Journal of Current Glaucoma Practice

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2021 | September-December | Volume 15 | Issue 3

EDITORIAL

Sylvia L Groth

New Strategies for Automated Perimetry: Historical Perspective and Future Innovations

[Year:2021] [Month:September-December] [Volume:15] [Number:3] [Pages:3] [Pages No:103 - 105]

   DOI: 10.5005/jp-journals-10078-1321  |  Open Access |  How to cite  | 

CLINICAL TECHNIQUE

Nathalie Chiam, Shamira Perara

Water Gonioscopy: A Technique for Intraoperative Visualization of the Anterior Chamber Angle

[Year:2021] [Month:September-December] [Volume:15] [Number:3] [Pages:3] [Pages No:106 - 108]

Keywords: Anterior chamber angle, Gonioscopy, Minimally invasive glaucoma surgery, Surgical technique, Total internal reflection

   DOI: 10.5005/jp-journals-10078-1314  |  Open Access |  How to cite  | 

Abstract

Aim and objective: To describe a technique of lens-free gonioscopy that allows the anterior chamber angle to be visualized intraoperatively, without the use of a gonioscopy lens. Background: Minimally invasive glaucoma surgery (MIGS) is an increasingly popular treatment option for mild to moderate glaucoma. We describe a technique of lens-free gonioscopy that allows visualization of the anterior chamber angle without the use of a lens. This simple intraoperative technique may be used to inspect the placement of MIGS devices within the angle. Technique: To perform a water gonioscopy, the surgeon sits temporal to the eye. The patient's head is turned 20–45° away from the surgeon, and the operating microscope is tilted 15–30° toward the surgeon. A reservoir of balanced salt solution is allowed to collect in the crater formed by the nose bridge and the bony orbital rim, external to the corneal surface. This body of liquid obliterates the cornea–air interface and hence allows visualization of the anterior chamber. In contrast to gonioscopy using a gonioscopy lens, water gonioscopy offers a lower magnification, ultra-wide field of view for angle visualization. Conclusion: Water gonioscopy is a useful technique that anterior segment surgeons might use for quick visualization of the anterior chamber angle without the need for additional equipment. Clinical significance: This is a simple technique that surgeons can use to visualize the anterior chamber angles intraoperatively. It is especially useful for MIGS that are placed within the anterior chamber angle, but this technique may also be used during other anterior segment surgeries, such as visualizing the haptics of an anterior chamber intraocular lens or checking for retained lens fragments in the anterior chamber angles.

ORIGINAL RESEARCH

Brian E Yu, Ronald Cheung, Cindy Hutnik, Monali S Malvankar-Mehta

Prevalence of Obstructive Sleep Apnea in Glaucoma Patients: A Systematic Review and Meta-analysis

[Year:2021] [Month:September-December] [Volume:15] [Number:3] [Pages:8] [Pages No:109 - 116]

Keywords: Glaucoma, Obstructive sleep apnea, Prevalence

   DOI: 10.5005/jp-journals-10078-1301  |  Open Access |  How to cite  | 

Abstract

Aim and objective: Obstructive sleep apnea (OSA) is a known systemic risk factor associated with glaucoma. The purpose of the study was to determine the overall prevalence of sleep apnea among patients with glaucoma. Design: A systematic review and meta-analysis. Participants: Not applicable. Materials and methods: A systematic literature search was performed through MEDLINE, EMBASE, and CINAHL and gray literature using Clinical Trials.gov, and ProQuest Dissertations and Theses and conferences held through the Association for Research in Vision and Ophthalmology, American Academy of Ophthalmology, and Canadian Society of Ophthalmology was done until June 10, 2020. Eligible articles were identified by reviewing the retrieved results. Data extracted included the total number of patients with glaucoma and the proportion of glaucoma patients with a co-occurring diagnosis of OSA. STATA 15.0 was used to perform the meta-analysis. Results: 544 articles were gathered from the databases and 40 records were collected via the gray literature search. Ten studies with 956 subjects were included for analysis. The results of the meta-analysis demonstrated a significant rate of OSA among glaucoma patients (ES = 0.17; CI: [0.08, 0.25]). Conclusion: We examine the prevalence of OSA in glaucoma patients and conclude that the prevalence of OSA in glaucoma patients is higher. Clinical significance: The findings in the ongoing investigation on the link between glaucoma and OSA continue to be unclear. The results from this study contribute to evidence of an association between the two diseases.

ORIGINAL RESEARCH

Hyunsoo J Jang, Brian Yu, William Hodge, Monali S Malvankar-Mehta

Repeat Selective Laser Trabeculoplasty for Glaucoma Patients: A Systematic Review and Meta-analysis

[Year:2021] [Month:September-December] [Volume:15] [Number:3] [Pages:8] [Pages No:117 - 124]

Keywords: Glaucoma, Intraocular pressure, Laser, Meta-analysis, Repeat selective laser trabeculoplasty, Selective laser trabeculoplasty, Systematic review, Trabeculoplasty

   DOI: 10.5005/jp-journals-10078-1302  |  Open Access |  How to cite  | 

Abstract

Aim and objective: To evaluate repeat selective laser trabeculoplasty (SLT) for treating primary open-angle glaucoma (POAG). Materials and methods: PubMed, CINAHL, and EMBASE were systematically searched along with grey literature. All English articles that measured intraocular pressure (IOP) before and after repeat SLT on adult patients with POAG were included. Studies were not filtered by location or publication date. Covidence was used to screen imported articles. Risk of bias assessment and data extraction was performed after screening. Meta-analysis was performed using STATA 16.0. Fixed-effect or random-effects models were developed depending on the presence of heterogeneity. Results: Database and grey literature search identified 512 unique studies. After duplicate removal and screening, 12 articles were included and data from included studies were synthesized. Nine articles were included in the meta-analysis. Three studies were prospective observational studies, and nine studies were retrospective chart reviews. Due to the presence of heterogeneity, a random-effects model has been utilized that suggested significant IOP reduction (IOPR) by repeat SLT at 24 months follow-up. Conclusion: Based on our results, repeat SLT could be an effective procedure in reducing IOP for patients with glaucoma for up to 24 months. Efficacy of third, fourth, or further SLT remains to be verified. More data from long-term, high-quality randomized-controlled trials (RCTs) are required to make conclusions. Clinical significance: Repeat SLT may be an effective treatment for lowering IOP with minimal complications or safety issues. This may allow the use of SLT as a primary treatment for POGA, allowing the discontinuation of medications or eye drops and lead to additional benefits.

ORIGINAL RESEARCH

Mark A Chia, Edward Trang, Ashish Agar, Algis J Vingrys, Jenny Hepschke, George YX Kong, Angus W Turner

Screening for Glaucomatous Visual Field Defects in Rural Australia with an iPad

[Year:2021] [Month:September-December] [Volume:15] [Number:3] [Pages:7] [Pages No:125 - 131]

Keywords: Computers, Cross-Sectional study, Glaucoma, Handheld, Mass screening, Visual field tests, Visual fields

   DOI: 10.5005/jp-journals-10078-1312  |  Open Access |  How to cite  | 

Abstract

Aim and objective: Developing improved methods for early detection of visual field defects is pivotal to reducing glaucoma-related vision loss. The Melbourne Rapid Fields screening module (MRF-S) is an iPad-based test, which allows suprathreshold screening with zone-based analysis to rapidly assess the risk of manifest glaucoma. The versatility of MRF-S has potential utility in rural areas and during infectious pandemics. This study evaluates the utility of MRF-S for detecting field defects in non-metropolitan settings. Materials and methods: This was a prospective, multicenter, cross-sectional validation study. Two hundred and fifty-two eyes of 142 participants were recruited from rural sites through two outreach eye services in Australia. Participants were tested using MRF-S and compared with a reference standard; either Zeiss Humphrey Field Analyzer or Haag-Streit Octopus performed at the same visit. Standardized questionnaires were used to assess user acceptability. Major outcome measures were the area under the curve (AUC) for detecting mild and moderate field defects defined by the reference tests, along with corresponding performance characteristics (sensitivity, specificity). Results: The mean test duration for MRF-S was 1.88 minutes compared with 5.92 minutes for reference tests. The AUCs for mild and moderate field defects were 0.81 [95% confidence interval (CI): 0.75–0.87] and 0.87 (95% CI: 0.83–0.92), respectively, indicating very good diagnostic accuracy. Using a risk criterion of 55%, MRF-S identified moderate field defects with a sensitivity and specificity of 88.4 and 81.0%, respectively. Conclusion and clinical significance: The MRF-S iPad module can identify patients with mild and moderate field defects while delivering favorable user acceptability and short test duration. This has potential application within rural locations and amidst infectious pandemics.

ORIGINAL RESEARCH

Thomas Hannen, Sylvain El-Khoury, Rajesh Patel, Faustin Ngounou, Paul-Rolf Preussner

Comparison of the Automated Pattern–Noise (PANO) Glaucoma Test with the HFA, an FDT Stimulus, and the Fundus Area Cup-to-disk Ratio

[Year:2021] [Month:September-December] [Volume:15] [Number:3] [Pages:7] [Pages No:132 - 138]

Keywords: Frequency doubling technology, Glaucoma, Healthcare research, Humphrey field analyzer, Pattern–Noise, Visual field

   DOI: 10.5005/jp-journals-10078-1317  |  Open Access |  How to cite  | 

Abstract

Aim and objective: To compare the results of a new automated glaucoma test—Pattern–Noise (PANO)—to the Humphrey Visual Field Analyzer-II (HFA), the fundus area cup-to-disk ratio (CDR), and a frequency doubling technology (FDT) stimulus. Materials and methods: This was a prospective study performed in the West-Region of Cameroon. Two hundred and nineteen eyes of 122 adult patients were included with a clinical suspicion of normal-tension or primary open-angle glaucoma and no other major ocular pathology. Eyes were examined with PANO, HFA (24-2 SITA standard), and FDT-stimulus in a randomized order followed by clinical assessment of the CDR. Results: Parametric correlation of the mean contrast threshold of PANO with the mean contrast threshold of FDT-stimulus, total deviation of HFA, and area CDR was 0.94, −0.85, and 0.62, respectively (p < 0.001 for all values). Spatial distribution of sensitivity thresholds is highly correlated (p < 0.001) at all points in the visual field between PANO and HFA. With cut-off values of 3 ± 1 dB for HFA mean deviation and 4 ± 1 for PANO mean contrast threshold and after eliminating borderline cases, PANO's sensitivity was 95% and specificity 60%. The mean patient age was 45.2 ± 15.8 years. Mean thresholds of PANO and FDT-stimulus decreased with increasing age. Mean examination time was 7.1 ± 1.8 minutes for PANO, 5.9 ± 1.3 minutes for HFA, and 4.7 ± 1.3 minutes for FDT-stimulus. The mean percentage of false-positives per examination was 4.95% for PANO, 4.62% (p = 0.025) for FDT-stimulus, and 2.10% for HFA. Conclusion: The results showed that PANO was successful in suspecting the presence of glaucoma. Pattern–Noise examination led to findings that were significantly correlated to HFA, FDT stimulus, and area CDR. Some patterns of defect were also correlated. Furthermore, PANO showed a reasonable examination time and error rate. Clinical significance: Affordable and robust visual field devices are lacking in large parts of the developing world. Comparing them to established methods is a prerequisite to their clinical use.

ORIGINAL RESEARCH

Jessica Sze Chia Ng, Yi Xin Tan, Nor Amalina Ahmad Alwi, Kar Ming Yee, Ahmad Hazri Abdul Rashid, Ka-Liong Tan, Chuei Wuei Leong

In Vitro Toxicity Evaluation of New Generic Latanost® and Latacom® as an Ophthalmic Formulation

[Year:2021] [Month:September-December] [Volume:15] [Number:3] [Pages:5] [Pages No:139 - 143]

Keywords: Eye irritation, Generic, Glaucoma, Latanoprost, Timolol

   DOI: 10.5005/jp-journals-10078-1319  |  Open Access |  How to cite  | 

Abstract

Aim and objective: To evaluate the safety of two new generic ophthalmic formulations, Latanost® (latanoprost) and Latacom® (latanoprost and timolol) by utilizing the three-dimensional reconstructed human cornea-like epithelium (RhCE) tissue constructs as an in vitro model in the assessment of ocular irritation. Materials and methods: In vitro irritation test was conducted on Latanost® (LTN) and Latacom® (LTC) and their corresponding innovators, Xalatan® (XLT) and Xalacom® (XLC), respectively, by using RhCE. According to the OECD guidelines No. 492 on the testing of chemicals, the ophthalmic formulations were assessed via topical exposure of the formulations on in vitro RhCE tissue. Cell viability was measured by MTT assay. Results: The mean cell viability percentage of LTN and XLT was 70.5 and 75.7%, respectively, whereas, for LTC and XLC, the percentage viability was 95.3 and 85.7%, respectively. The two new generic formulations (LTN and LTC) did not reduce the cell viability of the RhCE tissue to ≤60%. Thus, both can be considered as nonirritant. Conclusion: Both newly developed generics are nonocular irritants. Clinical significance: This study informs the safety assessment of new generic antiglaucoma ophthalmic solutions applicable for long-term glaucoma treatment. The formulations aim to keep eye irritation to a minimum level.

CASE REPORT

Laëtitia J Niegowski, Kevin Gillmann, J-M Baumgartner

XEN-Augmented Deep Sclerectomy: Step-by-step Description of a Novel Surgical Technique for the Management of Open-angle Glaucoma

[Year:2021] [Month:September-December] [Volume:15] [Number:3] [Pages:5] [Pages No:144 - 148]

Keywords: Case report, Glaucoma, Illustrated, Intraocular pressure, Minimally-invasive glaucoma surgery, Non-penetrating, Stent, Surgery, XEN

   DOI: 10.5005/jp-journals-10078-1311  |  Open Access |  How to cite  | 

Abstract

Aim and background: The present case report describes a novel surgical technique combining XEN gel stent implantation and deep sclerectomy: XEN-augmented deep sclerectomy (XEN-DS). Case description: An active 96-year-old Caucasian woman suffering from pseudoexfoliative glaucoma (PEXG) presented with intraocular pressure (IOP) of 24 mm Hg and a double arcuate visual field defect [mean deviation (MD) −9.6 dB] in her only functional eye despite maximal medical therapy. Considering (1) the magnitude of IOP reduction sought, (2) the risk of complications associated with trabeculectomies and glaucoma drainage devices, and (3) the risk of missed appointments due to the patient's personal and social circumstances, it was decided to tailor the surgical treatment to this patient's specific characteristics combining two existing surgical techniques. Following conjunctival dissection, a superficial scleral flap was lifted 2 mm more posteriorly than in conventional DS, and a XEN gel stent was implanted ab externo through the anterior wall of the deep sclerectomy, into the anterior chamber. A mitomycin C-soaked autologous space maintainer was used. No peri- or postoperative complications were observed. Following XEN-DS, her IOP stabilized between 5 mm Hg and 8 mm Hg through 6 months, and her visual field MD improved to −1.5 dB. Discussion: The present case report is a proof of concept for this novel surgical technique, confirming that XEN-DS has the potential to achieve substantial and persistent IOP reductions in PEXG with a satisfactory safety profile. Clinical studies are warranted to confirm these results.

CASE REPORT

Suneeta Dubey, Kanika Jain, Saptarishi Mukhejee

Iridocorneal Endothelial Syndrome with Coexisting Macular Edema and Neurosensory Detachment: An Unusual Case Report

[Year:2021] [Month:September-December] [Volume:15] [Number:3] [Pages:4] [Pages No:149 - 152]

Keywords: Cogan–Reese syndrome, ICE syndrome, Iridocorneal endothelial syndrome, Macular edema, Neurosensory detachment, Progressive iris atrophy

   DOI: 10.5005/jp-journals-10078-1315  |  Open Access |  How to cite  | 

Abstract

The iridocorneal endothelial (ICE) syndrome is a sporadic, unilateral condition characterized by abnormalities of the cornea, anterior chamber angle, and iris affecting middle-aged women (3rd to 5th decade). It consists of three variants: progressive iris atrophy, Cogan–Reese syndrome—diffuse nevus or iris nodules, and Chandler syndrome—corneal endothelial abnormalities leading to corneal edema. This syndrome has an abnormal corneal endothelial cell layer (proliferative endotheliopathy), which migrates across the angle and onto the surface of the iris. It is a potentially blinding condition as a result of secondary glaucoma and/or corneal decompensation. Although few case reports have shown an association of ICE syndrome with macular edema; however, our case was unique in the sense that it was associated with neurosensory detachment (NSD). It can be suggested that PG analogs are not a good idea to be prescribed for secondary glaucoma management in patients with ICE syndrome as it can predispose to the development of macular edema with NSD.

CASE REPORT

Raquel Burggraaf-Sánchez de las Matas, Laura Such-Irusta, Enrique A Alfonso-Muñoz, Héctor Mascarós-Mena, Aitor Lanzagorta-Aresti, Jorge Mataix-Boronat, Carolina Font-Julià

Late-onset Endophthalmitis after XEN45® Implantation: A Retrospective Case Series and Literature Review

[Year:2021] [Month:September-December] [Volume:15] [Number:3] [Pages:8] [Pages No:153 - 160]

Keywords: Endophthalmitis, Microinvasive glaucoma surgery, Minimally penetrating glaucoma surgery, Needling, Retrospective case series, Safety-profile, XEN45® gel stent

   DOI: 10.5005/jp-journals-10078-1316  |  Open Access |  How to cite  | 

Abstract

Aim and objective: To report the incidence of late-onset endophthalmitis following XEN45® stent implantation. Background: Long-term safety profile and efficacy in relation to the so-called microinvasive glaucoma surgery (MIGS) techniques are still under evaluation. The XEN45® gel stent entails a bleb formation and often requires postoperative conjunctival management, differing from the current reviewed concept of minimally invasive procedures. Endophthalmitis has been described among the complications, triggered in the majority of cases by tube extrusion. Cases description: From our chart of 293 eyes operated on between November 2016 and November 2019, five (1.7%) patients developed endophthalmitis, which took place in the months 3, 4, 5, 11, and 14 after surgery, respectively. Sixty percent had undergone previous needling procedures. All of them showed a previous flat bleb and developed perforation of the conjunctiva caused by the distal portion of the tube. One patient was early eviscerated due to a fateful course. Treatment consisted of intravitreal, oral, and topical antibiotics, as well as topical corticosteroids. Eighty percent underwent device withdrawal, conjunctival gap suturing, anterior chamber washout, aqueous humor (AH) tab extraction (one positive for S. epidermidis and one for Streptococcus agalactiae), and pars plana vitrectomy. A second patient was eviscerated due to phthisis bulbi. Out of three remaining patients, one underwent vitrectomy for retinal detachment, while two patients required glaucoma surgery for intraocular pressure control. The final VA was ≤20/125 in all patients. Conclusion: The XEN45® device appears to trigger endophthalmitis by extruding the stent or unnoticed leakage through conjunctival defects. Special attention should be paid to flat and avascular blebs. Clinical significance: This series shows a higher rate of endophthalmitis (1.7%) compared with previous studies with a significant sample size (0.4–1.4%).

CASE REPORT

Vincenzo Ramovecchi, Fabrizio Franco, Giuseppe Ruben Barbera

XEN Gel Staining with Trypan Blue: A Simple and Effective Technique to Improve Device Visualization during Implantation

[Year:2021] [Month:September-December] [Volume:15] [Number:3] [Pages:3] [Pages No:161 - 163]

Keywords: Complications, Glaucoma, Minimally invasive glaucoma surgery, XEN implant

   DOI: 10.5005/jp-journals-10078-1318  |  Open Access |  How to cite  | 

Abstract

The Xen Gel Stent (Allergan, Irvine, CA, USA) is a hydrophilic collagen-based gelatin tube of 6 mm in length which creates a channel of communication between the anterior chamber and the subconjunctival space allowing aqueous humor outflow. XEN is an ab interno, minimally invasive, glaucoma surgery device which has a better safety profile and offers a less invasive way of lowering intraocular pressure. Unfortunately, one of its weaknesses is that visualization of the implant during surgery is difficult, and this difficulty may be exacerbated, for instance, by a subconjunctival hemorrhage. The purpose of this paper is to describe a simple and effective technique for improving device visualization (XEN 45 μm) during the implantation.

CASE REPORT

Soshian Sarrafpour, Isaiah Davies, Osama Ahmed, Ji Liu, Christopher C Teng

Cataract Surgery in Malignant Glaucoma from Complete Subluxation of Lens into Anterior Chamber

[Year:2021] [Month:September-December] [Volume:15] [Number:3] [Pages:4] [Pages No:164 - 167]

Keywords: Anterior chamber lens subluxation, Case report, Irido-zonulo-hyaloido-vitrectomy, Malignant glaucoma, Surgical management, Traumatic cataract

   DOI: 10.5005/jp-journals-10078-1320  |  Open Access |  How to cite  | 

Abstract

Aim and objective: To report an unusual and difficult case of malignant glaucoma induced by a traumatic mature cataract that had migrated into the anterior chamber in a developmentally delayed patient. Background: Malignant glaucoma can present due to multiple mechanisms, including trauma-induced cataract migration into the anterior chamber. Case description: A developmentally delayed female in her 40s with a history of self-abuse was found to have malignant glaucoma in the setting of a traumatic cataract that had migrated in front of the iris into the anterior chamber. Exam under anesthesia and ultrasound biomicroscopy (UBM) demonstrated complete subluxation of the lens into the anterior chamber. Perioperative techniques included prophylactic pars plana vitrectomy to alleviate posterior pressure as well as the creation of an irido-zonulo-hyaloido-vitrectomy (IZHV), which allowed for reformation of the anterior chamber. These maneuvers allowed for cataract surgery to be performed through a clear corneal incision, with anterior chamber intraocular lens implantation. The patient had improved vision, pressure, and pain. Conclusion: Malignant glaucoma can present in unique ways and the presence of a flat anterior chamber and increased posterior pressure can make surgery challenging. Initial pars plana vitrectomy in addition to the creation of an IZHV can help relieve posterior pressure and facilitate cataract extraction. It is important to factor in patient-specific situations and goals while selecting an intraocular lens. Clinical significance: Traumatic cataracts and malignant glaucoma can present in unique scenarios that may prove difficult to treat. Certain techniques can facilitate these challenging surgeries and provide the optimal outcome for patients.

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