Owner Obtained Intraocular Pressure Measurements in Canine Primary Angle Closure Glaucoma: A Pilot Study in 14 Dogs.

To explore the long-term efficacy and safety of laser peripheral iridectomy for primary angle closure glaucoma (PACG). It was a retrospective case series study. Data were collected from those patients who received laser peripheral iridectomy (LPI) for acute or chronic PACG from April 1992 through October 2002 at the Peking Union Medical College Hospital. Only patients who were followed for at least 5 years were included in this study. The control of intraocular pressure (IOP), visual acuity and managements after LPI were analyzed. All of the studied eyes were re-classified into three categories according to the status of anterior chamber angle, optic nerve head and visual field before LPI: primary angle closure suspect (PACS), primary angle closure (PAC) and primary angle closure glaucoma (PACG). Satisfactory control of IOP was defined as the IOP was less than 21 mm Hg (1 mm Hg = 0.133 kPa) without any medications after LPI. No satisfactory control of IOP was defined as the IOP was greater than 21 mm Hg after LPI, yet could be controlled below 21 mm Hg by anti-glaucoma medications. A failure in IOP control was defined as an acute attack of angle closure developed or filtering surgery was required to control IOP after LPI. Chi-square analysis was used for comparison of IOP control in different groups. One hundred and thirty one patients (251 eyes) with PACG were eligible for this study. The mean follow-up period was (9.2 +/- 3.7) years. Of the 251 eyes, 18 eyes (7.2%) were identified as PACS, 98 eyes (39.0%) PAC, 129 eyes (51.4%) PACG, and 6 eyes (2.4%) could not be classified owing to the lack of the information on the optic nerve head and visual field before LPI. The rates of satisfactory control of IOP were 27.1% in all eyes, and 88.9% (16/18), 38.8% (38/98) and 10.9% (14/129) in PACS, PAC and PACG eyes respectively. The rates of no satisfactory control of IOP were 59.8% in all eyes, and 5.6% (1/18), 48.0% (47/98) and 75.2% (97/129) in PACS, PAC and PACG eyes respectively. The rates of failure in IOP control were 13.1% in all eyes, and 5.6% (1/18), 13.3% (13/98) and 14.0% (18/129) in PACS, PAC, PACG eyes respectively. The difference in IOP control between PACS, PAC and PACG eyes was statistically significant (chi(2) = 59.08, P = 0.000). Only 8 eyes had an acute attack of angle closure after LPI. No long-term complications after LPI were observed in all eyes. The IOP control after LPI in PACG eyes is not so good as expected. However, most of PACG eyes after LPI are free of acute attack of angle closure. PACG eyes should be given close and regular follow-up in a long-term to monitor the IOP control and the progression of PACG after LPI.

To evaluate corneal hysteresis (CH) and intraocular pressure (IOP) measured by the Ocular Response Analyzer in Chinese subjects with primary angle-closure glaucoma (PACG), assess their relationship with Goldmann applanation tonometry (GAT) measurements, and compare this with subjects with primary open-angle glaucoma (POAG) and normal controls. In this prospective observational study, consecutive subjects with PACG and POAG without prior intraocular surgery were enrolled from glaucoma clinics. Normal subjects were recruited from an ongoing population-based study. One eye of each subject underwent standardized ocular examination and IOP measurement by GAT and the Ocular Response Analyzer. Corneal hysteresis and corneal-compensated IOP were compared between groups. Of the 443 subjects recruited, 131 had PACG, 162 had POAG, and 150 were normal. Corneal hysteresis was lower in PACG (9.1 mm Hg; 95% confidence interval [CI], 8.7 to 9.4 mm Hg) and POAG (9.5 mm Hg; 95% CI, 9.2 to 9.5 mm Hg) eyes compared with control eyes (10.4 mm Hg; 95% CI, 10.1 to 10.6 mm Hg; P<.001 for both), with no difference (P=.16) in CH found between PACG and POAG eyes. After adjusting for age, sex, and IOP measurement by GAT, CH persisted to be lower only in eyes with PACG in comparison with control eyes (9.4 vs 10.1 mm Hg; P=.006). Eyes with POAG had lower CH than control eyes but the difference was not statistically significant (9.6 vs 10.1 mm Hg; P=.06). Corneal hysteresis was lower in eyes with glaucoma. After adjusting for age, sex, and IOP measurement by GAT, a persistently lower hysteresis was noted in eyes with PACG compared with other groups.

The intraocular pressure is the force required to maintain aqueous flow. Normally it varies with the rate of aqueous formation and the resistance to outflow encountered at the trabecular meshwork. Additional outflow resistance may occur from various pathologic closures of the chamber angle including anterior displacement of the iris root. In primary angle closure glaucoma, the iris root is displaced forward without apparent cause, and the angle closure is usually associated with shallowing of the anterior chamber. This discussion is concerned solely with the pathogenesis of primary angle closure glaucoma associated with a shallow anterior chamber. <h3>Clinical Features</h3> Clinically, this disease appears to be acquired since it almost always occurs after the fourth decade. It is characterized by a slow progressive shallowing of the anterior chamber which may antedate by several years rise in intraocular pressure. The pressure rise may be explosive, indicating that critical closure of the angle can

Glaucoma: The ‘Black hole’ of irreversible blindness

To evaluate intraocular pressure (IOP) fluctuation during office hours and its predictive factors in untreated primary angle-closure suspects (PACS); post-iridotomy primary angle closure (PAC) and primary angle-closure glaucoma (PACG) eyes with or without IOP-lowering medication(s) as appropriate and medically treated primary open-angle glaucoma (POAG) eyes. One-hundred seventeen eyes (29 PACS, 30 PAC, 28 PACG, and 30 POAG) of 117 patients were included in this cross-sectional study. The subjects underwent hourly IOP measurements with Goldmann tonometer from 0800 to 1700 hours. Subjects with PAC and PACG had laser peripheral iridotomy at least 2 weeks prior to the inclusion. SD of office-hour IOP readings was the main outcome measure. IOP fluctuation differed between the groups (P=0.01; Kruskal-Wallis Test). Post hoc Mann-Whitney U-tests showed significantly less IOP fluctuation in PACS compared with PACG (P<0.01). Peak office-hour IOP was observed in the morning in untreated subjects and in the early afternoon in treated subjects. A stepwise linear regression model identified the presence of peripheral anterior synechiae (PAS), thickness of lens, large vertical cup-to-disc ratio (VCDR), and PAC category as significant predictive factors associated with office-hour IOP fluctuation. Diurnal IOP fluctuation in asymptomatic PACSs was less than that in treated PACG subjects and was at least comparable to that in treated PAC and POAG subjects. The greater the amount of PAS, the thicker the lens, the larger the VCDR, the greater was the IOP fluctuation during office hours.

The aim of this study is to describe the ocular and demographic features of Caucasian patients newly presenting with primary angle closure glaucoma and the proportion of workload it represents at a tertiary university hospital glaucoma service. A retrospective case notes review was conducted for all Caucasian patients newly diagnosed with narrow angles, primary angle closure, acute primary angle closure and primary angle closure glaucoma that were seen over a period of 2 years. Demographic and ocular variables were compared and statistical analysis was carried out with the paired t-test and chi-squared test. Number of primary open angle closure glaucoma and acute angle closure cases were compared with total number of new referrals to the department, new patients diagnosed with glaucoma and population numbers for the North East of Scotland. One hundred and four patients were analysed. Twenty-four (23.1%) had narrow angles, 30 (28.8%) had primary angle closure and 50 (48.1%) had primary angle closure glaucoma. Twelve (11.5%) presented with acute primary angle closure. There was no significant difference for gender, age, hypermetropia or visual acuity between groups. Primary angle closure glaucoma constituted 22.9% (50/128) of newly diagnosed glaucoma cases. Based on the 2001 Scotland census, the crude annual incidence of newly diagnosed primary angle closure glaucoma was estimated at 14.8 per 100 000 and 3.6 per 100 000 for acute primary angle closure in the over-45-year-old population. Our study confirms that primary angle closure glaucoma is uncommon in Caucasians, but not as rare as originally perceived as it makes up a fair proportion (22.9%) of glaucoma workload.

Clear lens extraction in eyes with primary angle closure and primary angle-closure glaucoma

Acute Primary Angle Closure Structural Damage

To compare intraocular pressure (IOP) and anterior segment parameters between eyes with unilateral primary angle closure glaucoma (PACG) and their fellow eyes with primary angle closure (PAC) or primary angle closure suspect (PACS). Subjects underwent anterior segment imaging using 360-degree swept-source optical coherence tomography (SS-OCT, CASIA Tomey, Nagoya, Japan) and ocular investigations including gonioscopy and IOP measurement. Each SS-OCT scan (divided into 8 frames, 22.5 degrees apart) was analysed and an average was obtained for the following anterior segment parameters: iridotrabecular contact (ITC), angle opening distance (AOD750), iris thickness and curvature, anterior chamber width, depth and area (ACW, ACD and ACA) and lens vault (LV). Among 132 unilateral PACG subjects (mean age: 62.91 ± 7.2 years; 59.1% male), eyes with PACG had significantly higher presenting IOP (24.81 ± 0.94 vs. 18.43 ± 0.57 mmHg, p < 0.001), smaller gonioscopic Shaffer grade (2.07 ± 0.07 vs. 2.31 ± 0.07, p < 0.001) and a greater extent of peripheral anterior synechiae (PAS, 1.21 ± 0.21 vs. 0.54 ± 0.16 clock hours, p = 0.001). PACG eyes also exhibited increased ITC, ITC area, greater LV and smaller AOD750, ACD and ACA (all p < 0.05). Using the forward stepwise regression model, an increase in 1 mmHg in presenting IOP before laser peripheral iridotomy (LPI)increases the odds of having PACG by 9% (95% confidence interval 5%-14%). PACG eyes have higher presenting IOP, smaller anterior segment parameters, greater extent of PAS, and larger LV compared to their fellow eyes with angle closure. Narrower anterior chamber dimensions and higher presenting IOP before LPI may increase risk of chronic elevated IOP and glaucomatous optic neuropathy after LPI.

To investigate the effect of change of body posture from supine to lateral decubitus position (LDP) on intraocular pressure (IOP) in healthy young subjects. We evaluated 38 eyes of 19 healthy young Korean subjects. IOP was measured using Tonopen XL in both eyes in the sitting and supine position, 5 and 30 min after right LDP and 5 min after returning to the supine position. A week later, IOP was measured in the same sequence except that the subjects assumed the left LDP. The eye on the lower side in the LDP was termed as a dependent eye. The mean IOP of the dependent eyes increased significantly at 5 min after changing from supine to right (16.26 ± 2.73 mmHg versus 18.54 ± 2.95 mmHg, p < 0.01) or left LDP (15.53 ± 2.41 mmHg versus 17.53 ± 3.37 mmHg, p < 0.01); this IOP increase in the dependent eyes persisted at 30 min after changing to right (18.47 ± 2.97 mmHg, p < 0.01) or left LDP (17.79 ± 2.20 mmHg, p < 0.01). Upon returning to the supine position, IOP of the dependent eyes decreased significantly (16.83 ± 2.67 mmHg, p < 0.01 for right LDP and 16.47 ± 2.32 mmHg, p < 0.01 for left). However, this effect of the positional change was not found in the non-dependent eyes (all, p > 0.05). Mean IOP in the dependent eye was significantly higher than that in the non-dependent eye at 30 min after changing to the right (+0.89 ± 1.52 mmHg) or left LDP (+1.84 ± 2.03 mmHg). The postural change from supine to LDP significantly increased IOP of the dependent eyes.

Selective laser trabeculoplasty (SLT) should be explored as a therapeutic option in eyes with angle closure. To assess the intraocular pressure (IOP)-lowering efficacy of SLT in eyes with primary angle closure (PAC) and PAC glaucoma (PACG). Randomized clinical trial at tertiary eye care institutions of 100 patients diagnosed as having PAC or PAC glaucoma in which the angles had opened at least 180° (visible posterior trabecular meshwork on gonioscopy) after laser iridotomy. Recruitment and baselinewere completed from June 2009 to April 2012 and 6-month follow-up was completed from December 2009 to November 2012. Eligible patients with a baseline IOP greater than 21 mm Hg were randomized to either SLT or prostaglandin analog (PGA; travoprost, 0.004%). The SLT was repeated if the IOP reduction was less than 20.0% from baseline at the 1- or 3-month follow-up visit. The primary outcome measure was the change in IOP from baseline to the final follow-up visit (at 6 months). The frequency of additional postoperative treatments and complications were secondary outcomes. Fifty patients (96 eyes) were randomized to SLT and 50 patients (99 eyes) to PGA medical therapy. At 6 months, 49 patients in the SLT group and 47 in the PGA group completed follow-up. Analysis was based on intent to treat. At 6 months, IOP decreased by 4.0 mm Hg (95% CI, 3.2-4.8) in the SLT group (P < .001) and by 4.2 mm Hg (95% CI, 3.5-4.9) in the PGA group (P < .001). There were no differences between the SLT and PGA groups in the absolute mean reduction of IOP (4.0 vs 4.2 mm Hg, respectively; P = .78) or in the percentage of reduction in IOP (16.9% vs 18.5%, respectively; P = .52). Complete success (IOP ≤21 mm Hg without medications) was achieved in 60.0% eyes of the SLT group, compared with 84.0% of eyes in the PGA group (P = .008). No patients required glaucoma surgery. Additional medications were required in 22.0% of patients in the SLT group compared with 8.0% in the PGA group (P = .05). One patient in the SLT group (2.0%) had a transient posttreatment IOP spike greater than 5 mm Hg. The mean endothelial cell count showed a significant decrease from baseline in the SLT arm (4.8% decrease; P = .001). No other events such as persistent uveitis or increase in peripheral anterior synechiae were noted in eyes that underwent SLT. Two patients in the PGA group exited owing to drug-related complications (1 patient with uveitis and 1 with allergic conjunctivitis). Eyes with PAC or PACG respond to SLT in the short term, but the overall long-term therapeutic effectiveness needs further evaluation. clinicaltrials.gov Identifier: NCT01004900.

Substantial proportion of primary angle closure glaucoma (PACG) eyes showed glaucomatous worsening after successful lens extraction and intraocular pressure (IOP) control, which may suggest that an earlier intervention may be required to prevent PACG. The purpose of this study was to investigate the longitudinal clinical course of the primary angle closure (PAC) disease spectrum, including PAC, primary angle closure suspect (PACS), and PACG patients, who underwent lens extraction. This retrospective observational study included 77 eyes from patients with PACS, PAC, and PACG who underwent lens extraction and were followed up for >2 years after surgery. The mean, peak, and fluctuation of IOP were analyzed before and after lens extraction among groups. Visual field (VF) mean deviation was compared immediately after lens extraction and the final follow-up. Postoperative glaucoma progression determined by 3 criteria (optic disc/retinal nerve fiber layer photographs, optical coherent tomography, and VF) was compared among the 3 groups. Seventeen PACS, 24 PAC, and 36 PACG eyes were included. The mean and peak IOP, and IOP fluctuation IOP were significantly reduced postoperatively in all groups. Postoperative VF mean deviation was significantly aggravated only in the PACG group (from -7.26 to -8.82 dB, P<0.001). The prevalence of postoperative glaucoma progression by at least 1 criterion was significantly higher in PACG, and none of the eyes with PACS and PAC showed VF conversion (PACS, PAC, PACG; 11.8%, 12.5% vs. 61.1% in disc/retinal nerve fiber layer, 11.8%, 8.3% vs. 63.9% in optical coherent tomography, 0%, 0% vs. 33.3% in VF, all P<0.001). In the PAC spectrum, lens extraction achieved significant IOP reduction. However, despite IOP control, a substantial proportion of PACG eyes showed glaucomatous progression. This result may suggest that lens extraction should be performed early to prevent PACG.

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This study set out to evaluate the influences of uneventful phacoemulsification on the anterior segment parameters obtained with the Pentacam rotating Scheimpflug camera and intraocular pressure (IOP). A total of 42 eyes of 34 patients (26 men, eight women) were evaluated preoperatively, and at 1, 3 and 6 months postoperatively with the Pentacam. Intraocular pressure was measured with the Goldmann applanation tonometer. The non-parametric paired t-test was used to compare preoperative and 1-, 3- and 6-month postoperative measurements of anterior chamber depth (ACD), anterior chamber volume (ACV), anterior chamber angle (ACA) width, central corneal thickness (CCT), the central 3-, 5- and 7-mm corneal volume (CV), pupil size, and IOP. Pearson's correlation test was used to evaluate the relationships between IOP and ACD, ACV and ACA width. The differences between ACD, ACV, ACA and IOP values taken preoperatively and those taken postoperatively at 1, 3 and 6 months were statistically significant (p<0.05). The differences between CCT, central 3-, 5- and 7-mm CV, and pupil size measurements taken preoperatively and those taken postoperatively at 1, 3 and 6 months were not statistically significant (p>0.05). The decrease in IOP was not correlated with the changes in ACD, ACV and ACA (p>0.05). Uneventful phacoemulsification significantly reduced IOP, increased ACD and ACV, and widened the ACA. However, alterations in CV, CCT and pupil size values were not statistically significant. Alterations in ACD, ACV, ACA and IOP remain stable after the first month of surgery.

INTRODUCTION. The purpose of the study was to evaluate the intraocular pressure (IOP) lowering effect of lens removal in eyes with primary angle closure glaucoma (PACG) and primary angle closure (PAC). MATERIALS AND METHODS. This study was a retrospective analysis of 114 eyes of 97 patients (83 women, 14 men; mean age 69.9 years) with PACG and PAC treated with lens extraction. Outcome measures: age, gender, visual acuity, IOP reduction over time, preoperative and postoperative number of IOP-lowering medications, axial length, intraocular lens (IOL) power, requirement for additional anti-glaucoma operations, and complications. Patients were divided into three groups: 1) patients with PAC (22 eyes) with mean follow-up 12.2 months; 2) patients with PACG with a history of previous acute angle closure (AAC) (39 eyes) with mean follow-up 15.4 months; and 3) patients with PACG without a history of previous AAC (53 eyes), with mean follow-up 13.5 months. Laser iridotomy was performed in all treated eyes prior to the surgery. RESULTS. In the group with PAC mean IOP was reduced from 42.2 ± 15.4 mm Hg (mean ± SD) under 2.6 IOP-lowering medications to 20.2 ± 10.4 mm Hg under 1.1 IOP-lowering medications (mean IOP reduction 52.1%). In the group with PACG with a history of previous AAC mean IOP was reduced from 29.0 ± 15.7 mm Hg under 2.1 IOP-lowering medications to 17.0 ± 7.5 mm Hg under 0.7 IOP-lowering medications (mean IOP reduction 41.3%). In the group with PACG without a history of previous AAC (53 eyes) mean IOP was reduced from 22.8 ± 8.0 mm Hg under 1.75 IOP-lowering medications to 18.8 ± 7.4 mm Hg under 1.5 IOP-lowering medications (mean IOP reduction 17.5%). In all three groups statistically significant improvement of visual acuity as a result of surgery was observed. There were no statistically significant differences between the three groups with regard to AXL or IOL power. Intraoperative complications were noticed in eight cases, and postoperative complications were noticed in four cases. The number of anti-glaucoma medications was reduced, but 17 eyes needed additional anti-glaucoma procedures. CONCLUSIONS. Lens extraction in eyes with PACG and PAC resulted in significant IOP reduction in all groups. The most pronounced IOP reduction was achieved in the group with PAC, where lens extraction was performed up to 60 days from AAC. Visual acuity was significantly improved as a result of surgery in all three study groups.