +/- 13.1%) compared to patients with OHT (1.2 +/- 3.6%) and healthy controls (0.1 +/- 0.5%) (p < 0.0001). The area under the receiver operating characteristic (ROC) curve was 0.806 for NTG vs healthy controls, and 0.812 for POAG vs OHT. Absolute filling defects are significantly correlated to the global indices mean deviation (r = -0.63, p < 0.0001), pattern standard deviation (r = 0.61, p < 0.0001), and corrected pattern standard deviation (r = 0.62, p < 0.0001) and significantly correlated to horizontal (r = 0.50, p < 0.0001) and vertical (r = 0.53, p < 0.0001) cup-to-disc-ratios. CONCLUSIONS: Fluorescein filling defects of the optic disc representing capillary dropout are present in NTG and POAG. The extent of these filling defects is correlated to visual field loss and morphological damage. Fluorescein angiography may be useful in the diagnosis and management of NTG and POAG.     

Difference of optic disc topography between a low-tension group and a high-tension group in normal-tension glaucoma patients

PURPOSE: Glaucomatous visual field loss and optic disc damage differ by intraocular pressure (IOP) levels. In this study, we compared the optic disc topography in the high-tension group and the low-tension group in normal-tension glaucoma (NTG). METHOD: We selected NTG patients with mean deviation (MD) > or = -10.00 dB and the highest recorded IOP of < 14 mmHg or > or = 17 mmHg without glaucoma treatment. We classified NTG eyes into the following two groups: 1) a low-tension group with the highest recorded IOP of < 14 mmHg, 2) a high-tension group with the highest recorded IOP of > or = 17 mmHg. The optic disc parameters in the low-tension group eyes were compared with those in the high-tension group eyes using a Heidelberg Retina Tomograph. RESULTS: Nineteen eyes of nineteen patients were selected for each group. The cup/disc area ratio in the global sector, and the rim volume in the nasal sector of the low-tension group had deteriorated more than in the high-tension group. CONCLUSIONS: The disc topography is different between the low-tension group and the high-tension group in the nasal sector, suggesting that different pathogenetic mechanisms exist in the optic disc damage in NTG.