METHODS: This cross-sectional study was conducted on 171 primary angle closure patients (268 eyes). Visual acuity, refraction, and ocular biometry (central anterior chamber depth [ACD], axial length [AL], and lens thickness) were recorded. Vitreous cavity length (VL) and relative lens position (RLP) were calculated.
RESULTS: A total of 92 Primary Angle Closure Suspect (PACS), 30 Primary Angle Closure (PAC), and 146 Primary Angle Closure Glaucoma (PACG) eyes were included. Chinese ethnicity formed the majority (n = 197, 73.5%), followed by Malay (n = 57, 21.3%) and Indian (n = 14, 5.2%). There was a significant female preponderance with a female to male ratio of 1.85. Mean age was 65.7 ± 7.7 years. Mean spherical equivalent was +0.33 ± 1.29 D. Approximately half (n = 137, 51%) of the eyes were hyperopic (spherical power ≥+0.5), with PACG having the highest percentage of hyperopia (n = 69, 50.4%). Myopia and emmetropia were present in 48 (17.9) and 83 (31%) eyes, respectively. Although AL and VL in myopia patients were significantly longer than emmetropic and hyperopic eyes (p < 0.001), the ACD was not significantly different (p = 0.427). While the RLP is smaller in myopic eyes, lens thickness was increased in hyperopic eyes. PACG was significantly higher in elderly patients compared to PACS and PAC (p = 0.005). A total of 37 (13.8%) eyes were blind (vision worse than 3/60) and 19 of them (51.3%) were female patients.
CONCLUSION: A decrease in RLP is predictive of angle closure disease in myopic eyes, whereas increased lens thickness contributes to angle closure disease in hyperopic eyes.
PURPOSE: The purpose of this study was to investigate the clinical characteristics, including 24-hour ocular perfusion pressure and risk of progression in patients with baseline central VF defect, as compared with those with peripheral VF defect in NTG.
DESIGN: This was a prospective, longitudinal study.
METHODS: A total of 65 NTG patients who completed 5 years of follow-up were included in this study. All the enrolled patients underwent baseline 24-hour intraocular pressure and blood pressure monitoring via 2-hourly measurements in their habitual position and had ≥5 reliable VF tests during the 5-year follow-up. Patients were assigned to two groups on the basis of VF defect locations at baseline, the central 10 degrees, and the peripheral 10- to 24-degree area. Modified Anderson criteria were used to assess global VF progression over 5 years. Kaplan-Meier analyses were used to compare the elapsed time of confirmed VF progression in the two groups. Hazard ratios for the association between clinical risk factors and VF progression were obtained by using Cox proportional hazards models.
RESULTS: There were no significant differences between the patients with baseline central and peripheral VF defects in terms of demography, clinical, ocular and systemic hemodynamic factors. Eyes with baseline defects involving the central fields progressed faster (difference: βcentral=-0.78 dB/y, 95% confidence interval=-0.22 to -1.33, P=0.007) and have 3.56 times higher hazard of progressing (95% confidence interval=1.17-10.82, P=0.025) than those with only peripheral defects.
CONCLUSION: NTG patients with baseline central VF involvement are at increased risk of progression compared with those with peripheral VF defect.
METHODOLOGY: We performed a cross-sectional cohort study on healthy subjects and patients with glaucoma. The AngioVue Enhanced Microvascular Imaging System was used to capture the optic nerve head and macula images during one visit. En face segment images of the macular and optic disc were studied in layers. Microvascular density of the optic nerve head and macula were quantified by the number of pixels measured by a novel in-house developed software. Areas under the receiver operating characteristic curves (AUROC) were used to determine the accuracy of differentiating between glaucoma and healthy subjects.
RESULTS: A total of 24 (32 eyes) glaucoma subjects (57.5±9.5-y old) and 29 (58 eyes) age-matched controls (51.17±13.5-y old) were recruited. Optic disc and macula scans were performed showing a greater mean vessel density (VD) in healthy compared with glaucoma subjects. The control group had higher VD than the glaucoma group at the en face segmented layers of the optic disc (optic nerve head: 0.209±0.05 vs. 0.110±0.048, P<0.001; vitreoretinal interface: 0.086±0.045 vs. 0.052±0.034, P=0.001; radial peripapillary capillary: 0.146±0.040 vs. 0.053±0.036, P<0.001; and choroid: 0.228±0.074 vs. 0.165±0.062, P<0.001). Similarly, the VD at the macula was also greater in controls than glaucoma patients (superficial retina capillary plexus: 0.115±0.016 vs. 0.088±0.027, P<0.001; deep retina capillary plexus: 0.233±0.027 vs. 0.136±0.073, P<0.001; outer retinal capillary plexus: 0.190±0.057 vs. 0.136±0.105, P=0.036; and choriocapillaris: 0.225±0.053 vs. 0.153±0.068, P<0.001. The AUROC was highest for optic disc radial peripapillary capillary (0.96), followed by nerve head (0.92) and optic disc choroid (0.76). At the macula, the AUROC was highest for deep retina (0.86), followed by choroid (0.84), superficial retina (0.81), and outer retina (0.72).
CONCLUSIONS: Microvascular density of the optic disc and macula in glaucoma patients was reduced compared with healthy controls. VD of both optic disc and macula had a high diagnostic ability in differentiating healthy and glaucoma eyes.
METHODS: A cross-sectional study was conducted involving 150 Malay PACG patients between April 2014 and August 2016. Ocular examination was performed including Humphrey visual field (HVF) 24-2 analysis assessment. On the basis of the 2 consecutive reliable HVFs, the severity of glaucoma was scored according to modified Advanced Glaucoma Intervention Study (AGIS) by 2 masked investigators and classified as mild, moderate, and severe. Those with retinal diseases, neurological diseases, memory problem, and myopia ≥4 diopters were excluded. Their smoking status and details were obtained by validated questionnaire from Singapore Malay Eye Study (SiMES). The duration of smoking, number of cigarettes per day, and pack/year was also documented. Multiple linear regression analysis was conducted.
RESULTS: There was a significant association between education level and severity of PACG (P=0.001). However, there was no significant association between cigarette smoking and severity of glaucoma (P=0.080). On the basis of multivariate analysis, a linear association was identified between cigarette smoked per day (adjusted b=0.73; 95% CI: 0.54, 1.45; P<0.001) and body mass index (adjusted b=0.32; 95% CI: 0.07, 1.35; P=0.032) with AGIS score.
CONCLUSIONS: There was no significant association between cigarette smoking and severity of PACG. Cigarette smoked per day among the smokers was associated with severity of PACG. However, because of the detrimental effect of smoking, cessation of smoking should be advocated to PACG patients.
METHODS: Scanning electron microscopy was performed on P50 and P200 devices. Bench-top flow studies were performed to find the resistances of the devices. Devices were also incorporated into a perfused, ex vivo porcine sclera model to test and compare their control of pressure, with and without overlying scleral flaps, and with trabeculectomies.
RESULTS: The luminal dimensions of the P200 device were 206.4±3.3 and 204.5±0.9 μm at the subconjunctival space and anterior chamber ends, respectively. Those of the P50 device were 205.0±5.8 and 206.9±3.7 μm, respectively. There were no significant differences between the P200 and P50 devices (all P>0.05). The resistances of the P200 and P50 devices were 0.010±0.001 and 0.054±0.002 mm Hg/μL/min, respectively (P<0.05). Equilibrium pressures with overlying scleral flaps were 17.81±3.30 mm Hg for the P50, 17.31±4.24 mm Hg for the P200, and 16.28±6.67 mm Hg for trabeculectomies (P=0.850).
CONCLUSIONS: The luminal diameters of both devices are externally similar. The effective luminal diameter of the P50 is much larger than 50 μm. Both devices have low resistance values, making them unlikely to prevent hypotony on their own. They lead to similar equilibrium pressures as the trabeculectomy procedure when inserted under the scleral flap.
METHODS: Observational study. Nonglaucomatous patients on NIPD underwent systemic and ocular assessment including mean arterial pressure (MAP), body weight, serum osmolarity, visual acuity, IOP measurement, and ASOCT within 2 hours both before and after NIPD. The Zhongshan Angle Assessment Program (ZAAP) was used to measure ASOCT parameters including anterior chamber depth, anterior chamber width, anterior chamber area, anterior chamber volume, lens vault, angle opening distance, trabecular-iris space area, and angle recess area. T tests and Pearson correlation tests were performed with P<0.05 considered statistically significant.
RESULTS: A total of 46 eyes from 46 patients were included in the analysis. There were statistically significant reductions in IOP (-1.8±0.6 mm Hg, P=0.003), MAP (-11.9±3.1 mm Hg, P<0.001), body weight (-0.7±2.8 kg, P<0.001), and serum osmolarity (-3.4±2.0 mOsm/L, P=0.002) after NIPD. All the ASOCT parameters did not have any statistically significant changes after NIPD. There were no statistically significant correlations between the changes in IOP, MAP, body weight, and serum osmolarity (all P>0.05).
CONCLUSIONS: NIPD results in reductions in IOP, MAP, body weight, and serum osmolarity in nonglaucomatous patients.
METHODS: The model exploits the principle of dynamic and geometric similarity, so while dimensions were up to 30× greater than actual, the flow had similar properties. Scleral flaps were represented by transparent 0.8- and 1.6-mm-thick silicone sheets on an acrylic plate. Dyed 98% glycerin, representing the aqueous humor was pumped between the sheet and plate, and the equilibrium pressure measured with a pressure transducer. Image analysis based on the principle of dye dilution was performed using MATLAB software.
RESULTS: The pressure drop across the flap was larger with thinner flaps, due to reduced rigidity and resistance. Doubling the surface area of flaps and reducing the number of sutures from 5 to 3 or 2 also resulted in larger pressure drops. Flow direction was affected mainly by suture number and position, it was less toward the sutures and more toward the nearest free edge of the flap. Posterior flow of aqueous humor was promoted by placing sutures along the sides while leaving the posterior edge free.
CONCLUSION: We demonstrate a new physical model which shows how changes in scleral flap thickness and shape, and suture number and position affect pressure and flow in a trabeculectomy.
METHODS: Young healthy volunteers of either sex aged between 19-24 years, participated in the sessions using URNB/ULNB (n = 52) and FURNB/FULNB (n = 28). The nostril dominance was calculated from signals recorded on the PowerLab equipment, representing pressure changes at the end of the nostrils during respiration. The IOP was measured with Tono-Pen. The subjects were divided into 4 groups viz. right nostril dominant (RND), left nostril dominant (LND), transitional right nostril dominant (TRND) and transitional left nostril dominant (TLND) groups. The IOP data 'before and after' URNB/ULNB or FURNB/FULNB were compared by using paired t-test. The baseline data of IOP between the groups were analysed by using independent samples t-test.
RESULTS: The URNB decreased the IOP in the LND and TLND (p < 0.01) and also in the RND (p < 0.05) groups but not significantly in the TRND group. The ULNB decreased the IOP in the RND group (p < 0.01) only. The FURNB significantly reduced the IOP (p < 0.05) only in the LND and RND groups. The FULNB decreased the IOP but not significantly. The baseline IOP did not differ significantly between the LND, RND, TLND and TRND groups.
CONCLUSION: The URNB/FURNB reduced the IOP, while ULNB/FULNB failed to increase the IOP significantly. It is suggested that the lowering of IOP by URNB indicated sympathetic stimulation.
METHODS: In this cross-sectional study, 30 severe glaucoma patients, 30 mild glaucoma patients and 30 age-matched controls were recruited. All subjects underwent standard automated perimetry, RNFL analysis and 3 T MRI examinations. Glaucoma patients were classified according to the Hodapp-Anderson-Parish classification. Pearson's correlation coefficient was used to correlate ON volume with RNFL, and receiver operating curve (ROC) analysis was performed to determine the sensitivity and specificity of ON volume in detecting glaucoma severity.
RESULTS: Optic nerve volume was significantly lower in both the left and right eyes of the severe glaucoma group (168.70 ± 46.28 mm(3); 167.40 ± 45.36 mm(3)) than in the mild glaucoma group (264.03 ± 78.53 mm(3); 264.76 ± 78.88 mm(3)) and the control group (297.80 ± 71.45 mm(3); 296.56 ± 71.02 mm(3)). Moderate correlation was observed between: RNFL thickness and ON volume (r = 0.51, p <0.001), and in mean deviation of visual field and optic nerve volume (r = 0.60, p
METHODS: Diurnal variation of intraocular pressure was measured in 202 eyes of suspected open-angle glaucoma patients and 100 control eyes, at 4-hourly intervals for 24 hours (phasing). Based on the phasing results, optic disc changes and visual field defects, the patients were diagnosed as primary open angle glaucoma (POAG), normal tension glaucoma (NTG), ocular hypertension (OHT), or physiologic cup (PC), or still remained as glaucoma suspects due to inconclusive diagnosis. The last group (glaucoma suspects) was then followed up 6-monthly for their eventual outcome.
RESULTS: The highest percentage of suspected glaucoma patients had peak (maximum) readings in the mid-morning (10-11 A.M.) and trough (minimum) readings after midnight (2-3 A.M.); the highest percentage of control group had peak readings in the late evening (6-7 P.M.) and trough readings after midnight (2-3 A.M.). The mean amplitude of variance was 6 mm Hg in suspected glaucoma group and 4 mm Hg in the control group. After 'phasing', 18.8% of the suspected glaucoma patients were diagnosed as POAG, 16.8% as NTG, 5% as OHT, and 28.7% as physiologic cup; 30.9% remained as glaucoma suspects. After 4 years follow-up, 70% of the glaucoma suspects still remained as glaucoma suspects, 6.7% developed NTG and another 6.7% POAG; 16.6% were normal.
CONCLUSIONS: Serial measurement of IOP ( phasing) in a 24-hour period is still needed, in order not to miss the peak and the trough IOP readings in suspected open-angle glaucoma patients, which helps in better management of glaucoma. Among 30.9% of patients who remained as glaucoma suspects after the initial phasing, 13.4% developed NTG/POAG over a period of 4 years.
METHODS: This retrospective study analysed data of 60 eyes from 30 patients with bilateral uveitic glaucoma who had undergone glaucoma surgery in both eyes on separate occasions. Humphrey VF progression was assessed using the Progressor software.
RESULTS: The pre-operative IOP between the FE (43.1 ± 7.7 mmHg) and SE (40 ± 8.7 mmHg) was not statistically significant (p = 0.15). IOP reduction was greater in the FE (64 %) than SE (59.7 %) post-operatively, but the mean IOP at the final visit in the FE (12.3 ± 3.9 mmHg) and SE (14.5 ± 7 mmHg) was not statistically different (p = 0.2). There was no significant change in mean logMAR readings pre and post-operatively (0.45 ± 0.6 vs 0.37 ± 0.6, p = 0.4) or between the FE and SE. The number of SE with CDR > 0.7 increased by 23 % compared to the FE. From 23 available VFs, five SE (21.7 %) progressed at a median of five locations (range 1-11 points) with a mean local slope reduction of 1.74 ± 0.45 dB/year (range -2.39 to -1.26), whereas only one FE progressed. However, there was no significant difference between mean global rate of progression between the FE (-0.9 ± 1.6 dB/year) and SE (-0.76 ± 2.1 dB/year, p = 0.17) in the Humphrey VF.
CONCLUSION: In eyes with bilateral uveitic glaucoma requiring glaucoma surgery, the SEs had more progressed points on VF and glaucomatous disc progression compared to FEs at the final visit.