Objective: In previous decades, glaucoma has been primarily attributed to elevated intraocular pressure (IOP), but this has gradually been replaced by the development of optic neuropathy as the central concept of glaucoma in developed countries. However, there still remain strong controversies in the definition of glaucoma in China. In this current review, we are going to discuss these controversies and elaborate on the historical transitions of the definition of glaucoma both in China and developed countries. Furthermore, we will briefly describe the "ocular-cranial pressure gradient" theory and discuss the relationship between glaucoma and degenerative diseases of the central nervous system (CNS) in order to show the complex pathogenesis of glaucoma and the importance for the modification to the definition of glaucoma. Data Sources: We performed a comprehensive search in both PubMed and SinoMed using the following keywords: (a) "primary glaucoma" and "guideline," (b) "ocular-cranial pressure gradient," and (c) "glaucoma," "Alzheimer's disease," and "Parkinson's disease." The literature search included the related articles with no restrictions on publication date. Study Selection: The primary references were Chinese and English articles including (a) original guidelines and expert consensuses of primary glaucoma, (b) reviews focusing on the differences between various versions of these guidelines and consensuses, and (c) papers about ocular-cranial pressure gradient theory and the relationship between glaucoma and CNS degenerative diseases. Results: The definitions and classifications of both primary open-angle glaucoma and primary angle-closure glaucoma differ between Chinese glaucoma consensuses and international primary glaucoma guidelines. Chinese definitions and classifications put more emphasis on the IOP, while international guidelines put more emphasis on the presence of optic neuropathy. The ocular-cranial pressure gradient theory and the research on the relationship between glaucoma and CNS degenerative diseases have provided new directions for exploring the pathogenesis of glaucoma. Conclusions As regards the definition and classification of primary glaucoma, we find that there are still some discrepancies between Chinese expert consensuses and international guidelines. Glaucoma is a disease with complex etiologies, while its common characteristic is a specific optic neuropathy. The current definition and understanding of glaucoma is an ongoing and evolving process, reflecting our latest available evidence on its pathogenesis. Chinese ophthalmology community may need to update our guidelines, accommodating these latest developments.
China ; Glaucoma ; diagnosis ; physiopathology ; Glaucoma, Angle-Closure ; diagnosis ; physiopathology ; Glaucoma, Open-Angle ; diagnosis ; physiopathology ; Humans ; Intraocular Pressure ; physiology ; Ophthalmology ; methods

PURPOSE: To compare the clinical and anterior segment anatomical features in primary angle closure sub-groups based on configurations of iris root insertion. METHODS: Primary angle closure patients were imaged using anterior segment optical coherence tomography. Anterior chamber depth, iris curvature, iris thickness (IT) at the scleral spur and 500, 750, and 1,500 µm from the scleral spur (IT(0), IT(500), IT(750), and IT(1500)), lens vault, iris area, angle opening distance (AOD(500)), angle recess area (ARA(750)), and trabecular iris space area (TISA(750)) were measured. Iris root insertion was categorized into a non-basal insertion group (NBG) and basal insertion group (BG). RESULTS: In total, 43 eyes of 39 participants belonged to the NBG and 89 eyes of 53 participants to the BG. The mean age of participants was greater in the NBG than the BG (62.7 ± 5.7 vs. 59.8 ± 7.3 years, p = 0.043), and the baseline intraocular pressure was higher in the BG than the NBG (16.4 ± 4.4 vs. 14.9 ± 3.3 mmHg, p = 0.037). The BG showed a greater IT(0) (0.265 ± 0.04 vs. 0.214 ± 0.03 mm, p < 0.001) and iris area (1.59 ± 0.24 vs. 1.52 ± 0.27 mm2, p = 0.045), lower ARA(750) (0.112 ± 0.08 vs. 0.154 ± 0.08 mm2, p = 0.017) and AOD(500) (0.165 ± 0.07 vs. 0.202 ± 0.08 mm, p = 0.014) compared to the NBG. CONCLUSIONS: The BG had a narrower anterior chamber angle, thicker peripheral iris, and higher pretreatment intraocular pressure.
Anterior Eye Segment/*diagnostic imaging ; Female ; Glaucoma, Angle-Closure/diagnosis/physiopathology/*surgery ; Gonioscopy ; Humans ; *Intraocular Pressure ; Iridectomy/*methods ; Iris/diagnostic imaging/*surgery ; Lens, Crystalline/diagnostic imaging ; Male ; Middle Aged ; Prospective Studies ; Tomography, Optical Coherence/*methods

PURPOSE: To investigate the use of ganglion cell inner plexiform layer (GC-IPL) thickness, as measured by spectral domain optical coherence tomography, to detect central visual field (VF) progression. METHODS: This study included 384 eyes from 384 patients (219 preperimetric and 165 perimetric glaucomatous eyes; average follow-up, 4.3 years). Photographic assessment of retinal nerve fiber layer (RNFL) and serial VF analysis were performed to detect glaucoma progression in the central (within 10°) area. Study inclusion required at least five serial spectral domain optical coherence tomography exams at different visits. The long-term test-retest variability of average GC-IPL thicknesses was calculated in 110 stable preperimetric glaucomatous eyes. The sensitivity and specificity of GC-IPL measurements for the detection of central VF progression were calculated in an event-based analysis using the calculated variability as a cut-off and were compared with those of central RNFL photographic assessment. RESULTS: The intersession test-retest variability, defined as the 95% confidence interval, was 1.76 µm for average GC-IPL thickness. The sensitivity and specificity of the average GC-IPL thickness for detecting central VF progression were 60.7% and 78.9%, respectively. Among six sectors, the inferonasal GC-IPL sector showed the highest sensitivity (53.6%). The sensitivity of the ≥1 sector GC-IPL to detect central VF progression was significantly higher than that of central RNFL photographic progression (p = 0.013). Other GC-IPL parameters showed comparable sensitivity and specificity to detect central VF progression compared with RNFL photographic progression. CONCLUSIONS: Serial GC-IPL measurements show comparable performance in the detection of central glaucomatous VF progression to RNFL photographic assessment.
Disease Progression ; Female ; Follow-Up Studies ; Glaucoma/*diagnosis/physiopathology ; Humans ; *Intraocular Pressure ; Macula Lutea/*diagnostic imaging ; Male ; Middle Aged ; ROC Curve ; Retinal Ganglion Cells/*pathology ; Retrospective Studies ; Time Factors ; Tomography, Optical Coherence/*methods ; *Visual Fields

PURPOSE: To compare changes in corneal endothelial cell density (CECD) after Ahmed glaucoma valve (AGV) implantation and trabeculectomy. METHODS: Changes in corneal endothelium in patients that underwent AGV implantation or trabeculectomy were prospectively evaluated. Corneal specular microscopy was performed at the central cornea using a non-contact specular microscope before surgery and 6 months and 12 months after surgery. The CECD, hexagonality of the endothelial cells, and the coefficient of variation of the cell areas were compared between the two groups. RESULTS: Forty eyes of 40 patients with AGV implantation and 28 eyes of 28 patients with trabeculectomy were studied. Intraocular pressure in the AGV implantation group was significantly higher than that in the trabeculectomy group (p < 0.001), but there was no significant difference in other clinical variables between the two groups. In the AGV implantation group, the mean CECD significantly decreased by 9.4% at 6 months and 12.3% at 12 months compared with baseline values (both, p < 0.001), while it decreased by 1.9% at 6 months and 3.2% at 12 months in the trabeculectomy group (p = 0.027 and p = 0.015, respectively). The changes at 6 months and 12 months in the AGV implantation group were significantly higher than those in the trabeculectomy group (p = 0.030 and p = 0.027, respectively). In the AGV implantation group, there was a significant decrease in the CECD between baseline and 6 months and between 6 months and 12 months (p < 0.001 and p = 0.005, respectively). However, in the trabeculectomy group, a significant decrease was observed only between baseline and 6 months (p = 0.027). CONCLUSIONS: Both the AGV implantation group and the trabeculectomy group showed statistically significant decreases in the CECD 1 year after surgery. The decrease in CECD in the AVG implantation group was greater and persisted longer than that in the trabeculectomy group.
Cell Count ; Endothelium, Corneal/*pathology ; Female ; Follow-Up Studies ; Glaucoma/diagnosis/physiopathology/*surgery ; *Glaucoma Drainage Implants ; Humans ; *Intraocular Pressure ; Male ; Middle Aged ; Postoperative Period ; Prospective Studies ; Prosthesis Implantation/*methods ; Time Factors ; Trabeculectomy/*methods ; Treatment Outcome

PURPOSE: To investigate the risk factors for initial central scotoma (ICS) compared with initial peripheral scotoma (IPS) in normal-tension glaucoma (NTG). METHODS: Fifty-six NTG patients (56 eyes) with an ICS and 103 NTG patients (103 eyes) with an IPS were included. Retrospectively, the differences were assessed between the two groups for baseline characteristics, ocular factors, systemic factors, and lifestyle factors. Also, the mean deviation of visual field was compared between the two groups. RESULTS: Patients from both ICS and IPS groups were of similar age, gender, family history of glaucoma, and follow-up periods. Frequency of disc hemorrhage was significantly higher among patients with ICS than in patients with IPS. Moreover, systemic risk factors such as hypotension, migraine, Raynaud's phenomenon, and snoring were more prevalent in the ICS group than in the IPS group. There were no statistical differences in lifestyle risk factors such as smoking or body mass index. Pattern standard deviation was significantly greater in the ICS group than in the IPS group, but the mean deviation was similar between the two groups. CONCLUSIONS: NTG Patients with ICS and IPS have different profiles of risk factors and clinical characteristics. This suggests that the pattern of initial visual field loss may be useful to identify patients at higher risk of central field loss.
Female ; Humans ; Incidence ; *Intraocular Pressure ; Low Tension Glaucoma/*complications/diagnosis/physiopathology ; Male ; Middle Aged ; Optic Disk/*pathology ; Republic of Korea/epidemiology ; Retrospective Studies ; Risk Assessment/*methods ; Risk Factors ; Scotoma/diagnosis/*epidemiology/etiology ; Visual Fields/*physiology

PURPOSE: To compare the clinical characteristics of unilaterally progressing glaucoma (UPG) and simultaneously bilaterally progressing glaucoma (BPG) in medically treated cases. METHODS: Primary open angle glaucoma patients were classified as having UPG or BPG according to an assessment of optic disc and retinal nerve fiber layer photographs and visual field analysis. Risk factors including the presence of systemic diseases (hypertension, diabetes, cerebrovascular accident, migraine, and dyslipidema) were compared between the UPG and BPG groups. Baseline characteristics and pre- and post-treatment intraocular pressure (IOP) were compared between the progressing eye (PE) and the non-progressing eye (NPE) within the same patient in the UPG group and between the faster progressing eye and the slower progressing eye in the BPG group. RESULTS: Among 343 patients (average follow-up period of 4.2 years), 43 were categorized into the UPG group and 31 into the BPG group. The prevalence of all analyzed systemic diseases did not differ between the two groups. PEs in the UPG group had more severe pathology in terms of baseline visual field parameters than NPEs (mean deviation -6.9 ± 5.7 vs. -2.9 ± 3.9 dB, respectively; p < 0.001). However, baseline IOP, mean follow-up IOP, and other clinical characteristics were not significantly different between the PE and the NPE in the UPG group. The progression rate was significantly higher in the faster progressing eye in patients with BPG than in the PE for patients with UPG (-3.43 ± 3.27 vs. -0.70 ± 1.26 dB/yr, respectively; p = 0.014). CONCLUSIONS: There were no significant differences in the prevalence of systemic diseases between the UPG and BPG groups. Simultaneously bilaterally progressing patients showed much faster progression rates than those with a unilaterally progressing eye.
Disease Progression ; Female ; Follow-Up Studies ; Glaucoma, Open-Angle/*diagnosis/physiopathology ; Humans ; Intraocular Pressure/*physiology ; Male ; Middle Aged ; Optic Disk/*pathology ; Retina/*pathology ; Retrospective Studies ; Time Factors ; Visual Fields/*physiology

PURPOSE: We compared the abilities of Stratus optical coherence tomography (OCT), Heidelberg retinal tomography (HRT) and standard automated perimetry (SAP) to detect the progression of normal tension glaucoma (NTG) in patients whose eyes displayed localized retinal nerve fiber layer (RNFL) defect enlargements. METHODS: One hundred four NTG patients were selected who met the selection criteria: a localized RNFL defect visible on red-free fundus photography, a minimum of five years of follow-up, and a minimum of five reliable SAP, Stratus OCT and HRT tests. Tests which detected progression at any visit during the 5-year follow-up were identified, and patients were further classified according to the state of the glaucoma using the mean deviation (MD) of SAP. For each test, the overall rates of change were calculated for parameters that differed significantly between patients with and without NTG progression. RESULTS: Forty-seven (45%) out of 104 eyes displayed progression that could be detected by red-free fundus photography. Progression was detected in 27 (57%) eyes using SAP, 19 (40%) eyes using OCT, and 17 (36%) eyes using HRT. In early NTG, SAP detected progression in 44% of eyes, and this increased to 70% in advanced NTG. In contrast, OCT and HRT detected progression in 50 and 7% of eyes during early NTG, but only 30 and 0% of eyes in advanced NTG, respectively. Among several parameters, the rates of change that differed significantly between patients with and without progression were the MD of SAP (p = 0.013), and the inferior RNFL thickness (p = 0.041) and average RNFL thickness (p = 0.032) determined by OCT. CONCLUSIONS: SAP had a higher detection rate of NTG progression than other tests, especially in patients with advanced glaucoma, when we defined progression as the enlargement of a localized RNFL defect. The rates of change of the MD of SAP, inferior RNFL thickness, and average RNFL thickness differed between NTG patients with and without progression.
Disease Progression ; Female ; Humans ; Intraocular Pressure/*physiology ; Low Tension Glaucoma/*diagnosis/physiopathology ; Male ; Middle Aged ; Retina/*pathology ; Tomography, Optical Coherence/*methods ; Visual Field Tests/*methods ; Visual Fields/*physiology

PURPOSE: To examine the prevalence of visual field deterioration in contralateral eyes of patients with worsening open-angle glaucoma and to evaluate the spatial concordance of visual field deterioration between both eyes. METHODS: One hundred sixteen open-angle glaucoma patients who underwent 8 or more visual field examinations over > or =6 years of follow-up were included. The rates of the fast and slow components of visual field decay for each of 52 visual field test locations were calculated with point-wise exponential regression analysis. The spatial concordance of visual field deterioration in contralateral eyes was evaluated with a concordance ratio (calculated as the number of overlapping locations divided by the total number of deteriorating locations) and by comparing the rate of decay in corresponding modified glaucoma hemifield test clusters. RESULTS: The average visual field mean deviation (+/-standard deviation [SD]) was -8.5 (+/-6.4) dB and the mean (+/-SD) follow-up time was 9.0 (+/-1.6) years. Sixty-three patients had mild damage, 23 had moderate damage, and 30 had severe damage. The mean concordance ratio (+/-SD) was 0.46 (+/-0.32) for the mild group, 0.33 (+/-0.27) for the moderate group, and 0.35 (+/-0.21) for the severe group. Thirty-one patients (27%) had deterioration in concordant locations (p < 0.05). Visual field deterioration was greater in the superior hemifield than the inferior hemifield (p < 0.05) when evaluated with both the concordance ratio and modified glaucoma hemifield test cluster analysis methods. CONCLUSIONS: There is only fair spatial concordance with regard to visual field deterioration between the both eyes of an individual. We conclude that testing algorithms taking advantage of inter-eye spatial concordance would not be particularly advantageous in the early detection of glaucomatous deterioration.
Aged ; Female ; Glaucoma, Open-Angle/diagnosis/*epidemiology/physiopathology ; Humans ; Male ; Middle Aged ; Prevalence ; Space Perception/*physiology ; Vision Disorders/diagnosis/*epidemiology/physiopathology ; Visual Field Tests ; Visual Fields/*physiology

PURPOSE: Multifocal visual evoked potential (mfVEP) is a newly introduced method used for objective visual field assessment. Several analysis protocols have been tested to identify early visual field losses in glaucoma patients using the mfVEP technique, some were successful in detection of field defects, which were comparable to the standard automated perimetry (SAP) visual field assessment, and others were not very informative and needed more adjustment and research work. In this study we implemented a novel analysis approach and evaluated its validity and whether it could be used effectively for early detection of visual field defects in glaucoma. METHODS: Three groups were tested in this study; normal controls (38 eyes), glaucoma patients (36 eyes) and glaucoma suspect patients (38 eyes). All subjects had a two standard Humphrey field analyzer (HFA) test 24-2 and a single mfVEP test undertaken in one session. Analysis of the mfVEP results was done using the new analysis protocol; the hemifield sector analysis (HSA) protocol. Analysis of the HFA was done using the standard grading system. RESULTS: Analysis of mfVEP results showed that there was a statistically significant difference between the three groups in the mean signal to noise ratio (ANOVA test, p < 0.001 with a 95% confidence interval). The difference between superior and inferior hemispheres in all subjects were statistically significant in the glaucoma patient group in all 11 sectors (t-test, p < 0.001), partially significant in 5 / 11 (t-test, p < 0.01), and no statistical difference in most sectors of the normal group (1 / 11 sectors was significant, t-test, p < 0.9). Sensitivity and specificity of the HSA protocol in detecting glaucoma was 97% and 86%, respectively, and for glaucoma suspect patients the values were 89% and 79%, respectively. CONCLUSIONS: The new HSA protocol used in the mfVEP testing can be applied to detect glaucomatous visual field defects in both glaucoma and glaucoma suspect patients. Using this protocol can provide information about focal visual field differences across the horizontal midline, which can be utilized to differentiate between glaucoma and normal subjects. Sensitivity and specificity of the mfVEP test showed very promising results and correlated with other anatomical changes in glaucoma field loss.
Adult ; Aged ; *Early Diagnosis ; Evoked Potentials, Visual/*physiology ; Female ; Follow-Up Studies ; Glaucoma/complications/*diagnosis/physiopathology ; Humans ; Intraocular Pressure/*physiology ; Male ; Middle Aged ; Reproducibility of Results ; Retrospective Studies ; Scotoma/*diagnosis/etiology/physiopathology ; Visual Field Tests/*methods ; Visual Fields/*physiology ; Young Adult

PURPOSE: Multifocal visual evoked potential (mfVEP) is a newly introduced method used for objective visual field assessment. Several analysis protocols have been tested to identify early visual field losses in glaucoma patients using the mfVEP technique, some were successful in detection of field defects, which were comparable to the standard automated perimetry (SAP) visual field assessment, and others were not very informative and needed more adjustment and research work. In this study we implemented a novel analysis approach and evaluated its validity and whether it could be used effectively for early detection of visual field defects in glaucoma. METHODS: Three groups were tested in this study; normal controls (38 eyes), glaucoma patients (36 eyes) and glaucoma suspect patients (38 eyes). All subjects had a two standard Humphrey field analyzer (HFA) test 24-2 and a single mfVEP test undertaken in one session. Analysis of the mfVEP results was done using the new analysis protocol; the hemifield sector analysis (HSA) protocol. Analysis of the HFA was done using the standard grading system. RESULTS: Analysis of mfVEP results showed that there was a statistically significant difference between the three groups in the mean signal to noise ratio (ANOVA test, p < 0.001 with a 95% confidence interval). The difference between superior and inferior hemispheres in all subjects were statistically significant in the glaucoma patient group in all 11 sectors (t-test, p < 0.001), partially significant in 5 / 11 (t-test, p < 0.01), and no statistical difference in most sectors of the normal group (1 / 11 sectors was significant, t-test, p < 0.9). Sensitivity and specificity of the HSA protocol in detecting glaucoma was 97% and 86%, respectively, and for glaucoma suspect patients the values were 89% and 79%, respectively. CONCLUSIONS: The new HSA protocol used in the mfVEP testing can be applied to detect glaucomatous visual field defects in both glaucoma and glaucoma suspect patients. Using this protocol can provide information about focal visual field differences across the horizontal midline, which can be utilized to differentiate between glaucoma and normal subjects. Sensitivity and specificity of the mfVEP test showed very promising results and correlated with other anatomical changes in glaucoma field loss.
Adult ; Aged ; *Early Diagnosis ; Evoked Potentials, Visual/*physiology ; Female ; Follow-Up Studies ; Glaucoma/complications/*diagnosis/physiopathology ; Humans ; Intraocular Pressure/*physiology ; Male ; Middle Aged ; Reproducibility of Results ; Retrospective Studies ; Scotoma/*diagnosis/etiology/physiopathology ; Visual Field Tests/*methods ; Visual Fields/*physiology ; Young Adult