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High-tension glaucoma (HTG) is one of the most common forms of primary open angle glaucoma. The purpose of this study was to assess in HTG brain, whether the elevated intraocular pressure (IOP) had an effect on the brain morphological alterations via structural MRI. We acquired T1WI structural MRI images from 56 subjects including 36 HTG patients and 20 healthy controls. We tested whether the brain morphometry was associated with the mean IOP in HTG patients. Moreover, we conducted moderation analysis to assess the interactions between subject type (HTG - healthy controls) and IOP. In HTG group, cortical thickness was negatively correlated with the mean IOP in the left rostral middle frontal gyrus, left pars triangularis, right precentral gyrus, left postcentral gyrus, left superior temporal gyrus (p < 0.05, FDR corrected). Four of the five regions negatively correlated with mean IOP showed reduced cortical thickness in HTG group compared with healthy controls, which were the left rostral middle frontal gyrus, left pars triangularis, left postcentral gyrus and left superior temporal gyrus (p < 0.05, FDR corrected). IOP moderated the interaction between subject type and cortical thickness of the left rostral middle frontal gyrus (p = 0.0017), left pars triangularis (p = 0.0011), left postcentral gyrus (p = 0.0040) and left superior temporal gyrus (p = 0.0066). Elevated IOP may result brain morphometry alterations such as cortical thinning. The relationship between IOP and brain morphometry underlines the importance of the IOP regulation for HTG patients.

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Purpose. The aim of this study was to compare the results of optical coherence tomography angiography (OCTA) and optical coherence tomography (OCT) examinations in patients with normal-tension glaucoma (NTG) in comparison to high-tension pseudoexfoliative glaucoma (HTG) patients at the early stage of glaucoma. Material and methods. The studied groups consisted of patients in the early stage of NTG (70 eyes) and the early stage of HTG (71 eyes). In NTG and HTG groups, a detailed ophthalmic examination was performed. Optic disc OCT with peripapillary RNFL measurements and OCTA examination with the evaluation of the macula and optic disc were performed for all participants using Zeiss Cirrus 5000. Results. NTG and HTG groups were statistically similar as far as the MD was concerned, and both groups had early glaucoma. When evaluating the RNFL thickness, the only statistical difference between early NTG and HTG was observed in the thicknesses in the temporal sector of peripapillary RNFL, with thinner values in the NTG group (53.94 vs. 59.94, p = 0.0071). When the OCTA results of the macula and optic disc were evaluated, there were no statistical differences between early NTG and HTG. Conclusions. The vascular density and flow parameters assessed in OCTA were equal between early NTG and HTG, and therefore the involvement of vascular factors in NTG pathogenesis could not be confirmed. Our results confirm the preponderance of more frequent temporal RNFL involvement in early NTG.

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INTRODUCTION: The aim of this study was to compare the patterns of visual field (VF) defects in primary angle-closure glaucoma (PACG) to control groups of eyes with high-tension glaucoma (HTG) and normal-tension glaucoma (NTG). METHODS: Forty-eight eyes with PACG were enrolled, and control eyes with HTG and NTG matched for age, sex, and mean deviation of VF defect were selected. VF tests were performed using the 24-2 program of the Humphrey field analyzer. VF defects were classified into six patterns with the Ocular Hypertension Treatment Study classification system and were categorized into three stages (early, moderate, and advanced). Each hemifield was divided into five regions according to the Glaucoma Hemifield Test (GHT). The mean total deviation (TD) of each GHT region was calculated. RESULTS: Compared with HTG and NTG groups, the partial arcuate VF defects were more common in the PACG group. In the PACG group, the nasal GHT region in the inferior hemifield had the worst mean TD (-8.48 ± 8.62 dB), followed by the arcuate 1 (-7.81 ± 7.91 dB), arcuate 2 (-7.46 ± 7.43 dB), paracentral (-7.19 ± 7.98 dB), and central (-5.14 ± 6.24 dB) regions; the mean TD of the central region was significantly better than those for all other regions (all p < 0.05). A similar trend was observed in the superior hemifield in the PACG group but not the VF hemifields of the HTG and NTG groups. CONCLUSION: Patterns of VF defect in PACG patients differ from those with HTG and NTG. This discrepancy might be due to the differences in the pathogenic mechanisms of glaucomatous optic neuropathy.

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Purpose: To investigate the association between the apolipoprotein E (APOE) E4 dementia-risk allele and prospective longitudinal retinal thinning in a cohort study of suspect and early manifest glaucoma. Design: Retrospective analysis of prospective cohort data. Participants: This study included all available eyes from participants recruited to the Progression Risk of Glaucoma: Relevant SNPs [single nucleotide polymorphisms] with Significant Association (PROGRESSA) study with genotyping data from which APOE genotypes could be determined. Methods: Apolipoprotein E alleles and genotypes were determined in PROGRESSA, and their distributions were compared with an age-matched and ancestrally matched normative cohort, the Blue Mountains Eye Study. Structural parameters of neuroretinal atrophy measured using spectral-domain OCT were compared within the PROGRESSA cohort on the basis of APOE E4 allele status. Main Outcome Measures: Longitudinal rates of thinning in the macular ganglion cell-inner plexiform layer (mGCIPL) complex and the peripapillary retinal nerve fiber layer (pRNFL). Results: Rates of mGCIPL complex thinning were faster in participants harboring ≥1 copies of the APOE E4 allele (ß = -0.13 µm/year; P ≤0.001). This finding was strongest in eyes affected by normal-tension glaucoma (NTG; ß = -0.20 µm/year; P = 0.003). Apolipoprotein E E4 allele carriers were also more likely to be lost to follow-up (P = 0.01) and to demonstrate a thinner average mGCIPL complex (70.9 µm vs. 71.9 µm; P = 0.011) and pRNFL (77.6 µm vs. 79.2 µm; P = 0.045) after a minimum of 3 years of monitoring. Conclusions: The APOE E4 allele was associated with faster rates of mCGIPL complex thinning, particularly in eyes with NTG. These results suggest that the APOE E4 allele may be a risk factor for retinal ganglion cell degeneration in glaucoma.

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Secondary glaucoma is a typical normal tissue complication following radiation therapy involving ocular radiation exposure at high fractionated dose (several tens of Gy). In contrast, recent studies in acutely exposed Japanese atomic bomb survivors showed a significantly increased risk for normal-tension glaucoma (NTG, a subtype of primary open-angle glaucoma) at much lower dose, but such information is not available in any other cohorts. We therefore set out to evaluate the incidence of risk for primary glaucoma and its subtypes in a Russian cohort of Mayak Production Association nuclear workers who received chronic radiation exposure over many years. Of these, we found a significantly increased relative risk (RR) of NTG incidence (RR = 1.88 95% confidence intervals (CI): 1.01, 3.51; p = 0.047) in workers exposed to gamma rays at cumulative brain absorbed dose above >1 Gy. We observed the linear relationship between NTG incidence and brain absorbed gamma dose with an excess relative risk per unit brain absorbed dose of 0.53 (95% CI: 0.01, 1.68; p < 0.05), but not for any other subtypes nor for total primary glaucoma. Such elevated risk of radiogenic NTG incidence, if confirmed in other cohorts, has significant implications for normal tissue complications in radiotherapy patients receiving ocular radiation exposure, and for ocular radiation protection in radiation workers.

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PURPOSE: To compare forecasted changes in mean deviation (MD) for patients with normal-tension glaucoma (NTG) and high-tension open-angle glaucoma (HTG) at different target intraocular pressures (IOPs) using Kalman filtering, a machine learning technique. DESIGN: Retrospective cohort study. PARTICIPANTS: From the Collaborative Initial Glaucoma Treatment Study or Advanced Glaucoma Intervention Study, 496 patients with HTG; from Japan, 262 patients with NTG. METHODS: Using the first 5 sets of tonometry and perimetry measurements, each patient was classified as a fast progressor, slow progressor, or nonprogressor. Using Kalman filtering, personalized forecasts of MD changes over 2.5 years' follow-up were generated for fast and slow progressors with HTG and NTG with IOPs maintained at hypothetical IOP targets of 9 to 21 mmHg. Future MD loss with different percentage IOP reductions from baseline (0%-50%) were also assessed for the groups. MAIN OUTCOME MEASURES: Mean forecasted MD change at different target IOPs. RESULTS: The mean (± standard deviation) patient age was 63.5 ± 10.5 years for NTG and 66.5 ± 10.9 years for HTG. Over the 2.5-year follow-up, at target IOPs of 9, 15, and 21 mmHg, respectively, the mean forecasted MD losses for fast progressors with NTG were 2.3 ± 0.2, 4.0 ± 0.2, and 5.7 ± 0.2 dB; for slow progressors with NTG, losses were 0.63 ± 0.02, 1.02 ± 0.03, and 1.49 ± 0.07 dB; for fast progressors with HTG, losses were 1.8 ± 0.1, 3.4 ± 0.1, and 5.1 ± 0.1 dB; and for slow progressors with HTG, losses were 0.55 ± 0.06, 1.04 ± 0.08, and 1.59 ± 0.10 dB. Fast progressors with NTG had greater MD decline than fast progressors with HTG at each target IOP (P ≤ 0.007 for all). The MD decline for slow progressors with HTG and NTG were similar (P ≥ 0.24 for all target IOPs). Fast progressors with HTG had greater MD loss than those with NTG with 0%-10% IOP reduction since baseline (P ≤ 0.01 for all), but not 25% (P = 0.07) or 50% (P = 0.76) reduction since baseline. CONCLUSIONS: Machine learning algorithms using Kalman filtering techniques demonstrate promise at forecasting future MD values at different target IOPs for patients with NTG and HTG.

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BACKGROUND: High-tension glaucoma (HTG) is associated with functional changes in the brain, and elevated intraocular pressure (IOP) is one of the major causes. PURPOSE: To evaluate the effects of high IOP on the brain in patients with HTG by using resting-state functional magnetic resonance imaging (rs-fMRI). MATERIALS AND METHODS: Thirty-six patients with HTG and 20 age- and gender-matched healthy controls (HCs) were recruited and underwent IOP examination and rs-fMRI scan. Voxel-wise functional connectivity (FC) values were obtained between the Brodmann Area (BA) 17 (primary visual cortex) and the rest of the brain, two-sample t test was performed between HTG group and HCs. Correlation analysis was performed between FC and clinical information. RESULTS: Compared with HCs, HTG patients demonstrated decreased FC between BA 17 and the right precuneus gyrus, decreased FC between BA 17 and the right superior frontal gyrus (SFG) (GRF corrected at voxel level P<0.001 and cluster level P<0.05, two-tailed). FC between BA 17 and the right SFG showed significantly negative correlation with right eyes' IOP and mean IOP. CONCLUSION: HTG patients had abnormal FC changes between the visual cortex and multiple functional brain regions related to visual sense, memory consolidation and cognitive processing, which provided image support for the pathophysiology research of HTG, and revealed new targets for the accurate treatment of HTG.

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Background and Objective: Glaucoma is a progressive optic neuropathy in which the optic nerve is damaged. The optic nerve is exposed not only to intraocular pressure (IOP) in the eye, but also to intracranial pressure (ICP), as it is surrounded by cerebrospinal fluid in the subarachnoid space. Here, we analyse ICP differences between patients with glaucoma and healthy subjects (HSs). Materials and Methods: Ninety-five patients with normal-tension glaucoma (NTG), 60 patients with high-tension glaucoma (HTG), and 62 HSs were included in the prospective clinical study, and ICP was measured non-invasively by two-depth transcranial Doppler (TCD). Results: The mean ICP of NTG patients (9.42 ± 2.83 mmHg) was significantly lower than that of HSs (10.73 ± 2.16 mmHg) (p = 0.007). The mean ICP of HTG patients (8.11 ± 2.68 mmHg) was significantly lower than that of NTG patients (9.42 ± 2.83 mmHg) (p = 0.008) and significantly lower than that of HSs (10.73 ± 2.16 mmHg) (p < 0.001). Conclusions: An abnormal ICP value could be one of the many influential factors in the optic nerve degeneration of NTG patients and should be considered as such instead of just being regarded as a "low ICP".

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AIM OF THE STUDY: The purpose of the present study was to determine if swept-source optical coherence tomography angiography (OCTA) of the superficial plexus in the macular region can detect differences between high-tension open-angle glaucoma (HTG) and normal-tension glaucoma (NTG). MATERIALS AND METHODS: In this prospective study 60 eyes from 60 patients (40 HTG; 20 NTG) underwent fovea centred 3 × 3 mm cube macula OCTA imaging by a swept-source OCTA device (Plex Elite, Zeiss, Jena, Germany). Quantitative analysis of the vasculature at the superficial plexus was performed by assessing the Perfusion Density (PD), defined as the total area of perfused vasculature per unit area in a region of measurement, for each group, respectively. Besides, macular ganglion cell layer thickness and mean deviation from visual field testing was assessed and correlated with PD. RESULTS: Average superficial PD of the measured 3 × 3 mm field was comparable between HTG and NTG (P = .567). In both groups a significant relation of PD and age (HTG: r = -0.48, p = .002; NTG: r = -0.615; p = .004) was shown, indicating reduced PD with increasing age. For both groups a positive correlation between PD and mean deviation (MD) (HTG: r = 0.492, p = .003; NTG: r = 0.530, p = .029) as well as PD and GCL thickness was shown (r = 0.486, p = .002 vs. r = 0.389; p = .09). However, the latter did not reach statistical significance in the NTG group. CONCLUSION: PD at the central 3 mm around the fovea is comparable between HTG and NTG. Significant correlation with age and MD was shown in both groups.

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PURPOSE: To investigate brain morphological alterations of high-tension glaucoma patients and explore the association between brain morphological changes and elevated intraocular pressure. METHODS: Thirty-six patients with high-tension glaucoma and 20 healthy controls were collected and underwent structural MRI scan. Surface-based morphometry and voxel-based morphometry were applied to assess cortical thickness and subcortical gray matter volume of the enrolled subjects. The association between brain morphometry and intraocular pressure was assessed by partial correlation. RESULTS: Compared with healthy controls, high-tension glaucoma patients showed decreased cortical thickness in the bilateral superior temporal gyrus, bilateral superior parietal gyrus, bilateral lateral occipital gyrus, left fusiform gyrus, left medial orbitofrontal gyrus, right precentral gyrus, and right superior frontal gyrus (p < 0.05). High-tension glaucoma patients also showed reduced gray matter volume in the right hippocampus, bilateral putamen, and bilateral thalamus (p < 0.05). In addition, brain morphological correlates of mean intraocular pressure were found in the left rostral middle frontal gyrus, right precentral gyrus, and left postcentral gyrus in high-tension glaucoma group (p < 0.05). CONCLUSION: High-tension glaucoma patients experienced morphological reduction in the visual and nonvisual areas throughout the entire brain. Elevated intraocular pressure may contribute to the reduction of cortical thickness in certain areas in the progression of the disease.

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PURPOSE: To evaluate parafoveal and peripapillary perfusion in healthy, glaucoma suspect, normal-tension glaucoma, and primary open-angle glaucoma subjects. PATIENTS AND METHODS: This was a retrospective cross-sectional study with optical coherence tomography angiography imaging with RTVue XR Avanti (Optovue, Inc., Fremont, CA) of 56 eyes (14 healthy, 14 glaucoma suspect, 16 normal-tension glaucoma, and 12 primary open-angle glaucoma) at a tertiary academic referral center. Parafoveal and peripapillary superficial vessel density and parafoveal superficial retinal thickness were the main parameters of interest. Area under receiver operating characteristic curves were calculated. RESULTS: There were significant decreases in parafoveal superficial vessel density in primary open-angle (40.06±4.54%, P<0.001) and normal-tension glaucoma (42.82±5.16%, P=0.010) but not suspect eyes (45.72±4.37%, P=0.916) compared to healthy eyes (48.10±2.82%). Similarly, decreases were observed in parafoveal inner retinal thickness in primary open-angle (83.19±14.29 µm, P<0.001) and normal-tension glaucoma eyes (94.97±12.44 µm, P=0.035), but not suspect eyes (99.93±9.00 µm, P=0.648), compared to healthy controls (107.00±9.55 µm). Only primary open-angle glaucoma eyes displayed significant changes in peripapillary vessel density (37.63±7.19%) compared to healthy controls (49.12±2.80%, P<0.001). Further statistical adjustment for sex and age revealed a significant decrease in parafoveal vessel density in suspects relative to controls (P=0.039). Diagnostic accuracy of parafoveal vessel density was high with an area under the curve of 0.833±0.073 for normal-tension glaucoma and 0.946±0.049 for primary open-angle glaucoma. CONCLUSION: Parafoveal vessel density was significantly reduced in glaucomatous eyes, with good diagnostic accuracy. These findings provide further evidence that these changes may be useful in the diagnosis and monitoring of disease in glaucoma patients.

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PURPOSE: To evaluate the effects of high intraocular pressure (IOP) on central nervous system in patients with high-tension glaucoma (HTG) by using resting-state functional magnetic resonance imaging (rs-fMRI). METHODS: Thirty-six patients with HTG and twenty age- and gender-matched healthy controls (HCs) were recruited and underwent IOP measurement and rs-fMRI scan. The whole brain regional homogeneity (ReHo) value was calculated among the enrolled subjects. Two-sample t tests with permutation test and threshold-free cluster enhancement was performed between HTG group and HCs. Correlation analyses between IOP and ReHo values were conducted. RESULTS: Compared with HCs, HTG group showed increased ReHo values in the left lobule 8 of cerebellar hemisphere, left lobule 4 and 5 of cerebellar hemisphere and left fusiform gyrus (FG) (p < 0.05). HTG group showed decreased ReHo value in the left middle frontal gyrus (MFG) (p < 0.05). Intraocular pressure of the left eye in HTG group experienced a significant positive correlation with ReHo value of the left FG (r = 0.370, p = 0.026), IOP of the right eye in HTG group showed a significant negative correlation with ReHo value in the left MFG (r = -0.421, p = 0.011). CONCLUSION: Resting-state fMRI ReHo analyses associated elevated IOP with abnormal regional activity in several brain regions related to higher visual function and visual memory consolidation. High-tension glaucoma patients also showed diminished integration of visual information and cerebellar function. These results may provide imaging support for pathophysiological research of HTG and may reveal new targets for the accurate treatment of HTG.

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PURPOSE: Assessment of the diagnostic ability of segmented macular inner retinal layer thickness and peripapillary retinal nerve fiber layer (pRNFL) measured by spectral-domain optical coherence tomography (SD-OCT) in patients with normal-tension (NT) and high-tension (HT) perimetric and preperimetric glaucoma. METHODS: The 212 participants included 45 healthy subjects, 55 patients with ocular hypertension, 56 patients with preperimetric glaucoma, and 56 patients with perimetric glaucoma. The preperimetric and perimetric groups were further subdivided into NT and HT groups. Sectoral and global thickness of macular retinal nerve fiber layer (mRNFL), ganglion cell layer (mGCL), inner plexiform layer (mIPL), ganglion cell complex (mGCC), and pRNFL were measured using SD-OCT (Spectralis, Heidelberg Engineering, Germany). Diagnostic performance was ascertained by sectoral and global comparison of the sensitivities at specificity ≥ 95%. RESULTS: For all layers, the largest thickness decrease was reported in the HT perimetric group. In all groups, the sensitivities of mGCL showed a comparable diagnostic value to pRNFL in order to distinguish between healthy subjects and glaucoma patients. In the perimetric group, mGCL (85.7%) exhibited higher sensitivities than mRNFL (78.6%) and mGCC (78.6%). Both mRNFL and pRNFL demonstrated equal diagnostic performance in the HT perimetric group (88.5 and 96.2%), in the NT groups, mRNFL was inferior to all other layers. CONCLUSION: The sensitivities of mGCL and mRNFL were comparable to the sensitivities of pRNFL. In clinical application, mGCL and mRNFL, with a focus on the temporal and inferior sectors, may provide a convincing supplementation to pRNFL. CLINICAL TRIAL REGISTRATION: Erlangen Glaucoma Registry www.clinicaltrials.gov ID: NCT00494923.

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RELEVANCE: Vascular factors may be involved in the development of both high tension glaucoma (HTG) and normal tension (NTG) glaucoma; however, they may be not exactly the same. Autonomic dysfunction characterized by heart rate variability (HRV) is one of the possible reasons of decrease in mean ocular perfusion pressure (MOPP). PURPOSE: To compare the shift of the HRV parameters in NTG and HTG patients after a cold provocation test (CPT). METHODS: MOPP, 24-hour blood pressure and HRV were studied in 30 NTG, 30 HTG patients, and 28 healthy subjects. The cardiovascular fitness assessment was made before and after the CPT. The direction and magnitude of the average group shifts of the HRV parameters after CPT were assessed using the method of comparing regression lines in order to reveal the difference between the groups. RESULTS: MOPP and minimum daily diastolic blood pressure were decreased in HTG and NTG patients compared to healthy subjects. There was no difference in MOPP between HTG and NTG before the CPT. However, all HRV parameters reflected the predominance of sympathetic innervation in glaucoma patients compared to healthy subjects (P < 0.05).Before the CPT, the standard deviation of NN intervals (SDNN) of HRV was lower in HTG compared to NTG, 27.2 ± 4.1 ms and 35.33 ± 2.43 ms (P = 0.02), respectively. After the CPT, SDNN decreased in NTG by 1.7 ms and increased in HTG and healthy subjects by 5.0 ms and 7.09 ms, respectively (P < 0.05). The analysis of relative shift of other HRV parameters after the CPT also revealed a significant difference between NTG and HTG in regard to the predominance of sympathetic innervation in NTG compared to HTG. CONCLUSION: Patients with NTG have more pronounced disturbance of autonomic nervous system than HTG patients, which is manifested with the activation of sympathetic nervous system in response to CPT. This finding refers to the NTG pathogenesis and suggests the use of HRV assessment in glaucoma diagnosis and monitoring.

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PURPOSE: The aim of this study is to determine and compare the changes in the retinal vasculature in eyes with high-tension glaucoma (HTG) or normal-tension glaucoma (NTG). METHODS: The right eyes of 43 HTG subjects, 33 NTG subjects, and 51 age- and sex-matched normal subjects were included in this cross-sectional study. Signals were projected from the internal limiting membrane to retinal pigment epithelium. The retinal perfused vessel densities in the peripapillary and parafoveal regions were measured automatically with optic coherence tomography angiography and the split-spectrum amplitude-decorrelation angiography algorithm. RESULTS: Compared with normal eyes, glaucomatous eyes had a smaller retinal nerve fibre layer (RNFL) thickness, smaller full parafoveal retinal thickness, and lower retinal perfused vessel density (PVD) in the peripapillary and parafoveal regions (all P < 0.01). The visual field, RNFL and retinal thicknesses, and PVD in the parafoveal region in the HTG eyes were similar to those in the NTG eyes. However, the NTG eyes had a significantly lower mean PVD than the HTG eyes in the peripapillary region. When the different sectors of the peripapillary region were studied, the difference was still significant in most sectors (all P < 0.05), except the inferotemporal sector (P = 0.676). CONCLUSIONS: The retinal perfused vessel density is significantly reduced in HTG and NTG eyes, and more prominently in the peripapillary region in NTG eyes.

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PURPOSE: To compare the in vivo lamina cribrosa position in patients with normal-tension glaucoma (NTG) and high-tension glaucoma (HTG). METHODS: The comparative cross-sectional study included three age- and sex-matched groups: 26 eyes of 26 NTG patients, 26 eyes of 26 HTG patients and 25 eyes of 25 healthy controls. Serial horizontal B-scan images of the optic nerve head were obtained from each eye using enhanced depth imaging optical coherence tomography. Mean and maximum lamina cribrosa depths were measured in 11 equally spaced horizontal B-scans. Statistical analysis was conducted to compare lamina cribrosa depth among the three groups and to correlate lamina cribrosa depth with age, retinal nerve fibre layer (RNFL) thickness and visual field (VF) mean deviation (MD). The area under the receiver operating characteristic curve (AUC) for lamina cribrosa depth was calculated. RESULTS: Mean and maximum lamina cribrosa depths were significantly greater in HTG than in NTG eyes, and in NTG than in normal eyes in all 11 scans (all p < 0.05). The AUCs of the averaged mean and averaged maximum lamina cribrosa depths in HTG eyes (0.977 and 0.988, respectively) were significantly greater than those in NTG eyes (0.735 and 0.765, respectively; both p < 0.01). Lamina cribrosa depth was found to have a negative correlation with age in HTG eyes; however, the same association was not found in NTG or controls. Neither RNFL thickness nor VF MD was significantly correlated with lamina cribrosa depth in each group. CONCLUSIONS: The lamina cribrosa is more posteriorly located in HTG than in NTG eyes, as well as in NTG eyes compared with healthy controls. The lamina cribrosa depth can help differentiate HTG from normal eyes, but it does not reach a good level of diagnostic accuracy for detecting NTG.

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PURPOSE: To compare visual field (VF) and nerve fibre loss in 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: In a retrospective, pair-matched, comparative study, 126 eyes with NTG and 126 eyes with HTG were matched according to the same glaucomatous ONH damage based on rim volume, rim area and disc size measured by the Heidelberg Retina Tomograph (HRT III). Visual field by Humphrey perimetry and nerve fibre layer thickness measured by scanning laser polarimetry (GdxVCC) were compared between both groups. RESULTS: Based on the HRT, NTG and HTG displayed comparable structural damage of the ONH without a statistically significant difference between both groups (mean, NTG/HTG: disc area 2.32/2.32 mm², p =0.342; rim area 1.03/1.00 mm², p = 0.279; rim volume 0.2/0.19 mm³; p = 0.274). Eyes with NTG had significantly less VF damage than eyes with HTG (mean, NTG/HTG: mean deviation (MD) -3.69/-9.77 dB, p = 0.0001; pattern standard deviation (PSD) 4.80/7.17 dB, p = 0.0001). The nerve fibre layer of NTG patients was thicker than that of HTG patients (mean, NTG/HTG: GDx total: 46.9/44.0 µm, p = 0.073; GDx superior: 57.2/49.9 µm, p = 0.0001; GDx inferior: 54.9/49.7 µm, p = 0.001). CONCLUSIONS: At an equal level of glaucomatous structural damage of the ONH indicated by cupping, rim area and rim volume, NTG patients seem to have a less affected visual field and a better preserved nerve fibre layer than HTG patients.

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PURPOSE: To compare the levels of serum homocysteine, vitamin B12, vitamin B6 and folate in patients with normal-tension glaucoma, pseudoexfoliation glaucoma and high-tension glaucoma. METHODS: Thirty-two healthy subjects, 35 patients with normal-tension glaucoma, 22 patients with pseudoexfoliation glaucoma and 31 patients with high-tension glaucoma were included in the present study. Fasting venous samples were collected from all the participants. The levels of serum homocysteine, vitamin B12, vitamin B6 and folate were measured. One-way analysis of variance was used for the comparison of homocysteine, vitamin B12, vitamin B6 and folate levels among the 4 groups. RESULTS: The mean homocysteine levels in the pseudoexfoliation glaucoma and high-tension glaucoma group were 17.91 +/- 5.11 and 17.60 +/- 3.89 micromol/l, respectively, which were significantly higher than that of the control group (p = 0.014, p = 0.013, respectively). The mean vitamin B6 levels in the pseudoexfoliation glaucoma and high-tension glaucoma group were 17.67 +/- 14.32 and 17.00 +/- 10.58 nmol/l, respectively, which were significantly lower than that of the control group (p = 0.026, p = 0.008, respectively). CONCLUSIONS: Hyperhomocysteinemia may play a role as a risk factor in the development or progression of pseudoexfoliation glaucoma and high-tension glaucoma.

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PURPOSE: To evaluate the relationship between optic disc and retinal nerve fiber layer (RNFL) measurements obtained with the optical coherence tomography (OCT) and the Heidelberg retina topography (HRT) in normal, normal tension glaucoma (NTG), and high tension glaucoma (HTG). METHODS: Normal, NTG and HTG subjects who met inclusion and exclusion criteria were evaluated retrospectively. One hundred seventy eyes of 170 patients (30 normal, 40 NTG, and 100 HTG) were enrolled. Complete ophthalmologic examination, HRT, OCT, and automated perimetry were evaluated. RESULTS: Disc area, cup area and cup/disc area ratio measured with HRT were significantly different between NTG and HTG (all p0.05). Mean deviation and corrected pattern standard deviation measured by automated perimetry was significantly correlated with mean and inferior RNFL thickness in both NTG and HTG (Pearson's r, p<0.05). Mean RNFL thickness/disc area ratio was significantly larger in HTG than NTG (35.21+/-18.92 vs. 31.30+/-10.91, p=0.004). CONCLUSIONS: These findings suggest that optic disc and RNFL damage pattern in NTG may be different from those of HTG.

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PURPOSE: To compare quantitative polarimetric measurements in eyes with NTG and HTG using GDx-VCC. Both groups were matched by age and glaucoma stage based on the Humphrey visual field test. METHODS: We retrospectively reviewed the records of 146 patients who underwent Humphrey field analysis (HFA) and GDx-VCC. We compared outcomes of retinal nerve fiber layer (RNFL) parameters among the three groups by ANOVA and between each pair of groups using the Tukey-Kramer Post-Hoc test. We also evaluated the sensitivity and specificity of GDx-VCC in detecting glaucoma in each group. RESULTS: The mean age and HFA mean deviation (MD) were 55.6+/-9.5 years and -0.8+/-1.5 dB in 47 control patients, 59.4+/-9.0 years and -5.77+/-4.38 dB in 49 NTG patients, and 59.4+/-11.7 years and -8.09+/-6.77 dB in 51 HTG patients, respectively. All thickness parameters were lower in HTG patients compared to NTG patients, but there were no significant differences in ratio parameters between age-matched early HTG and NTG patients. The sensitivity of GDx-VCC was significantly higher in both early and total HTG patients compared to the respective groups of NTG patients. CONCLUSIONS: Compared to eyes with NTG, eyes with HTG showed reduced RNFL thickness and ratio parameters when patients were age and visual field matched. GDx-VCC appeared to be more sensitive in detecting RNFL damage in HTG patients.

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