原发性开角型青光眼HRT视盘参数和视野缺损的关系

目的 :探讨原发性开角型青光眼视盘参数和视野平均缺损之间的关系。方法 :用海德堡视网膜断层扫描仪和自动视野计测定 5 5名原发性开角型青光眼患者的视盘参数 (杯盘面积比、盘沿面积、盘沿容积、视杯容积、视杯形态测量、视杯高度变异轮廓和平均神经纤维层厚度 )和静态光阈值。视盘参数与视野平均缺损作相关分析和多元线性回归分析。结果 :盘沿面积与平均缺损显著相关 (r =0 3 5 0 ,P <0 0 5 )。盘沿面积每减少 1mm2 ,视野缺损绝对值增加 8 0 81dB。本研究没有发现其它 6个参数与平均缺损相关关系的显著性。结论 :盘沿面积在HRT众多参数中最能反映青光眼的视野平均缺损程度。     

原发性开角型青光眼视盘及视网膜血流的研究

目的探讨原发性开角型青光眼患者和正常人视盘及其周边视网膜血液供应是否存在差异.方法本研究采用了一种新型共焦扫描激光多普勒血流仪--海德堡视网膜血流仪(heidelberg retina     

Decreased blood flow at neuroretinal rim of optic nerve head corresponds with visual field deficit in eyes with normal tension glaucoma

PURPOSE: To determine the relationship between the blood flow parameters of the optic disc rim and the glaucomatous visual field changes. DESIGN: Observational cross-sectional study. METHODS: Tissue blood flow in the neuroretinal rim within the optic disc was determined with the Heidelberg retina flowmeter(HRF) in 54 eyes of 54 patients with normal tension glaucoma (NTG). Patients were selected whose visual field defects were confined to either the superior or inferior hemifield. Blood flow measurements were made in a 10 degrees x 2.5 degrees area of the superior and inferior neuroretinal rim within the optic disc. The mean blood flow (MBF) was calculated by the automatic full-field perfusion image analyzer program, and the ratio of the MBF in the superior to the inferior rim areas (the S/I ratio) was calculated from the same HRF image in order to minimize the variation of measurement condition. RESULTS: Inferior rim blood flow is less than superior rim blood flow in patients with superior hemifield defect, and superior rim blood flow is reduced compared to inferior in patients with inferior hemifield defect. The mean S/I ratios of the MBF in the patients with superior hemifield defect (1.46, n=37) was significantly higher than that in the patients with inferior hemifield defect (0.79, n=17; P<0.0001, Mann-Whitney U-test). CONCLUSIONS: The blood flow in the neuroretinal rim was found to correspond to the regional visual field defect in eyes with NTG. Reductions in flow were associated with reductions in function.     

Asymmetric visual field loss and retrobulbar haemodynamics in primary open-angle glaucoma

Purpose To investigate interocular differences in retrobulbar flow velocities in patients with asymmetric glaucomatous visual field loss.Methods Twenty-five patients with primary open-angle glaucoma (POAG) and asymmetric visual field loss were included in this study. Asymmetric visual field loss was defined as a difference of the global index mean deviation (MD) >6 dB between the two eyes. Flow velocities (peak systolic velocity PSV and end-diastolic velocity EDV) and resistive indices (RI) of the ophthalmic artery (OA), central retinal artery (CRA), and nasal and temporal posterior ciliary arteries were measured by means of colour Doppler imaging.Results MD of eyes with more severe glaucomatous visual field loss was −18.3±7.8 dB vs −6.8±5.5 dB (p<0.0001) in the less affected eyes. The PSV and the EDV of the CRA and the PSV of the OA were significantly decreased in eyes with more severe glaucomatous visual field loss (CRA PSV: 7.6±2.0 cm/s vs 8.3±1.7 cm/s, p=0.04; CRA EDV: 2.24±0.5 cm/s vs 2.55±0.6 cm/s, p<0.007; OA PSV: 29.7±9.9 cm/s vs 32.7±11.5 cm/s, p<0.02). None of the other differences in velocity or resistive index were significant.Conclusions Patients with asymmetric glaucomatous visual field loss exhibit asymmetric flow velocities of the CRA and OA. Patients with more severe damage display reduced flow velocities in retrobulbar vessels in POAG.     

Relationship between optic nerve head microcirculation and visual field loss in glaucoma

PURPOSE: To study the relationship between optic nerve head blood flow velocity and visual field loss in patients with primary open-angle glaucoma (POAG) and normal tension glaucoma (NTG). METHODS: This study included 44 eyes of 44 patients with POAG and 44 eyes of 44 patients with NTG. To evaluate optic nerve head blood flow velocity, the square blur rate (SBR) was measured by means of laser speckle flowgraphy. The correlation between SBR and Humphrey visual field indices was evaluated with linear regression analysis. RESULTS: In the NTG group, the average SBR at the superior and inferior temporal neuroretinal rim was positively correlated with mean deviation (MD) (r = 0.349, p = 0.020). The SBR at the superior or inferior temporal neuroretinal rim was positively correlated with the sum of the total deviations in the corresponding hemifields (r = 0.299, p = 0.049; r = 0.354, p = 0.019, respectively). The correlations between SBR and MD did not differ statistically between the NTG and POAG groups; however, no significant correlation between SBR and visual field indices was observed in the POAG group. CONCLUSION: These results suggested that the change in the circulation of the optic nerve head may be related to visual field damage in the NTG group but may be less involved in visual field damage in the POAG group.     

Morphology of the optic papilla in glaucoma. II. Secondary chronic open angle glaucoma

Previous studies have shown that the chronic open-angle glaucomas form a heterogeneous spectrum of diseases which have in common an open anterior chamber angle and glaucomatous optic nerve damage. Purpose of this study was to evaluate whether the appearance of the optic disc shows specific features among various types of secondary chronic open-angle glaucoma. METHODS: Clinical data and color-stereo optic disc photographs of 126 patients with pseudoexfoliative glaucoma and 47 patients with pigmentary glaucoma were compared with those of 501 patients with primary open-angle glaucoma (POAG) and of 481 normal subjects. The glaucoma groups did not differ in neuroretinal rim nor in perimetric mean defect. RESULTS: Mean optic disc area was significantly smaller in the pseudoexfoliative glaucoma eyes (2.54 +/- 0.51 mm2 vs. 2.71 +/- 0.63 mm2, p = 0.03) than in the primary open-angle glaucoma eyes. The pigmentary glaucoma group did not vary significantly from the primary open-angle glaucoma group in size of the optic disc. No significant differences were found for neuroretinal rim area, configuration of neuroretinal rim, depth of optic cup and diameters of the retinal arterioles and venules at the disc border between the secondary glaucoma groups and the POAG group respectively. Size of zone beta of the parapapillary atrophy was slightly, but not significantly smaller in the secondary glaucoma groups than in POAG. In the secondary glaucoma groups, the maximal intraocular pressure measurements were significantly (p < 0.001) higher than in the group with POAG. All glaucoma groups had a significantly smaller neuroretinal rim, significantly smaller retinal arterioles, and significantly larger parapapillary atrophy compared to the normal group. CONCLUSIONS: Except of a slightly smaller optic disc in eyes with pseudoexfoliative glaucoma, eyes with secondary glaucoma due to pseudoexfoliation or due to pigmentary dispersion do not vary significantly in their optic disc morphology compared to POAG and do not show pathognomonic features of the optic disc despite marked changes in the anterior segment of the eye.     

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.     

Papillary blood flow and morphological parameters of the optic nerve head in patients with normal tension glaucoma, primary open angle glaucoma and in healthy volunteers

The aim of the present study was to compare selected morphological parameters of the optic nerve head and papillary blood flow in patients with NTG, POAG and in healthy volunteers, as well as to find any possible correlation between selected morphological parameters and papillary blood flow. 21 glaucomatous and 31 normal eyes were diagnosed using HRT and HRF. Statistically significant differences within many morphological parameters like cup area, cup to disc, cup shape measure, rim volume, RFNL thickness, RFNL cross section and neuroretinal rim blood flow appeared. Nevertheless, in glaucoma patients no statistically significant differences between morphology and flow were found. The conclusion is that blood flow impairment within the neuroretinal rim is connected with glaucoma neuropathy development, nevertheless it is affected by other factors.     

Early detection of glaucoma by longitudinal monitoring of the optic disc structure

Computerized disc analysis (optic nerve-head analyzer, Rodenstock) and automated perimetry (Octopus 2000R, program G1) were used for the longitudinal monitoring of 25 subjects with elevated intraocular pressure (47 eyes). The mean follow-up time was 17.9 months (range, 12–30 months). The average number of disc examinations per eye during the follow-up period was 4.4 (range, 3–7). A progressive decrease in neuroretinal rim area was observed in 8 of 47 eyes. This continuous decrease is nonphysiological and must be interpreted as a valid sign of ongoing glaucomatous damage. It apparently precedes visual field defects, as all eyes showing continuous loss of neuroretinal rim area have had normal visual fields up to the present. Of the remaining 47 eyes, 21 showed a slight increase or no change in neuroretinal rim area. These eyes obviously did not suffer from progressive glaucomatous nerve-head damage during the follow-up period. A total of 18 eyes showed either considerable fluctuations or only a slight decrease in neuroretinal rim area; no decision can yet be made as to whether or not these eyes actually suffered glaucomatous damage.     

Optic disc progression and rates of visual field change in treated glaucoma

Purpose: To investigate the relationship between optic disc progression and rates of visual field (VF) change in patients with treated glaucoma. Methods: Glaucoma patients with repeatable VF loss, ≥8 SITA‐Standard 24‐2 VF tests and good quality optic disc stereophotographs evaluated over a 10‐year period were included. Optic disc photographs were reviewed for signs of glaucoma progression (neuroretinal rim change, widening of retinal nerve fibre layer defect, disc haemorrhage and enlargement of beta‐zone parapapillary atrophy) by two glaucoma specialists masked to their temporal sequence. Disagreements were adjudicated by a third grader. VF progression was evaluated using automated pointwise linear regression (PLR) and defined as at least two adjacent test points progressing >1.0 dB/year at p < 0.01. VF progression outcomes were compared with photograph review results. Results: Three‐hundred and eighty nine eyes (389 patients; mean age 64.9 ± 13.0 years; mean baseline MD, ?7.1 ± 5.1 dB) were included. Most patients had primary open angle glaucoma (54%). Eighty‐two eyes (21%) had confirmed optic disc progression and 115 eyes (29%) met the VF PLR criteria. Eyes with documented optic disc progression had more rapid rates of VF change (?0.66 ± 0.7 versus ?0.36 ± 0.7 dB/year, p < 0.01) and met the VF PLR endpoint more often (univariate OR = 1.85, p = 0.02; multivariate OR = 1.78, p = 0.03) than eyes without optic disc progression. There was moderate spatial consistency between the location of the optic disc progression and the hemifield with more rapid progression (81%, kappa = 0.40). Conclusions: Treated glaucomatous eyes with documented optic disc progression are at increased risk of diminished visual function over time and may require more aggressive therapy to prevent future vision loss. Among the indicators of structural progression, disc haemorrhage was the single most significant predictor for VF deterioration.     

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.     

Association between lower optic nerve laser Doppler blood volume measurements and glaucomatous visual field progression

AIM: To perform a preliminary assessment of the relation between optic nerve circulatory parameters and glaucomatous visual field progression. METHODS: This study included 29 eyes of 23 patients with open angle glaucoma that had typical glaucomatous nerve fibre bundle visual field defects and increased cup to disc ratios. Laser Doppler flowmetry (Oculix) was used to measure relative optic nerve blood volume (Vol), velocity (Vel) and flow in the superior temporal (ST) and inferior temporal (IT) neuroretinal rim of the optic nerve. After blood flow measurements patients were followed for 6-62 months (mean 33 (SD 17) months) and 2-11 Humphrey visual fields (4.7 (2.6) fields) were obtained. Progression of glaucoma was assessed by the slope of the corrected pattern standard deviation (CPSD) values versus time, which was calculated manually for each eye using regression analysis. RESULTS: A significant negative correlation was observed between Vol in the IT rim and the CPSD slope (r=-0.56, p=0.002); patients with lower Vol tended to show faster progression of glaucomatous field damage than those with higher Vol. When the eyes were arbitrarily divided into two groups according to lower Vol (0.32 (0.06) arbitrary units, AU, n=15) or higher Vol (0.49 (0.06) AU, n=14), those with lower Vol had significantly worse mean CPSD slopes (0.50 (0.48) dB/year) than those with higher Vol (-0.67 (1.38) dB/year; Student's t test, p=0.009). CONCLUSIONS: In the IT rim, the area most prone to develop glaucomatous field damage, lower Vol is associated with subsequently faster CPSD progression. These measurements suggest that circulatory abnormalities may have a role in the development of glaucoma.     

原发性开角型青光眼HRT视盘结构参数与视野缺损相关性研究

目的探讨出现视野缺损与未出现视野缺损的原发性开角型青光眼视盘结构参数的异同及视盘参数与视野平均缺损（MD）的相关性。方法应用海德堡视网膜断层扫描仪（HRT-Ⅱ）和Octopus101视野G2程序对29例（50只眼）原发性开角型青光眼患者进行检查，对出现视野缺损与未出现视野缺损的原发性开角型青光眼视盘结构参数进行比较，检测结果进行t检验；对出现视野缺损的原发性开角型青光眼组的视盘各参数与视野平均缺损进行简单相关分析。结果视野出现缺损组与未出现缺损组的原发性开角型青光眼患者的视盘参数除视盘面积和轮廓线高度变化值外，其余各视盘参数间差异均有显著性（P〈0．01）；对出现视野缺损的原发性开角型青光眼患者HRT视盘各参数与MD进行相关分析显示，盘沿面积与MD间相关性最强（r=0．65，P=0．001）。结论HRT视盘参数能够较准确反映与视野损害相一致的青光眼性视盘改变，盘沿面积在HRT众多参数中最能反映青光眼的视野平均缺损程度。     

Predictive factors of the optic nerve head for development or progression of glaucomatous visual field loss

PURPOSE: To evaluate which morphologic features of the optic disc are predictive factors for the development or progression of visual field loss in chronic open-angle glaucoma. METHODS: The prospective observational clinical study included 763 eyes of 416 white subjects with ocular hypertension and chronic open-angle glaucoma. During the follow-up time (mean, 67.4 months; median, 65.1; range, 6.2-104.5), all patients underwent repeated qualitative and morphometric evaluation of color stereo optic disc photographs and white-on-white visual field examination. Progression of glaucomatous visual field damage was defined by point-wise regression analysis for each of the 59 locations in the visual field. Outcome measures were qualitative and quantitative morphologic optic nerve head parameters. RESULTS: Development or progression of glaucomatous visual field defects was detected in 106 (13.9%) eyes. At baseline of the study, neuroretinal rim area was significantly (P < 0.002) smaller, the beta zone of parapapillary atrophy (P < 0.003, nasal sector) was significantly larger, and age was significantly higher (P < 0.003) in the progressive study group than in the nonprogressive study group. Both study groups did not vary significantly in size of the optic disc and the alpha zone of parapapillary atrophy. Cox proportional hazard regression analysis revealed that the progression of glaucomatous visual field loss depended significantly on the area of the neuroretinal rim (P < 0.001) and age (P < 0.001), but was independent of diameter of the retinal arterioles and veins. CONCLUSIONS: Morphologic predictive factors for development or progression of glaucomatous visual field defects in whites are small neuroretinal rim area and large beta zone of parapapillary atrophy. Age is an additional nonmorphologic parameter. Progression of glaucomatous optic nerve head changes is independent of the size of the optic disc and alpha-zone of parapapillary atrophy and retinal vessel diameter.     

Assessment of optic disk blood flow in patients with open-angle glaucoma

PURPOSE: To characterize optic disk blood flow in patients with open-angle glaucoma compared with age-matched healthy control subjects. METHODS: In this prospective cross-sectional study, 90 eyes of 90 patients with open-angle glaucoma and 61 eyes of 61 age-matched healthy control subjects were evaluated. Flow in the optic disk cup and the neuroretinal rim were assessed with scanning laser Doppler flowmetry. Fundus pulsation amplitude in the cup and the macula were assessed with laser interferometry. Visual field mean deviation was measured with the Humphrey 30 to 2 program. RESULTS: Flow in the neuroretinal rim (-18%, P =.002), and in the cup (-46%, P <.001) and fundus pulsation amplitude in the cup (-33%, P <.001) and in the macula (-24%, P <.001) were significantly lower in patients with open-angle glaucoma compared with healthy control subjects. A significant association between blood flow measurements in the cup and fundus pulsation amplitudes in the cup was observed in both study cohorts. A significant association was also observed between the mean defect from visual field testing and ocular hemodynamic parameters. CONCLUSIONS: Reduced optic disk perfusion in patients with open-angle glaucoma is evidenced from two independent methods in the present study. Moreover, our data indicate that reduced ocular blood flow in these patients is linked to visual field changes. It remains to be established whether compromised optic disk and choroidal blood flow contributes to optic disk damage in glaucomatous eyes or is a secondary functional phenomenon.     

Optic disc morphometry correlated with confocal laser scanning Doppler flowmetry measurements in normal-pressure glaucoma

PURPOSE: To examine the relationship between morphologic optic disc parameters and hemodynamic parameters as measured by confocal laser scanning Doppler flowmetry in patients with normal-pressure glaucoma. METHODS: The study included 91 eyes of 54 patients with normal-pressure glaucoma (mean age: 57.7 +/- 9.8 years), and 136 eyes of 77 age-adjusted normal controls. Color stereo optic disc photographs were morphometrically examined, and confocal laser scanning flowmetry (Heidelberg Retinal Flowmeter) in the neuroretinal rim inside of the optic disc, and in the retina close to the temporal and nasal border of the optic nerve head was performed. RESULTS: Mean confocal laser scanning flowmetric measurements in the neuroretinal rim, temporal parapapillary retina, and nasal parapapillary retina were significantly (P<0.03) lower in the normal-pressure glaucoma group than in the age-adjusted control group. Correspondingly, mean confocal laser scanning flowmetric measurements within the neuroretinal rim decreased significantly, with relatively low correlation coefficients, decreasing neuroretinal rim area (P = 0.016; correlation coefficient r2 = 0.026), and increasing mean visual field defect (P = 0.011; r2 = 0.029). Measurements were statistically independent of alpha zone (P = 0.38; r2 = 0.004) and beta zone (P = 0.57; r2 = 0.002) of parapapillary atrophy. CONCLUSIONS: Confocal laser scanning flowmetric measurements within the neuroretinal rim were lower in eyes with normal-pressure glaucoma than in age-matched normal eyes. Confocal laser scanning flowmetric measurements decrease with increasing glaucomatous optic nerve damage. There is, however, a marked variability preventing a clear relationship between stage of glaucoma and decrease in confocal laser scanning flowmetric measurements. The correlation between parapapillary atrophy and confocal laser scanning flowmetric measurements is not statistically significant in normal-pressure glaucoma.     

原发性开角型青光眼不同发展阶段盘沿缺失的形态特征及其临床意义

目的:探讨青光眼病情发展阶段盘沿缺失的形态特征。方法:对青光眼92眼和正常人124眼进行立体彩色视盘照像,侧重分析盘沿的形态。结果:与视力正常眼比较,青光眼不同病情阶段盘沿缺失有其好发区域。早期青光眼盘沿缺失在视盘颞下极明显,中期青光眼盘沿缺失在颞上极较为明显,极晚期青光眼盘沿仅保留视盘鼻侧区域,并且鼻上区大于鼻下区。结论:青光眼盘沿缺失的形态特征与青光眼性视野缺损的发展及筛板的形态密切相关。     

Intravascular oxygen saturation in retinal vessels in normal subjects and open-angle glaucoma subjects

PURPOSE: To measure the oxygen saturation (SO(2)) in retinal arterioles and venules in patients with glaucomatous optic neuropathy. METHODS: We examined SO(2) in retinal arterioles and venules simultaneously by imaging spectrometry. Oxygen saturation was evaluated according to the difference of the extinction spectra of haemoglobin and oxyhaemoglobin. The arterio-venous difference (avD) was calculated by (SO(2art) - SO(2ven)). The optic nerve head topography was estimated by Heidelberg retinal tomography and the visual field using the Octopus G1. We examined one eye in each of 58 healthy persons (mean age 58.6 +/- 10.7 years; mean rim area 1.52 +/- 0.33 mm(2); mean defect 0.65 +/- 1.31 dB; mean intraocular pressure [IOP] 18.5 +/- 2.7 mmHg), 49 patients with normal-tension primary open-angle glaucoma (NTG) (mean age 63.0 +/- 8.5 years; mean rim area 0.89 +/- 0.34 mm(2); mean defect 5.4 +/- 4.1 dB; mean IOP 19.2 +/- 2.9 mmHg), and 45 patients with high-tension primary open-angle glaucoma (POAG) (mean age 62.6 +/- 10.3 years; mean rim area 0.97 +/- 0.47 mm(2); mean defect 7.1 +/- 6.4 dB; mean IOP 31.6 +/- 10.8 mmHg). RESULTS: The intraclass correlation coefficients of the SO(2) measurement were 0.82 (arteriole) and 0.59 (venule). In normal eyes, the SO(2art), SO(2ven) and avD were 92.3 +/- 3.4%, 55.7 +/- 6.8% and 36.6 +/- 7.0%, respectively. Equivalent data were 89.7 +/- 5.4%, 56.0 +/- 8.3% and 33.7 +/- 10.6%, respectively, in NTG eyes and 91.4 +/- 4.0%, 58.3 +/- 10.5% and 33.1 +/- 11.5%, respectively, in POAG eyes. Over all examined eyes, the arteriolar SO(2) and the retinal arterio-venous difference correlated significantly with the rim area. CONCLUSION: Eyes with NTG showed significantly decreased arteriolar SO(2). These changes were not seen in POAG patients.     

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.