NTG Eyes Research Articles

Optical coherence angiography of optic disc in eyes with primary open‐angle glaucoma and normal tension glaucoma with equal levels of structural damage

AbstractPurpose: To compare visual field (VF), nerve fibre and ganglion cell loss and changes in peripapillary vasculature in age matched patients with normal‐tension (NTG) and high tension glaucoma (HTG) at an equal level of glaucomatous structural damage of the optic nerve head (ONH).Methods: For the present study a retrospective analysis of patients with NTG and HTG was performed. One eye of each patient was randomly assigned for further analysis. To provide a reliable case by case match of HTG and NTG eyes, an equal optic disk size as measured by available spectral‐domain OCT system (RTVue XR OCT Avanti System; Optovue Inc., Fremont, CA) and an equal estimated excavation of the optic disk were chosen. Optic nerve head parameters, retinal nerve fibre layer (RNFL) ganglion cell (GCC) thickness and vessel densities (VD) in the peripapillary area were measured automatically by OCT with a respective software. Forty eyes with NTG, were matched according to the same glaucomatous ONH damage based on cup to disc ratio rim area and disc size with 40 eyes with HTG.Results: Mean age of patients was 68.5 ± 12 (27–84) years. The visual field index, RNFL, GCC thickness and peripapillary VDs in the HTG eyes were similar to those in the NTG eyes (mean VFI 79.6 vs. 78.8 p = 0.84, mean RNFL thickness 71.5 vs. 72.05 μm p = 0.87, mean GCC thickness 76.2 vs. 74.5 μm p = 0.62, mean peripapillary VD 43.6 vs. 43.8% p = 0.87). There was no difference in sectoral RNFL thickness and peripapillary VDs between HTG and NTG. In both groups, univariate regression analysis using the Pearson correlation coefficient showed VFI significantly correlated with RNFL thickness (NTG r = 0.423 p = 0.006 HTG r = 0.514 p = 0.002), and peripapillary VD (NTG r = 0.793 p < 0.001 HTG p = 0.534 p = 0.001) in both groups but with GCC thickness (NTG r = 0.585 p < 0.001) only in eyes with NTG.Conclusions: At an equal level of glaucomatous structural damage of the ONH indicated by cup to disk ratio and RNFL thickness, NTG patients seem to have same losses of peripapillary vasculature. Visual field index correlated with RNFL thickness and peripapillary vessel density in both groups.

IStent Trabecular Micro-Bypass Stent Implantation with Cataract Surgery in a Japanese Glaucoma Population.

IntroductionThis study assesses two-year efficacy and safety following implantation of a single trabecular micro-bypass stent (iStent®) with concomitant phacoemulsification cataract surgery in Japanese patients with open-angle glaucoma (OAG).Materials and MethodsThis retrospective, consecutive case series included eyes that underwent iStent implantation with phacoemulsification and were followed for 24 months postoperative. Efficacy and safety measures included intraocular pressure (IOP), number of glaucoma medications, adverse events, secondary surgeries, visual fields, and endothelial cell counts.ResultsOf 73 operated eyes, 53 eyes had 24 months of follow-up and are analyzed. Diagnoses included primary open-angle glaucoma (POAG, n=25), normal-tension glaucoma (NTG, n=16), and pseudoexfoliative glaucoma (PXG, n=12). At 24 months, mean IOP reduced by 18% to 13.6±3.0 mmHg versus 16.5±3.4 mmHg preoperatively (p<0.0001), and mean medication number reduced by 81% to 0.37±0.74 versus 1.96±0.98 preoperatively (p<0.0001). The percentage of medication-free eyes was 77% versus 0% preoperatively, and 81% of eyes had IOP ≤15 mmHg versus 42% preoperatively. Results were similarly favorable across glaucoma subtypes (POAG, NTG, PXG). Notably, mean IOP in NTG eyes decreased to 12.8±1.4 mmHg from 14.4±3.0 mmHg preoperatively (p=0.03), and medications decreased by 87% to 0.31±0.70 versus 2.38±0.72 preoperatively (p<0.0001). At 24 months, 81% of NTG eyes were medication-free (versus 0% preoperatively); 2 NTG eyes (13%) were on ≥2 medications (versus 100% preoperatively). Throughout the follow-up, visual fields and endothelial cell counts remained stable; 1 eye (1.9%) underwent filtration surgery.DiscussionFavorable safety and significant IOP and mediation reductions were achieved through two years following iStent implantation with phacoemulsification in a Japanese population. These gains were achieved across all glaucoma subtypes (including POAG, NTG, PXG).ConclusionThis real-world study supports the viability of iStent implantation to treat Japanese patients with glaucoma and shows that the benefits extend to those with NTG or PXG in addition to POAG.

Twenty-four–Hour Intraocular Pressure–Related Patterns from Contact Lens Sensors in Normal-Tension Glaucoma and Healthy Eyes: The Exploring Nyctohemeral Intraocular pressure related pattern for Glaucoma Management (ENIGMA) Study

To investigate 24-hour nyctohemeral intraocular pressure (IOP)-related patterns with contact lens sensors (CLSs) in eyes with primary open-angle glaucoma (POAG) with normal baseline IOP (i.e., normal-tension glaucoma [NTG]) and healthy controls. Prospective, case-control study. Thirty eyes of 30 patients with NTG, who had had a wash-out period for their IOP-lowering treatment, and 20 eyes of 20 healthy volunteer subjects. Patients and subjects were hospitalized for the purposes of 24-hour CLS (SENSIMED Triggerfish; Sensimed AG, Lausanne, Switzerland) measurement. The IOP-related patterns during wake and sleep times over the course of the 24 hours were compared between the 2 groups. The 24-hour ambulatory blood pressure and posture were monitored simultaneously. A generalized linear model was used to find the factors associated with NTG. The IOP-related patterns, including mean and standard deviation (SD) of measurements, amplitude of cosine-fit curve, acrophase (signal peak), and bathyphase (signal trough) values (millivolt equivalents [mVEq]). The SDs of the 24-hour CLS measurements were significantly greater in NTG eyes than in healthy controls (112.51±26.90 vs. 85.18±29.61 mVEq, P= 0.002). The amplitudes of cosine-fit curve (141.88±39.96 vs. 106.08±41.49 mVEq, P= 0.004) and acrophase values (277.74±129.80 vs. 190.58±127.88 mVEq, P= 0.024), mostly measured during nocturnal period, were significantly greater in NTG eyes than in healthy controls. The NTG subjects slept longer in the lateral decubitus posture than the healthy controls (199.1±137.8 vs. 113.2±86.2 minutes, P= 0.009). In the multivariable generalized linear model, the greater amplitude of cosine-fit curve (β= 0.218, P= 0.012) and greater time of decubitus posture during sleep (β= 0.180, P= 0.004) were found to be significantly associated with NTG. Continuous monitoring of 24-hour IOP-related values with CLS can be useful for assessment of glaucoma risk, especially for patients with NTG whose IOP appears to be in the normal range. Fluctuation of 24-hour IOP-related values and posture during sleep time might be associated with NTG.

The correlations between posterior scleral profile and autonomic dysfunction in normal tension glaucoma

AbstractPurposeTo investigate the association between autonomic dysfunction and posterior scleral profile in normal tension glaucoma.DesignObservational, cross‐sectional study.ParticipantsTwo hundred eight NTG patients.MethodComplete ophthalmic examination was performed in all patients including heart rate variability to evaluate autonomic dysfunction. Posterior scleral profile, which was identified by the disc tilt ratio, disc torsion, disc foveo angle and peripapapillary area(PPA) to disc ratio was measured from disc photographs. Patients were classified into the two groups according to the standard deviation value of the qualified normal to normal intervals(SDNN) of the heart‐rate‐variability assessment. Group 1 consisted of patients within the one standard deviation from the average of the SDNN measurements. And Group 2 consisted of patients outside one standard deviation from the average of the SDNN measurements, indicating that they had too higher or too lower SDNN of HRV. So Group 2 having deviated value was thought to have abnormality in HRV. Two groups were compared. Logistic regression analysis was used to determine the relationship between posterior scleral profile and abnormality of heart rate variability.Main outcome and measureAssociation between posterior scleral profile(axial length, tilt ratio, torsion ratio, disc foveo angle, PPA to disc ratio) and autonomic dysfunction.ResultsThe mean value of SDNN in 208 NTG patients was 33.71 and the standard deviation was 18.16. Group1 had a SDNN values between 15.55 and 51.87 and Group 2 had a SDNN value less than 15.55 or greater than 51.87. Among 208 NTG eyes, 164 (78.8%) were group 1 and 44 (21.2%) were group 2. Axial length was significantly longer in Group 2 than Group 1 (p = 0.008). Degree of disc torsion were significantily higher in Group 2 than group 1 (p &lt; 0.001). Although just short of statistical significance (p = 0.058), disc tilt ratio was higher in group 2. Torsion degree was the only factor related to heart rate variability in both univariate (p &lt; 0.001) and multivariate (p = 0.008) logistic regression analyses.ConclusionOur study results showed that the dysfunction of an autonomic control is associated with posterior scleral profile such like disc tilt ratio, torsion degree, axial length.

Rates of Ganglion Cell-Inner Plexiform Layer Thinning in Normal, Open-Angle Glaucoma and Pseudoexfoliation Glaucoma Eyes: A Trend-Based Analysis

The purpose of this study was to determine the rate of ganglion cell-inner plexiform layer (GCIPL) thinning by Cirrus high-definition optical coherence tomography (HD-OCT) in normal eyes and open-angle glaucoma (OAG) and pseudoexfoliation glaucoma (PXG) eyes. This was a longitudinal observational study. We evaluated 282 subjects who visited a glaucoma clinic of a tertiary hospital in Korea: 60 healthy eyes, 193 medically treated OAG eyes, and 29 medically treated PXG eyes with a minimum 3-year follow-up involving serial spectral-domain OCT measurement of GCIPL thickness. The rates of thinning in the GCIPL thickness of the global region, six macular sectors, and minimum thickness were determined by linear mixed model and compared among the normal, OAG, and PXG groups. Additionally, the GCIPL thinning rates were compared between normal-baseline-IOP OAG (normal-tension glaucoma [NTG]) and high-baseline-IOP OAG (high-tension glaucoma [HTG]) eyes. The mean rates of GCIPL thinning were -0.31 μm/y in the normal eyes, -0.49 μm/y in OAG, and -1.46 μm/y in PXG. The differences in the mean GCIPL thinning rates were statistically significant between OAG and PXG (normal versus OAG, P = 0.231; OAG versus PXG, P < 0.001; normal versus PXG, P < 0.001). Among the eyes with OAG, the treated NTG and HTG eyes showed no significant difference in GCIPL thinning rate (NTG versus HTG = -0.41 μm/y versus -0.66 μm/y, P = 0.123). We determined the GCIPL thinning rates for normal and undertreated OAG and PXG eyes. Differences existed among the normal eyes and glaucoma types, with PXG progressing significantly faster than OAG.

Positional and Curvature Difference of Lamina Cribrosa According to the Baseline Intraocular Pressure in Primary Open-Angle Glaucoma: A Swept-Source Optical Coherence Tomography (SS-OCT) Study.

PurposeTo investigate the variation of lamina cribrosa (LC) structure based on the baseline intraocular pressure (IOP) in eyes with primary open-angle glaucoma (POAG) and healthy individuals using swept-source optical coherence tomography.MethodsA total of 108 eyes with POAG and 61 healthy eyes were recruited. Based on the baseline IOP, the POAG eyes were divided into higher-baseline IOP (HTG; baseline IOP > 21 mmHg, n = 38 eyes) and lower-baseline IOP (NTG; baseline IOP ≤ 21 mmHg, n = 70 eyes). The anterior laminar insertion depth (ALID), mean LC depth (mLCD), and the LC curvature index (mLCD–ALID) were measured, and compared among the three groups. The regional variation of LC structure was evaluated by vertical-horizontal ALID difference.ResultsThe mLCD and LC curvature index were greatest in HTG eyes (520.3 ± 123.0 and 80.9 ± 30.7 μm), followed by NTG (463.2 ± 110.5 and 64.5 ± 30.7 μm) and healthy eyes (382.9 ± 107.6 and 47.6 ± 25.7 μm, all P < 0.001). However, there were no significant difference in ALID between HTG and NTG eyes. The vertical-horizontal ALID difference was larger in NTG eyes (72.8 ± 56.2 μm) than in HTG (32.7 ± 61.4 μm, P = 0.004) and healthy eyes (25.5 ± 34.8 μm, P < 0.001).ConclusionsLamina cribrosa position and curvature differed in POAG eyes with low and high IOP. This would support the theory that IOP induced biomechanical effects on the optic play a role on glaucoma.

Progression rate in glaucoma using spectral‐domain optical coherence tomography

AbstractPurpose To evaluate the thining rates of retinal nerve fiber layer (RNFL), macular and ganclion cell‐inner plexiform layer (GC‐IPL) thickness in eyes with POAG, NTG and ACG.Methods Retrospective cohort study included 145 eyes of 90 glaucoma patient(POAG 70; NTG 60; ACG 15). RNFL, macular and GI‐IPL thickness were measured by spectral‐domain optical coherence tomography (Cirrus SD‐OCT). Also all the patient was re‐classified as 3 groups according to visual field severity (early, moderate and advanced) and as 3 groups according to spherical equivalent (myopia, mild myopia and hyperopia). The meaningful thining was defined on exceed the age‐related physiological loss.Results The mean (±SD) follow‐up period was 3.86±0.16 years. ACG eyes showed highest progression rate of RNFLT in all of quadrant and clock hour. NTG eyes showed no significant different in average RNFLT but significantly higher RNFL thining rates than POAG in inferior quadrant. In ACG eyes, RNFLT thining rate is highest in clock‐hour‐6. In NTG eyes showed highest in clock‐hour‐7 while similar rate in clock‐hour‐7 and clock‐hour‐12 in POAG eyes. Thining of macular thickness is highest at outer inferior sector and thining of GC‐IPL is highest in inferior sector and inferior hemifield. Thining rate of RNFLT is slower in myopic eyes than mild myopic and hyperopic eyes. In the advanced group, thining rate of RNFLT is slower than early and moderate groups.Conclusion Reduction rate of RNFL, macular and GC‐IPL thickness calculated by Ciruss SD‐OCT is differ according to the types of glaucoma, spherical equivalent and severity of glaucoma.

Comparison of Normal- and High-Tension Glaucoma: Nerve Fiber Layer and Optic Nerve Head Damage

Purpose: The aim of this study was to investigate differences in the nerve fiber layer and glaucoma-induced structural optic nerve head (ONH) damage in patients with normal- (NTG) and high-tension (HTG) glaucoma. Methods: In this retrospective pair-matched comparative study, 22 NTG and 22 HTG eyes were matched according to the same glaucomatous damage based on rim volume, rim area and disk size, as measured by Heidelberg retinal tomography (HRT III). Visual fields (VF) were assessed by Humphrey perimetry, and nerve fiber layer thickness was determined both by scanning laser polarimetry (GDxVCC) and spectral-domain optical coherence tomography (SD-OCT). Comparisons of all measured parameters were made between NTG and HTG groups. Results: Based on HRT results, both NTG and HTG eyes displayed comparable structural damage to the ONH (NTG/HTG, mean: disk area, 2.30/2.31 mm², p = 0.942; rim area, 1.02/0.86 mm², p = 0.082; rim volume, 0.19/0.17 mm³, p = 0.398). NTG eyes had significantly less VF damage than HTG eyes (NTG/HTG, mean deviation: -4.23/-12.12 dB, p = 0.002; pattern standard deviation: 5.39/8.23 dB, p = 0.022). The inferior nerve fiber layer of NTG patients was significantly thicker than that of HTG patients (NTG/HTG, mean: GDx inferior: 53.5/46.3 µm, p = 0.046). SD-OCT revealed a significantly thicker nerve fiber in NTG compared with HTG patients in all quadrants (NTG/HTG, total mean: 72.72/58.45 µm, p = 0.002). Conclusion: At comparable glaucomatous stages, nerve fiber loss was more advanced in HTG patients compared with NTG patients.

Goldmann applanation tonometry compared with corneal-compensated intraocular pressure in the evaluation of primary open-angle Glaucoma

BackgroundTo better understand the role of corneal properties and intraocular pressure (IOP) in the evaluation of primary open-angle glaucoma (POAG); and to determine the feasibility of identifying glaucomatous optic neuropathy (GON) using IOP corrected and uncorrected for corneal biomechanics.MethodsRecords from 1,875 eyes of consecutively evaluated new patients were reviewed. Eyes were excluded if central corneal thickness (CCT) or Ocular Response Analyzer (ORA) measurements were unavailable. Presence or absence of GON was determined based on morphology of the optic disc, rim and retinal nerve fiber layer at the time of clinical examination, fundus photography and Heidelberg Retinal Tomography. Goldmann-applanation tonometry (GAT) in the untreated state was recorded and Goldmann-correlated (IOPg) and corneal-compensated IOP (IOPcc) were obtained using the ORA. Glaucomatous eyes were classified as normal or high-tension (NTG, HTG) using the conventional cutoff of 21 mm Hg. One eligible eye was randomly selected from each patient for inclusion.ResultsA total of 357 normal, 155 HTG and 102 NTG eyes were included. Among NTG eyes, IOPcc was greater than GAT (19.8 and 14.4 mm Hg; p < 0.001) and the difference between IOPcc and GAT was greatest for this subgroup of patients with NTG (p ≤ 0.01). The maximum combined sensitivity and specificity for detection of GON occurred at 20.9 mm Hg for GAT (59%, 90%) and 18.4 mm Hg for IOPcc (85%, 85%) and the area under the curve was greater for IOPcc (0.93 vs. 0.78; p < 0.001).ConclusionsIOPcc may account for measurement error induced by corneal biomechanics. Compared to GAT, IOPcc may be a superior test in the evaluation of glaucoma but is unlikely to represent an effective diagnostic test.

Visual Field Progression Differences between Normal-Tension and Exfoliative High-Tension Glaucoma

To compare the pattern, location, and rate of visual field (VF) change in normal-tension (NTG) and exfoliative high-tension glaucoma (XHTG). Records of all patients with glaucoma in the New York Glaucoma Progression Study with five or more VF tests were reviewed. Patients were divided into NTG (all known IOP < 21 mm Hg) and XHTG (untreated IOP >or= 21 mm Hg) groups. Automated pointwise linear regression analysis determined global and localized rates of change. There were 139 NTG and 154 XHTG eyes. Patients with XHTG were significantly older than those with NTG (mean +/- SD: 72.6 +/- 9.4 years vs. 62.7 +/- 12.8 years, P < 0.01), had higher mean IOPs (16.5 +/- 3.2 mm Hg vs. 13.3 +/- 2.0 mm Hg, P < 0.01) and greater central corneal thickness (CCT, 544.0 +/- 35.7 microm vs. 533.9 +/- 35.9 microm; P = 0.01). During a similar period, XHTG progressed globally almost twice as rapidly as did NTG (-0.64 +/- 0.7 dB/y vs. -0.35 +/- 0.3 dB/y, P < 0.01), which became nonsignificant after adjustment for differences in age, mean IOP, and CCT. In a multivariate model, variables significantly associated with progression were higher mean IOP (odds ratio [OR]: 1.09, P = 0.03) and decreased CCT (OR/40 mum thinner: 1.37, P = 0.03). Progression within the paracentral VF was more common in the NTG group (75% vs. 57.3%, P = 0.04). The most important factor associated with paracentral progression among eyes that reached a progression outcome was the diagnosis of NTG. XHTG and NTG eyes progress at a similar global rate after adjustment for differences in IOP, CCT, and age. However, NTG eyes progress more often in the central VF, independent of other factors. Glaucoma surveillance in eyes with open-angle glaucoma and statistically normal IOP should include periodic assessment of the central field.

Relationships between central corneal thickness and optic disc topography in eyes with glaucoma, suspicion of glaucoma, or ocular hypertension

To identify relationships between central corneal thickness (CCT) and optic disc topography, as determined by scanning laser ophthalmoscopy (SLO), for patients seen in a specialist glaucoma service. 272 eyes of 144 patients with primary open angle glaucoma (POAG; n = 71), normal tension glaucoma (NTG; n = 50), ocular hypertension (OH; n = 48) and those considered to be suspicious for glaucoma (GS; n = 103) underwent ultrasonic pachymetry and optic disc topography by SLO. Correlations between CCT and SLO parameter values were identified. A Bonferroni correction for multiple comparisons was performed and a p value of <0.0042 was considered significant. Mean CCT values were 533 mum (POAG), 530 mum (NTG), 550 mum (GS), and 565 mum (OH). As a group the GS and OH eyes had significantly thicker CCT values than eyes with POAG. In addition, the NTG eyes had significantly thinner CCT values than GS and OH eyes. Overall multiple SLO parameters correlated with CCT even after accounting for co-variance with age, refraction and inclusion of both eyes. Sub-group analysis indicated that 'optic disc rim area' positively correlated with CCT (r = 0.378) and 'cup to disc area ratio' negatively correlated with CCT (r = -0.370) in the POAG group. In the GS group the parameter 'area below reference' (a measure of cup volume) and 'mean cup depth' had negative correlations with CCT (r = -0.297 and -0.323) indicating that eyes with thinner than average corneal thickness measurements had larger and deeper cups. Thinner corneas appear to be associated with larger and deeper optic disc cups in the eyes of patients seen in a specialist glaucoma service.

Frequency Doubling Technology and Scanning Laser Tomography in Eyes With Generalized Enlargement of Optic Disc Cupping

To characterize functional and structural changes in eyes with generalized enlargement of optic disc cupping (vertical cup/disc ratio > or = 0.8), normal intraocular pressure, normal standard achromatic automated perimetry (SAP) results, and no other ophthalmoscopic findings suggesting glaucoma (large C/D eyes) using frequency doubling technology (FDT) and the Heidelberg Retina Tomograph (HRT). This comparative observational case series included 30 large C/D eyes (30 subjects), 17 eyes (17 patients) with early-stage normal tension glaucoma with generalized enlargement of optic disc cupping (NTG eyes), and 25 eyes from 25 normal subjects (normal eyes). Results with Humphrey 30-2, FDT N-30 threshold programs, and HRT were compared among these groups. Large C/D eyes were subdivided into FDT-normal and -abnormal eyes according to the predetermined criteria and HRT parameters were compared among them. No significant difference was seen in HRT parameters between the large C/D and NTG eyes. In the large C/D eyes, FDT mean deviation was lower than in the normal eyes and higher than in the NTG eyes, whereas FDT pattern standard deviation was smaller than in the NTG eyes (P = 0.02-0.03). Among HRT parameters, only cup shape measure (CSM) showed significant negative correlation with FDT mean deviation in the large C/D eyes. Between FDT-normal and -abnormal subgroups, only CSM showed significant difference (P < 0.01). Frequency doubling technology showed abnormalities in large C/D eyes. Only CSM showed significant correlation with FDT result and difference between those with normal and abnormal FDT results. In management of large C/D eyes, FDT and CSM will be useful to detect functional and structural change.

Myopia and advanced-stage open-angle glaucoma

Objective To investigate the effect of myopic refraction on the central visual field in patients with advanced open-angle glaucoma (OAG). Design Multicenter cross-sectional study. Participants Three hundred thirteen OAG eyes (176 eyes of 176 primary open-angle glaucoma [POAG] patients and 137 eyes of 137 normal-tension glaucoma [NTG] patients) with clear ocular media and a mean deviation (MD) <−15 dB. Patients with a recorded maximum intraocular pressure (IOP) of 22 mmHg or greater were classified as POAG, and those with an IOP of 21 mmHg or less were classified as NTG. Methods Multiple regression analysis was used to study the influence of refraction on 12 central test points of the C30-2 Humphrey program, and the differences in visual field defects between POAG and NTG eyes were examined using logistic discriminant analysis. In the multiple regression analysis, total deviation (TD) of the 12 test points was graded and used as the dependent variable, and MD and the spherical equivalent refraction were the explanatory variables. In the logistic discrimination analysis, TD, MD, and refraction were covariants that determined the OAG subtypes. Main outcome measures TD values of the 12 central test points (C30-2 program). Results Higher myopic refraction was significantly associated with more damage at a point just temporal and inferior to the fixation point in POAG eyes, whereas it was significantly associated with less damage at test points just temporal and superior to the fixation point in NTG eyes. After correcting for the influence of refraction, POAG eyes had significantly more damage at a test point just temporal and inferior to the fixation point, whereas NTG eyes had significantly more damage at those test points nasal and inferior to the fixation point. Conclusions High myopia constitutes a threat to the remaining lower cecocentral visual field and is one of the factors that interfere with the quality of vision in advanced OAG with high IOP but not low IOP.

The relationship between retrobulbar blood flow velocity and glaucoma damage. An intraindividual comparison

Glaucomatous optic nerve damage is thought to be influenced by ocular perfusion. The aim was to investigate if a difference in visual field and Heidelberg retinal tomography (HRT) between two eyes of an individual glaucoma patient is reflected in different blood flow velocities in retrobulbar vessels. Data from 53 patients including 26 normal tension glaucoma patients (NTG) and 27 high tension glaucoma patients (HTG) were evaluated retrospectively. In 38 patients asymmetric glaucomatous damage (AGD) could be demonstrated by both structural (HRT) and functional measures (static or Goldmann perimetry). In 15 patients there was symmetric glaucomatous damage (SGD). To discriminate between AGD and SGD we used a score for HRT and visual field. Color Doppler imaging (CDI) was performed with a Siemens Quantum 2000. No significant differences were found when comparing group means of intraindividual deviation of CDI in patients with AGD vs. SGD. Overall analysis of CDI values in NTG vs. HTG eyes also showed no significant differences. Nevertheless we measured decreased blood flow velocities for NTG compared to HTG eyes especially in short posterior ciliary arteries, peak systolic and end diastolic velocities. A simple correlation between retrobulbar blood flow velocities and glaucomatous damage could not be found. However, color Doppler images can give important additional information in the diagnosis of glaucoma, especially normal tension glaucoma.