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result(s) for
"Schlemm"
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Effect of digital ocular massage on intraocular pressure and Schlemm’s canal dimensions
by
Lau, Henry K. C.
,
Lam, Andrew Kwok-cheung
,
Wong, Antonia K. W.
in
692/499
,
692/699/3161/3169/3170
,
Adult
2024
Digital ocular massage has been reported to temporarily lower intraocular pressure (IOP). This could be related to an enhanced aqueous humor outflow; however, the mechanism is not clearly understood. Using anterior segment optical coherence tomography, the Schlemm’s canal (SC) and trabecular meshwork (TM) can be imaged and measured. Here, 66 healthy adults underwent digital ocular massage for 10 min in their right eyes. The IOP and dimensions of the SC and TM were measured before and after ocular massage. All subjects demonstrated IOP reduction from 15.7 ± 2.5 mmHg at baseline to 9.6 ± 2.2 mmHg immediately after, and median of 11.6 mmHg 5-min after ocular massage (Friedman’s test,
p
< 0.001). There was significant change in SC area (median 10,063.5 μm
2
at baseline to median 10,151.0 μm
2
after ocular massage, Wilcoxon test,
p
= 0.02), and TM thickness (median 149.8 μm at baseline to 144.6 ± 25.3 μm after ocular massage, Wilcoxon test,
p
= 0.036). One-third of the subjects demonstrated collapse of the SC area (−2 to −52%), while two-thirds showed expansion of the SC area (2 to 168%). There were no significant changes in SC diameter (270.4 ± 84.1 μm vs. 276.5 ± 68.7 μm, paired
t
-test,
p
= 0.499), and TM width (733.3 ± 110.1 μm vs. 733.5 ± 111.6 μm, paired
t
-test,
p
= 0.988). Eyes with a higher baseline IOP demonstrated a greater IOP reduction (Pearson correlation coefficient
r
= −0.521,
p
< 0.001). Eyes with smaller SC area at baseline showed greater SC area expansion (Pearson correlation coefficient = −0.389,
p
< 0.001). Greater IOP reduction appeared in eyes with greater SC area expansion (Pearson correlation coefficient
r
= −0.306,
p
= 0.01). Association between change in IOP and change in TM thickness was not significant (Spearman’s
ρ
= 0.015,
p
= 0.902). Simple digital ocular massage is an effective method to lower IOP values, and change in the SC area was significantly associated with IOP changes.
Journal Article
The effect of uneventful cataract surgery on Schlemm’s canal and the trabecular meshwork in cases with pseudoexfoliation
by
Bolac, Ruveyde
,
Tekcan, Hatice
,
Alpogan, Oksan
in
Canals (anatomy)
,
Cataract - complications
,
Cataract - diagnosis
2024
Purpose
To evaluate the effect of uneventful cataract surgery on Schlemm’s canal (SC) and the trabecular meshwork (TM) in cases with pseudoexfoliation (PX).
Methods
In this prospective study, 37 PX and 37 normal eyes, who underwent cataract surgery, were included. The PX group was further divided into two subgroups: PX syndrome (PXS) and PX glaucoma (PXG). Preoperative complete ophthalmologic examination, anterior segment (AS) imaging using a Scheimpflug camera, and measurements of SC length and area and TM thickness and length using AS optical coherence tomography (AS-OCT) were performed in all cases. All measurements were repeated at the first and third months after surgery.
Results
Preoperative intraocular pressure (IOP), AS parameters, SC, and TM values showed no significant differences between the groups (
p
> 0.05). After surgery, there was a significant increase in AS parameter values and a significant decrease in IOP values in both the PX and control groups (
p
< 0.05). The nasal and temporal SC area showed a significant increase in the PX group after surgery (
p
= 0.007,
p
= 0.003, respectively). In the subgroup analysis, the only significant change in the nasal and temporal SC area was in the PXS group (
p
= 0.006,
p
= 0.003, respectively).
Conclusion
Cataract surgery resulted in an increase in the SC area in patients with PXS. This increase may be due to multiple mechanisms including the IOP-lowering effect of cataract removal, change in AS, and removal of intraocular PX material after surgery.
Journal Article
Effectiveness and biocompatibility of a novel Schlemm’s canal microstent for glaucoma management
2024
To evaluate the effectiveness and biocompatibility of Wistend, a novel Schlemm’s canal (SC) microstent made of Nitinol designed to improve aqueous humor outflow. New Zealand white (NZW) rabbits were divided into blank, sham-operated and Wistend groups. ICare
®
Tonovet Plus
®
, swept-source optical coherence tomography (SS-OCT), slit lamp biomicroscopy, retinal camera and scanning electron microscopy (SEM) were used for preoperative and postoperative observations. Hematoxylin and Eosin (H&E) tissue staining was adopted for biocompatibility. A significant difference in intraocular pressure (IOP) between the Wistend group and the control groups was observed during the six-month follow-up. SS-OCT identified arc line internal reflections within the SC in the anterior chamber angle. Conjunctival congestion and edema gradually diminished in the early stages. No corneal vascularization, no anterior chamber inflammatory response and no significant tissue reactions were noted in any groups. SEM showed the Wistend’s windows and orifices remained clear, encircled by minimal incidental ocular tissue and free from blockage. Histopathological examination revealed no discernible differences between the Wistend-implanted and sham-operated eyes. These in vivo studies demonstrate the effectiveness and biocompatibility of the microstent. Our findings suggest a promising potential for Wistend in significantly reducing IOP and effectively facilitating the outflow of aqueous humor.
Journal Article
Relationship between Schlemm’s canal incision length and the results of ab interno gonioscopy-assisted transluminal suture trabeculotomy
by
Adachi, Miku
,
Tanabe, Hirotaka
,
Nagata, Yuki
in
692/699/3161
,
692/699/3161/3169/3170
,
Ab interno gonioscopy-assisted transluminal suture trabeculotomy (GATST)
2025
We retrospectively investigated the relationship between Schlemm’s canal incision length and the results of ab interno gonioscopy-assisted transluminal suture trabeculotomy (GATST) with/without cataract surgery in open-angle glaucoma patients at Tsukazaki Hospital from 2018–2021. The study included 113 eyes from 76 patients (age: 70.0 ± 10.8 years; female/male: 43 [56.6%]/33 [43.4%]). GATST with and without cataract surgery was performed on 87 (phakia) [77.0%] and 26 eyes (pseudophakia) [23.0%], respectively; 102 [90.3%] eyes had primary open-angle glaucoma, and 11 [9.7%] had pseudoexfoliation glaucoma. Intraocular pressure (IOP) significantly decreased at 3/6/12 months, and the antiglaucoma eyedrop number significantly decreased at 6/12 months (all P values < 0.001). Linear mixed-effects models showed that incision length had significant positive associations with IOP spikes, hyphema grade, and IOP changes (amount/percentage) at 6 months; surgical success rate (IOP ≤ 15 mmHg, ≥ 20% reduction, no additional surgeries [criterion B]) at 6/12 months; and surgical success rate (IOP ≤ 21 mmHg, ≥ 20% reduction, no additional surgeries [criterion A]) at 12 months (Ps < 0.05). There were no significant associations with IOP changes at 12 months, surgical success rate (criterion A) at 6 months, or antiglaucoma eyedrop number at either timepoint (Ps > 0.05). Longer incisions were more likely to produce greater IOP reduction, requiring more attention to IOP spikes/hyphema.
Journal Article
Interim Analysis of STREAMLINE® Surgical System Clinical Outcomes in Eyes with Glaucoma
2022
To characterize the clinical outcomes of a novel ab interno minimally invasive procedure with the STREAMLINE
Surgical System for creation of incisional goniotomies and canal of Schlemm viscodilation in eyes with mild to severe primary open-angle glaucoma (POAG).
In a prospective, single-arm, first-in-human case series, 20 eyes of 20 subjects with mild to severe POAG underwent creation of incisional goniotomies and canal of Schlemm viscodilation following phacoemulsification cataract extraction after washout of all intraocular pressure (IOP)-lowering medications. The angle surgery portion was performed with a single-use handpiece tipped with a microcannula that creates precise goniotomies through the trabecular meshwork into the canal of Schlemm and delivers a small volume of ophthalmic viscosurgical device directly into the canal via precise catheterization. Outcomes in this interim analysis included mean reduction in IOP and medications through 6 months of follow-up, as well as the proportion of eyes achieving IOP reduction ≥20% from baseline.
At month 6, mean IOP reduction of ≥20% from baseline was achieved in 89.5% of eyes (17/19). Mean (standard deviation) medicated IOP at screening was 16.3 (3.6) mmHg and unmedicated baseline IOP (after washout) was 23.5 (2.5) mmHg. Mean IOP was significantly reduced from baseline through 6 months of follow-up to 14.7 (2.4) mmHg (
<0.001), representing an IOP reduction of 8.8 mmHg (36.9%). Overall, 57.9% (11/19) of eyes decreased dependence on IOP-lowering medications by at least one medication, and 42.1% (8/19) were medication free. Mean medication use was reduced from 2.0 (0.8) at screening to 1.1 (1.1) at 6 months (
<0.001). Three eyes had transient IOP spikes treated with topical medications.
The creation of incisional goniotomies and canal of Schlemm viscodilation safely and effectively reduced IOP and the need for IOP-lowering medications by both clinically and statistically significant magnitudes in eyes with mild to severe POAG undergoing concomitant phacoemulsification cataract extraction through the first 6 months of follow-up.
Journal Article
In vivo measurement of trabecular meshwork stiffness in a corticosteroid-induced ocular hypertensive mouse model
2019
Ocular corticosteroids are commonly used clinically. Unfortunately, their administration frequently leads to ocular hypertension, i.e., elevated intraocular pressure (IOP), which, in turn, can progress to a form of glaucoma known as steroid-induced glaucoma. The pathophysiology of this condition is poorly understood yet shares similarities with the most common form of glaucoma. Using nanotechnology, we created a mouse model of corticosteroid-induced ocular hypertension. This model functionally and morphologically resembles human ocular hypertension, having titratable, robust, and sustained IOPs caused by increased resistance to aqueous humor outflow. Using this model, we then interrogated the biomechanical properties of the trabecular meshwork (TM), including the inner wall of Schlemm’s canal (SC), tissues known to strongly influence IOP and to be altered in other forms of glaucoma. Specifically, using spectral domain optical coherence tomography, we observed that SC in corticosteroid-treated mice was more resistant to collapse at elevated IOPs, reflecting increased TM stiffness determined by inverse finite element modeling. Our noninvasive approach to monitoring TM stiffness in vivo is applicable to other forms of glaucoma and has significant potential to monitor TM function and thus positively affect the clinical care of glaucoma, the leading cause of irreversible blindness worldwide.
Journal Article
Minimally invasive glaucoma surgery: current status and future prospects
2016
Minimally invasive glaucoma surgery aims to provide a medication-sparing, conjunctival-sparing, ab interno approach to intraocular pressure reduction for patients with mild-to-moderate glaucoma that is safer than traditional incisional glaucoma surgery. The current approaches include: increasing trabecular outflow (Trabectome, iStent, Hydrus stent, gonioscopy-assisted transluminal trabeculotomy, excimer laser trabeculotomy); suprachoroidal shunts (Cypass micro-stent); reducing aqueous production (endocyclophotocoagulation); and subconjunctival filtration (XEN gel stent). The data on each surgical procedure for each of these approaches are reviewed in this article, patient selection pearls learned to date are discussed, and expectations for the future are examined.
Journal Article
Evaluation of Schlemm’s canal with swept-source optical coherence tomography in primary angle-closure disease
2023
Purpose
To perform an in vivo evaluation of the changes in Schlemm’s canal (SC) among patients with primary angle-closure disease (PACD) using swept-source optical coherence tomography (SS-OCT).
Methods
Patients diagnosed with PACD who had not undergone surgery were recruited. The SS-OCT quadrants scanned herein included the nasal and temporal sections at 3 and 9 o’clock, respectively. The diameter and cross-sectional area of the SC were measured. A linear mixed-effects model was performed to analyze the effects of parameters on the SC changes. The hypothesis of interest was related to the angle status (iridotrabecular contact, ITC/open angle, OPN), which was further explored with pairwise comparisons of the estimated marginal means (EMMs) of the SC diameter and SC area. In the ITC regions, the relationship between the trabecular-iris contact length (TICL) percentage and SC parameters was also studied by a mixed model.
Results
A total of 49 eyes of 35 patients were included for measurements and analysis. The percentage of observable SCs in the ITC regions was only 58.5% (24/41), whereas it was 86.0% (49/57) in the OPN regions (χ
2
= 9.44,
p
= 0.002). ITC was significantly associated with a decreasing SC size. The EMMs for the diameter and cross-sectional area of SC at the ITC and OPN regions were 203.34 μm versus 261.41 μm (
p
= 0.006) and 3174.43 μm
2
versus 5347.63 μm
2
(
p
= 0.022), respectively. Sex, age, spherical equivalent refraction, intraocular pressure, axial length, extent of angle closure, history of acute attack and treatment with LPI were not significantly associated with SC parameters. In the ITC regions, a larger TICL percentage was significantly associated with a decrease in SC diameter and area (
p
= 0.003 and 0.019, respectively).
Conclusions
The morphologies of SC could be affected by the angle status (ITC/OPN) in patients with PACD, and ITC was significantly associated with a decreasing SC size. These changes in SC as described by OCT scans might help to elucidate the progression mechanisms of PACD.
Journal Article
Aging and intraocular pressure homeostasis in mice
2024
Age and elevated intraocular pressure (IOP) are the two primary risk factors for glaucoma, an optic neuropathy that is the leading cause of irreversible blindness. In most people, IOP is tightly regulated over a lifetime by the conventional outflow tissues. However, the mechanistic contributions of age to conventional outflow dysregulation, elevated IOP and glaucoma are unknown. To address this gap in knowledge, we studied how age affects the morphology, biomechanical properties and function of conventional outflow tissues in C57BL/6 mice, which have an outflow system similar to humans. As reported in humans, we observed that IOP in mice was maintained within a tight range over their lifespan. Remarkably, despite a constellation of age‐related changes to the conventional outflow tissues that would be expected to hinder aqueous drainage and impair homeostatic function (decreased cellularity, increased pigment accumulation, increased cellular senescence and increased stiffness), outflow facility, a measure of conventional outflow tissue fluid conductivity, was stable with age. We conclude that the murine conventional outflow system has significant functional reserve in healthy eyes. However, these age‐related changes, when combined with other underlying factors, such as genetic susceptibility, are expected to increase risk for ocular hypertension and glaucoma. Age and elevated intraocular pressure (IOP) are the two primary risk factors for the second leading cause of blindness in the world, glaucoma. Despite a number of age‐related changes to the IOP‐regulating tissues of the eye that should impair homeostatic function (decreased cellularity, increased pigment accumulation, increased cellular senescence and increased stiffness), we observed that IOP was stable with age. Thus, healthy eyes appear to have significant functional reserve for IOP regulation, but when combined with other underlying factors, such as genetic susceptibility, are predicted to increase risk for elevated IOP and glaucoma.
Journal Article
Short-Term Efficacy of Combined ab Interno Canaloplasty and Trabeculotomy in Pseudophakic Eyes with Open-Angle Glaucoma
2022
Purpose: To evaluate short-term outcomes of combined ab intemo canaloplasty and trabeculotomy in pseudophakic eyes with openangle glaucoma. Patients and Methods: Series included all pseudophakic eyes with open-angle glaucoma treated with up to 360[degrees] ab interno canaloplasty and up to 360[degrees] ab interno trabeculotomy using a purpose-engineered device (OMNI, Sight Sciences Inc). Data collected prior to surgery and out to 6-months postoperative. Surgical success defined as a 20% reduction in intraocular pressure (IOP) without increase in glaucoma medication, or discontinuation of at least one glaucoma medication without increase in IOP. Other primary endpoints included mean IOP and number of glaucoma medications. Results: The study included 67 eyes of 52 patients with a mean age of 76.5 [+ or -] 8.9 years. Preoperative mean IOP was 22.1 [+ or -] 8.0 mmHg on 2.3 [+ or -] 1.4 glaucoma medications. Pressure lowering effects were sustained out to 6 months postoperative with a mean IOP of 15.2 [+ or -] 4.9 mmHg (p < 0.001) and mean medication reduction of 0.7 [+ or -] 1.4 (p < 0.001). Surgical success rate was 69.8% (30 eyes) and correlated with preoperative IOP. Two patients required a secondary surgical intervention. Conclusion: Combined ab interno canaloplasty and trabeculotomy as a standalone procedure is an effective means of reducing IOP and medication burden in pseudophakic eyes with open-angle glaucoma. Keywords: glaucoma, pseudophakia, MIGS, Schlemm canal
Journal Article