Continuous 24-hour measurement of intraocular pressure in millimeters of mercury (mmHg) using a novel contact lens sensor: Comparison with pneumatonometry.

PURPOSE: To address the unmet need of continuous IOP monitoring, a Pressure-Measuring Contact Lens (PMCL) was developed to measure IOP in millimeters of mercury (mmHg) continuously over 24 hours. The present study assessed the reliability of the novel PMCL. METHODS: In this prospective open-label clinical study, healthy and open-angle glaucoma (OAG) subjects were fitted with the PMCL, and pneumatonometry was performed on study eyes (in absence of the PMCL) and on fellow eyes before, during, and after provocative tests. The primary outcome measures were (1) mean IOP difference between same-eye measurements, and (2) percentage of timepoints at which IOP measured by the PMCL was within 5 mmHg of that measured by pneumatonometry in the fellow eye. RESULTS: Eight subjects were analysed (4 healthy, 4 OAG). The average difference in successive IOP measurements made by pneumatonometry and with the PMCL was 2.0±4.3mmHg at placement-time, and 6.5±15.2mmHg at removal time. During water drinking test, a significant increase in IOP was detected both by PMCL in the study eye (2.4±2.5mmHg, p = 0.03) and by pneumatonometry in the fellow eye (1.9±1.9mmHg, p = 0.02). Over the 24-hour recording, 88.0% of IOP variations measured by the PMCL were within 5mmHg of that measured with the pneumatonometer in the fellow eye. A transient corneal erosion of severe intensity was observed following removal of the PMCL on one single eye, and may have affected measurement accuracy in that eye. CONCLUSIONS: This study is a proof-of-concept for this novel PMCL, and its results are encouraging, with a fair accuracy in IOP values measurement and good sensitivity to subtle IOP variations.

Relationship Between Contact Lens Sensor Output Parameters and Visual Field Progression in Open-angle Glaucoma: Assessment of a Practical Tool to Guide Clinical Risk-assessment.

PURPOSE: In recent years, new technologies have emerged to better analyze and interpret intraocular pressure (IOP) fluctuations. Among them is the progression report (PR), an algorithm based on continuous contact lens sensor (CLS) readings to estimate the likelihood of fast visual field (VF) glaucomatous progression. The objective of this study is to validate the PR. METHODS: In this retrospective study, 30 open-angle glaucoma patients were enrolled. Twenty-four hours IOP-related variations were recorded using a CLS. Recordings were used to generate PR. The likelihood of fast VF progression (<-1 dB/y mean deviation) was estimated by 2 masked assessors based on clinical parameters. At least 3 VF were performed over the 2 years following the initial assessment, to determine actual progression. RESULTS: Mean age was 65.9±10.45 years, with a mean baseline mean deviation of -5.4±5.1. After a mean follow-up of 29.5±12.9 months, 26.7% of eyes were assessed as fast progressors (-2.9±1.9 dBs/y). The average risk-score attributed by the PR was 42% [41% (slow) vs. 44% (fast); P=0.035]. Correlations between the 2 assessors were good (r=0.59), and identical to that between PR and the averaged assessors' gradings. Correlations between mean deviation progression rates and PR, Assessor 1 and Assessor 2's gradings were, r=0.57, 0.31, and 0.43, respectively. CONCLUSIONS: PR provided comparable predictions of the risk of fast VF progression as did physician estimates based on all available clinical data. With their relationship to the eye's biomechanical properties and the ocular tissues' response to pressure variations, CLS recordings may offer new information that complements conventional examinations.

Effect of surgical intraocular pressure lowering on retinal structures - nerve fibre layer, foveal avascular zone, peripapillary and macular vessel density: 1 year results.

OBJECTIVES: To determine the effect of surgical intraocular pressure (IOP) lowering on peripapillary retinal nerve fibre layer thickness (RNFL), fovea avascular zone (FAZ), peripapillary and macular vessel density (VD) in glaucoma using with optical coherence tomography angiography (OCT-A). METHODS: This was a prospective observational study performed at the Glaucoma Research Centre, Montchoisi Clinic, Lausanne. In total 40 eyes with open-angle glaucoma were included. OCT-A scans were performed before glaucoma surgery, and at 1-month, 3-month, 6-month, and 12-month post-operatively. AngioVue AngioAnalytic (Optovue Inc, Fremont, CA) software was used to analyse the RNFL, FAZ, peripapillary and macular VD. Changes were analysed using analysis of variance (ANOVA) models. RESULTS: Mean IOP dropped from 19.4 (±7.0) mmHg pre-surgery and stabilized at 13.0 (±3.1) mmHg at 12 months (p < 0.001). The number of topical medications reduced from 2.2 (±1.2) preoperatively to 0.4 (±0.8) at 1 year (p < 0.001). Peripapillary RNFL thickness was transiently increased at 1-month postoperatively (p = 0.03). Peripapillary VD fluctuated throughout the follow-up. Foveal VD showed increased perfusion at 3 and 6 months post-operatively with minimal changes at 1 month (p < 0.01). Glaucoma surgery had a significant effect initially on FAZ area (p = 0.03), FAZ perimeter (p = 0.02) and Acircularity Index (AI) (p = 0.04). By 12-months FAZ measurements had reversed to baseline values. CONCLUSIONS: Peripapillary and macular microcirculations responded differently to surgically induced IOP reduction. Peripapillary microcirculation was IOP-independent within the studied range of surgically-controlled IOP. Macular microcirculation, however, exhibited a "delayed response" followed by near-normal reperfusion after glaucoma surgery. FAZ parameters could be potentially useful modalities to assess vascular reperfusion after glaucoma surgery as, amongst all studied parameters, the area was the most sensitive to surgically induced IOP changes.

Acute emotional stress as a trigger for intraocular pressure elevation in Glaucoma.

BACKGROUND: Stress-induced activation of the sympathetic nervous system leads to a cascade of metabolic reactions. Emotional stress is a more specific form of stress in which the stressor is a psychological response to a situation subjectively perceived as traumatic. Stress hormones can have a wide range of effects on the body, however, it is still unclear if and how it can affect ophthalmic physiology. This report presents a case of severe ocular hypertension in which emotional stress was the only cause elicited, and explores potential aggravating factors. CASE PRESENTATION: A 78-year-old, personality type A, lady with a history of pseudo-exfoliative glaucoma presented with an acute asymmetrical raise in intraocular pressure (IOP) immediately following a family breakdown. Her IOP had previously remained stable following a deep sclerectomy in the right eye and an Ex-PRESS shunt in the left eye. Her examination was entirely normal otherwise, with a patent filtration and diffuse bleb as confirmed with anterior segment OCT imaging. Near-normalisation of her IOP was observed within 24 h, concomitantly with the reduction of her stress levels. No other cause for the transient acute hypertensive episode were found. CONCLUSIONS: This case report suggests that acute emotional stress could severely affect IOP in patients suffering from glaucoma. This could be important when looking after glaucoma patients. It would also suggest that the personnality types, and the emotional and social context are more factors to take into account in glaucoma studies. These observations are based on a single case report and would need to be verified on a larger scale.

Pattern Scanning Laser (PASCAL) for Peripheral Iridoplasty in Eyes With Plateau Iris Syndrome: A Novel Application.

PURPOSE: The purpose of this study was to evaluate safety and efficacy of pattern scanning laser (PASCAL) for peripheral iridoplasty in eyes with plateau iris syndrome. MATERIALS AND METHODS: This study was a retrospective review of cases that underwent PASCAL laser peripheral iridoplasty. Eyes with plateau iris syndrome confirmed on gonioscopy and ultrasound biomicroscopy were included in the study. Primary and secondary outcome measures were angle widening on gonioscopy and magnitude of intraocular pressure (IOP) reduction, respectively. RESULTS: Twelve eyes of 8 patients that completed 1-year follow-up were analyzed. Angle widening was noted in 46% of treated quadrants by at least 1 grade (Shaffer classification) at 1-month follow-up. A statistically significant IOP reduction was noted at 1 year from 20.6±4.8 to 17.8±3.8 mm Hg (P=0.01). At 1 month, 8 of 12 eyes (66.6%) achieved gonioscopic success (widening of the angle by at least 1 grade in 2 of 4 quadrants). At 1 year, 6 of 12 eyes (50%) achieved tonometric success (20% reduction or 3 mm Hg IOP reduction from the baseline without addition of new antiglaucoma medications). No adverse effects associated with PASCAL laser peripheral iridoplasty were observed. CONCLUSIONS: PASCAL laser iridoplasty can be a safe and effective alternative to argon laser peripheral iridoplasty in the management of eyes with plateau iris syndrome. Our findings need to be further validated on larger sample size and in different ethnicities.

Diurnal Variations of Peripapillary and Macular Vessel Density in Glaucomatous Eyes Using Optical Coherence Tomography Angiography.

PURPOSE: The purpose of this study was to investigate the diurnal variation in peripapillary and macular vessel density (VD) measurements using optical coherence tomographic angiography (OCT-A) and its correlation to intraocular pressure (IOP) changes in glaucoma patients. METHODS: Prospective, observational cross-sectional study including 37 patients (74 eyes; age, 63.8±12.9 y) with open-angle glaucoma. OCT-A imaging and IOP measurements were performed at 08:00, 11:00, 14:00, and 16:00 timepoints on a single day. At each timepoint, 2 scan protocols were used to generate 3-dimensional en face OCT angiograms: 4.5×4.5-mm scan centered on the optic nerve head and 6×6-mm scan centered on the fovea. For each scan mode, the "radial peripapillary capillary" segment, composed of the vasculature of the retinal nerve fiber layer and ganglion cell layer, was calculated. Two trained readers reviewed OCT-A image quality. Only scans with signal strength intensity (SSI) higher than 46 and without image artifacts interfering with measurements were included. Variation in VD measurements assessed using analysis of variance (ANOVA) and the association between VD and IOP changes assessed using linear mixed modeling methods. RESULTS: The optic nerve head and peripapillary VD measurements at 14:00 and 16:00 timepoints were greater than the measurements at 08:00 and 11:00 timepoints. The 14:00 and 16:00 VD measurements were statistically significantly greater (P<0.05) than the 08:00 measurements for the whole en face (50.1% and 50.1% vs. 49.4%), inside disc (50.6% and 50.5% vs. 49.6%), and average peripapillary (58.2% and 58.5% vs. 57.5%) VDs. The macular VD measurements at the 14:00 timepoint were greater than the measurements at 08:00 and 11:00 timepoints. Changes in VD were significantly associated with changes in SSI but not IOP. CONCLUSIONS: Diurnal changes in OCT-A-measured VD in glaucoma patients were small and clinically insignificant. These changes were not associated with IOP changes.

Optic Nerve Head Drusen: Imaging Using Optical Coherence Tomography Angiography.

PURPOSE: To describe findings and utility of optical coherence tomography angiography (OCTA) in optic nerve head drusen (ONHD). OBSERVATIONS: A 57-year-old white man presented with a decrease in contrast sensitivity of the inferior visual field in both eyes. Clinical examination, visual fields, optical coherence tomography, fundus autofluorescence and OCTA revealed ONHD bilaterally. A focal decrease in vessel density within the localization of ONHD in both eyes was demonstrated suggesting a connection between those findings. CONCLUSIONS AND IMPORTANCE: This is the first report in which peripapillary vessel density is analyzed using OCTA technology for this entity. OCTA could confirm the diagnosis and has the potential to assist with the diagnosis and evaluation of progression of ONHD.

Bilateral Acute Angle-closure after Intraocular Surgery.

We report the case of a 75-year-old woman who developed an acute bilateral angle-closure associated with choroidal effusion a day after an uneventful cataract surgery. The same patient had undergone a similarly uneventful cataract surgery two weeks before, under the same protocol, with no postoperative complication in the other eye. Medical treatment, including the use of oral sulfamide-related drugs (acetazolamide), topical beta-blockers and steroids led to a gradual decrease in intraocular pressure (IOP) and choroidal effusion. Despite initial reports suggesting a link between sulfamide-exposure and these rare forms of angle-closure, our report would suggest a more complex pathophysiology behind this intriguing phenomenon. How to cite this article: Hoskens K, Pinto LA, Vandewalle E, Verdonk N, Stalmans I. Bilateral Acute Angle-closure after Intraocular Surgery. J Curr Glaucoma Pract 2014;8(3):113-114.