Evaluation and correlation of corneal endothelium parameters with the severity of primary glaucoma

Purpose: To evaluate and correlate corneal endothelium parameters with the severity of primary glaucoma. Methods: This prospective case?control study was conducted on 150 eyes of 80 newly diagnosed primary open?angle glaucoma (POAG), chronic primary angle?closure glaucoma (cPACG), and normal?tension glaucoma (NTG) patients in a tertiary care center. Endothelial parameters including endothelial cell count (ECC), percentage of hexagonal cells, and coefficient of variation of cell size were analyzed. Glaucoma cases were further sub?grouped into early, moderate, and severe glaucoma and compared for endothelial parameters. Chi?square, Fischer’s exact test, independent sample t?test, and analysis of variance were performed using IBM® SPSS® Statistics version 28. Results: The ECC was markedly reduced in cases (2281 cells/mm2) versus controls (2611 cells/mm2) (P < 0.001). The POAG (2251 cells/mm2) and cPACG (2287 cells/mm2) eyes had significantly a lower ECC compared to healthy controls (P < 0.001), whereas NTG eyes had a lower mean ECC (2538 cells/mm2), but it was not statistically significant (P > 0.05) when compared with controls. The ECC decreased with an increase in severity as patients with early glaucoma had an ECC of 2284 cells/mm2, moderate 2261 cells/mm2, and severe 2086 cells/mm2, and the difference was statistically significant. Conclusion: A significant decrease in corneal ECC was observed in POAG and cPACG patients when compared with healthy controls of the same age group. Mechanical damage following an elevated intra?ocular pressure for a longer duration may be attributed to morphological and consequent functional damage to endothelial cells.

A comparative study of timolol plus either brimonidine (0.2%) or dorzolamide (2%) or latanoprost (0.005%) dual therapy in suboptimal responders to timolol (0.5%) monotherapy among patients of open-angle glaucoma, ocular hypertension and normal-tension glaucoma

Background: Studies comparing the efficacy and tolerability of the three fixed combinations of timolol with its monotherapy are not readily available. In this background, the current prospective observational study was planned. Aim and Objective: To evaluate and compare the intraocular pressure (IOP) reduction, change in visual field, and cup-disc ratio in glaucoma patients receiving timolol monotherapy vis-a-vis timolol based dual therapies among timolol sub-optimal responders. Materials and Methods: After obtaining written informed consent and fulfilling the inclusion-exclusion criteria, fifty consecutive newly diagnosed cases of glaucoma or ocular hypertension with risk factors were recruited in the study. They received timolol eye drop up to 4th week. Participants not responding to timolol monotherapy optimally received either timolol plus brimonidine or timolol plus dorzolamide or timolol plus latanoprost for another 12 weeks. Participants responding optimally (at least 30% reduction of baseline) were continued with timolol monotherapy. Besides IOP changes, effects on visual field, visual acuity, cup disc ratio, safety, tolerability, and rate of persistency to therapy were studied. Results: Fifteen participants (30%) achieved target IOP reduction at 4 weeks of timolol monotherapy. All four treatment groups achieved significant IOP reduction (P < 0.001) from baseline to 16th week. Participants receiving timolol followed by timolol plus latanoprost had shown the highest IOP reduction at 16th week both from baseline and 4th week value (ANOVA test, P = 0.027, P = 0.000 respectively). No change in visual field or visual acuity or cup disc ratio was noticed. Adverse drug reactions observed were mild and mostly self limiting. Conclusion: Timolol and latanoprost combination might be a better choice in sub-optimal responders to timolol whereas it is wise to continue timolol monotherapy in optimally responders.

Significance of non-intraocular pressure (IOP)-related factors particularly in normal tension glaucoma: Looking beyond IOP

Purpose: To study the relationship between intraocular pressure (IOP) and mean ocular perfusion pressure (MOPP) in patients with POAG and NTG. The secondary objective was to identify other contributory ischemic factors. Methods: This was an observational cross?sectional study from a tertiary eye hospital in patients who underwent full?day diurnal variation of tension (DVT). Blood pressure (BP) and IOP measurements were done every 3 h over 24 h. Mean arterial pressure (MAP) and MOPP were calculated. The nocturnal dip in BP was assessed; patients were classified as non?dippers, dippers, and over?dippers. The circadian MOPP fluctuation (CMF) was calculated using the Kruskal–Wallis test, and its relationship with type and severity of visual field was assessed. Results: In total, 149 patients were evaluated; 109 were classified as NTG, and 40 were classified as POAG. A nocturnal dip in BP was noted in 20% of NTG and 17.5% of POAG. The MAP was found to be lower in patients with NTG than POAG. In the NTG subgroup, we found that 20% of patients were over?dippers, 32% were dippers, and 48% were non?dippers. The CMF showed a greater fluctuation for over?dippers (P = 0.004 for the RE and 0.003 for the LE) than dippers and non?dippers. A weak positive correlation of CMF with the severity of fields was found. Conclusion: A 24?h monitoring of IOP, BP, MOPP, and assessment of systemic risk factors for primary glaucoma acts as an invaluable tool for the comprehensive management of NTG despite the limitations posed by DVT and BP recording

Normal tension glaucoma: reconsideration and reevaluation / 中华实验眼科杂志

Normal tension glaucoma (NTG) is almost the most difficult type of glaucoma to diagnose.The difficulty lies in the lack of specificity of the symptoms and signs of glaucomatous optic neuropathy (GON), so the reevaluation of NTG is a new understanding of GON.As a subtype of primary open-angle glaucoma (POAG), NTG is difficult to accurately conceptualize.One of the reasons is that the intraocular pressure (IOP) is closely linked to the occurrence of GON in POAG but not in NTG.GON seems to be secondary to a number of local or systemic disorders, including vascular dysfunction in the optic nerve head induced by compression (elevated IOP) or ischemia, hypoxia, migraine, Flammer syndrome, intracranial hypotension, low body mass index, low estrogen levels, nocturnal hypotension, obstructive sleep apnea-hypopnea syndrome, Alzheimer disease, Parkinson disease, and genetic background, which may influence the flow in the radial peripapillary capillaries (RPCs) and the underfilling of RPCs causing retinal ganglion cell damage.In some cases, GON does not progress with systemic diseases under control, and these systemic diseases are not risk factors for NTG but may be the cause of GON (or GON is one of the manifestations of these diseases). If these causes are not excluded and NTG is diagnosed only on the basis of GON, chamber angle opening, and normal IOP, it is easy to cause misdiagnosis, and the complete exclusion of these diseases is short of clinical significance in practice.In conclusion, the diagnosis of NTG may not be made before the other ocular or systemic disorders capable of presenting with GON are ruled out, and the concept and diagnostic criteria of NTG should be reconsidered.

Relationship between blood vessel density in optic disc area and visual field index and visual field defect morphology in patients with normal tension glaucoma / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To study the relationship between the changes of blood vessel density in optic disc area of normal tension glaucoma(NTG)and visual field index(VFI)of glaucoma and morphological staging of visual field defect. <p>METHODS: Totally 106 patients(106 eyes)with NTG and 79 patients(79 eyes)with primary open angle glaucoma(POAG)in the hospital between December 2018 and December 2020 were selected for cross-sectional study. Among them, 1 eye of binocular disease was selected as the sample by the random number table method, and another 92 healthy subjects with physical examination in the hospital were selected as control group. All three groups completed the optic disc blood vessel density, VFI detection and visual field defect morphological staging, and the relationship between optic disc blood vessel density and VFI and visual field defect morphological staging were analyzed.<p>RESULTS: The intraocular pressure in POAG group was significantly higher than that in NTG group and control group(<i>P</i><0.05). The whole optic disc area blood vessel density, large vessel density and capillary density of NTG group and POAG group were significantly lower than those of control group(<i>P</i><0.05)while the density of avascular area was significantly higher than that of control group(<i>P</i><0.05), and there were differences in various indicators between NTG group and POAG group(<i>P</i><0.05). The VFI of NTG group and POAG group was significantly lower than that of control group(<i>P</i><0.05)while the mean visual field defect(MD)was significantly higher than that of control group(<i>P</i><0.05), and there were no statistical differences in VFI and MD between NTG group and POAG group(<i>P</i>>0.05). With the increase in visual field defect morphology staging, the whole optic disc area blood vessel density and capillary density of patients with NTG showed a significant decrease(<i>P</i><0.05). The whole optic disc area blood vessel density and capillary density of patients with NTG were positively correlated with VFI and negatively correlated with visual field defect staging, and avascular area density was negatively correlated with VFI and positively correlated with visual field defect staging(all <i>P</i><0.05). <p>CONCLUSION:Optic disc blood vessel density of patients with NTG is significantly lower than that of patients with POAG and normal people, and it is significantly correlated with VFI and visual field defect morphological staging. Among them, capillary density has the highest correlation. It can be seen that OCTA has important clinical significance for NTG diagnosis, treatment and follow-up.

The Difference in Intraocular Pressure before and after Visual Field Test Measured by Rebound Tonometer

PURPOSE: To investigate the effect of a visual field (VF) test on intraocular pressure (IOP) and relevant parameters in a normal group and an open-angle glaucoma group, and to determine the appropriate time of IOP measurements.METHODS: The IOP was measured by a rebound tonometer before and after a VF test for the normal, normal-tension glaucoma, and high-tension glaucoma groups, and IOP differences after the VF tests were compared among groups. Parameters including age, sex, axial length, central corneal thickness, IOP before the VF test, the VF index, mean deviation, VF test duration, and usage of IOP lowering medications were investigated, and the correlations of these parameters with IOP changes after VF tests were determined using linear regression analyses.RESULTS: A total of 232 participants (232 eyes) included 55 normal subjects, 131 normal-tension glaucoma patients, and 46 high-tension glaucoma patients. The IOP differences after VF tests were not statistically significant in the normal and high-tension glaucoma groups, and the difference was 0.31 mmHg in the normal-tension glaucoma group (p = 0.013). Multivariate regression analyses revealed that axial length (p = 0.005) and IOP before the VF test (p < 0.001) were relevant factors in the total number of patients, and the axial length (p = 0.017), IOP before the VF test (p = 0.001), and duration (p = 0.029) were found to be significantly associated with IOP differences in the normal-tension glaucoma group.CONCLUSIONS: The IOP changes after VF tests using the rebound tonometer were significant in the normal-tension glaucoma group, but were within an acceptable range. The IOP value measured after a VF test is clinically valid in clinical practice.

Effect of brimonidine on central corneal thickness in normal tension glaucoma patients

Background: Brimonidine is a potent ocular hypotensive agent widely used in glaucoma treatment. A reduction in central corneal thickness can lead to an underestimation of intraocular pressure by Goldmann applanation tonometry and vice versa. The aim of this study is to determine whether brimonidine has an effect on central corneal thickness.Methods: 30 eyes of patients who attended the Ophthalmology OPD between the time period October 2017 and June 2018 who were newly diagnosed with normal tension glaucoma with no history of any systemic illness or not on any medication were included. Each patient underwent a complete ophthalmic evaluation including fundus examination, visual field assessment, intraocular pressure, central corneal thickness measurement by pachymetry before as well as 1 month and 6 months after starting treatment with 0.2% topical brimonidine twice daily.Results: Administration of brimonidine 0.2% resulted in an increase in central corneal thickness from 525±21 µm before starting brimonidine to 528±21 µm (p<0.05) after 1 month and 535±20 µm (p<0.001) after 6 months. It also resulted in a reduction in intraocular pressure from an initial value of 16±2 mmHg before starting brimonidine to 14±2 mmHg (p<0.05) and 13±2 mmHg (p<0.05), 1month and 6 months after starting treatment, respectively.Conclusions: The data presented in this study show that topical administration of 0.2% brimonidine twice daily results in a significant increase in central corneal thickness in patients with normal tension glaucoma.

Correlations between the Biomechanical Properties of Cornea and Optic Nerve Head in Glaucoma / 中山大学学报(医学科学版)

@#【Objective】 To examine a potential correlation between corneal biomechanical properties with lamina cribrosa thickness.【Methods】Thirty-two patients with POAG，20 with NTG，15 with OHT and 26 healthy controls were included in the cross- sectional study. The parameters of corneal biomechanical properties and lamina cribrosa thickness were compared among POAG，NTG，OHT and healthy subjects by mixed-model analysis of variance（ANOVA）. Spearman′ s coefficient of rank correlation analysis was used to assess the association between parameters of deformation response and clinical factors. 【Results】 The Cronbach′ s α of lamina cribrosa thickness was 0.911，and ICC was more than 0.8. Laminar thickness was thinner in the POAG and NTG groups than in the OHT group and Normal group（P < 0.05）. There were no significant differences between OHT and normal groups（P = 0.653）. Correlation analysis showed that LCT and some important corneal biomechanical properties had significant correlation （P = 0.000）. 【Conclusions】 LCT showed different characteristic in glaucoma，and it may be an important factor for glaucoma progression. LCT and corneal biomechanical properties showed significant correlation ，and corneal biomechanical properties may be used to evaluate the biomechanical properties of optic nerve.

Effects of monocular visual field injury on binocular visual field in patients with glaucoma / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM:To investigate the effect of the severity of monocular visual field loss on binocular visual field loss patients with primary angle-closure glaucoma, primary open angle glaucoma and normal tension glaucoma. <p>METHODS: According to the stage of binocular monocular field loss, 30 healthy and 120 glaucoma patients participants were classified as normal, early, moderate or severe. Binocular vision was determined by integrating the field of view and Esterman binocular field assessment. The monocular and binocular visual field parameters were compared within and between groups. <p>RESULTS:For patients with one eye at normal or early stage and the other with severe stage, the mean deviation of binocular comprehensive visual field was -2.8±1.1dB and -5.5±1.9dB, respectively, and Esterman's average score were 99.1%±1.7% and 95.6%±4.7%, respectively. When both eyes developed moderate or severe injury(moderate/moderate, moderate/severe or severe/severe), the mean deviation of binocular comprehensive visual field is lower than -6dB, and the Esterman average score of moderate/moderate group and moderate/severe group was 94.2%±6.0% and 94.3%±4.9%, respectively. However, when both eyes in the stage of severe injury, the average score of Esterman's rapidly decreased from more than 90% to 68.4%±26.3%.<p>CONCLUSION: If one eye is in a normal or early stage, the binocular vision can remain relatively intact. When the binocular progression to the moderate or severe stage, the mean deviation of binocular visual field defects measured by the binocular comprehensive visual field is significant, and only when the binocular progression to the severe stage, significant Esterman binocular visual field defects are detected.

Simplifying “target” intraocular pressure for different stages of primary open-angle glaucoma and primary angle-closure glaucoma

Lowering of intraocular pressure is currently the only therapeutic measure for Glaucoma management. Many longterm, randomized trials have shown the efficacy of lowering IOP, either by a percentage of baseline, or to a specified level. This has lead to the concept of 'Target” IOP, a range of IOP on therapy, that would stabilize the Glaucoma/prevent further visual field loss, without significantly affecting a patient's quality of life. A clinical staging of Glaucoma by optic nerve head evaluation and perimetric parameters, allows a patient's eye to be categorized as having – mild, moderate or severe Glaucomatous damage. An initial attempt should be made to achieve the following IOP range for both POAG or PACG after an iridotomy. In mild glaucoma the initial target IOP range could be kept as 15-17 mmHg, for moderate glaucoma 12-15 mmHg and in the severe stage of glaucomatous damage 10-12 mmHg. Factoring in baseline IOP, age, vascular perfusion parameters, and change on perimetry or imaging during follow up, this range may be reassessed over 6 months to a year. “Target” IOP requires further lowering when the patient continues to progress or develops a systemic disease such as a TIA. Conversely, in the event of a very elderly or sick patient with stable nerve and visual field over time, the target IOP could be raised and medications reduced. An appropriate use of medications/laser/surgery to achieve such a “Target” IOP range in POAG or PACG can maintain visual fields and quality of life, preventing Glaucoma blindness.

Research on optineurin(E50K)mutation and normal tension glaucoma / 中国医师进修杂志

Glaucoma is one of the leading causes of irreversible blindness.The progressive retinal ganglion cell death is the character of glaucoma which is often associated with elevated intraocular pressure. With the investigations on normal tension glaucoma (NTG), we find that the high intraocular pressure is not the only relevant factor. Research on NTG family has associated mutations in the optineurin(OPTN)gene with this disease, especially the E50K mutated OPTN.The molecular structures, localization, mutation, cellular function and pathogenic mechanism of OPTN has been gradually recognized.

Clinical Effectiveness of a Brinzolamide 1%-Brimonidine 0.2% Fixed Combination for Normal Tension Glaucoma in South Koreans

PURPOSE: This study evaluated the efficacy and safety of a brinzolamide 1%-brimonidine 0.2% fixed combination (BBFC) for normal tension glaucoma (NTG) in a South Korean population. METHODS: This study included 45 patients who were newly diagnosed with NTG and treated with BBFC as the first therapy from January 2016 through December 2016. The unilateral eye of NTG eyes of all patients were enrolled. If both eyes were eligible, the eye with the more severe glaucomatous change was selected. If the glaucomatous change was similar in both eyes, the right eye was selected. The patients received the BBFC twice a day. Diurnal intraocular pressure (IOP) was measured every 2 and 1/2 hours between 09:00 am and 04:30 pm. The IOP change with respect to body position (positional IOP) was measured at baseline and at 6 months after eyedrop instillation. Throughout the study, all side effects were recorded and monitored by the investigators. RESULTS: Ten patients were excluded due to an allergic reaction or follow-up loss. A total of 35 patients were enrolled in this study. The mean IOP was 15.32 ± 4.00 mmHg at baseline and 13.38 ± 3.30 mmHg at 6 months after BBFC instillation (p < 0.001). The IOP fluctuation decreased from 3.33 ± 3.10 to 2.35 ± 1.40 mmHg after BBFC instillation; however, the difference was not statistically significant (p = 0.150). The mean change in positional IOP showed a statistically significant reduction from 16.94 ± 3.18 to 14.80 ± 3.27 mmHg (p = 0.025). There was no serious adverse drug reaction except in three cases of allergic reaction. CONCLUSIONS: BBFC is effective for the reduction of mean IOP and positional IOP in NTG patients.

Association between Normal-tension Glaucoma and Allergic Rhinitis in a Korean Population-based Study

PURPOSE: The purpose of this study was to investigate the association between normal-tension glaucoma (NTG) and allergic rhinitis in a population-based setting using data from the Korea National Health and Nutrition Exam Survey (2010–2012). METHODS: The authors selected a total of 8,614 participants aged 40 years and older for this study. All participants completed an ophthalmic examination required for diagnosis of NTG based on the International Society for Geographical and Epidemiological Ophthalmology criteria. An interview regarding nasal symptoms was also performed. The included participants were classified into NTG (n = 604) and control (n = 8,010) groups. The authors compared the groups in terms of prevalence of allergic rhinitis and identified risk factors of NTG. RESULTS: In NTG patients, allergic rhinitis prevalence was 29.1% (176/604), which was significantly higher than that of the control group (25.0%, 2,000/8,010; p = 0.023). There were significant associations between NTG and allergic rhinitis (odds ratio [OR]= 1.34, 95% confidence interval [CI] = 1.12–1.62, p = 0.002), even after adjusting for potential confounders (age, sex, diabetes, hypertension, number, of family members, household income quartile, frequency of eating out, and smoking status). In particular, patients with NTG aged 60–69 years, those aged 70–79 years, and those who were male had significantly higher ORs for prior allergic rhinitis compared with control subjects (OR = 1.62, 95% CI = 1.16–2.26, p = 0.005; OR = 1.52, 95% CI = 1.06–2.18, p = 0.024; and OR = 1.42, 95% CI = 1.10–1.83, p = 0.007, respectively). CONCLUSIONS: This study showed a significant association between NTG incidence and allergic rhinitis, especially in males and elderly patients (>60 years of age). These results suggested that allergic rhinitis may have a potential role in the development of NTG. Therefore, ophthalmologists and allergic rhinitis patients should remain vigilant to this potential risk factor.

Choroidal Thickness in Thyroid-associated Ophthalmopathy between Normal Tension Glaucoma Using Optical Coherence Tomography

PURPOSE: To compare the macular choroidal thickness in patients with thyroid-associated ophthalmopathy (TAO) with those with normal tension glaucoma (NTG). METHODS: A total of 70 normal eyes, 74 eyes with TAO and 60 eyes with NTG were enrolled in this study. All patients underwent spectral-domain optical coherence tomography (SD-OCT) (Cirrus HD-OCT, Carl Zeiss Meditec Inc., Dublin, CA, USA). Macular choroidal thickness was assessed using enhanced depth imaging. The average macular choroidal thickness was defined as the average value of three measurements: at the fovea and at the points located 1.5 mm in the nasal and temporal directions from the fovea. Generalized estimating equations were used to uncover factors affecting the average macular choroidal thickness. RESULTS: The average, superior and inferior quadrant retinal nerve fiber layer thicknesses were significantly thinner in the NTG group compared with the TAO and control groups (p < 0.001). The average macular choroidal thickness of the TAO group, NTG group and controls was 281.01 ± 60.06 µm, 241.66 ± 55.00 µm and 252.07 ± 55.05 µm, respectively, which were significantly different (p = 0.013). The subfoveal, nasal and temporal side choroidal thicknesses were significantly thinner in the NTG group compared with the TAO group (p = 0.014, 0.012 and 0.034, respectively). Subjects with TAO were associated with a thicker average macular choroidal thickness compared with the NTG group after adjusting for age, sex, spherical equivalent and intraocular pressure (β = 32.61, p = 0.017). CONCLUSIONS: Macular choroidal thickness was significantly thicker in patients with TAO compared with those with NTG. Further evaluation is required to determine if a thick choroid in subjects with TAO has any role in glaucomatous optic neuropathy.

Comparison between Optic Disc Torsion of Fellow Eyes in Unilateral Normal-tension Glaucoma and Normal Eyes

PURPOSE: To determine the association between optic disc tilt and torsion of glaucomatous and fellow eyes of unilateral normal-tension glaucoma (NTG) patients and normal. METHODS: We measured optic disc tilt and torsion of 23 unilateral NTG patients and 23 normal controls by analyzing fundus photography and compared 3 groups. We also measured retinal nerve fiber layer (RNFL) thickness through optical coherence tomography in 23 unilateral NTG patients and compared the findings with those of normal eyes. RESULTS: The mean values of optic disc tilt ratio and torsion degree in glaucomatous eyes were 1.17 ± 0.19° and 15.57 ± 8.16°, respectively, while those in fellow eyes were 1.10 ± 0.10° and 8.26 ± 5.20°. There was no significant difference in tilt ratio (p = 0.109), but there was a significant difference in torsion degree (p = 0.001). The mean values of optic disc tilt ratio and optic disc torsion in the controls were 1.11 ± 0.07° and 3.25 ± 2.69°, respectively. Also, there was no significant difference in optic disc tilt ratio (p = 0.601), but a significant difference in optic disc torsion between fellow eyes and controls (p < 0.001). The RNFL thickness of the same torsion direction in unilateral NTG eyes was measured to be 49.35 ± 17.18 µm smaller than the normal value (mean RNFL thickness: 71.91 ± 16.92 µm). Reduced RNFL thickness of the same torsion direction between glaucomatous eyes and fellow eyes was significantly different (p < 0.001). In addition, it was confirmed that RNFL thickness was significantly decreased according to the degree of disc torsion (p = 0.024). CONCLUSIONS: The optic disc torsion showed a significant difference between glaucomatous and fellow eyes in unilateral NTG patients and normal controls. Also, the RNFL thickness significantly decreased according to the degree of the optic disc torsion. Therefore, fellow eyes of unilateral NTG patients need to be carefully monitored for the progression of glaucoma.

Relationship between Binocular Visual Function and Quality of Life in Bilateral Normal Tension Glaucoma Patients

PURPOSE: To analyze the effect of stereopsis and contrast sensitivity on the quality of life and to evaluate the relationship between integrated binocular visual field (IVF) and binocular visual function in bilateral normal tension glaucoma (NTG) patients. METHODS: Stereopsis and contrast sensitivity tests were performed and compared among 44 NTG patients and 32 normal subjects. The IVF was integrated using the best location method. The correlation between visual function and subscales of the National Eye Institute Visual Function Questionnaire 25 (NEI VFQ-25) was evaluated using univariate linear regression. RESULTS: Stereopsis and contrast sensitivity for the bilateral NTG patients were decreased compared to the normal controls. Stereopsis and contrast sensitivity exhibited a significant correlation with social functions related to vision and color vision among subscales of NEI VFQ-25. IVF mean deviation (MD) and better eye MD showed a significant correlation with stereopsis and contrast sensitivity, while worse eye MD showed no association. CONCLUSIONS: Deterioration of stereopsis and contrast sensitivity in NTG patients affects their quality of life related to social functions and color vision. Both IVF and better eye MDs are correlated with stereopsis and contrast sensitivity in NTG patients.

The Association between Corneal Biomechanical Properties and Initial Visual Field Defect Pattern in Normal Tension Glaucoma

PURPOSE: To investigate the association between corneal biomechanical properties and initial visual field defect pattern in normal tension glaucoma using an Ocular Response Analyzer (ORA; Reichert Instruments, Depew, NY, USA). METHODS: Forty-one patients with normal tension glaucoma were divided into 2 subgroups, 21 patients with initial paracentral scotomas and 20 patients with initial peripheral scotomas. The corneal biomechanical properties of corneal hysteresis (CH), corneal resistance factor (CRF), Goldmann-correlated intraocular pressure (IOPg), corneal-compensated IOP (IOPcc) measured by the ORA, central corneal thickness, and Goldmann applanation tonometry were comparatively analyzed between the 2 groups. RESULTS: The patients with initial peripheral scotomas were significantly younger than those with initial paracentral scotomas (49.45 ± 13.33 years vs. 58.14 ± 12.49 years, p = 0.035) and showed more myopia (− 2.42 ± 2.22 diopter vs. − 0.89 ± 2.22 diopter, p = 0.034). The mean CRF was significantly lower in the initial paracentral scotoma group than in the initial peripheral scotoma group. (9.45 ± 1.95 mmHg vs. 10.58 ± 2.05 mmHg; p = 0.041). No significant difference in CH, IOPg, or IOPcc was seen between the groups. CONCLUSIONS: CRF was significantly different between the initial paracentral scotoma group and initial peripheral scotoma group in normal tension glaucoma. Thus, CRF may be useful to predict initial central field loss in normal tension glaucoma.

24-hour Ambulatory Blood Pressure in Normal Tension Glaucoma: Associations with Retinal Vessel Diameter and Visual Field Defect Progression

PURPOSE: To investigate the correlation between 24-hour ambulatory blood pressure (BP) monitoring and peripapillary retinal vessel width and visual field (VF) defect progression in normal tension glaucoma (NTG) patients. METHODS: All patients were classified by 24-hour ambulatory BP monitoring as non-dipper (nocturnal dip < 10%) and dipper (nocturnal dip ≥ 10%) group. Vessel diameter, mean deviation (MD) value by VF test and VF progression from Glaucoma Progression Analysis (GPA) were compared among non-dipper and dipper groups. RESULTS: Retinal arterial diameter was wider in the non-dipper group compared to the dipper group (p = 0.015), while retinal venous diameter had no significant relationship between the two groups (p = 0.131). The MD value at baseline and 2 years after was worse in the non-dipper group than the dipper group, respectively (p = 0.006, p = 0.030). But, there was no significant relationship between nocturnal dip and GPA progression (p = 0.658). CONCLUSIONS: There was a statistically significant correlation between nocturnal dips and retinal arterial diameter and MD values. These results suggest that non-invasive fundus photography can predict hemodynamic features like nocturnal dip.

Progression of Visual Field Loss and Body Mass Index in Normal Tension Glaucoma

PURPOSE: To evaluate the association between body mass index (BMI) and visual field (VF) progression in normal tension glaucoma (NTG) patients. METHODS: We reviewed the medical records of 78 eyes of 78 NTG patients who were treated with eye drops for more than 18 months. Age, sex, existence of hypertension (HTN), diabetes mellitus (DM), refractive error, baseline intraocular pressure (IOP), IOP reduction ratio, baseline VF indices including mean deviation (MD) and pattern standard deviation, VF progression rate (MD slope, dB/year), number of eye drops, and BMI were analyzed. The progression of VF was determined by glaucoma change probability analyses (STATPAC 2) using a Humphrey field analyzer. RESULTS: The mean follow-up in consecutive eyes was 4.4 ± 2.7 years. A total of 18 eyes showed progression and 60 eyes did not. The VF progression rate (p 0.05). However, multiple linear regression analyses showed that a lower BMI was significantly associated with faster VF progression in the progression group (β = 0.078; standard error = 0.030; p = 0.027). CONCLUSIONS: In the group in which VF loss progressed despite treatment with eye drops, a lower BMI was associated with progression of VF loss in NTG patients.

Changes in pulsatile ocular blood flow in normal tension glaucoma patients / 国际眼科杂志(Guoji Yanke Zazhi)

AIM:To evaluate changes in pulsatile ocular blood flow in normal tension glaucoma ( NTG) patients. METHODS: In this prospective case control study color Doppler imaging ( CDI ) was used to determine ocular blood flow parameters- peak systolic velocity( Vmax ) , end diastolic velocity ( Vd ) , time average mean of maximum velocity ( TAmax ) , pulsatility index ( PI ) , resistive index ( RI ) and systolic/diastolic ratio ( S/D ) in ophthalmic artery ( OA ) , central retinal artery ( CRA ) and short posterior ciliary artery ( SPCA ) in NTG patients and a comparision was made with the normal subjects. Unpaired Student's t-test was used to compare the two groups and P≤0. 05 was considered significant. RESULTS:Vmax in OA, CRA and SPCA in the NTG group was decreased when compared to normals with P values 0. 605, 0. 254 and 0. 348 respectively. Vd in the NTG group was also decreased in all the three vessels when compared to the normal subjects with P values 0. 000, 0.014 and 0. 138 in OA, CRA, and SPCA respectively. The PI and RI were increased in all the vessels in the NTG group with P values 0. 000 and 0. 045 for the OA, 0. 000 and 0. 006 for the CRA and 0. 002 and 0. 024 for the SPCA. S/D ratio was increased in the NTG group as compared to normals with P values 0. 047, 0. 041 and 0. 189 in OA, CRA and SPCA respectively. CONCLUSION: This study concludes that CDI may provide an effective way of measuring part of the vascular component of glaucoma. We found decreased blood flow velocity and increased resistive indices in the ocular vasculature in the NTG group as compared to normal subjects.