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.

Magnetic resonance imaging reveals possible cause of diplopia after Baerveldt glaucoma implantation.

PURPOSE: To assess if ocular motility impairment, and the ensuing diplopia, after Baerveldt Glaucoma device (BGI) implantation, is related to the presence of a large fluid reservoir (bleb), using Magnetic Resonance Imaging (MRI). METHODS: In a masked observational study (CCMO-registry number: NL65633.058.18), the eyes of 30 glaucoma patients with (n = 12) or without diplopia (n = 18) who had previously undergone BGI implantation were scanned with a 7 Tesla MRI-scanner. The substructures of the BGI-complex, including both blebs and plate, were segmented in 3D. Primary outcomes were a comparison of volume and height of the BGI-complex between patients with and without diplopia. Comparisons were performed by using an unpaired t-test, Fisher's Exact or Mann-Whitney test. Correlations were determined by using Spearman correlation. RESULTS: The median volume and height of the BGI-complex was significantly higher in patients with compared to patients without diplopia (p = 0.007 and p = 0.025, respectively). Six patients had an excessively large total bleb volume (median of 1736.5mm3, interquartile range 1486.3-1933.9mm3), four of whom experienced diplopia (33% of the diplopia patients). Fibrotic strands through the BGI plate, intended to limit the height of the bleb, could be visualized but were not related to diplopia (75% versus 88%; p = 0.28). CONCLUSIONS: With MRI, we show that in a significant number of diplopia cases a large bleb is present in the orbit. Given the large volume of these blebs, they are a likely explanation of the development of diplopia in at least some of the patients with diplopia after BGI implantation. Additionally, the MR-images confirm the presence of fibrotic strands. As these strands are also visible in patients with a large bleb, they are apparently not sufficient to restrict the bleb height.

The long-term postoperative effect of the Baerveldt glaucoma drainage device and of a trabeculectomy on the corneal endothelium.

PURPOSE: To determine whether the postoperative corneal endothelial cell density (ECD) differs between glaucoma patients who underwent Baerveldt implant (BGI) surgery and patients who underwent a trabeculectomy (TE) over 5 years ago. METHODS: Cross-sectional, observational study including 34 patients who underwent TE and 36 patients who underwent BGI surgery 5-11 years ago, as part of a randomized clinical trial. None of the patients had a history of intraocular surgery prior to their glaucoma surgery. Central and peripheral ECD was measured by using a non-contact specular microscope. RESULTS: Central and peripheral ECD in the TE group was 2285 ± 371 cells/mm2 (mean ± SD) and 2463 ± 476 cells/mm2 , respectively. Central and peripheral ECD in the BGI group was 1813 ± 745 cells/mm2 and 1876 ± 764 cells/mm2 , respectively. The central and peripheral ECD was statistically significantly higher in the TE group than in the BGI group (p = 0.001 for both). Additional intraocular surgical interventions were more prevalent in the BGI group (23) than in the TE group (5) (p < 0.001). In a subanalysis, without eyes that had undergone additional surgical interventions, only the peripheral ECD was statistically significantly higher in the TE group compared with the BGI group (p = 0.011). For the BGI group, a longer postoperative period resulted in a lower central ECD (r = -0.614, p = 0.004). CONCLUSION: Long-term ECD in eyes that underwent a BGI was considerably lower compared with eyes that underwent a TE, mainly in the peripheral cornea. This suggests that BGI causes a larger decrease of ECD than TE. Additionally, the decrease after BGI appears to continue for a longer period than after TE.

Ocular motility changes and diplopia in sutured versus unsutured implantation of the Baerveldt glaucoma device.

PURPOSE: To investigate the effect of two surgical techniques in primary Baerveldt glaucoma implant (BGI) surgery, that is the sutured technique and the unsutured (free) plate technique, on the ocular motility and prevalence of diplopia. We hypothesize that the free plate technique results in a lower diplopia prevalence. METHODS: We performed a prospective study of patients who underwent BGI surgery with the free plate technique and compared them with patients from a previous study who had undergone BGI surgery with the sutured technique. Their ductions, ocular alignment and fusion range and the prevalence of diplopia were measured before surgery and at 3 months, 6 months and 1 year postoperatively. RESULTS: We analysed 57 free plate and 51 sutured plate patients. One year postoperatively, we found no statistically significant difference in the prevalence of diplopia between the two techniques. All duction changes between baseline and 1-year follow-up were restrictions and occurred statistically significantly more frequently in the free plate than in the sutured plate group (p = 0.03; 60% versus 34%). About the ocular alignment, in the horizontal direction, a change in exodirection was more common in both groups, while in the vertical direction, a hyperdeviation of the operated eye was more common. The vertical ocular alignment change was smaller in the free plate group than in the sutured plate group (p = 0.04 at near and p = 0.02 at distance). CONCLUSIONS: One year postoperatively, the prevalence of diplopia was not significantly different between patients with the sutured plate and patients with the free plate technique. Both surgical techniques induce diplopia and changes in ocular motility and/or in ocular alignment.

Primary baerveldt versus trabeculectomy study after 5 years of follow-up.

PURPOSE: Although the Baerveldt glaucoma implant (BGI) initially was reserved for refractory glaucoma, its role in the surgical management of glaucoma has shifted towards a primary treatment choice. We performed a randomized prospective study to compare BGI surgery and trabeculectomy (TE) in patients without previous ocular surgery. METHODS: We included 119 glaucoma patients without previous ocular surgery. One eye of each subject was randomized to either a BGI or TE. Follow-up visits were at 1 day, 2 weeks, 6 weeks, 3 months, 6 months and 1, 2, 3, 4 and 5 years postoperatively. Primary outcomes were intraocular pressure (IOP) and failure rate. Secondary outcomes were medication, anterior chamber laser flare value and complications. RESULTS: After 5 years, an IOP of 12.7 ± 3.9 mmHg (mean ± SD) was achieved in the TE group and 12.9 ± 3.9 mmHg in the BGI group. We found no statistically significant difference in failure rate between the groups (p = 0.72). More BGI patients needed additional medication to control their IOP (85%; 1.9 ± 1.2 types of glaucoma medication) compared to the TE patients (57%; 0.5 ± 0.9 types of glaucoma medication). Diplopia was significantly more present in the BGI group than in the TE group (27% versus 4%; p < 0.001). The self-limiting complication rate was similar in both groups. CONCLUSIONS: Our study demonstrates that, in the long term, the final IOP and failure rate are similar after TE and BGI surgery. However, the need for additional medication after BGI surgery is higher than after TE. Also, the increased risk of developing diplopia after BGI surgery must be taken into consideration.

Motility Changes and Diplopia After Baerveldt Glaucoma Drainage Device Implantation or After Trabeculectomy.

PURPOSE: The purpose of this study was to quantify any diplopia and motility changes after the implantation of a Baerveldt glaucoma implant (BGI) or after trabeculectomy (TE). METHODS: We analyzed 51 patients with a BGI and 52 patients with a TE from a prospective cohort study. To quantify any diplopia, we asked patients about the presence of diplopia at 1 year after surgery. To quantify any ocular motility changes, we measured ductions in eight gaze directions, the patients' ocular alignment and their fusion range before and 1 year after surgery. RESULTS: In the BGI group, 14 patients (28%) experienced diplopia compared with one patient (2%) in the TE group (P < 0.001). Duction changes were more commonly observed in the BGI group (35%) than in the TE group (19%). In the BGI group, ductions were mostly restricted in elevation (13%; P < 0.001), in abduction (13%), in elevation in 25° adduction (13%; P = 0.044), and in elevation in 25° abduction (25%; P < 0.001). In 32% of the patients, their near horizontal ocular alignment shifted, notably in exodirection (P = 0.04). The fusion range decreased significantly in the horizontal direction (-12.6° ± 10.3°, mean ± standard deviation; P = 0.01). CONCLUSIONS: BGI surgery was significantly associated with postoperative diplopia and impaired eye motility (reduced ductions), mostly present in abduction, elevation, elevation in 25° adduction, and elevation in 25° abduction. Even without impaired ductions, diplopia could come about. TRANSLATIONAL RELEVANCE: By studying diplopia across glaucoma patients prospectively with diplopia questionnaires and extensive orthoptic measurements, we gain better insight into its occurrence.

Primary Baerveldt versus trabeculectomy study after one-year follow-up.

PURPOSE: To compare a Baerveldt implant and trabeculectomy with respect to intraocular pressure (IOP) and failure rate at 1 year of follow-up. Secondary outcomes are pharmacological therapy and complications at 1 year of follow-up. METHODS: This was a randomized, comparative study. A total of 119 glaucoma patients without previous ocular surgery were included at the Rotterdam Eye Hospital, the Netherlands. One eye of each subject was randomized to either a Baerveldt glaucoma drainage device (BGI) or trabeculectomy (TE). Follow-up visits were conducted at 1 day, 2 weeks, 6 weeks, 3 months, 6 months and 1 year after surgery. RESULTS: After one year, the final IOP was equivalent for both treatment groups: 14 ± 4 mmHg (mean ± SD) for the Baerveldt group versus 13 ± 4 mmHg for the trabeculectomy group. Statistically, we found no significant difference in failure rate between the two groups. However, the Baerveldt group needed significantly more medication to decrease IOP. Overall, self-limiting complication rate was similar in both groups. Diplopia, a serious complication, was significantly more present in the BGI group. CONCLUSION: One year after surgery, TE shows better results than the BGI. The final IOP, IOP reduction and failure rate are similar, but the need for additional IOP lowering medication in the BGI group is higher as well as the complication rate. The increased risk of developing diplopia after placement of a BGI must be taken into consideration.

Surgical outcomes of the Baerveldt Glaucoma Implant: differences between surgical techniques in the Rotterdam Eye Hospital.

PURPOSE: During the last decades, the Baerveldt Glaucoma Implant (BGI) has proven effective in the surgical treatment of glaucoma. Various surgical procedures have been used for its implantation and these may yield different clinical outcomes and different intraoperative and postoperative complications. We evaluated the success rate of BGI and compared complications between 2 different surgical implantation techniques. METHODS: Retrospective analyses of medical records of consecutive adult patients who underwent a BGI implantation at the Rotterdam Eye Hospital between September 2007 and August 2008. Patients were divided by the surgical implantation technique. Success was defined as an intraocular pressure ≥6 mm Hg and ≤21 mm Hg as well as a reduction of ≥20% from preoperative values. Other outcome measures were intraoperative and postoperative complications and surgical revisions of the BGI. RESULTS: A total of 173 BGI procedures were performed during the study period. Only first-ever BGI implantations in adult patients were analyzed, yielding 141 implants for the analyses. The length of follow-up averaged 11.5 months (range, 0.3 to 24.7 mo) and the mean (SD) preoperative intraocular pressure was 25.6 (8.6). Overall success rates were 75% and 83%, respectively, for the 2 different groups (P=0.40 for differences between groups). Nine patients (6%) needed a reoperation, whereas complications were documented in another 9 patients without significant differences between groups. CONCLUSIONS: Overall complication rates of the BGI were low and they combined with high success rates. Outcomes did not differ between the various surgical techniques. The choice of a certain technique might therefore be based on differences in costs and length of surgery between these techniques.

Miotics after modern cataract surgery are history.

PURPOSE: The aim of this study was to investigate the usefulness of a long-acting miotic (physostigmine) after phacoemulsification in preventing peripheral anterior synechiae (PAS), lens dislocation, and high postoperative intraocular pressure. METHODS: This was a prospective randomized controlled trial of 400 patients (400 eyes) scheduled for phacoemulsification. Patients were randomly assigned either to receive a single application of physostigmine ointment directly after phacoemulsification or not. The main outcome measures were the change of intraocular pressure (IOP) before and after surgery, number of extra outpatient clinic visits within 4 weeks postoperatively, verbal rating pain scale (VRS), status of the angle by gonioscopy, and best corrected visual acuity (BCVA). RESULTS: There was no significant difference in IOP and BCVA between both groups. There were more patients who reported a VRS score of more than 3 in the physostigmine group (P=0.021). PAS or (anterior) lens dislocation was not observed. CONCLUSION: In eyes without co-morbidity, the routine use of physostigmine ointment has lost its rationale.

Single perioperative subconjunctival steroid depot versus postoperative steroid eyedrops to prevent intraocular inflammation and macular edema after cataract surgery.

PURPOSE: To compare the efficacy of dexamethasone 0.1% eyedrops after phacoemulsification versus a single perioperative subconjunctival injection of betamethasone acetate 5.7 mg/mL to prevent anterior segment inflammation and macular edema. SETTING: Rotterdam Eye Hospital, Rotterdam, The Netherlands. DESIGN: Randomized clinical trial. METHODS: Patients scheduled for cataract surgery were randomly assigned to receive a perioperative subconjunctival injection of betamethasone acetate 5.7 mg/mL (Group 1) or postoperative administration of dexamethasone 0.1% eyedrops (Group 2). Primary outcomes were foveal thickness and macular edema on optical coherence tomography (OCT) and anterior chamber flare by a laser flare meter preoperatively and 4 weeks postoperatively. Secondary outcomes were intraocular pressure, need for additional outpatient clinic visits, phacoemulsification energy, verbal-rating pain scale, and corrected distance visual acuity. RESULTS: The study enrolled 400 patients (400 eyes). Four weeks postoperatively, the mean flare values were significantly higher in Group 1 than in Group 2 (P=.003). The incidence of macular edema on OCT and clinically significant macular edema were not significantly different between groups (P=.685 and P=.386, respectively). No significant difference was observed in any other outcome measure. CONCLUSION: A single subconjunctival betamethasone acetate injection appears to be a useful alternative to prolonged postoperative administration of dexamethasone eyedrops in controlling intraocular inflammation and development of macular edema after phacoemulsification.

Trypan blue capsular staining to "find" the leading edge of a "lost" capsulorhexis.

PURPOSE: To describe an effective surgical technique to visualize an obscured leading edge of a capsulorhexis. DESIGN: Prospective, interventional case series. METHODS: In six eyes of six patients in which the capsulorhexis was started but could no longer be seen during surgery, the anterior chamber was irrigated to remove all viscoelastic, and 0.3-ml trypan blue 0.06% was applied onto the anterior lens capsule to stain and visualize the leading edge of the capsulorhexis. RESULTS: In all patients, the leading edge of the capsulorhexis was quickly visualized by using the dye. No adverse reactions were observed up to 1 year after surgery. CONCLUSION: Trypan blue staining of the anterior lens capsule is an effective and apparently safe technique to "find" a "lost" capsulorhexis during surgery.