Effectiveness and cost-effectiveness of MicroShunt implantation versus standard trabeculectomy for open-angle glaucoma (a SIGHT study): study protocol of a multicentre randomised controlled trial.

BACKGROUND: Trabeculectomy is the "gold standard" initial surgical procedure for open-angle glaucoma worldwide. During the last decade, the introduction of less invasive procedures, including new bleb-forming surgery such as the MicroShunt, has altered the approach of glaucoma management. At present, there is insufficient evidence comparing the effectiveness between these procedures nor versus trabeculectomy. Furthermore, there is no data available on patient impact and cost-effectiveness. This study aims to address this gap in evidence and establish whether MicroShunt implantation is non-inferior compared to trabeculectomy with regard to effectiveness and whether it is cost-effective. METHODS: A multicentre, non-inferiority, randomised controlled trial (RCT) studying open-angle glaucoma with an indication for surgery will be conducted. Patients with previous ocular surgery except for phacoemulsification are excluded, as are patients with ocular comorbidity compromising the visual field or requiring a combined procedure. After informed consent is obtained, patients will be randomly allocated to the intervention, a PRESERFLO™ MicroShunt implantation, or the control group, trabeculectomy, using block randomisation (blocks of 2, 4 or 6 patients). In total, 124 patients will be randomised in a 1:1 ratio, stratified by centre. The primary endpoint will be intraocular pressure (IOP) one year after surgery. Secondary outcomes include IOP-lowering medication use, treatment failure, visual acuity, visual field progression, additional interventions, adverse events, patient-reported outcome measures (PROMs), and cost-effectiveness. Study outcomes will be measured up to 12 months postoperatively. DISCUSSION: This study protocol describes the design of a multicentre non-inferiority randomised controlled trial. To this date, cost-effectiveness studies evaluating the MicroShunt have not been undertaken. This multicentre RCT will provide more insight into whether MicroShunt implantation is non-inferior compared to standard trabeculectomy regarding postoperative IOP and whether MicroShunt implantation is cost-effective. TRIAL REGISTRATION: ClinicalTrials.gov, Identifier: NCT03931564 , Registered 30 April 2019.

[Chloroquine retinopathy]. / Retinopathie door chloroquine.

BACKGROUND: Chloroquine (CQ) and hydroxychloroquine (HCQ) can induce retinopathy. The risk of this severe, irreversible ophthalmological complication significantly increases with duration of treatment (> 5 years) and dosage of medication (for CQ > 2.3 mg/kg/day and HCQ > 5.0 mg/kg/day). Other important risk factors are renal failure, concomitant tamoxifen use and pre-existing retinopathy or maculopathy. CASE DESCRIPTION: We describe a 46-year old woman with chronic discoid lupus erythematosus who developed bull's-eye maculopathy as a consequence of treatment with CQ in varying doses of 100-300 mg/day for five years. Treatment with CQ was subsequently discontinued. CONCLUSION: All patients treated with CQ or HCQ should be referred to the ophthalmologist for baseline testing within 1 year after starting treatment. If there are no risk factors, patients who are treated with CQ or HCQ should undergo annual ophthalmological testing from 1 year, respectively 5 years after start of treatment. The risk factors need to be rechecked at each outpatient check-up because these factors can affect the required frequency of ophthalmological check-ups.

Outcomes of severe uveitic glaucoma treated with Baerveldt implant: can blindness be prevented?

PURPOSE: To evaluate long-term outcomes on efficacy and safety of severe uveitic glaucoma treated with a Baerveldt glaucoma implant (BGI). METHODS: A retrospective study of 47 eyes of 47 patients with uveitic glaucoma treated by a BGI between September 2002 and September 2015. Main outcome measures were intraocular pressure (IOP), number of glaucoma medications, course of the uveitis, visual acuity (VA) and complications. RESULTS: Mean IOP dropped from 30.6 ± 8.1 mmHg with 3.6 ± 1.1 glaucoma medications at baseline to 10.6 ± 4.3 mmHg with 1.0 ± 1.3 glaucoma medications after a mean follow-up of 63.6 ± 43.1 months. In the majority of cases, IOP remained stable during follow-up. However, especially in several patients with viral uveitis, episodes with IOP peaks were observed during a flare-up despite a functioning implant. These peaks remained below preoperative levels. During follow-up, 16 patients (34%) experienced a clinically significant VA loss, mainly because of late-stage glaucoma or hypotony maculopathy. Early postoperative complications were transient choroidal effusion (n = 5), shallow/flat anterior chamber (n = 4), hyphaema (n = 2) and suprachoroidal haemorrhage (n = 1). The most important late postoperative complication was hypotony maculopathy (n = 5), three of these in juvenile idiopathic arthritis (JIA) patients. CONCLUSION: The BGI is an effective and safe treatment for patients with refractive secondary glaucoma due to uveitis. In a majority of patients, VA remains stable and a low and stable IOP is maintained over time with an acceptable number of complications. In particular, patients with viral uveitis and glaucoma should be closely monitored for IOP peaks that may occur during episodes of a flare-up of uveitis, whereas at the other end of the spectrum, patients with JIA seem much more prone to hypotony maculopathy.

Corneal endothelial cell loss after Baerveldt glaucoma drainage device implantation in the anterior chamber.

PURPOSE: To investigate central and peripheral corneal endothelial cell density (ECD) in relation to Baerveldt (BV) glaucoma drainage device (GDD) tube corneal (TC) distance. METHODS: Prospective study of all patients scheduled for glaucoma tube surgery with 36 months follow-up. A BV GDD was inserted into the anterior chamber (AC). Anterior segment optical coherence tomography (AS-OCT) scans were made to determine the TC distance. Central and peripheral ECD was measured, preoperatively and at 3, 6, 12, 24 and 36 months postoperatively. RESULTS: Fifty-three eyes were included [primary open-angle glaucoma, (n = 13); secondary glaucoma, (n = 30); and primary angle-closure glaucoma, (n = 10)]. Central ECD significantly decreased during follow-up, with a mean decrease of 4.54% per year (p < 0.001), and 6.57% in the peripheral quadrant closest to the BV GDD tube (PQC, p < 0.001). In the PQC, a yearly decrease of 1.57% was shown after transiridial tube placement versus 7.43% after placement 'free' into the AC (p = 0.006). Endothelial cell (EC) loss was related to TC distance (mean 1.69 mm), with a central loss of 6.20% and 7.25% in the PQC per year with shorter TC distances, versus a central loss of 4.11% and 5.77% in the PQC per year with longer TC distances (outside mean ± 2SD, p < 0.001). A difference in EC loss by glaucoma subtype was not identified. CONCLUSION: The TC distance is of significant influence on corneal ECD, a shorter TC distance causing more severe EC loss, especially in the PQC. Transiridial placement of the BV GDD tube seems safer than placement 'free' into the AC.

Baerveldt drainage tube motility in the anterior chamber.

PURPOSE: To investigate the stability in position of the Baerveldt glaucoma drainage tube over time and to study movement of the drainage tube in the anterior chamber (AC) under varying light conditions. METHODS: This prospective study included 70 eyes with implantation of a Baerveldt glaucoma drainage tube in the anterior chamber. Anterior segment optical coherence tomography (AS-OCT) images were made preoperatively to quantify AC depth. AS-OCT images were made twice under photopic and twice under scotopic conditions, in the angle parallel to the Baerveldt tube to quantify drainage tube position, at 3, 6, 12, and 24 months postoperatively. Tube-corneal (T-C) and tube-iris (T-I) distances were measured. Additionally, the central AC depth and the peripheral angle opening (AOD 500) were determined. Two subgroups were distinguished according to tube position: free in the AC (group 1, n = 48) and transiridal (group 2, n = 22). RESULTS: After 24 months of follow-up, the drainage tube was found to move statistically significantly closer (0.12 mm) to the corneal endothelium in group 1 (p<0.01). There was no statistically significant difference in T-C distance over time in group 2. The T-C distance did not differ under photopic versus scotopic circumstances (p = 0.32). In both groups, the T-I distance was larger under scotopic conditions, a result of pupil dilation. CONCLUSIONS: The Baerveldt glaucoma drainage tube remained in a stable position when a transiridal implantation was performed, whereas the tube moved closer to the endothelium when placed free into the AC. Transiridal implantation of the Baerveldt tube seems a safe alternative for tube implantation with respect to tube motility.

Evaluation of the comparability and repeatability of four wavefront aberrometers.

PURPOSE: To compare total ocular aberrations and corneal aberrations identified with four different aberrometers and to determine the repeatability and interobserver variability. METHODS: In this prospective comparative study, 23 healthy subjects underwent bilateral examination with four aberrometers: the Irx3 (Hartmann-Shack; Imagine Eyes, Orsay, France), Keratron (Hartmann-Shack; Optikon, Rome Italy), iTrace (ray-tracing; Tracey Technologies, Houston, TX), and OPD-Scan (Automated Retinoscopy; Nidek, Gamagori, Japan). Six images per eye were obtained. Second-, third- and fourth-order spherical aberrations were exported for 5.0-mm pupils. RESULTS: Significant differences in measurements were found for several total ocular aberrations (defocus [2,0], astigmatism [2,2], trefoil [3,-3], trefoil [3,3], and spherical aberration [4,0]) and corneal aberrations (defocus [2,0] and astigmatism [2,2]). The Irx3 showed the highest repeatability in measuring total ocular aberrations, followed by the Keratron, OPD-Scan, and iTrace. The repeatability of the corneal aberration measurements was highest for the iTrace, followed by the Keratron and OPD-Scan. The OPD-Scan showed a lower interobserver variability, compared with the Irx3, Keratron, and iTrace. CONCLUSIONS: Total ocular and corneal aberrations are not comparable when measured with different aberrometers. Hartmann-Shack aberrometers showed the best repeatability for total ocular aberrations and iTrace for corneal aberrations. It would be worthwhile in the future to evaluate aberrometers in patients with more aberrant eyes.

Reproducibility of anterior chamber angle measurements with anterior segment optical coherence tomography.

PURPOSE: To study the reproducibility and variability of iridocorneal angle (ICA) measurements by using anterior segment optical coherence tomography (AS-OCT) by expert and nonexpert observers. METHODS: Twenty-three healthy volunteers (nonexperts with a basic knowledge of ophthalmology) acquired five consecutive AS-OCT images in the enhanced anterior segment single mode in the 180° to 0° meridian of the right eyes of their peers. Two experts and the 23 nonexperts analyzed the images. The ICA software tool was used to determine the angle opening distance (AOD) and the trabecular iris surface area (TISA) at 500 and 750 µm. A random intercept model was fitted to evaluate the variability of acquiring an image. For both the experts and the nonexperts, inter- and intraobserver variability of analyzing an AS-OCT image was determined with the coefficient of variation (CV). Reproducibility was qualified by using the intraclass correlation coefficient (ICC). RESULTS: There was no statistically significant difference in the variability of acquiring an image. The range of intraobserver variability in image analysis was from 9.4% to 12.5% in the experts and from 4.2% to 17.4% in the nonexperts. Interobserver variability was 10.7% in the experts and 10.2% in the nonexperts. The reproducibility was high, 0.875 and 0.942 in the experts and 0.906 in the nonexperts. CONCLUSIONS: The overall reproducibility of the ICA measurements with the AS-OCT is good in open angles. Inter- and intraobserver variability showed similar mean values of reproducibility between the experts and nonexperts. The wide range of intraobserver variation in the nonexperts suggests that this group should undergo extensive instruction before routinely analyzing AS-OCT images.

Baerveldt implant for secondary glaucoma due to iris melanoma.

BACKGROUND: Proton beam therapy (PBT) is effective in the treatment of iris melanoma. Reported complications after PBT are radiation-induced cataract and raised intraocular pressure (IOP). Filtering glaucoma surgery has generally been avoided because of fears of seeding. CASE REPORT: A 37-year-old man presented with a self-discovered, pigmented lesion on his right iris. Four years later, the pigmented lesion was diagnosed as an iris melanoma, because of documented growth. The patient was treated with PBT but developed secondary glaucoma one month later. The IOP could not be controlled despite maximal medical therapy and selective laser trabeculoplasty (SLT). Finally, Baerveldt implant surgery was performed, resulting in an IOP lowering to 10 mmHg and stabilization of the glaucomatous visual field loss. CONCLUSION: Our case demonstrates that Baerveldt implant surgery is a reasonable therapy for glaucoma following successful radiotherapy of iris melanoma.