The optic disc hemifield test

PURPOSE: To evaluate whether an optic disc hemifield test comparing the superior half of the optic disc with the inferior disc half is useful for glaucoma diagnosis. METHODS: The clinical observational study included 1268 patients with primary or secondary open-angle glaucoma and 649 normal subjects. The glaucoma group was divided into 1118 patients with glaucomatous visual field defects ("perimetric glaucoma"), and 150 patients with optic nerve head changes and normal visual fields ("preperimetric glaucoma"). Color stereo optic disc photographs were morphometrically evaluated. The optic disc area was divided into four sectors: temporal horizontal (60 degrees), superotemporal (90 degrees), inferotemporal (90 degrees), and nasal (120 degrees). Area and width of the neuroretinal rim were measured, and the ratio of superotemporal-to-inferotemporal rim area, the ratio of superior (12 o'clock)-to-inferior (6 o'clock) rim width, the difference of inferotemporal minus superotemporal rim area, and the difference of inferior rim width minus superior rim width were calculated. RESULTS: For the differentiation between the normal group and the whole glaucoma group, and for the differentiation between the normal group and the preperimetric glaucoma group, respectively, areas under the ROC curves were significantly smaller for the parameters of the optic disc hemifield test (superior-to-inferior rim width ratio: 0.448 and 0.412, respectively; and superotemporal-to-inferotemporal rim area ratio: 0.395 and 0.434, respectively) than for any other rim parameter tested such as inferotemporal rim area (0.827 and 0.745, reps.), total rim area (0.814 and 0.741, respectively), and superotemporal rim area (0.781 and 0.705, respectively). DISCUSSION: An optic disc hemifield test with the parameters superior-to-inferior rim width ratio and superotemporal-to-inferotemporal rim area ratio is not markedly helpful for the morphometric diagnosis of glaucomatous optic nerve damage, either in the preperimetric stage or in the perimetric stage of the disease.     

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.     

Monitoring glaucoma progression with visual evoked potentials of the blue-sensitive pathway

PURPOSE: To determine the value of visual evoked potentials with blue-on-yellow pattern stimulation in follow-up of glaucoma. METHODS: This prospective longitudinal concurrent study included a heterogeneous cohort of two groups, perimetric (n = 161) and preperimetric (n = 118), of patients with chronic open-angle glaucoma and 113 healthy control subjects. In the preperimetric glaucoma group, patients showed glaucomatous abnormalities of the optic disc, maximum intraocular pressure higher than 21 mm Hg, and unremarkable computerized visual field examination results. Patients underwent up to three VEP measurements with blue-on-yellow pattern stimulation, as well as qualitative and morphometric evaluation of color stereo optic disc photographs. Mean follow-up time between measurements was 24 months. VEP measurements were separately analyzed in preperimetric subjects, with and without progression of optic nerve damage. Progression of glaucoma was defined as increasing loss of neuroretinal rim. RESULTS: A separate analysis of VEP peak times in patients in the preperimetric group, with and without progression of glaucomatous optic nerve damage, showed no significant difference at baseline but a significant prolongation (P = 0.01) in patients with progressive disease, 2 years before morphologic changes were evident. VEPs in patients with nonprogressive disease were statistically unchanged during the observation period. The perimetric group and both preperimetric groups showed significantly prolonged VEP peak times in comparison with the control group (P < 0.001). CONCLUSIONS: In addition to photographic evaluation to detect glaucomatous disc atrophy, the blue-on-yellow VEP may be an objective electrophysiological tool for monitoring patients with glaucoma, because peak times are significantly associated with progression of optic nerve damage.     

Ranking of optic disc variables for detection of glaucomatous optic nerve damage

PURPOSE: To describe optic disc variables assessed by evaluation of clinical optic disc photographs and to compare sensitivity and specificity of these optic disc parameters in identifying patients with ocular hypertension who have nerve fiber layer defects and normal visual fields and patients with visual field defects. METHODS: The study included 500 normal subjects, 132 patients with ocular hypertension with retinal nerve fiber layer defects and normal visual fields (preperimetric glaucoma), and 840 patients with glaucomatous visual field defects. Color stereo optic disc photographs were morphometrically evaluated. RESULTS: Highest diagnostic power for the separation between the normal group and the preperimetric glaucoma group had the vertical cup-to-disc diameter ratio corrected for its dependence on the optic disc size, total neuroretinal rim area, rim-to-disc area ratio corrected for disc size, and cup-to-disc area ratio corrected for disc size. Diagnostic power was lower for rim area in the temporal inferior and temporal superior disc sector, cup area corrected for disc size, and horizontal cup-to-disc diameter ratio corrected for disc size. Less useful for the differentiation between the normal subjects and the preperimetric glaucoma group were size of zones alpha and beta of parapapillary chorioretinal atrophy, and ratios of neuroretinal rim width and rim area comparing various optic disc sectors with each other. CONCLUSIONS: In subjects with ocular hypertension with retinal nerve fiber layer defects and normal conventional achromatic visual fields, the vertical cup-to-disc diameter ratio corrected for optic disc size, total neuroretinal rim area, rim-to-disc area ratio, and cup-to-disc area ratio corrected for disc size are the most valuable optic disc variables for early detection of glaucomatous optic nerve damage. Correction for optic disc size is necessary for optic disc variables directly or indirectly derived from the optic cup. Parapapillary atrophy is less important in the early detection of glaucoma.     

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.     

Combined use of frequency doubling perimetry and polarimetric measurements of retinal nerve fiber layer in glaucoma detection

PURPOSE: The aim of this study was to evaluate the diagnostic usefulness of the combined use of frequency-doubling technology (FDT) perimetry and polarimetry of the retinal nerve fiber layer. DESIGN: Cross-sectional study. METHODS: Seventy ocular hypertensive patients (normal optic disk and standard perimetry, elevated intraocular pressure [>21 mm Hg]), 59 patients with "preperimetric" open-angle glaucoma (glaucomatous optic disk atrophy, elevated intraocular pressure [>21 mm Hg], no visual field defect in standard perimetry), 105 patients with "perimetric" open-angle glaucoma (glaucomatous optic disk atrophy and clearly marked visual field defect), and 73 control subjects had FDT screening (protocol: C-20-5) and polarimetric measurements (GDx). Criteria for exclusion: optic disks larger than 4 mm(2), media opacities, patients younger than 33 years or older than 66 years. None of the subjects had earlier FDT perimetry. One eye of each patient and control subject entered the statistical evaluation. Database and statistical software were used for case-wise recalculation of all missed localized probability levels to create a FDT screening score. RESULTS: At a predefined specificity of 94.5% in control eyes, discrimination between "perimetric" glaucoma and normal subjects is superior using the FDT perimetry (sensitivity = 84.8%) in comparison to polarimetry (sensitivity = 63.8%), whereas sensitivity is similar with both methods in "preperimetric" patients (GDx, FDT: 25.4%). In several cases, patients classified as glaucomatous by the GDx are not the same patients as identified by the FDT perimetry. Therefore, a two-dimensional discrimination analysis can increase correct positive classification. Using a linear combination of the present FDT screening score and polarimetry ("the number"), 92.4% of "perimetric" glaucoma eyes and 44.1% of "preperimetric" glaucoma eyes have been classified as glaucomatous. CONCLUSION: Joint usage of polarimetry and FDT perimetry indicate that a combination of different techniques which can uncover different glaucoma properties, might be helpful in early glaucoma detection.     

The diagnostic value of optic nerve imaging in early glaucoma

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

Überschwellige periphere Stimulation bei präperimetrischen Glaukomen

BACKGROUND AND PURPOSE: Early glaucomatous visual field defects can occur outside the central 30 degrees , which is usually examined in perimetric tests used for glaucoma diagnosis and screening. This study aimed to evaluate the diagnostic value of peripheral suprathreshold stimulation in open angle glaucoma before the development of reproducible visual field damage in standard 30 degrees automatic white-on-white perimetry. METHODS: A total of 352 eyes of 352 patients (ages 35-69 years; visual acuity 0.8 or better) from the Erlanger Glaucoma Registry were included in this study. They were divided into two groups: normal eyes and preperimetric glaucoma. All patients underwent a standardized glaucoma examination including Octopus 500EZ static perimetry (G1 program, all three phases); 95 eyes of 95 patients also received a 135-point suprathreshold test pattern of the Humphrey Field Analyzer (model 750i) for detecting peripheral visual field defects. Sensitivity and specificity were calculated for any single test point in phase 3 of the G1 test pattern and the Humphrey 135-point pattern. A score was calculated, and cluster analysis was performed. RESULTS: In 33 of 176 (18.8%) eyes with preperimetric glaucoma, the score was 3 or higher in phase 3 of the G1 program (normal eyes: 19 of 196; 9.7%). For both examination modalities, the highest sensitivity was found in test locations in the superior nasal midperiphery, corresponding to neuroretinal rim loss predominantly in the inferotemporal sector in early glaucomatous optic disc atrophy. CONCLUSION: Positive test results using suprathreshold stimulation in the midperiphery can be found in patients with preperimetric glaucoma at a significantly higher frequency than in normal subjects. Longitudinal studies will show whether such tests can be useful for predicting perimetric manifestation of the disease.     

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.     

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.     

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.     

Optic nerve head topographic measurements and retinal nerve fiber layer thickness in physiologic large cups

PURPOSE: To evaluate the parameters of optic nerve head (ONH) and retinal nerve fiber layer (RNFL) in patients with large cup/disc ratio (CDR) and normal neuroretinal rim configuration who have normal perimetry (physiologic large cups, LC) and to compare these parameters with those of the normal and early glaucoma patients. METHODS: Using Heidelberg retinal tomography (HRT) and optical coherence tomography (OCT), 30 patients with LC, 29 normal subjects, and 31 early glaucoma patients were examined. One eye from each subject was randomly selected. RESULTS: Significant differences between LC and glaucomatous eyes (GE) were found in parameters indicating loss of nerve fibers, such as rim area, rim volume, and mean RNFL thickness. However, there was no difference between LC and normal eyes (NE) in RNFL thickness, rim area, and rim volume. LC was able to be defined as a normal central excavation with a large disc and large CDR with a normal rim area. CONCLUSIONS: HRT ONH parameters and RNFL thickness obtained with OCT may be useful for differentiating between glaucoma and LC eyes.     

New technologies for diagnosing and monitoring glaucomatous optic neuropathy.

BACKGROUND: Recently, instruments have been developed to provide real-time, quantitative measurements of the optic disc and retinal nerve fiber layer (RNFL) for use in glaucoma management. Our objective is to (1) provide an overview of two of these instruments, the confocal scanning laser ophthalmoscope (Heidelberg Retina Tomograph, HRT) and scanning laser polarimeter (Nerve Fiber Analyzer, NFA) and (2) compare measurements obtained with these instruments to clinical features used in the diagnosis of glaucoma. METHODS: Twenty glaucoma patients, 4 normal subjects and 20 glaucoma subjects were included. All subjects had images obtained with the HRT and NFA, and RNFL and optic disc photography completed within 5 weeks of each other. The HRT results were compared with qualitative evaluation of stereophotographs of the optic disc, and NFA results were compared against a semi-quantitative RNFL photograph severity score. RESULTS: Twenty-five (57%) subjects had thinning of the neuroretinal rim identified by evaluation of stereoscopic optic disc photographs. Despite overlap, HRT measurements of rim volume, rim area, and rim/disc ratio were significantly smaller in eyes with evidence of rim thinning than in eyes with no evidence of rim thinning. Moderate to severe RNFL damage was detected by evaluation of photographs in 25 (57%) of subjects. NFA RNFL thickness measures were smaller in eyes with moderate to severe RNFL damage than in relatively healthy eyes. CONCLUSIONS: Previous studies have documented the reproducibility of these instruments and suggested analytic techniques for improving their ability to differentiate between normal and glaucoma eyes. Our results indicate that despite overlap in values, these instruments provide measurements that reflect clinically relevant features of the optic disc and RNFL. Whether these technologies can improve our ability to detect glaucomatous progression over time needs to be determined with well-designed longitudinal studies and comparison with established diagnostic techniques for evaluating glaucomatous optic neuropathy.     

Inter-eye differences in chronic open-angle glaucoma patients with unilateral disc hemorrhages

OBJECTIVE: Flame-shaped optic disc hemorrhages are a hallmark of glaucomatous optic neuropathy. The purpose of this study was to evaluate which parameters differ between companion eyes with and without an optic disc hemorrhage in patients with chronic open-angle glaucoma. DESIGN: Comparative (companion eye) observational case series. PATIENTS: The study included 99 white patients with bilateral chronic open-angle glaucoma and unilateral flame-shaped optic disc hemorrhages. METHODS: All patients underwent qualitative and morphometric evaluation of color stereo optic disc photographs. MAIN OUTCOME MEASURES: Size and shape of the optic disc, neuroretinal rim and parapapillary atrophy, diameter of the retinal vessels, intraocular pressure measurements, and both mean value and loss variance value of the visual field examination. RESULTS: In an intraindividual inter-eye comparison, the eyes with disc hemorrhages and the contralateral eyes without disc bleeding did not vary significantly (P > 0.20) in size and shape of the optic disc and neuroretinal rim, optic cup depth, size of alpha and beta zone of parapapillary atrophy, retinal vessel diameter, intraocular pressure measurements, refractive error, and perimetric indices. CONCLUSIONS: In bilateral chronic open-angle glaucoma, the development of unilateral optic disc hemorrhages does not depend on inter-eye differences in size and shape of the optic disc, neuroretinal rim and parapapillary atrophy, diameter of the retinal vessels, intraocular pressure measurements, or visual field loss.     

Testing for glaucoma with frequency-doubling perimetry in normals, ocular hypertensives, and glaucoma patients

BACKGROUND: The aim of this study was to evaluate the diagnostic usefulness of the FDT perimeter protocol (C-20-5) in combination with a database system for analysis of single test locations. METHODS: One hundred seventy-three ocular hypertensive eyes, 116 "preperimetric" open-angle glaucoma eyes (glaucomatous optic disc atrophy, elevated intraocular pressure, no visual field defects in standard white-on-white perimetry), 199 "perimetric" open-angle glaucoma eyes (glaucomatous optic disc atrophy and visual field defects), and 151 control eyes underwent FDT screening and conventional white-on-white perimetry. Four repeated measurements were carried out in 15 glaucoma patients at 2-h intervals to judge reproducibility of all test locations. The present screening strategy begins testing at the normal 5% probability level. If a stimulus is not detected, further targets are presented. FDT-Viewfinder and statistics software were used for case-wise recalculation of all missed localized probability levels and correlation with corresponding test locations using conventional perimetry. RESULTS: Analysis of repeated measurements in patients reveals that variation of single test points can be considerable. However, the numbers of missed test-stimuli calculated globally or in quadrants are significantly correlated with corresponding Octopus visual field defects (Spearman rank correlation P<0.001). Using a predefined specificity of 96% in control eyes, 11% of ocular hypertensive eyes, 28.5% of "preperimetric" glaucoma eyes and 86.9% of "perimetric" glaucoma eyes have been classified glaucomatous using an overall score and with consideration of different cut-off points in right and left eyes. CONCLUSION: Point-wise analysis of FDT screening results can be helpful for classification of patient groups and consideration of the individual learning curve in repeated measurements. The C-20-5 protocol of the FDT perimeter is able to detect a considerable proportion of glaucomatous patients.     

Scanning laser polarimetry versus frequency-doubling perimetry and conventional threshold perimetry: changes during a 12-month follow-up in preperimetric glaucoma. A pilot study.

PURPOSE: To evaluate the possibility for detecting the progression in preperimetric primary open angle glaucoma (POAG) using scanning laser polarimetry (SLP), frequency-doubling technology (FDT), and conventional automated perimetry (AP). PATIENTS AND METHODS: 22 eyes of 11 preperimetric POAG patients were evaluated using SLP (Nerve Fiber Analyzer, GDx), AP (Humphrey 24-2 threshold test) and FDT (30 degrees threshold test). All eyes had intraocular pressure (IOP) higher than 21 mmHg before treatment, but were consistently lower than 22 mm Hg with unchanged topical medication before and during the study. At the initial evaluation session optic nerve heads showed mild glaucomatous changes but the visual fields were normal (MD better than 2.0 dB, Glaucoma Hemifield Test: within normal limits or borderline). AP and FDT measurements were repeated 6 months later, and all three tests were repeated 12 months after the first investigation. RESULTS: IOP, AP and FDT measurements showed no statistically significant changes during the 12-month follow up period. In contrast to this, a tendency for a glaucomatous type decrease was seen with SLP in the retinal nerve fibre layer (RNFL) thickness parameters (mean superior and inferior sector thickness values, ellipse average thickness and maximal modulation). The mean decrease of RNFL thickness in the superior and inferior sectors was 2.77 microm and 2.48 microm, respectively. Using the two-way nested ANOVA, which considers the relation between the right and left eyes of the subjects, the decrease was statistically significant (p=0.021) for the inferior sector RNFL thickness. CONCLUSION: The results suggest that scanning laser polarimetry is a useful technique to detect and measure glaucomatous progression in early glaucoma. Scanning laser polarimetry of the RNFL may help to detect and quantify early progression even if worsening is not seen with perimetry and FDT tests.     

Iris colour, optic disc dimensions, degree and progression of glaucomatous optic nerve damage

PURPOSE: To evaluate whether iris colour influences size and shape of the optic nerve head and risk for glaucoma progression. METHODS: The hospital-based observational study included 1973 eyes of 1012 Caucasian subjects with ocular hypertension or chronic open-angle glaucoma. For all patients, colour stereo optic disc photographs were evaluated, and corneal pachymetry and achromatic perimetry were performed. Main outcome measures were optic nerve head parameters, the development or progression of visual field defects and iris colour. RESULTS: In most of the study groups, size of the optic disc, neuroretinal rim, alpha zone and beta zone of parapapillary atrophy, retinal vessel diameter and central corneal thickness did not differ significantly between eyes with blue, green, brown and mixed iris colour. In the normal-pressure glaucoma group, neuroretinal rim area was smallest in the population with mixed-coloured eyes and largest in the group of eyes with brown irides (P = 0.001 after correction for inter-eye dependency and multiple testing). For the ocular hypertensive subjects and glaucoma patients with follow-up examinations, the rate of development or progression of glaucomatous visual field loss was not significantly associated with iris colour (P = 0.060). CONCLUSIONS: In Caucasian subjects, iris colour does not have a major association with the size of the optic nerve head structures, central corneal thickness and retinal arterial diameter. In Caucasian patients with ocular hypertension or chronic open-angle glaucoma, an influence of iris colour on the risk for development or progression of glaucomatous visual field defects could not be confirmed.     

Einfluss zilioretinaler Gefäße auf funktionelle Schädigungen beim Offenwinkelglaukom

PURPOSE: The pattern of functional perimetric loss and morphologic neuroretinal rim loss in glaucoma depends on the localization of the central retinal vessel trunk in the lamina cribrosa. The purpose of the present study was to determine if the pattern of perimetric loss and rim loss are influenced by the presence and position of cilioretinal arteries. PATIENTS AND METHODS: Using automated perimetry and 15 degrees color stereo optic disc photographs of the optic disc, we compared 20 open-angle glaucoma patients exhibiting cilioretinal arteries in the temporal horizontal disc region with 70 open-angle glaucoma patients without cilioretinal arteries. RESULTS: Eyes with cilioretinal arteries and eyes without cilioretinal arteries did not differ significantly in global visual field indices nor in the mean defect for the central 10 degrees. No differences were detected for the areas of optic disc, neuroretinal rim, ratios of the temporal horizontal area-to-total area of rim and ratio of temporal horizontal rim area-to-nasal rim area. CONCLUSIONS: In contrast to the position of the central retinal vessel trunk, the presence and position of cilioretinal arteries do not markedly influence the pattern of glaucomatous damage.     

Quantification of optic nerve head topography in optic neuritis: a pilot study

AIMS: To investigate optic nerve head topography in patients with optic neuritis compared to controls using the Heidelberg retina tomograph-II (HRT-II) and to determine if detected changes are related to visual function and electrophysiology. METHODS: 25 patients with a previous single episode of unilateral optic neuritis and 15 controls were studied with HRT-II, visual evoked potentials, and pattern electroretinogram. Patients also had testing of visual acuity, visual field, and colour vision. RESULTS: In affected eyes compared to fellow eyes, there was reduction of both the mean retinal nerve fibre layer (RNFL) thickness at the disc edge (p = 0.009) and the neuroretinal rim volume (p = 0.04). In affected eyes compared to control eyes, the three dimensional optic cup shape measure was increased (p = 0.01), indicative of an abnormal cup shape. There were no other significant differences in HRT-II measures. Within patient interocular difference correlation was used to investigate the functional relevance of these changes and demonstrated associations between RNFL thickness change and changes in visual acuity, visual field, and colour vision. Colour vision change was also associated with change in neuroretinal rim volume. CONCLUSIONS: HRT detects functionally relevant changes in RNFL thickness and neuroretinal rim volume between eyes affected by optic neuritis and unaffected fellow eyes.     

Parapapillary chorioretinal atrophy in normal and glaucoma eyes. II. Correlations

The parapapillary chorio-pigment-epithelio-retinal atrophy in glaucomatous eyes is significantly larger than in normal eyes. In a previous study its area and frequency have been measured in 582 eyes of 321 patients with chronic primary open-angle glaucoma and in 390 eyes of 231 normal subjects. In the current study the parapapillary changes were correlated with intrapapillary morphometric data and with perimetric indices. The parapapillary chorioretinal atrophy was significantly correlated with the neuroretinal rim area, the horizontal and vertical cup/disc ratios, the quotient of horizontal to vertical cup/disc ratio, the retinal nerve fiber layer score, and the mean visual field loss. It was larger in the same sector where the neuroretinal rim loss was more marked. The correlation coefficients were generally higher for zone "Beta," characterized by complete chorioretinal atrophy with visible large choroidal vessels and sclera, than for zone "Alpha," which showed irregular hypo- and hyperpigmentation. The parapapillary chorioretinal atrophy was correlated in location and time with the intrapapillary glaucomatous changes. It deserves attention in glaucoma diagnosis and follow-up. Its evaluation is especially valuable in eyes with small optic nerveheads (disc size less than 1.6 mm2) in which the intrapapillary glaucomatous changes occur later than the parapapillary ones.