Normal Tension Glaucoma Group Research Articles

The Fluctuation of Intraocular Pressure Measured by a Contact Lens Sensor in Normal-Tension Glaucoma Patients and Nonglaucoma Subjects.

We compared the fluctuation of intraocular pressure (IOP) in normal-tension glaucoma (NTG) patients and individuals with nonglaucoma eyes. We obtained continuous IOP values using a SENSIMED Triggerfish contact lens sensor. The eyes of 12 nonglaucoma subjects and 14 NTG patients were examined. In all 26 subjects, the IOP fluctuation was measured continuously for 24 hours with a contact lens sensor. We evaluated the range of IOP fluctuations over the 24-hour period separately for diurnal IOP and nocturnal IOP and identified each subject's maximum value. The range of IOP fluctuation were analyzed, cutoff level of IOP fluctuation was calculated using receiver operating characteristic curve analyses. The mean IOP in the NTG eyes was 11.5±2.4 mm Hg and that in the nonglaucoma eyes was 12.7±2.0 mm Hg, a nonsignificantly difference (P=0.175). The 24-hour range of IOP fluctuations in the NTG group was significantly larger than that of the nonglaucoma group (P=0.007). The percentage of NTG patients who had the peak time of IOP fluctuation during nocturnal sleep was 57.1%, whereas the corresponding rate for the nonglaucoma eyes was 91.7%. The cutoff level of IOP fluctuation for glaucoma was 442 mVeq (sensitivity=1.00; specificity=0.571). The range of IOP fluctuation was larger in the eyes with NTG than in the nonglaucoma eyes. This larger fluctuation might be one of the reasons underlying the aggravation of the visual field by NTG. Measurements of 24-hour continuous IOP might be one of the useful methods to distinguish NTG from nonglaucoma eyes.

ALTERED AUTONOMIC BALANCE IN NORMAL TENSION GLAUCOMA

Objective: To study autonomic imbalance if any in normal tension glaucoma (NTG)patients by heart rate variability (HRV)and head-up tilt (HUT)test.Methods: The study subjects of age between 45 and 65 years of either sex comprised 20 patients with NTG (Group ІІ)and 20 age- and sex-matched healthy controls (Group І). Different variables of time and frequency domain of HRV were analyzed at rest, during HUT and the recovery period.Results: Highly significant decrease in value of root mean square successive difference observed in Group ІІ (p<0.000)in comparison to controls. The high-frequency variables (HF [nu]and HF [ms2])were significantly less (p<0.000)and low frequency (LF)/HF ratio was significantly high (p<0.000) in Group ІІ.Conclusion: During stress test, i.e., HUT there was the greater withdrawal of parasympathetic input to heart; hence, there was relatively oversympathetic activity due to sympatho-vagal imbalance.Keywords: Stress test, Sympatho-vagal imbalance, Autonomic function test.

Cognitive functions and normal tension glaucoma.

Purpose:Only a few studies have analyzed the potential link between glaucoma and cognitive function impairment. They have found controversial results. This study aims to perform quick cognitive function assessment with clock drawing test (CDT) using two different scoring systems and compare between normal tension glaucoma (NTG) and cataract patients.Methods:Totally, 30 NTG and 30 patients with cataracts were included in a prospective, pilot study. The predrawn circle was given, and patients were asked to draw the clock showing a time of 11:10. The test was evaluated using two methods – Freund method using a 7-point scoring scale (optimal cutoff ≤4) and Rakusa using a 4-point scoring scale (optimal cutoff ≤3). The level of significance was set at P < 0.05.Results:CDT result was significantly better in cataract group than in NTG group: 3.5 (2) versus 2 (2) by Freund, (P = 0.003) and 6.5 (1) versus 4.5 (2.75) by Rakusa, respectively (P = 0.004). Sixty percent (n = 18) of NTG group and 10% (n = 3) of cataract group patients completed the CDT in the specific picture manner (the short hand on 11 and the long hand between 11 and 12), (P = 0.001).Conclusions:Lower CDT results were seen in NTG patients according to two different scoring systems. NTG patients showed a specific manner of drawing. Further prospective studies are needed to investigate the CDT reliability as fast screening test of cognitive function impairment in glaucoma patients.

Foveal Avascular Zone in Normal Tension Glaucoma Measured by Optical Coherence Tomography Angiography.

Aim To measure diameter of foveal avascular zone (FAZ), FAZ area, and vessel density using Optical Coherence Tomography Angiography (OCT-A) in patients with normal tension glaucoma (NTG) and to establish the possible role of OCT-A in diagnosis and follow-up of patients with NTG. Methods Twenty-one eyes of 21 patients with NTG and 30 eyes of 30 healthy subjects underwent complete ophthalmic examination as well as OCT-A on ZEISS AngioPlex. 3 × 3 macula scans were used to measure vertical, horizontal, and maximum diameter of FAZ by two graders. Mean values and interobserver variability were analyzed. Image J was used for analysis of FAZ area and vessel density. Results Mean vertical diameter (t = 5.58, p < 0.001), horizontal diameter (t = 3.59, p < 0.001), maximum diameter (t = 5.94, p < 0.001), and FAZ area (t = 5.76, p < 0.001) were statistically significantly enlarged in the NTG group compared to those in the control group. Vessel density (t = −5.80, p < 0.001) was statistically significantly decreased in the NTG group compared to that in the control group. Conclusion OCT-A could have an important role in the future in diagnosis of patients with NTG. In patients with NTG, there is larger FAZ area, while the vessel density is reduced in comparison to the control group.

Change in Central Corneal Thickness After the Discontinuation of Latanoprost in Normal Tension Glaucoma-Change in Central Corneal Thickness After Stop of Latanoprost

To assess the impact of latanoprost on central corneal thickness (CCT) after ceasing medication in patients with normal tension glaucoma (NTG). A total of 46 eyes from 46 NTG patients, and 44 eyes from 44 individuals with glaucoma suspect (controls), were included in this retrospective study. Newly diagnosed early NTG patients (visual field mean deviation >-6.00) were administered latanoprost 0.005% monotherapy once a day. CCTs were measured by ultrasound pachymetry before treatment, for 5 years during treatment, and for 2 years after ceasing treatment. Mean CCT was reduced significantly in the NTG group during treatment [544.4 ± 35.8 μm vs. 531.4 ± 32.5 μm (n = 46), P < 0.001]. After ceasing latanoprost treatment, mean CCT increased [531.4 ± 32.5 μm vs. 544.6 ± 37.1 μm (n = 46), P < 0.01] over the course of 2 years. In the control group, however, mean CCT was not significantly different [553.5 ± 27.5 μm vs. 561.8 ± 24.7 μm (n = 44), P = 0.06] at the 7-year follow-up. Latanoprost significantly reduced CCT in NTG patients after 5 years of treatment; however, the reduction was reversed 2 years after discontinuation of treatment.

Optical Coherence Tomography Angiography Analysis of Perfused Peripapillary Capillaries in Primary Open-Angle Glaucoma and Normal-Tension Glaucoma.

To compare perfused peripapillary capillary density in primary open-angle glaucoma (POAG), normal-tension glaucoma (NTG), and normal patients using optical coherence tomography angiography (OCT-A). A retrospective review of POAG, NTG, and normal patients imaged with OCT-A was performed. En face OCT angiograms identifying peripapillary vessels were obtained using a spectral-domain OCT system (Avanti RTVue-XR). A custom image analysis approach identified perfused peripapillary capillaries, quantified perfused capillary density (PCD), and generated color-coded PCD maps for 3.5- and 4.5-mm-diameter scans. We compared PCD values, PCD maps, standard automated perimetry (Humphrey visual field [HVF]) parameters, and OCT retinal nerve fiber layer (RNFL) thickness analyses across all groups. Forty POAG, 26 NTG, and 26 normal patients were included. Annular PCD in POAG (34.24 ± 6.76%) and NTG (37.75 ± 3.52%) patients was significantly decreased compared to normal patients (42.99 ± 1.81%) in 4.5-mm scans (P < 0.01 and P < 0.01, respectively). Similar trends and statistical significances were seen in 3.5-mm scans. Linear regression analysis resulted in moderate correlations between annular PCD values and other glaucomatous parameters. Pearson coefficients comparing annular PCD from 4.5-mm scans in POAG and NTG groups to HVF mean deviation, HVF pattern standard deviation, and average RNFL thickness all showed statistical significance (P < 0.05). Color maps showed that POAG and NTG patients had a reduction of perfused capillaries that progressed in size when comparing early, moderate, and severe glaucoma groups. Optical coherence tomography angiography can uniquely identify changes in peripapillary PCD in glaucoma patients. Optical coherence tomography angiography may offer insights into the pathophysiology of glaucomatous damage and risk factors for disease progression.

Reduced vascular response in patients with normal tension glaucoma in response to hypoxia

PurposeIncreased evidence exists on an association between normal tension glaucoma (NTG) and endothelial dysfunction. Moreover, it is recognized that glaucomatous damage is linked to episodes with hypoxia. The aim of our study was to investigate the vascular response after hypoxia in patients with NTG compared to controls.MethodsThe vascular response was evaluated after hypoxia by Peripheral Arterial Tonometry (PAT) and recorded as Reactive Hyperemic Index (RHI). All subjects went through two days of investigation. In random order the first visit included either hypoxia or normoxia with successive measurements. Hypoxia/normoxia was induced in 2 h through a tightly fitting face mask. Additionally, the peripheral circulation was measured by a thermographic camera. Blood samples were taken before, during and after hypoxia/normoxia to evaluate stress factors such as cathecolamines. The two days of investigation were at least three weeks apart.ResultsRHI measurements showed a tendency of greater difference between hypoxia and normoxia in the NTG group. Thermographic images showed a tendency of colder temperatures in the fingertips of the NTG patients before hypoxia compared to the controls. A significant difference in temperature between the hypoxia day and the normoxia day was seen in the NTG group after both 2 h of hypoxia/normoxia and half an hour after the mask was removed. Adrenalin levels differed significantly in response to hypoxia in the control group, whereas no significant change was observed in response to hypoxia in patients with NTG.ConclusionsOver all, the vascular response to hypoxia was less prominent in patients with NTG compared to controls. This confirms a decreased ability to regulate the vascular tonus in response to vascular stress (hypoxia) in patients with NTG.

Central corneal thickness in newly diagnosed glaucoma patients in South West Ethiopia: a cross-sectional study

BackgroundReports of central corneal thickness (CCT) among glaucoma patients, particularly for pseudoexfoliative glaucoma (PXG) and Primary Angle Closure Glaucoma (PACG) are scarce in the Sub-Saharan African (SSA) population. The aim of this study is to evaluate CCT in black patients with newly diagnosed glaucoma and ocular hypertension (OHT) in South West Ethiopia.MethodsThis was a prospective study undertaken with an ultrasonic pachymeter from June 2014 to February 2015 in Jimma University Specialized Hospital. Patients aged 18 years and older newly diagnosed with glaucoma or OHT were included.ResultsA total of 162 eyes of 162 subjects were included. Hundred and fifty five subjects were glaucomatous: (67 PXG, 42 Primary Open Angle Glaucoma (POAG), 28 PACG, 14 Normal Tension Glaucoma (NTG), 5 Juvenile Open Angle Glaucoma (JOAG) and 6 (OHT). The mean age was 59.3 ± 12.8 years.For the whole sample, CCT was 518.67 (±39.97) μm. OHT group had significantly greater CCT (576.33 ± 49.32 μm) than the glaucomatous groups (p = 0.004). POAG (506.69 ± 35.08 μm) and NTG (510.79 ± 44.37 μm) groups had thinner CCT than PXG (520.48 ± 38.95 μm), PACG (524.00 ± 37.16 μm), and JOAG (518.00 ± 30.82 μm) groups, but this was not statistically significant (p = 0. 296). There was a statistically significant decline of CCT with advanced age (P = 0.02). There wasn’t significant difference of average CCT between the ethnic groups (P = 0.3) and gender (P = 0.064).ConclusionThe mean CCT of Ethiopian glaucoma patients is thinner than Caucasians and similar to those reported from previous studies in Sub Saharan Africa. OHT patients had thicker CCT; there was no statistically significant difference observed in average CCT amongst glaucoma subtypes.

Short-term reproducibility of intraocular pressure and ocular perfusion pressure measurements in Chinese volunteers and glaucoma patients.

BackgroundTo evaluate the short-term reproducibility of diurnal intraocular pressure (IOP) and ocular perfusion pressure (OPP) measurements in normal volunteers, untreated normal-tension glaucoma (NTG) and primary open-angle glaucoma (POAG) patients.MethodsFifty-four healthy volunteers (control group), 67 NTG patients and 54 POAG patients were recruited. The IOPs of both eyes were measured with a Goldmann applanation tonometer at 3-h intervals over 2 consecutive days. Blood pressure (BP) measurements were collected at the same times. The mean IOP/OPP, peak IOP/OPP, trough IOP/OPP and IOP/OPP fluctuations on each day were also calculated. The intraclass correlation coefficients (ICCs) were used to evaluate the reproducibilities.ResultsIn the control group, the ICCs of mean IOP, peak IOP, trough IOP and IOP fluctuation were 0.921, 0.889, 0.888, and 0.661, respectively, and the ICCs of the mean OPP, peak OPP, trough OPP and OPP fluctuations were 0.962, 0.918, 0.953, and 0.680, respectively. In the NTG group, the ICCs of the mean IOP, peak IOP, trough IOP and IOP fluctuation were 0.862, 0.741, 0.798, and 0.290, respectively, and the ICCs of the mean OPP, peak OPP, trough OPP and OPP fluctuations were 0.947, 0.828, 0.927, and −0.008, respectively. In the POAG group, the ICCs of the mean IOP, peak IOP, trough IOP and IOP fluctuation were 0.857, 0.666, 0.808, and 0.546, respectively, and the ICCs of the mean OPP, peak OPP, trough OPP and OPP fluctuation were 0.934, 0.842, 0.910, and 0.093, respectively.ConclusionThe IOP measurements within a single day were not highly reproducible in the short-term. The normal volunteers exhibited better IOP and OPP reproducibilities than the glaucoma patients. The IOP and OPP fluctuations could not be accurately evaluated based on the IOP or OPP measurements within a single day.

Optic Disc Perfusion in Primary Open Angle and Normal Tension Glaucoma Eyes Using Optical Coherence Tomography-Based Microangiography.

PurposeTo investigate optic disc perfusion differences in normal, primary open-angle glaucoma (POAG), and normal tension glaucoma (NTG) eyes using optical microangiography (OMAG) based optical coherence tomography (OCT) angiography technique.DesignCross-sectional, observational study.SubjectsTwenty-eight normal, 30 POAG, and 31 NTG subjects.MethodsOne eye from each subject was scanned with a 68 kHz Cirrus HD-OCT 5,000-based OMAG prototype system centered at the optic nerve head (ONH) (Carl Zeiss Meditec Inc, Dublin, CA). Microvascular images were generated from the OMAG dataset by detecting the differences in OCT signal between consecutive B-scans. The pre-laminar layer (preLC) was isolated by a semi-automatic segmentation program.Main Outcome MeasuresOptic disc perfusion, quantified as flux, vessel area density, and normalized flux (flux normalized by the vessel area) within the ONH.ResultsGlaucomatous eyes had significantly lower optic disc perfusion in preLC in all three perfusion metrics (p<0.0001) compared to normal eyes. The visual field (VF) mean deviation (MD) and pattern standard deviation (PSD) were similar between the POAG and NTG groups, and no differences in optic disc perfusion were observed between POAG and NTG. Univariate analysis revealed significant correlation between optic disc perfusion and VF MD, VF PSD, and rim area in both POAG and NTG groups (p≤0.0288). However, normalized optic disc perfusion was correlated with some structural measures (retinal nerve fiber layer thickness and ONH cup/disc ratio) only in POAG eyes.ConclusionsOptic disc perfusion detected with OMAG was significantly reduced in POAG and NTG groups compared to normal controls, but no difference was seen between POAG and NTG groups with similar levels of VF damage. Disc perfusion was significantly correlated with VF MD, VF PSD, and rim area in glaucomatous eyes. Vascular changes at the optic disc as measured using OMAG may provide useful information for diagnosis and monitoring of glaucoma.

Effect of Morphological and Functional Parameters on Ocular Pulse Amplitudes: An Analysis in Ocular Hypertension and Different Types of Glaucoma

Background and Purpose: Ocular blood flow imbalance and the loss of autoregulation are widely believed to be important factors in the pathogenesis of glaucoma. The purpose of this study was to investigate the impact of morphometric and functional changes on ocular pulse amplitude (OPA) in normal tension glaucoma (NTG), primary open-angle glaucoma (POAG), pseudoexfoliation-glaucoma (PEX) and ocular hypertension (OHT). Patients and Methods: This prospective study included 172 patients with manifest glaucoma and OHT. All patients were examined with dynamic contour tonometry (DCT), Goldmann applanation tonometry (GAT), Heidelberg retina tomography II (HRT), and Octopus visual field analysis (program 30II). In order to identify potential determinants of OPA, a generalised linear model (GLM) analysis was defined. As effect sizes, we included gender as a factor and intraocular pressure (measured by DCT [IOP]), optic disc area, cup area, mean deviation (MD), central corneal thickness (CCT), cup-disc ratio (CDR), and patient age as covariates. Results: Mean OPA was lower in patients with NTG than in other groups. In the generalised linear model in the entire population, a larger OPA was associated with a larger IOP and female gender. In the NTG group, we did not identify effect sizes, whereas, in the OHT group, IOP (measured with DCT) and MD, in the POAG group IOP (measured with DCT) and gender and in the PEX group MD and gender showed a positive effect on OPA. Conclusions: In this study, we showed that in the NTG group neither demographic nor morphological or functional factors affected OPA. However, in the OHT and POAG groups, OPA was influenced by IOP (measured with DCT), in the OHT and PEX group by MD and in the POAG and PEX groups by gender.

The Effects of Nocturnal Dip and Blood Pressure Variability on Paracentral Scotoma in Early Open-Angle Glaucoma

ABSTRACTPurpose: To evaluate the effect of nocturnal dip and blood pressure (BP) variability on paracentral scotoma in early open-angle glaucoma. Methods: The present study included 72 early normal-tension glaucoma (NTG) patients and 34 early primary open-angle glaucoma (POAG) patients. Nocturnal dip and weighted standard deviation (wSD) were determined by 24-hour ambulatory BP monitoring (24-hr ABPM). The mean deviation (MD) and pattern deviation (PD) were measured with visual field. Correlations between nocturnal dip and/or BP variability and paracentral scotoma were assessed using Student’s t-test, Pearson’s correlation test, and linear logistic regression analysis. Results: The systolic and diastolic nocturnal dip and paracentral scotoma occurrence demonstrated a statistically significant correlation in the early NTG group (systolic nocturnal dip: p=0.047, diastolic nocturnal dip: p=0.011). In the early NTG group, the subgroup with paracentral scotoma had a greater nocturnal dip than those patients without paracentral scotoma (systolic nocturnal dip: p=0.000; diastolic nocturnal dip: p=0.000). In the early NTG group, the subgroup with paracentral scotoma had higher wSD of SBP than the patients without paracentral scotoma (p=0.003). In the logistic regression analysis of the factors that can affect paracentral scotoma SBP dip and SBP, wSD appeared to significantly affect the occurrence of paracentral scotoma in the early NTG group. Conclusions: Early NTG patients with paracentral scotoma have nocturnal dip and large BP variability. Therefore, in early glaucoma patients, particularly in early NTG with paracentral scotoma, nocturnal dip and BP variability should be assessed with 24-hr ABPM.

Risk Factors for Normal and High-Tension Glaucoma in Poland in Connection with Polymorphisms of the Endothelial Nitric Oxide Synthase Gene.

AimThe purpose of this study was to evaluate the influence of polymorphisms of the eNOS gene on the clinical status of patients with normal and high tension glaucoma.Methods266 Polish Caucasian patients with primary open angle glaucoma were studied. Of the 266, 156 had normal tension glaucoma (NTG) and 110 high tension glaucoma (HTG). DNA material was isolated from peripheral venous blood using commercial kits. Real-time PCR reaction was used to amplify the promoter site of the endothelial nitric oxide synthase (eNOS) gene, including the single nucleotide polymorphism (SNP) site T-786C and part of the 7th exon of eNOS, including G894T SNP. Genotypes were determined with TaqMan SNP Genotyping Assays.ResultsThere were no significant differences in frequencies of the allelic variants of both polymorphisms. In G894T SNP, however, the wild GG form was more common in the HTG group. The SNP of the eNOS gene did not significantly influence the progression rate in either of the groups studied. There were no differences in variants of the eNOS gene regarding the necessity for and success of surgery and the progression of the disease. In the NTG group, no statistical correlation was observed between G894T, T786C polymorphism variants, and risk factors such as optic disc haemorrhages, optic disc notches, and peripapillary atrophy. Mean diastolic and systolic pressure during the day and night were lowest in NTG patients with the CC variant of the T786C polymorphism. No statistical correlation was observed between the G894T and T786C polymorphisms and capillaroscopic examination results.ConclusionsGenotype frequencies are similar for both the eNOS G894T and T-786C polymorphisms in NTG and HTG patients. These polymorphisms do not correlate with risk factors and do not influence the state of the capillary system in NTG patients. Systolic blood pressure is lower in NTG patients with mutated alleles of both polymorphisms.

Cognitive performance of primary open-angle glaucoma and normal-tension glaucoma patients.

To assess cognitive performance differences among primary open-angle glaucoma (POAG) patients, normal-tension glaucoma (NTG) patients, and healthy control (C) subjects. A total of 60 participants (20 POAG, 20 NTG, and 20 C subjects) were included in this study. A detailed ophthalmologic examination was performed on all participants. A spectral domain-optical coherence tomography (SD-OCT) system was used to measure the ganglion cell-inner plexiform layer (GC-IPL) and retinal nerve fiber layer (RNFL) thicknesses. To assess the cognitive performance of all participants, detailed neurological examinations, including the mini-mental state examination (MMSE), were performed by the same neurologist. There were no significant differences among the groups in terms of age (p =0.348) or gender (p =0.935). The mean RNFL thicknesses were significantly different among the groups (85.2 ± 14.7, 76.8 ± 10.3, and 91.4 ± 7.7 µm in the POAG, NTG, and C subjects, respectively; p <0.001). The mean GC-IPL thicknesses were 77.5 ± 9.7 µm in the POAG group, 73.4 ± 7.8 µm in the NTG group, and 78.8 ± 3.8 µm in the C group. Differences among the groups were not statistically significant (p =0.085). MMSE scores were 26.1 ± 1.4, 25.7 ± 2.3, and 28.8 ± 0.9 in the POAG, NTG, and C groups, respectively. There were significant differences among the three groups (p <0.001). Specifically, there were significant differences between the NTG and C groups (p <0.001), and between the POAG and C groups (p =0.001). There was no significant difference between the POAG and NTG groups (p =0.595). There appear to be similar risk factors in glaucoma and neurodegenerative disorders that cause deterioration in cognitive performance. Comparing the low MMSE scores of the POAG and NTG patients with the scores of healthy C participants supports our hypothesis. Consequently, it is recommended that a neurologist should also examine glaucoma patients.

Lamina depth and thickness correlate with glaucoma severity.

Purpose:To evaluate the correlation between lamina cribrosa (LC) morphology and glaucoma severity in patients with primary forms of open-angle glaucoma (OAG) using enhanced depth imaging spectral-domain optical coherence tomography (SD-OCT) and Humphrey visual field test (HVF).Subjects and Methods:Patients with OAG (n = 166), divided into normal-tension glaucoma (NTG) and high-tension glaucoma (HTG) groups (n = 66 and n = 100), were imaged using SD-OCT to obtain horizontal B-scan images of the optic nerve head (ONH). Laminar depth (LD) and laminar thickness (LT) were measured at the center of ONH.Results:The mean (±standard deviation) values of LD, LT, and visual field mean deviation (MD) were 555.4 ± 142.3 μm, 179.9 ± 49.7 μm, and − 5.7 ± 6.4 dB, respectively. In the multivariate linear regression analysis, LD, LT, and intraocular pressure (IOP) were significantly correlated with MD (P = 0.007, P = 0.037, and P = 0.004, respectively). In the subgroup analyses, only LD was associated with MD in the NTG group (n = 66), whereas LT and IOP were correlated with MD in the HTG group (n = 100). Neither axial length nor central corneal thickness was associated with LD or LT.Conclusions:Glaucoma severity, as measured by HVF MD, shows significant correlations with LD and LT, with greater severity associated with increasing LD and decreasing LT. Normal- and high-tension OAG patients have different associations with LD and LT, which implies that the pathogenesis of these two entities might be different.

Postural and diurnal fluctuations in intraocular pressure across the spectrum of glaucoma

AimsTo evaluate postural fluctuations (PFs) and diurnal variation (DV) of intraocular pressure (IOP) in patients with untreated glaucoma, glaucoma suspects and healthy volunteers, and study their relationship, if any, to...

Comparison of visual field defects between newly detected chronic simple glaucoma and normotensive glaucoma

Objective : To study and compare the visual field defects in subjects with newly detected primary open angle glaucoma and normotensive glaucoma using HUMPHREY FIELD ANALYSER 30-2 swedish interactive thresholding algorithm(SITA) standard technique and to establish specific visual field loss patterns in each group and establish varied pathomechanisms. Methods: A prospective study 37 eyes of 25 patients with normal tension glaucoma(NTG) and chronic simple glaucoma(CSG). Patients were subjected to visual field testing using HUMPHREY FIELD ANALYSER(HFA) 30-2, SITA(Swedish interactive thresholding algorithm) standard method. Results: There was significant preponderance of early visual field defects in patients with NTG in comparison to patients with CSG (64% compared to 32.4%). Strong statistical differences were found in number of patients with scotomas falling with 6 degrees of central fixation (p<_0.001) in NTG comparing with CSG. Conclusion : results suggest that field defects between chronic simple and normotensive glaucoma do not differ in most aspects except for those in NTG group being closer to fixation and should not be used to underline different pathomechanisms in the two groups.

Long-term effect of latanoprost on central corneal thickness in normal-tension glaucoma: five-year follow-up results.

To evaluate the long-term effect of latanoprost on central corneal thickness (CCT) in patients with normal-tension glaucoma (NTG). This retrospective study included 41 eyes of 41 NTG patients and 40 eyes of 40 individuals with glaucoma suspect (controls). Newly diagnosed NTG patients with no previous glaucoma treatment were administered latanoprost 0.005% monotherapy once a day. CCTs were measured by ultrasound pachymetry before treatment and followed up annually for 5 years. A significant reduction in mean CCT was observed in the NTG group [542.3±36.2 μm vs. 533.7±32.9 μm (n=41), P<0.001], but not in the control group [547.4±24.7 μm vs. 546.8±25.0 μm (n=40), P=0.59] at 5-year follow-up. In the NTG group, the CCT reduction mainly occurred during the first year of treatment (542.3±36.2 μm vs. 536.9±32.8 μm, P=0.001), and no significant correlation was found between CCT and intraocular pressure reductions (r=0.16, P=0.32). Latanoprost significantly reduced CCT in NTG patients after 5 years of treatment. Serial observations of CCT might be helpful for the proper interpretation of glaucoma status in NTG patients.

Higher serum lipids and oxidative stress in patients with normal tension glaucoma, but not pseudoexfoliative glaucoma.

This study entailed a cross-examination of oxidant/antioxidant balance, high-density lipoprotein (HDL)-linked paraoxonase 1 (PON1) phenotypes, and levels of serum routine lipids among patients with normal tension glaucoma (NTG) or pseudoexfoliative glaucoma (PEXG) compared with healthy control groups. We aimed to investigate the links between oxidative stress (OS), HDL-related antioxidant enzyme activities and dyslipidemia in distinct subtypes of glaucoma. The study included 32 patients with NTG, 31 patients with PEXG, and 40 control subjects. Levels of PON1 and arylesterase enzymatic activity, total oxidant status (TOS), and total antioxidant status were measured by spectrophotometry and OS indexes (OSI) were calculated. The phenotype distribution of PON1 was determined using the dual substrate method. Blood serum levels of HDL, low-density lipoprotein, total cholesterol (TC), and triglyceride (TG) were measured. The TOS and OSI values in the NTG group were significantly higher compared with the other groups (both p < 0.01). The phenotype distribution found in the glaucoma and control groups were NTG: QQ, 59.4%; QR, 37.5%; RR, 3.1%; PEXG: QQ, 45.1%; QR, 48.4%; RR, 6.5%; and in the control group: QQ, 42.5%; QR, 50.0%; RR, 7.5%. Serum TC levels were significantly higher than the control in both NTG and PEXG groups, whereas TG was significantly higher in NTG only (p < 0.01 and p < 0.02, respectively). Hyperlipidemia, OS and variations in phenotype distribution of PON1 may play a role in the pathogenesis of different types of glaucoma.

Measuring Blood Viscosity in Normal Tension Glaucoma Patients

Purpose: Non-intraocular pressure (IOP) factors such as vascular factors have been identified as contributing to normal tension glaucoma. However, there is not an established range of haemorheological factors considered normal, nor are there standardized tests. In this study, we investigated differences in blood viscosity and haemorheological parameters between patients with normal tension glaucoma (NTG) and normal controls using a new instrument called the BVD-RO1 (BIO-VISCO. Inc., Jeonju, Korea). Methods: Twenty patients with NTG and 20 age-matched normal controls were included in the study. Haemorheological parameters of the venous blood samples, including blood viscosity at the shear rates of 300 (high shear rate) and 1 (low shear rate) s−1 were measured using an automated scanning capillary tube viscometer. Results: More hematocrit concentration was detected in the NTG group than in the control group (p < 0.05). Furthermore, higher blood viscosities at the high (p < 0.01) and low (p < 0.01) shear rates were found in the NTG group. Conclusions: The NTG patients differed in blood viscosity with the control group. This may signify the importance of hemodynamic factors in the pathogenesis of NTG. J Korean Ophthalmol Soc 2015;56(5):753-758