scholarly journals Angle stability and outflow in excisional ab interno trabeculectomy with active versus passive chamber management

2017 ◽  
Author(s):  
Chao Wang ◽  
Yalong Dang ◽  
Susannah Waxman ◽  
Xiaobo Xia ◽  
Robert N Weinreb ◽  
...  
Keyword(s):  
Anterior Chamber ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Glaucoma Surgery ◽  
Training Model ◽  
Training System ◽  
Angle Stability ◽  
Ab Interno Trabeculectomy ◽  
The Right ◽  
Ab Interno

Purpose: To compare the intraoperative angle stability and the postoperative outflow of two ab interno trabeculectomy devices that excise the trabecular meshwork. The newer device has an active aspiration and irrigation port while the older requires viscoelastic to maintain the anterior chamber. We hypothesized that anterior segment optical coherence tomography (ASOCT) allows quantifying the intraoperative behavior in a microincisional glaucoma surgery (MIGS) pig eye training model. Methods: Twelve freshly enucleated porcine eyes were measured with ASOCT at baseline, at the beginning of the procedure and at its conclusion to determine the anterior chamber depth (ACD) and the nasal angle in degrees. The right and left eye of pairs were randomly assigned 24 to an active dual blade goniectome (aDBG) and a passive dual blade goniectome (pDBG) group, 25 respectively. The aDBG had an irrigation and aspiration port while the pDBG required surgery 26 under viscoelastic. We performed the procedures using our MIGS training system with a 27 standard, motorized ophthalmic operating microscope. We estimated outflow by obtaining 28 canalograms with fluorescent spheres. Results: In aDBG, the nasal angle remained wide open during the procedure at above 90° and 30 did not change towards the end (100±10%, p=0.9). In contrast, in pDBG, ACD decreased by 31 51±19% to 21% below baseline (p<0.01) while the angle progressively narrowed by 40±12% 32 (p<0.001). Canalograms showed a similar extent of access to the outflow tract with the aDBG 33 and the pDBG (p=0.513). The average increase for the aDBG in the superonasal and inferonasal 34 quadrants was between 27 to 31% and for the pDBG between 15 to 18%. Conclusion: ASOCT demonstrated that active irrigation and aspiration improved anterior 36 chamber maintenance and ease of handling with the aDBG in this MIGS training model. The 37 immediate postoperative outflow was equally good with both devices.

scholarly journals Angle stability and outflow in excisional ab interno trabeculectomy with active versus passive chamber management

2017 ◽  
Author(s):  
Chao Wang ◽  
Yalong Dang ◽  
Susannah Waxman ◽  
Xiaobo Xia ◽  
Robert N Weinreb ◽  
...  
Keyword(s):  
Anterior Chamber ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Glaucoma Surgery ◽  
Training Model ◽  
Training System ◽  
Angle Stability ◽  
Ab Interno Trabeculectomy ◽  
The Right ◽  
Ab Interno

Purpose: To compare the intraoperative angle stability and the postoperative outflow of two ab interno trabeculectomy devices that excise the trabecular meshwork. The newer device has an active aspiration and irrigation port while the older requires viscoelastic to maintain the anterior chamber. We hypothesized that anterior segment optical coherence tomography (ASOCT) allows quantifying the intraoperative behavior in a microincisional glaucoma surgery (MIGS) pig eye training model. Methods: Twelve freshly enucleated porcine eyes were measured with ASOCT at baseline, at the beginning of the procedure and at its conclusion to determine the anterior chamber depth (ACD) and the nasal angle in degrees. The right and left eye of pairs were randomly assigned 24 to an active dual blade goniectome (aDBG) and a passive dual blade goniectome (pDBG) group, 25 respectively. The aDBG had an irrigation and aspiration port while the pDBG required surgery 26 under viscoelastic. We performed the procedures using our MIGS training system with a 27 standard, motorized ophthalmic operating microscope. We estimated outflow by obtaining 28 canalograms with fluorescent spheres. Results: In aDBG, the nasal angle remained wide open during the procedure at above 90° and 30 did not change towards the end (100±10%, p=0.9). In contrast, in pDBG, ACD decreased by 31 51±19% to 21% below baseline (p<0.01) while the angle progressively narrowed by 40±12% 32 (p<0.001). Canalograms showed a similar extent of access to the outflow tract with the aDBG 33 and the pDBG (p=0.513). The average increase for the aDBG in the superonasal and inferonasal 34 quadrants was between 27 to 31% and for the pDBG between 15 to 18%. Conclusion: ASOCT demonstrated that active irrigation and aspiration improved anterior 36 chamber maintenance and ease of handling with the aDBG in this MIGS training model. The 37 immediate postoperative outflow was equally good with both devices.

scholarly journals Angle stability and outflow in excisional ab interno trabeculectomy with active versus passive chamber management

2017 ◽  
Author(s):  
Chao Wang ◽  
Yalong Dang ◽  
Susannah Waxman ◽  
Nils A Loewen
Keyword(s):  
Optical Coherence Tomography ◽  
Anterior Chamber ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Glaucoma Surgery ◽  
Training Model ◽  
Angle Stability ◽  
Ab Interno Trabeculectomy ◽  
Porcine Eyes ◽  
Ab Interno

Purpose: To compare the intraoperative angle stability and the postoperative outflow of two ab interno trabeculectomy devices that excise the trabecular meshwork. The newer device has an active aspiration and irrigation port while the older requires viscoelastic to maintain the anterior chamber. We hypothesized that anterior segment optical coherence tomography (ASOCT) allows quantifying the intraoperative behavior in a microincisional glaucoma surgery (MIGS) pig eye training model. Methods: Twelve freshly enucleated porcine eyes were measured with ASOCT at baseline, at the beginning of the procedure and at its conclusion to determine the anterior chamber depth (ACD) and the nasal angle

scholarly journals Rapid learning curve assessment in an ex vivo training system for microincisional glaucoma surgery

2017 ◽  
Author(s):  
Yalong Dang ◽  
Susannah Waxman ◽  
Chao Wang ◽  
Hardik A Parikh ◽  
Igor I Bussel ◽  
...  
Keyword(s):  
Learning Curve ◽  
Ex Vivo ◽  
Glaucoma Surgery ◽  
Training Model ◽  
Training System ◽  
Half Maximum ◽  
Confined Space ◽  
Ex Vivo Model ◽  
Mixed Effect ◽  
Ab Interno

Purpose: Microincisional glaucoma surgeons operate in a highly confined space, making it difficult to learn by observation or assistance alone. We hypothesized that an ex vivo model would allow for better refinement of technique, quantification of progress, and computation of a learning curve. Methods: Seven trainees without angle surgery experience performed nine ab interno trabeculectomies in pig eyes (n=63) after preparing with training slides and videos. Trainees placed the eyes on a tiltable mannequin head, visualized the trabecular meshwork gonioscopically through an ophthalmic microscope, and removed it by trabectome-mediated ablation. An expert surgeon observed, guided, and rated the procedure using an Operating Room Score (ORS). The extent of accessed outflow beds was estimated with canalograms using fluorescent microspheres. Data was fit using mixed effect models. Results: ORS reached a half-maximum on an asymptote after only 2.5 eyes. Surgical time decreased by 0.9 minutes per eye in linear fashion. The ablation arc followed an asymptotic function with a half-maximum inflection point after 5.3 eyes. The mean ablation arc improved from 73 to 135 degrees. Canalograms revealed that this progress did not correlate well with improvement in outflow instead suggesting that about 30 eyes are needed for true mastery. Conclusion: This inexpensive pig eye model provides a safe and effective training model for ab interno trabeculectomy and allows for quantification of outcomes. Trainees without prior angle surgery experience improved quickly. Actual outflow improvements progressed at a slower rate, which serves as a reminder to remain humbly committed to training.

scholarly journals Ocular biometric changes after trabeculectomy

2019 ◽  
Vol 147 (5-6) ◽  
pp. 341-347
Author(s):  
Marija Radenkovic ◽  
Gordana Stankovic-Babic ◽  
Jasmina Djordjevic-Jocic ◽  
Maja Zivkovic ◽  
Marija Trenkic-Bozinovic ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Anterior Chamber ◽  
Axial Length ◽  
Spontaneous Recovery ◽  
Open Angle Glaucoma ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Glaucoma Surgery ◽  
Biometric Analysis ◽  
The Difference

Introduction/Objective. Trabeculectomy is a conventional filtration procedure in surgical glaucoma treatment. Even after successful trabeculectomy, the patient?s visual acuity can be reduced. Studies (1991) showed that changes in visual acuity occur due to changes of corneal curvature and anterior chamber depth. Anterior chamber depth change for 1 mm results in about 2 diopters change in refractive sphere. Simultaneous with anterior segment changes, anti-glaucoma surgery effect can also be manifested in posterior segment of the eye: choroidal thickness, axial length and the ocular perfusion. Axial length reduction after trabeculectomy was supposed according to biometry, more pronounced if intraocular pressure is higher preoperatively, or in the first postoperative week with spontaneous recovery to preoperative values one year after surgery. A study was conducted at the Clinic for Eye Diseases in Nis to determine the difference in pre/post-operative values of biometry on 60 patients with glaucoma. Methods. In this study we used retrospective-prospective biometric analysis in patients with open-angle glaucoma. Results. Anterior chamber depth was significantly different during the observed period, for 1.1 mm in first week (p < 0.0001) in the whole group and glaucoma type. The mean axial length varies considerably during the observed period, shorter for 0.39 mm in first week (p < 0.05). Conclusion. By analyzing biometric parameters, a postoperative difference of biometry with spontaneous recovery was determined. There is a difference in postoperative visual acuity of patients compared to preoperative, with spontaneous recovery at the end of the follow-up.

scholarly journals Differential Canalograms Detect Outflow Changes from Trabecular Micro-Bypass Stents and Ab Interno Trabeculectomy

2016 ◽  
Author(s):  
Hardik A Parikh ◽  
Ralitsa T. Loewen ◽  
Pritha Roy ◽  
Joel S. Schuman ◽  
Kira L. Lathrop ◽  
...  
Keyword(s):  
Effective Treatment ◽  
Surgical Training ◽  
Ex Vivo ◽  
Training Model ◽  
Risk Profile ◽  
Training System ◽  
Ab Interno Trabeculectomy ◽  
Intraoperative Guidance ◽  
Ab Interno ◽  
Reduced Flow

The increasing prevalence of glaucoma, a leading cause of blindness, makes the development of safer and more effective treatment more urgent. Recently introduced microincisional glaucoma surgeries that enhance conventional outflow offer a favorable risk profile but can be unpredictable. Two paramount challenges are the lack of an adequate surgical training model for new surgeries and the absence of pre- or intraoperative guidance to sites of reduced flow. To address both, we developed an ex vivo training system and a differential, quantitative canalography method to assess outflow enhancement by trabecular micro-bypass (TMB) implantation or by ab interno trabeculectomy (AIT). TMB resulted in insignificant (p>0.05) outflow increases of 13+/-5%, 14+/-8%, 9+/-3%, and 24+/-9% in the inferonasal, superonasal, superotemporal, and inferotemporal quadrants. AIT caused a 100+/-50% (p=0.002), 75+/-28% (p=0.002), 19+/-8%, and 40+/-21% increase in those quadrants. AIT eyes had a 7.5 (p=0.01), 5.7 (p=0.004), 2.3, and 1.8-fold greater outflow enhancement than matching quadrants of paired TMB-implanted eyes. Quantitative canalography demonstrated that TMB, when successful, provided focal outflow enhancements, while AIT achieved a more extensive access to outflow pathways including and beyond the surgical site itself.

scholarly journals Rapid learning curve assessment in an ex vivo training system for microincisional glaucoma surgery

2017 ◽  
Author(s):  
Yalong Dang ◽  
Susannah Waxman ◽  
Chao Wang ◽  
Hardik A Parikh ◽  
Igor I Bussel ◽  
...  
Keyword(s):  
Learning Curve ◽  
Ex Vivo ◽  
Glaucoma Surgery ◽  
Training Model ◽  
Training System ◽  
Half Maximum ◽  
Confined Space ◽  
Ex Vivo Model ◽  
Mixed Effect ◽  
Ab Interno

Purpose: Microincisional glaucoma surgeons operate in a highly confined space, making it difficult to learn by observation or assistance alone. We hypothesized that an ex vivo model would allow for better refinement of technique, quantification of progress, and computation of a learning curve. Methods: Seven trainees without angle surgery experience performed nine ab interno trabeculectomies in pig eyes (n=63) after preparing with training slides and videos. Trainees placed the eyes on a tiltable mannequin head, visualized the trabecular meshwork gonioscopically through an ophthalmic microscope, and removed it by trabectome-mediated ablation. An expert surgeon observed, guided, and rated the procedure using an Operating Room Score (ORS). The extent of accessed outflow beds was estimated with canalograms using fluorescent microspheres. Data was fit using mixed effect models. Results: ORS reached a half-maximum on an asymptote after only 2.5 eyes. Surgical time decreased by 0.9 minutes per eye in linear fashion. The ablation arc followed an asymptotic function with a half-maximum inflection point after 5.3 eyes. The mean ablation arc improved from 73 to 135 degrees. Canalograms revealed that this progress did not correlate well with improvement in outflow instead suggesting that about 30 eyes are needed for true mastery. Conclusion: This inexpensive pig eye model provides a safe and effective training model for ab interno trabeculectomy and allows for quantification of outcomes. Trainees without prior angle surgery experience improved quickly. Actual outflow improvements progressed at a slower rate, which serves as a reminder to remain humbly committed to training.

scholarly journals Changes in anterior segment optical coherence tomography following pars plana vitrectomy without tamponade

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Alireza Khodabande ◽  
Massood Mohammadi ◽  
Hamid Riazi-Esfahani ◽  
Shahab Karami ◽  
Massood Mirghorbani ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Anterior Chamber ◽  
Pars Plana Vitrectomy ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Optical Coherence ◽  
Mean Values ◽  
Iop Measurement ◽  
Pars Plana ◽  
The Mean

Abstract Background To evaluate changes in anterior segment morphology on anterior segment optical coherence tomography (AS-OCT) following pars plana vitrectomy (PPV) without tamponade. Methods Patients who underwent PPV without tamponade for epiretinal membrane were evaluated. Eligible patients underwent intraocular pressure (IOP) measurement and AS-OCT preoperatively as well as 1 month and 6 months post-operatively. Anterior chamber width (ACW), anterior chamber depth (ACD), trabecular iris angle (TIA), angle opening distance at 500 and 750 µm (AOD), and trabecular iris space area at 500 and 750 µm (TISA) at four quadrants were recorded and analyzed. Additionally, the mean values of TIA (MTIA), AOD (MAOD), and TISA (MTISA) for each eye (mean of four quadrants) were analyzed. Results 23 patients completed the study. The mean age of participants was 56.4 ± 3.6 years of age and 13/23 (56%) were female. Mean IOP of patients was 18.1 ± 1.1, 18.3 ± 1.1, and 18.1 ± 1.2 preoperatively,1 month post-operatively, and 6 months post-operatively, respectively. (p = 0.83). No difference was detected post-operatively in measurements of ACW, ACD, MTIA, MAOD500, MAOD750, MTISA500, and MTISA750. Conclusion Pars plana vitrectomy without tamponade was not associated with changes in anterior chamber morphology.

Effect of light backscattering from anterior segment structures on automated flare meter measurements

2021 ◽  
pp. 112067212110393
Author(s):  
Murat Hasanreisoglu ◽  
Cem Kesim ◽  
Duygu Yalinbas ◽  
Mervenur Yilmaz ◽  
Nur Sena Uzunay ◽  
...  
Keyword(s):  
Anterior Chamber ◽  
Scattered Light ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Laser Flare Photometry ◽  
Aqueous Flare ◽  
Group I ◽  
Lens Density ◽  
Laser Flare ◽  
Group Ii

Background: To evaluate effect of maximal anterior cortical lens density, iris scatter and anterior chamber depth on laser flare photometry. Methods: Patients diagnosed with clinical uveitis were enrolled in the study. Clinical flare gradings were recorded upon the Standardization of Uveitis Nomenclature. Aqueous flare was measured with an automated device (Kowa FM-700). Back-scattering from anterior cortical lens and anterior iris surface was calculated from Scheimpflug images. A curvilinear regression model was used to calculate estimated values for each clinical grade. These values were used to split cases in Group I (laser flare photometry lower than estimated) and Group II (laser flare photometry higher than estimated). Mean anterior chamber depth, pupil aperture, maximal anterior cortical lens density and iris scatter values were compared between two groups. A stepwise multiple regression analysis was performed to determine the effect of clinical flare gradings and ocular parameters on aqueous flare measurements. Results: The study included 228 eyes of 114 cases. Scheimpflug images were obtained from 105 eyes. Estimated aqueous flare measurements (in photons/milliseconds) were 4.87, 8.50, 14.81, 25.83, 45.04 and 136.93 for 0, 0.5+, 1+, 1.5+, 2+ and 3+ clinical flare respectively. Group II had higher maximal anterior cortical lens density than Group I (96.6 ± 37.1 vs 77.9 ± 17.1 pixel unit, p = 0.001). The measured aqueous flare was significantly related to clinical flare, maximal anterior cortical lens density and pupil aperture (adjusted R2: 0.480, p < 0.001). Conclusion: The back-scattered light from anterior cortical lens could affect laser flare photometry measurements. This effect might be quantified by Scheimpflug imaging.

scholarly journals Effect of peripheral iridectomy on VEGF-A and TGF-β levels in rabbit aqueous humour

2022 ◽  
Vol 22 (1) ◽  
Author(s):  
Annabel C. Y. Chew ◽  
Li-Fong Seet ◽  
Stephanie W. L. Chu ◽  
Nyein C. Lwin ◽  
Tina T. Wong
Keyword(s):  
Anterior Chamber ◽  
Aqueous Humour ◽  
Glaucoma Surgery ◽  
Filtration Surgery ◽  
Glaucoma Filtration Surgery ◽  
Peripheral Iridectomy ◽  
New Zealand White Rabbits ◽  
The Right ◽  
Tgf Β1 ◽  
Time Point

Abstract Background Peripheral iridectomy (PI), routinely performed during glaucoma filtration surgery, may contribute to scarring. This study aims to determine whether PI alters the concentrations of VEGF-A and TGF-β isoforms in the rabbit aqueous humour. Methods Anterior chamber paracentesis (ACP) was performed in both eyes of six New Zealand white rabbits, with additional surgical PI performed in the right eyes. Eyes were examined on postoperative days (PODs) 1, 7, 30 and 60 by means of the tonopen, slit-lamp biomicroscopy, and bead-based cytokine assays for TGF-β and VEGF-A concentrations in the aqueous humor. Results ACP caused a significant reduction in intraocular pressure (IOP) from mean preoperative 11.47 ± 1.01 mmHg to 5.67 ± 1.63 mmHg on POD 1 while PI did not cause further IOP reduction. Limbal conjunctival vasculature appeared slightly increased on POD 1 in both ACP and PI eyes with PI also causing mild bleeding from damaged iris vessels. Two PI eyes developed fibrinous anterior chamber reaction and/ or peripheral anterior synechiae. Aqueous VEGF-A levels were not significantly different between eyes treated with ACP and PI. Aqueous TGF-β concentrations distributed in the ratio of 4:800:1 for TGF-β1:TGF-β2:TGF-β3 respectively. While aqueous TGF-β2 was not significantly induced by either procedure at any time point, TGF-β1 and TGF-β3 were significantly induced above baseline levels by PI on POD 1. Conclusion PI increases the risk of inflammation. The combined induction of aqueous TGF-β1 and TGF-β3 by PI in glaucoma surgery may impact surgery success in glaucoma subtypes sensitive to these isoforms.

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