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.     

Differences in parapapillary atrophy between glaucomatous and normal eyes: the Beijing Eye Study

PURPOSE: To determine in a population-based study whether parapapillary atrophy is associated with glaucoma. DESIGN: Population-based cross-sectional study. METHODS: The Beijing Eye Study included 4,439 of 5,324 subjects invited to participate (response rate, 83.4%). Mean age was 56.2 +/- 10.6 years (range, 40 to 101 years). Color optic disk photographs (30 degrees) were examined morphometrically. Parapapillary atrophy was divided into alpha and beta zones. Glaucomatous optic nerve atrophy was defined by a glaucomatous optic nerve head appearance. RESULTS: After excluding highly myopic eyes, data from 4,003 (90.2%) subjects entered the statistical analysis. Glaucomatous optic nerve damage was detected in 93 (2.3%) subjects. The beta zone of parapapillary atrophy as a whole and measured separately in four disk sectors was significantly larger and occurred significantly more frequently in the glaucomatous group than in the nonglaucomatous group (beta zone total area, 1.21 +/- 1.92 mm2 vs 0.32 +/- 0.99 mm2; P < .001). In multiple regression analysis, area of beta zone was significantly associated with age (P < .001), myopic refractive error (P < .001), and presence of glaucomatous optic nerve damage (P < .001), with no significant difference between chronic open-angle glaucoma (n = 72) and chronic angle-closure glaucoma (n = 21; beta zone area, 1.20 +/- 0.39 mm2 vs 1.19 +/- 0.46 mm2; P = .69). CONCLUSIONS: In a population-based setting, the beta zone of parapapillary atrophy is significantly larger and occurs more frequently in glaucomatous eyes than in normal eyes of Chinese adults, with no marked difference between chronic open-angle glaucoma and primary angle-closure glaucoma.     

Parapapillary autofluorescence as indicator for glaucoma

BACKGROUND: A pronounced fundus autofluorescence (lipofuscin) occurs in eyes with AMD. Parapapillary lipofuscin accumulation in the retinal pigment epithelial cells was observed in eyes with advanced glaucoma histologically. The aim of this study was to evaluate the parapapillary autofluorescence (PAF) in vivo in healthy eyes (controls), and in eyes with primary open angle glaucoma (POAG), pseudoexfoliation glaucoma (PSXG) or normal tension glaucoma (NTG). PATIENTS AND METHODS: Controlled cross-sectional analysis was performed on 281 consecutive eyes (98 controls, 95 POAG, 32 PSXG, 56 NTG). Eyes with fundus pathologies were excluded. The confocal scanning laser ophthalmoscope HRA II (Heidelberg Retina Angiograph II) was used after lipofuscin-excitation with an argon blue laser (488 nm) to detect PAF in the spectrum above 500 nm. PAF area and PAF distance to the optic nerve head were analyzed using the HRA standard software. Two experienced ophthalmologists classified independently the stage of glaucomatous optic nerve head atrophy (GONHA) using 15 degrees fundus photographs. RESULTS: Vital optic nerve heads had smaller PAF areas (stage 0: 0.07 +/- 0.09 mm (2)) in contrast to advanced stages of GONHA (stages 1 to 4: 0.27 +/- 0.46 mm (2); p < 0.001; logistic regression Cox and Snell: r = 0.7; p = 0.015). The PAF distance to the optic nerve head was lower in controls (0.12 +/- 0.08 mm) than in eyes with POAG, PSXG, or NTG (0.25 +/- 0.21 mm, Bonferroni: p < 0,004). The PAF area correlated significantly with the stage of GONHA (stage 1: 0.23 +/- 0.23 mm (2), stage 2: 0.24 +/- 0.19 mm (2), stages 3 and 4: 0.34 +/- 0.73 mm (2), p < 0.01). No significant difference of PAF area was found between the glaucoma types. However, the distance between PAF and optic nerve head was higher in POAG (0.28 +/- 0.26 mm) than in NTG (0.24 +/- 0.07 mm) or in PSXG (0.18 +/- 0.07 mm, Bonferroni: p < 0.03). CONCLUSIONS: A pronounced fundus autofluorescence was detected as a sign of increased lipofuscin accumulation in the parapapillary atrophic zone of eyes with POAG, PSXG, and NTG in contrast to controls. The PAF analysis may provide an indicator for glaucomas in the future.     

Analysis of macular volume in normal and glaucomatous eyes using optical coherence tomography

PURPOSE: To evaluate macular volume in normal and glaucomatous eyes using optical coherence tomography (OCT). DESIGN: Case control study. METHOD: The authors assessed 272 eyes of 164 subjects as part of an institutional study at New England Eye Center in Boston, Massachusetts; 202 eyes were in the study group and 70 eyes in the control group. Eyes were categorized as normal (70 eyes of 43 subjects), glaucoma suspect (70 eyes of 44 subjects), early glaucoma (70 eyes of 47 subjects), or advanced glaucoma (62 eyes of 43 subjects). Subjects underwent analysis with the commercially available OCT1 unit. Optical coherence tomography macular neurosensory retinal thickness maps were used to calculate macular volume for comparison to Humphrey visual field testing, intraocular pressure measurement, and stereo biomicroscopy of the optic nerve head and nerve fiber layer. RESULTS: Using repeated measures regression, macular volume in normal (2.37 +/- 0.11 mm(3)) glaucoma suspect (2.33 +/- 0.16 mm(3)), and early glaucoma eyes (2.27 +/- 0.13 mm(3)) was significantly greater than in eyes with advanced glaucoma (2.12 +/- 0.23 mm(3), P =.0001, P =.0001, and P =.0008, respectively). Macular volume in normal eyes was significantly greater than in early glaucoma eyes (P =.01). CONCLUSIONS: Optical coherence tomography retinal macular volume correlates with known structural defects of glaucoma, providing a potential objective and quantitative parameter for evaluation. Our data show a significant difference in macular volume between normal, glaucoma suspect, and early glaucoma eyes, compared with advanced glaucomatous eyes as well as between normal and early glaucomatous eyes. This correlates with a trend of decreasing macular volume in eyes with more advanced disease.     

Retinal nerve fiber layer measurements using laser scanning polarimetry in different stages of glaucomatous optic nerve damage

PURPOSE: To evaluate the diagnostic value of polarimetric measurements of the retinal nerve fiber layer (RNFL) thickness in different stages of glaucomatous optic nerve damage. METHODS: The study included 92 eyes of 46 controls (age 41.0+/-13.7 years) and a heterogeneous group of 232 eyes of 135 patients with different stages of glaucomatous optic nerve damage (age 54.0+/-10.2 years; 68 patients with primary open-angle glaucoma, 56 with normal-pressure glaucoma and 11 patients with secondary glaucoma due to primary dispersion syndrome or pseudoexfoliation syndrome). All control subjects and patients underwent complete ophthalmological examinations including scanning laser polarimetry of the RNFL using the GDx (Laser Diagnostic Technologies, San Diego, Calif.) and 15 degrees color stereo optic disc photographs. Only subjects and patients with disc area less than 3.4 mm(2) were included in the study. The total glaucoma group were divided into four subgroups according to the morphological criteria of the neuroretinal rim. RESULTS: The stage of morphological glaucomatous optic nerve damage was classified as follows: stage 0: n=92, stage 1: n=103, stage 2: n=65, stage 3: n=40, and stage 4: n=19. Differences in mean polarimetric retardation between controls and eyes with glaucoma were significant for all parameters except the variable symmetry. The most significant differences between controls and eyes with glaucomatous optic nerve damage were found with the "number" variable assigned by the neural network analysis ( P<0.001). With increasing stage of glaucomatous optic nerve damage, separation of the variable "the number" increased significantly. At a predetermined specificity of 90% the sensitivity of the groups with different stages of morphological glaucomatous optic nerve damage increased from 32% for stage 1 to 90% for stage 4. CONCLUSION: Polarimetric measurement of the RNFL thickness is significantly associated with morphological glaucomatous optic nerve damage. The fast performance, easy handling, and low cost of RNFL polarimetry mean that it can be included in the routine examination of glaucoma patients. Further study and refinement of this technique are indicated to improve its usefulness in both clinical diagnosis and in population-based case identification.     

Preperimetric glaucoma diagnosis by confocal scanning laser tomography of the optic disc

AIM: To evaluate the ability of confocal scanning laser tomography of the optic nerve head to detect glaucomatous optic nerve damage in ocular hypertensive eyes without visual field defects. METHODS: The study included 50 normal subjects, 61 glaucoma patients with glaucomatous changes in the optic disc and visual field, and 102 "preperimetric" patients with increased intraocular pressure, normal visual fields, and glaucomatous appearance of the optic disc as evaluated on colour stereo optic disc photographs. For all individuals, confocal scanning laser tomographs of the optic nerve head were taken using the Heidelberg retina tomograph (HRT; software 2.01). RESULTS: Almost all investigated HRT variables varied significantly (p < 0.05) between the normal eyes and preperimetric glaucoma eyes with pronounced overlap between the two study groups. Corresponding to the overlap, sensitivity and specificity values were relatively low when HRT variables were taken to differentiate between normal and preperimetric glaucoma eyes. At a given specificity of 95% highest sensitivities were found for the variables "rim area in the superior disc sector" (24.8%), "nerve fibre layer thickness in the inferior disc sector" (26.5%), and "rim volume in the superior disc sector" (25.5%). A multivariate approach increased sensitivity to 42.2% at a given specificity of 95%. For the glaucoma group highest sensitivity values were reached by rim volume in the superior disc sector (73.8%) and rim area (72.1%); the multivariate approach reached 83.6%. CONCLUSIONS: Owing to pronounced overlapping between the groups, confocal scanning laser tomography of the optic nerve head has relatively low diagnostic power to differentiate between normal eyes and preperimetric glaucoma eyes. One of the reasons may be the biological interindividual variability of quantitative optic disc variables.     

Quantitative evaluation of the optic nerve head in patients with unilateral visual field loss from primary open-angle glaucoma

Measurable structural alterations of the optic nerve head may precede visual field abnormalities in early open-angle glaucoma. The authors studied the optic nerve heads of 10 patients with unilateral visual field loss from primary open-angle glaucoma, and 12 age- and sex-matched normal subjects. Topographic optic nerve head parameters were measured with a system of computerized image analysis (Rodenstock Analyzer, G. Rodenstock Instrumente GMBH, Munich, W. Germany). In patients with asymmetric primary open-angle glaucoma, eyes with normal visual fields had a slightly larger mean (+/- standard error of the mean) disc rim area (0.90 +/- 0.04 mm2) than eyes with glaucomatous visual field defects (0.78 +/- 0.05 mm2). However, both sets of eyes in the asymmetric primary open-angle glaucoma patients had smaller mean disc rim areas (P less than 0.0007) than did the control group (1.27 +/- 0.09 mm2). These findings support the hypothesis that loss of the optic disc rim can be detected before perimetric abnormalities develop in primary open-angle glaucoma.     

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.     

In-vivo measurement of autofluorescence in the parapapillary atrophic zone of optic discs with and without glaucomatous atrophy

BACKGROUND: To assess the level of autofluorescence (lipofuscin) of atrophic parapapillary zones in different stages of glaucomatous optic disc atrophy. METHODS: Controlled cross-sectional prospective analysis of 79 consecutive eyes (15 normals as controls, 26 with ocular hypertension, 38 with primary open angle glaucoma). Eyes with retinal diseases or retinal pigment epithelial pathologies were excluded. The confocal scanning laser ophthalmoscope (HRA, Heidelberg Retina Angiograph) was used after lipofuscin excitation with argon blue laser (488 nm) to detect parapapillary autofluorescence in a spectrum above 500 nm. Size, extension of the parapapillary autofluorescent area and its mean distance to the optic nerve head were measured using the HRA standard software. Additional optic nerve head photographs taken with the 15 degrees Zeiss telecentric fundus camera (30 degrees camera with 2 x magnifier) were examined by two experienced ophthalmologists to determine the stage of glaucomatous optic disc atrophy (stages 0 to 4). RESULTS: Very small autofluorescent areas were found in vital discs (optic nerve glaucoma stage 0) in the parapapillary atrophic area (0.08 +/- 0.12 mm (2)) in contrast to glaucomatous discs in stage 1 (0.24 +/- 0.26 mm (2)) and stages 2, 3 and 4 (0.59 +/- 1.29 mm (2), logistic regression analysis r = 0.71; P = 0.029). The circular extension of the autofluorescent area correlated borderlined with the stage of the glaucomatous disc atrophy (higher glaucoma stages: r = 0.82; P = 0.09). The autofluorescent area was larger in OHT than in controls (0.11 mm (2) vs. 0.04 mm (2), P < 0.03). The circular extension of the autofluorescent area was longer in OHT than in controls (0.5 mm vs. 1.15 mm, P < 0.04). CONCLUSIONS: As a sign of pronounced lipofuscin accumulation in the parapapillary atrophic zone higher degrees of fundus autofluorescence can be detected in OHT and manifest primary open angle glaucoma in contrast to normals. The lipofuscin accumulation is correlated with the stage of progression of glaucoma and the stage of optic disc atrophy. The detection of active parapapillary autofluorescent areas especially in OHT may offer the ophthalmologist an important tool for early diagnosis.     

Optical coherence tomography measurement of the retinal nerve fiber layer in normal and juvenile glaucomatous eyes

The aim of this study was to quantitatively assess and compare the thickness of the retinal nerve fiber layer (RNFL) in normal and glaucomatous eyes of children using the optical coherence tomograph. The mean RNFL thickness of normal eyes (n=26) was compared with that of glaucomatous eyes (n=26). The eyes were classified into diagnostic groups based on conventional ophthalmological physical examination, Humphrey 30-2 visual fields, stereoscopic optic nerve head photography, and optical coherence tomography. The mean RNFL was significantly thinner in glaucomatous eyes than in normal eyes: 95+/-26.3 and 132+/-24.5 microm, respectively. More specifically, the RNFL was significantly thinner in glaucomatous eyes than in normal eyes in the inferior quadrant: 87+/-23.5 and 122+/-24.2 microm, respectively. The mean and inferior quadrant RFNL thicknesses as measured by the optical coherence tomograph showed a statistically significant correlation with glaucoma. Optical coherence tomography may contribute to tracking of juvenile glaucoma progression.     

Translimbal laser photocoagulation to the trabecular meshwork as a model of glaucoma in rats

PURPOSE: To develop and characterize a model of pressure-induced optic neuropathy in rats. METHODS: Experimental glaucoma was induced unilaterally in 174 Wistar rats, using a diode laser with wavelength of 532 nm aimed at the trabecular meshwork and episcleral veins (combination treatment group) or only at the trabecular meshwork (trabecular group) through the external limbus. Intraocular pressure (IOP) was measured by a tonometer in rats under ketamine-xylazine anesthesia. Possible retinal vascular compromise was evaluated by repeated fundus examinations and by histology. The degree of retinal ganglion cell (RGC) loss was assessed by a masked, semiautomated counting of optic nerve axons. Effects of laser treatment on anterior ocular structures and retina were judged by light microscopy. RESULTS: After the laser treatment, IOP was increased in all eyes to higher than the normal mean IOP of 19.4 +/- 2.1 mm Hg (270 eyes). Peak IOP was 49.0 +/- 6.1 mm Hg (n = 108) in the combination group that was treated by a laser setting of 0.7 seconds and 0.4 W and 34.0 +/- 5.7 mm Hg (n = 46) in the trabecular group. Mean IOP after 6 weeks was 25.5 +/- 2.9 mm Hg in glaucomatous eyes in the combination group compared with 22.0 +/- 1.8 mm Hg in the trabecular group. IOP in the glaucomatous eyes was typically higher than in the control eyes for at least 3 weeks. In the combination group, RGC loss was 16.1% +/- 14.4% at 1 week (n = 8, P = 0.01), 59.7% +/- 25.7% at 6 weeks (n = 88, P < 0.001), and 70.9% +/- 23.6% at 9 weeks (n = 12, P < 0.001). The trabecular group had mean axonal loss of 19.1% +/- 14.0% at 3 weeks (n = 9, P = 0.004) and 24.3% +/- 20.2% at 6 weeks (n = 25, P < 0.001), increasing to 48.4% +/- 32.8% at 9 weeks (n = 12, P < 0.001). Laser treatment led to closure of intertrabecular spaces and the major outflow channel. The retina and choroid were normal by ophthalmoscopy at all times after treatment. Light microscopic examination showed only loss of RGCs and their nerve fibers. CONCLUSIONS: Increased IOP caused by a laser injury to the trabecular meshwork represents a useful and efficient model of experimental glaucoma in rats.     

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.     

Image of optic nerve disc with laser scanning tomography and results of static perimetry in children with juvenile glaucoma

The aim of our research was to estimate the correlation between optic nerve head parameters examined with laser scanning ophthalmoscope and results of central, visual field (MD and PSD) in the youth and the evaluation the role of this correlation in juvenile glaucoma early diagnosis. MATERIAL: Three groups of patients. Group I consisted of 32 eyes (16 children) with juvenile glaucoma in which trabeculectomy was performed. There were 72 eyes of 32 children with glaucoma juvenile suspect in the group II. Control group (III) contained 20 eyes of 10 children without glaucoma. The age of patients ranged from 9 to 18 years. The mean intraocular pressure was 16 mmHg in the I group, 18 mmHg in the II group and 15.6 mmHg in the III group. Simple Regression Analysis of mean values of biomorphometric parameters of optic nerve head for Mean Defect of central visual field was used in all three groups. RESULTS: The statistically significant correlation between Vol. B and MD was observed in the I group. There was no such correlation in the II group, but correlation between Av. Sl. and MD was presented. In the III group mean value of MD was the smallest one and correlated with Vol. B. Statistically significant correlation between mean values of PSD and Vol. B was observed in the I and II group, between PSD and Vol. A in group III. CONCLUSION: There was the correlation between optic nerve head parameters and mean deviation of retinal sensitivity of central visual field in the youth. This examination can be helpful in early diagnosis of primary juvenile glaucoma.     

Tageszeitliche Schwankungen von Messungen der Papilla Nn. optici mit dem konfokalen Laser-Scanning-Tomographen

PURPOSE: The aim of this study was to evaluate whether confocal laser scanning tomographic measurements of the optic nerve head depend on the time of day when the examinations are performed. PATIENTS: Thirty-two eyes of 20 subjects repeatedly underwent optic disc confocal laser scanning tomography using the Heidelberg Retina Tomograph I. Operated by a single examiner, measurements were performed at 10 a.m. and 4 p.m. on the same day. RESULTS: Comparing both measurements, differences in optic cup area (0.119+/-0.126 mm(2); p=0.89), neuroretinal rim area (0.120+/-0.131 mm(2); p=0.86), cup volume (0.069+/-0.086 mm(3); p=0.86), rim volume (0.083+/-0.090 mm(3); p=0.51), and retinal nerve fiber layer thickness (0.075+/-0.063 mm; p=0.31) were statistically not significant. Intraocular pressure differences between morning and afternoon ranged between 0 and 14 mmHg. CONCLUSIONS: Confocal laser scanning tomographic measurements of the optic nerve head are not markedly influenced by the time of day.     

Optic nerve disc in unilateral myopia in children

PURPOSE: The evaluation of biomorphometric parameters of optic nerve head of the eyes in myopic anisometropia, to state if glaucoma similar changes described in adults were present. MATERIAL AND METHODS: 17 children, 14 girls and 3 boys at the age from 7-18 years, mean 12.6 years with unilateral myopia of mean value 8.6 D. The parameters of optic nerve disc: total contour area (TCA), cup/disc ratio (C/D), neuroretinal rim area (Rim), volume of neuroretinal rim (Vol. A), cup volume (Vol. B), maximum slope (MSL) and average slope angle (ASL) were examined using laser scanning ophthalmoscope in the TopSS system of Laser Diagnostic Technologies Inc. The I group consists of myopic eyes, in the II group there were emmetropic eyes of the same children. RESULTS: Refraction in the I group ranged from -4.5 to -12 D, mean -8.6 D, in the II group from 0 to + 1.0 D, mean 0.07 D. The mean axial length of eyeballs was 25.57 SD 1.9 mm in the I and 22.47 SD 1.09 mm in II group--the difference was significant. There was not statistically significant difference between TCA in the I (mean 1.19 SD 0.75 mm2) and II group (mean 2.13 SD 0.49 mm2). Mean C/D ratio and cup volume were significantly smaller in myopic (C/D 0.23 SD 0.16 Vol. B -0.06 SD 0.05) than in emmetropic eyes (C/D 0.33 SD 0.11 mm3, Vol. B -0.18 SD 0.14 mm3). CONCLUSIONS: Optic nerve disc images in myopic and glaucomatous eyes in children are different. Smaller optic disc cup in myopic than in emmetropic eyes can show, that children myopic eyeballs enlarged without nerve fibers atrophy.     

Laser Doppler flowmetry in asymmetric glaucoma

PURPOSE: To evaluate the relationship between extent of glaucoma damage and optic nerve blood flow, we investigated optic nerve head bloodflow in patients with asymmetric glaucoma damage between their two eyes and also in glaucomatous eyes with asymmetric damage inferiorly versus superiorly. METHODS: From our institutional practice, 16 subjects with asymmetric glaucoma damage between their two eyes and 25 eyes of 20 patients with asymmetric damage superiorly versus inferiorly were included in the study. Determinations of relative optic nerve head blood flow, velocity, and volume were obtained with laser Doppler flowmetry in the superotemporal and inferotemporal neuroretinalrim and in the cup. Means of flow (Flow(3)), velocity (Vel(3)), and volume (Vol(3))were calculated from these three measurement sites, and eyes or hemidisks with greater glaucomatous damage were compared to eyes or hemidisks with less damage. RESULTS: For subjects with asymmetric glaucoma damage between eyes, Flow(3) and Vel(3) were significantly lower in the eyes with worse glaucoma damage(mean difference = 2.09, p = 0.005, and mean difference = 0.05, p = 0.002,respectively). When comparing optic disks displaying within-eye asymmetry, the hemidisk with greater damage showed significantly lower blood velocity than the hemidisk with less damage (mean difference = 0.05, p = 0.013); however,no difference in blood flow or volume was detected. CONCLUSIONS: This study provides additional evidence that impaired optic nerve circulation is associated with the extent of glaucomatous pathology.     

Correlation between retinal ganglion cell death and chronically developing inherited glaucoma in a new rat mutant

Glaucoma is a progressive optic neuropathy with characteristic optic disc changes, retinal ganglion cell loss and progressive visual field defects. Elevated intraocular pressure is considered to be a major risk factor in glaucomatous neuropathy. This study aimed to characterize and document a new chronic glaucoma model in the rat with respect to the effect of elevated intraocular pressure on overall retinal dysfunction and retinal ganglion cell loss, and to elucidate the possible mechanisms underlying this cell loss. Intraocular pressure (IOP) was measured in rats using a Tonopen. RGCs were retrogradely labeled with the fluorescent dye, 4-[didecylaminostyryl]-N-methyl-pyridinium-iodide (4-Di-10 ASP) and quantified on retinal flat mounts using fluorescence microscopy. The optic nerve head was examined fundoscopically. Changes in the histological appearance of the whole eyes was studied in paraffin sections, and immunohistochemistry was carried out on cryostat sections. The levels of mRNA for several genes were compared between control and glaucomatous retinae using semi-quantitative RT-PCR. Mutant animals are affected with either a unilateral or bilateral enlargement of the globes having an IOP that ranged from 25 to 45 mmHg, as compared to control values of 12-16 mmHg. The IOP of glaucomatous eyes increased significantly with age to attain a value of 35+/-7.3 at 1.5 years. Concomitant with the rise in IOP, the number of labeled RGCs continued to decrease in number with age. A total of 1887+/-117RGC mm(-2) could be labeled in wild-type control and juvenile mutant pre-glaucomatous retinas, whereas this number dropped to 92+/-26RGC mm(-2) at 1.5 years. Ophthalmoscopy revealed atrophied optic nerve heads in the affected eyes. The pars plicata and the pars plana of the ciliary body of glaucomatous eyes were hypertrophied and elongated, respectively. The anterior chamber was narrow and the irido-corneal angle open in glaucoma eyes. The mRNA of glial-fibrillary-acidic protein, endothelin-1, STAT-3 and STAT-6 increased in the retinas correlating with the severity and duration of the disease. Changes in the expression of GFAP and endothelin-1 could be confirmed using immunohistochemistry. This model may help to address several fundamental issues in the pathogenesis of glaucoma and aid in the development of neuroprotective strategies.     

Macular and retinal nerve fiber layer analysis of normal and glaucomatous eyes in children using optical coherence tomography

PURPOSE: To evaluate macular and nerve fiber layer (NFL) thickness in normal and glaucomatous eyes of children 3 to 17 years old using optical coherence tomography (OCT-3). DESIGN: Observational cross-sectional study. METHODS: One hundred fifty-six eyes of 79 patients were enrolled in this institutional study. Fifty-two eyes (33.3%) met criteria for glaucoma and 104 (66.7%) were normal. There were 44 female (55.6%) and 35 male (44.3%) subjects whose ages ranged from 3 to 17 years old (mean 9.5 years, standard deviation 3.5 years, median 9 years). The OCT-3 (Carl Zeiss Meditec, Dublin, California) was used to obtain a fast macular thickness map as well as a fast retinal NFL map of each eye. Data from specific locations around the macula, as well as total macular volume, was analyzed. Similarly, the retinal NFL scan reports average NFL thickness from specific locations around the optic nerve. Data from the superior temporal and inferior temporal sections was analyzed. RESULTS: There was a statistically significant difference in macular thickness and NFL thickness when normal eyes were compared against those with glaucoma, in all quadrants studied (all P values 相似文献   

Optic disk size in chronic glaucoma: the Beijing eye study

PURPOSE: To evaluate whether eyes with chronic glaucoma have a larger or smaller optic disk than normal eyes. DESIGN: Population-based, cross-sectional cohort study. METHODS: The study included 4439 subjects out of 5324 subjects invited to participate with an age of 40+ years. Color optic disk photographs (45 degrees ) were morphometrically examined. RESULTS: After exclusion of aphakic eyes, pseudophakic eyes, and highly myopic eyes, data of 3989 subjects entered the statistical analysis. The mean optic disk area did not vary significantly (P > .05) between the nonglaucomatous group (2.61 +/- 0.50 mm(2)), eyes with glaucomatous appearance of the optic disk (2.69 +/- 0.63 mm(2)), eyes with glaucomatous optic disks and visual field defects (2.66 +/- 0.70 mm(2)), and eyes with elevated intraocular pressure (2.63 +/- 0.49 mm(2)). CONCLUSIONS: In adult Chinese, optic disk size may not markedly differ between normal eyes and eyes with chronic glaucoma.