Hypotony Failure Criteria in Glaucoma Surgical Studies and Their Influence on Surgery Success.

PURPOSE: Review hypotony failure criteria used in glaucoma surgical outcome studies and evaluate their impact on success rates. DESIGN: Systematic literature review and application of hypotony failure criteria to 2 retrospective cohorts. PARTICIPANTS: A total of 934 eyes and 1765 eyes undergoing trabeculectomy and deep sclerectomy (DS) with a median follow-up of 41.4 and 45.4 months, respectively. METHODS: Literature-based hypotony failure criteria were applied to patient cohorts. Intraocular pressure (IOP)-related success was defined as follows: (A) IOP ≤ 21 mmHg with ≥ 20% IOP reduction; (B) IOP ≤ 18 mmHg with ≥ 20% reduction; (C) IOP ≤ 15 mmHg with ≥ 25% reduction; and (D) IOP ≤ 12 mmHg with ≥ 30% reduction. Failure was defined as IOP exceeding these criteria in 2 consecutive visits > 3 months after surgery, loss of light perception, additional IOP-lowering surgery, or hypotony. Cox regression estimated failure risk for different hypotony criteria, using no hypotony as a reference. Analyses were conducted for each criterion and hypotony type (i.e., numerical [IOP threshold], clinical [clinical manifestations], and mixed [combination of numerical or clinical criteria]). MAIN OUTCOME MEASURES: Hazard ratio (HR) for failure risk. RESULTS: Of 2503 studies found, 278 were eligible, with 99 studies (35.6%) lacking hypotony failure criteria. Numerical hypotony was predominant (157 studies [56.5%]). Few studies used clinical hypotony (3 isolated [1.1%]; 19 combined with low IOP [6.8%]). Forty-nine different criteria were found, with IOP < 6 mmHg, IOP < 6 mmHg on ≥ 2 consecutive visits after 3 months, and IOP < 5 mmHg being the most common (41 [14.7%], 38 [13.7%], and 13 [4.7%] studies, respectively). In both cohorts, numerical hypotony posed the highest risk of failure (HR, 1.51-1.21 for criteria A to D; P < 0.001), followed by mixed hypotony (HR, 1.41-1.20 for criteria A to D; P < 0.001), and clinical hypotony (HR, 1.12-1.04; P < 0.001). Failure risk varied greatly with various hypotony definitions, with the HR ranging from 1.02 to 10.79 for trabeculectomy and 1.00 to 8.36 for DS. CONCLUSIONS: Hypotony failure criteria are highly heterogenous in the glaucoma literature, with few studies focusing on clinical manifestations. Numerical hypotony yields higher failure rates than clinical hypotony and can underestimate glaucoma surgery success rates. Standardizing failure criteria with an emphasis on clinically relevant hypotony manifestations is needed. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found after the references.

Analytical model for managing hypotony after implantation surgery of a glaucoma drainage device.

The main aim of glaucoma treatment is to reduce the intraocular pressure (IOP). One of the most common surgical treatments of glaucoma is the implantation of a glaucoma drainage device to drain the aqueous humor from the anterior chamber to a filtration bleb, where the aqueous humor is absorbed. In some cases, the excess of drainage causes ocular hypotony, which constitutes a sight-threatening complication. To prevent hypotony after this intervention, surgeons frequently introduce a suture into the device tube, which increases the hydraulic resistance of the tube and, therefore, the IOP. This study aims to provide an analytical model to correct hypotony following implantation surgery of a glaucoma drainage device, which may help glaucoma surgeons decide on hypotony treatment. The results indicate that the IOP after implanting a cylindrical tube around 300 µm in diameter is essentially the same as that built up in the filtering bleb and can hardly be controlled by introducing a straight suture unless the suture diameter is slightly lower than that of the tube. On the contrary, when the tube diameter is smaller than, for example, 100 µm, significant reductions of the IOP can be obtained by introducing a thin suture into the tube.

Micropulse transscleral cyclophotocoagulation using a standard protocol in patients with refractory glaucoma naive of cyclodestruction.

PURPOSE: To assess the efficacy and safety of a standardized micropulse transscleral diode laser cyclophotocoagulation procedure in refractory glaucoma. METHODS: Retrospective, interventional study in a series of 37 consecutive patients with refractory glaucoma, cyclodestructive procedure-naive, who underwent micropulse transscleral diode laser cyclophotocoagulation from December 2016 to October 2017. A successful laser treatment was defined as (1) intraocular pressure between 6 and 18 mm Hg; (2) 20% of baseline intraocular pressure reduction; (3) no additional glaucoma medications; (4) no decrease in vision due to complications or change in intraocular pressure; and (5) no need for additional glaucoma surgery except micropulse transscleral diode laser cyclophotocoagulation retreatment. RESULTS: Mean age was 60.2 years. Mean follow-up was 9.7 ± 3.9 months. The mean preoperative intraocular pressure (28.7 mm Hg) significantly decreased to 21.0 mm Hg at 1 month, 18.5 mm Hg at 3 months, 18.4 mm Hg at 6 months, and 18.5 mm Hg at 12 months (p < 0.01 at all time points). The mean number of preoperative glaucoma medications (4.7) decreased to 4.0 at 1 month (p = 0.14), 4.5 at 3 months (p < 0.05), 3.9 at 6 months (p < 0.05), and 3.6 at 12 months (p < 0.05). At 1 year, the success rate was 35% with a mean intraocular pressure lowering of 36%. One patient had hypotony and a loss of best-corrected visual acuity. Mild transient postoperative inflammation was observed in 8% of the cases. CONCLUSION: Using a standardized procedure, micropulse transscleral diode laser cyclophotocoagulation allows a mild intraocular pressure decrease with a low rate of complications and thus achieves a relatively good profit risk benefit, mostly for moderately hypertensive refractory glaucoma.

Loss of Pressure Control Resulting from Tube Bending during Glaucoma Drainage Tube Perforations.

PURPOSE: Tube perforations are a common method of achieving early intraocular pressure control with ligated glaucoma drainage devices (GDDs). Our purpose was to investigate how bending GDD tubes affects the performance of needle perforations. DESIGN: Experimental report. PARTICIPANTS: Twenty silicone GDD tubes attached to 27 G Rycroft cannulae tied with 7-0 Vicryl 10 mm from the cannulae tips. METHODS: Silicone GDD tubing was fitted over a 27 G Rycroft cannula and tied with a 7-0 suture 10 mm from the cannula tip. The tube was perforated 4 mm from the cannula tip with a 25 G needle (tube was kept straight). The tube was secured in a 50-mm water bath. Aqueous food dye was infused through the cannula from an adjustable height. The tube was observed under magnification while the height of the fluid column was adjusted to establish the pressure gradient at which the tube leaked dye (opening pressure) and ceased to leak (closing pressure), while the tube was held straight and bent 90 degrees. Measurements were repeated after a second perforation and a third perforation. Ten tubes were tested this way with 3 sequential slits. The entire experiment was repeated with another 10 tubes, but this time the tube was allowed to bend within the 3.5-mm open prongs of a needle holder during needle perforation. MAIN OUTCOME MEASURES: Opening and closing pressures. RESULTS: For each tube, the opening and closing pressures were similar and highly reproducible, but there was wide variation between tubes. In the tubes kept straight when perforated, the opening/closing pressure ranged from 5 to 25 cmH2O. The opening and closing pressures of slits made in the bent tube were significantly lower, frequently leaking at <1 cmH2O. Bending the tube after perforation could close a slit and prevent leakage at high perfusion pressure. The second and third successive perforations caused lower opening and closing pressures. CONCLUSIONS: Tube perforations behave like pressure-sensitive valves, opening whenever intraluminal pressure increases above a specific value. However, we found a large variation in the performance of fenestrations made with a 25-G hypodermic needle. Allowing the GDD tube to bend during needle perforation increases the risk of very low opening and closing pressures.

Management of Ocular Hypotony After Tube Surgery Using Bent Intraluminal Stents.

PURPOSE: We aimed to report a surgical technique for the management of ocular hypotony after tube surgery. METHODS: We occluded the tube with ab interno insertion of 2 bent 5-0 polypropylene threads into the tube lumen. Bent stents were used to prevent stent displacement. RESULTS: Our case series revealed that this procedure effectively resolved hypotony. Among the 3 cases, the stents were removed in 1 case and left in place in 2 cases. In all cases, the stent location remained stable without displacement. CONCLUSION: The insertion of bent intraluminal stents into the tube may be a useful method for the management of ocular hypotony after tube surgery.

Intraocular Pressure Reduction After Real-world Cataract Surgery.

PRéCIS:: A large cohort undergoing cataract extraction was retrospectively analyzed to ascertain the degree of real-world intraocular pressure (IOP) reduction in normal eyes and those with glaucoma, and a predictive formula was developed. PURPOSE: The purpose of this study was to define the real-world degree of IOP reduction after cataract extraction to guide its role as an isolated intervention for glaucoma. MATERIALS AND METHODS: A retrospective analysis was carried out of clinical data collected in 8 clinical sites in the United Kingdom from an electronic medical record system between January 2006 and May 2015. A total of 20,508 eyes without known pathology and 2251 eyes from patients with glaucoma undergoing phacoemulsification and intraocular lens insertion were included. Eyes with intraoperative complications, undergoing additional procedures, axial lengths outside 22 to 26.5 mm, preoperative IOP under 6 mm Hg or over 30 mm Hg, and copathology, except for amblyopia or glaucoma, were excluded. The main outcome measure was the change in preoperative IOP compared with the next recorded visit for up to 12 weeks. RESULTS: In eyes without pathology, the mean reduction in IOP was 1.40 mm Hg (±3.74) compared with 1.03 (±5.02), P-value <0.001, in eyes with a diagnosis of glaucoma. A multiple linear regression model identified preoperative IOP, a glaucoma diagnosis, preoperative corrected visual acuity, age, and axial length as determinants of IOP reduction. The model was validated against an independent cohort. CONCLUSIONS: We quantify mean IOP reduction achieved in a real-world setting from cataract surgery alone. In glaucomatous eyes where angle closure is not differentiated, phacoemulsification alone yields only a modest reduction of IOP.

Intraocular Pressure After Cataract Surgery Combined With Ab Interno Trabeculectomy Versus Trabecular Micro-bypass Stent: An Intrasubject Same-surgeon Comparison.

PRECIS: Combining Trabectome or iStent with phacoemulsification equally reduces intraocular pressure (IOP) and IOP-lowering medication burden during a 24-month follow-up, with a possible advantage to the Trabectome in the early postoperative period. PURPOSE: Intrasubject same-surgeon comparison between phacoemulsification combined with Trabectome (Phaco/Trabectome) versus one first-generation iStent (Phaco/iStent). SETTINGS: Private glaucoma and cataract practice. DESIGN: This is a retrospective interventional case series. METHODS: Data collected at 3 to 4 and 20 to 24 hours and up to 30 months following Phaco/Trabectome in 1 eye and Phaco/iStent in the contralateral eye in patients with bilateral visually-significant cataract and open-angle glaucoma. Evaluations included IOP, intraocular pressure-lowering medications (IOPmeds), visual acuity, and complications. RESULTS: Forty-five patients (90 eyes) were identified (age 76.5, 57 to 95 y). At 3 to 4 hours, IOP was above baseline in 12 and 13 eyes following Phaco/Trabectome and Phaco/iStent, respectively, but the degree of IOP elevation was smaller (P=0.048) following Phaco/Trabectome: 4.3 mm Hg, 2.0 to 6.6 mm Hg (95% confidence interval) versus Phaco/iStent: 8.7 mm Hg, 3.8 to 13.6 mm Hg. At 20 to 24 hours, compared with baseline, IOP was significantly lower after Phaco/Trabectome (P=0.004) but not after Phaco/iStent (P=0.14) although the rate of hyphema was higher following Phaco/Trabectome (12/45 vs. 2/45 eyes, P=0.007). IOP reduction from baseline at 3 to 4 hours was significantly larger (P=0.020) in the 21 eyes with hyphema: -3.9, -6.4 to -1.4 versus the 69 eyes without hyphema: -0.3, -2.0 to +1.4. At 1, 6, 12, and 24 months, IOP and number of IOPmeds were similar and significantly lower compared with baseline following either procedure. No complications were encountered in either group. CONCLUSIONS: Combined phacoemulsification with either Trabectome or first-generation iStent similarly lowers IOP and IOPmeds burden at 1, 6, 12, and 24 months following surgery. The Trabectome may have an advantage in lowering IOP faster and lessening the degree of IOP elevations in the early postoperative period.

MP3 Plus: A Modified Micropulse Transscleral Cyclophototherapy Technique for the Treatment of Refractory Glaucoma.

PRéCIS:: In advanced refractory glaucoma which has failed prior MP3 laser, MP3 Plus is effective in reducing intraocular pressure (IOP) without significant complications. It is also useful as a temporizing procedure before incisional surgery. PURPOSE: To evaluate the efficacy and safety of MP3 Plus, a novel technique using modified micropulse transscleral cyclophototherapy (MPTCP) in eyes with refractory glaucoma or failed MPTCP treatment. METHODS: This is a retrospective interventional case series. In total, 32 consecutive eyes from 29 patients with uncontrolled IOPs who had previous MPTCP or refractory glaucoma underwent MP3 Plus, a modified MPTCP where additional discrete pulses are applied. The main outcome measurement was IOP at 1, 3, 6, and 12 months postprocedure, with success defined as a 20% reduction in baseline IOP, an IOP of 25 mmHg or less, and no need for further reoperation. We collected and analyzed visual acuity, number of glaucoma medications, and complications. RESULTS: The patients had an average of 1.4±0.9 glaucoma procedures before treatment, where 87.5% underwent one or more previous MPTCP with suboptimal response. Of the eyes presenting for follow-up, 51.6% (n=31), 37.0% (n=27), 35.7% (n=28), and 25.9% (n=27) achieved the primary outcome at 1, 3, 6, and 12 months, respectively. Baseline IOP was 33.7±11.6 mmHg (n=32 eyes) and posttreatment IOP at 1, 3, 6, and 12 months were 21.0±9.0 mmHg (n=31; P<0.0001), 26.2±10.8 mmHg (n=25; P<0.0001), 23.2±9.4 mmHg (n=20; P<0.05), and 24.6±9.8 mmHg (n=16; P<0.001), respectively. There was a reduction in glaucoma medications from 3.4±0.8 preoperatively to 2.8±1.2 (n=16; P<0.05) at 12 months. There were no cases of prolonged inflammation or hypotony. CONCLUSIONS: MP3 Plus is effective and safe in lowering IOP in eyes with refractory glaucoma after previous failed MPTCP.

Conjunctival bleb compression as a treatment for hypotony post XEN45 implant in uveitic glaucoma.

PURPOSE: Over-filtration and subsequent hypotony are recognised complications of penetrating glaucoma procedures, especially when augmented with antimetabolites. Patients with uveitis are especially at risk of hypotony and this can reduce the final acuity achieved, compromise surgical outcomes and adversely affect the inflammatory status. The incidence of hypotony following XEN45 implant insertion is higher for uveitic patients and we present a method of surgically addressing this hypotony with transconjunctival compression sutures that are placed over the overdraining XEN45 implant. METHODS: We present a retrospective case series of consecutive uveitic glaucoma patients who had conjunctival compression sutures between 2015 and 2018 following XEN45 insertion, at the Manchester Royal Eye Hospital, UK. Two 9/0 nylon sutures were placed in a horizontal figure-of-eight conformation transconjunctivally across the overdraining bleb: one directly over the XEN45 implant and one at the posterior limit of the implant in order to restrict flow. RESULTS: Three patients underwent conjunctival compression sutures following XEN45 implant-related hypotony and all three had successful resolution of their hypotony and visual symptoms. No patients required long-term topical agents to control their intraocular pressure. CONCLUSION: Conjunctival compression sutures are an effective option for addressing persistent hypotony following XEN45 implant insertion in patients with uveitic glaucoma.

Cauterized suture for complete tube occlusion of Ahmed glaucoma valve in hypotony maculopathy.

PURPOSE: To present our experience treating hypotony maculopathy with a simple, minimally invasive, and removable ab interno tube Ahmed glaucoma valve occlusion. METHODS: Under topical anesthesia a 5-0 polypropylene suture (Prolene; Ethicon) was inserted into the Ahmed glaucoma valve tube. The length of the tube was measured, and an external suture cauterization was performed to allow an easier and safer fixation in the tube. The suture was introduced into the tube itself with the viscoelastic 27-gauge cannula. RESULTS: This technique was performed in three cases of hypotony maculopathy with a complex history of medical treatments: a 4-year-old boy with Donnai-Barrow syndrome and previous pars plana vitrectomy that developed hypotony maculopathy the day after Ahmed glaucoma valve insertion and two male patients (69 and 49 years old) that underwent hypotony maculopathy after cyclophotocoagulation as a last option to reduce intraocular pressure. One of the men had three filtering surgeries, two 5-fluorouracil needlings and Ahmed glaucoma valve insertion. The other male patient had keratoplasty and posterior Ahmed glaucoma valve insertion. In the three cases, both hypotony and maculopathy were reversed within a week and a month, respectively, after Ahmed glaucoma valve occlusion with no complications. When hypotony maculopathy develops it seems suitable to occlude completely the Ahmed glaucoma valve tube to swiftly reverse clinical and anatomic changes. CONCLUSION: Intraluminal Ahmed glaucoma valve occlusion with cauterized suture is a simple, quick, reversible, and effective technique that may offer a minimally invasive way to resolve hypotony maculopathy in complex cases and avoid severe loss of vision.

INCIDENCE AND RISK FACTORS FOR HYPOTONY AFTER 25-GAUGE PARS PLANA VITRECTOMY WITH NONEXPANSILE ENDOTAMPONADE.

PURPOSE: The purpose of this study was to assess the incidence and risk factors for early postoperative hypotony after 25-gauge pars plana vitrectomy with nonexpansile endotamponade. METHODS: A retrospective study of consecutive patients who underwent 25-G pars plana vitrectomy. Hypotony was defined as an intraocular pressure of 5 mmHg or less after surgery and ocular hypertension as an intraocular pressure greater than 21 mmHg. RESULTS: Overall, 307 eyes of 307 patients with a mean age of 61.7 ± 14.3 of which 56.7% were males were included. Hypotony was identified in 5.2% of cases (n = 16) at Day 1 and 0.7% (n = 2) at Week 1 with no hypotony-related complications. The hypotony group had a higher number of previous vitreoretinal surgeries (1.5 ± 1.1 vs. 0.4 ± 0.7, P < 0.001) and a higher prevalence of preoperative ocular hypertension (22.2% vs. 4.8%, P = 0.02), pseudophakia (77.8% vs. 48.4%, P = 0.01), silicone oil removal (61.1% vs. 8.3%, P < 0.001), and external diathermy performed (55.6% vs. 20.1%, P = 0.001). In stepwise multivariate analysis, significant parameters were silicone oil removal (R = 16.34%, odds ratio 13.45, P < 0.001), pseudophakia (R = 5.69%, odds ratio 3.65, P = 0.03), and younger age (R = 2.68%, odds ratio 0.96, P = 0.04). CONCLUSION: Silicone oil removal is a significant risk factor for early postoperative hypotony after 25-G pars plana vitrectomy.

Risk Factors Associated with Failure of Direct Cyclopexy in the Treatment of Small to Moderate Tramatic Cyclodialysis Clefts.

BACKGROUND: To evaluate the risk factors associated with failure to correct hypotony using direct cyclopexy in patients with traumatic cyclodialysis cleft. METHODS: In a series of 116 patients with traumatic cyclodialysis who underwent direct cyclopexy at Zhongshan Ophthalmic Center from January 2008 to August 2018, the clinical correlation between the risk factors and failure of the operation were retrospectively studied, after adjusting for other potential confounders. RESULTS: The curative ratio after one procedure was 82.76%, whereas 20 (17.24%) eyes experienced treatment failure after the first surgery. The degree of anterior chamber angle closure was significantly wider in patients with a failed first surgery than in patients for whom one procedure was a success (p = .046). The risk of failure to achieve closure increased as the angle-closure exceeded 5 clock hour (odds ratio, 10.39; 95% confidence interval, 1.75-61.72; p = .010). An analysis of the recurrent position indicated that an angle closure exceeding 5 clock hour may impede accurate cleft location and is thus associated with an increased risk of failure to correct hypotony. CONCLUSION: Exceeding the threshold of 5 clock hour in anterior chamber angle closure may impede accurate cleft location and, thus, present a higher risk of failure to correct hypotony using direct cyclopexy. These patients may need injection of a viscoelastic agent into the anterior chamber by paracentesis to deepen the anterior chamber and to delineate the clefts using gonioscopy pre- or intraoperatively.

Double-Session Micropulse Transscleral Laser (CYCLO G6) as a Primary Surgical Procedure for Glaucoma.

PRéCIS:: Double-session micropulse transscleral laser was an effective and safe treatment strategy for eyes that have not undergone glaucoma surgery previously. PURPOSE: To evaluate the safety and effectiveness of double-session micropulse transscleral laser (MP3) as a primary treatment modality for glaucoma. MATERIALS AND METHODS: Patients who underwent MP3 therapy with double sessions in each hemifield, with a follow-up period of at least 6 months, were retrospectively considered. Patients were categorized into 2 groups: GI (no previous glaucoma surgery) and GII (with previous glaucoma surgery). Success was defined by either achieving a final intraocular pressure (IOP) between 6 and 18 mm Hg and an IOP reduction of >20%, or a minimum 50% reduction in the number of glaucoma medications, at the last visit, without any serious complications. RESULTS: Eighty-four eyes were included in the GI group and 101 in the GII group, with the latter demonstrating relatively higher preoperative IOP (31.1±5.4 vs. 26.2±6.9 mm Hg, P<0.001). Final IOP (14.9±5.2 vs. 13.6±4.1 mm Hg, P=0.06), average MP3 treatment time (358.0±50.7 vs. 362.7±67.8 s, P=0.5), and follow-up duration (10.8±5.1 vs. 12.3±5.4 mo, P=0.06) were similar between the groups. The percentage reduction with regard to glaucoma medication was higher in GI than in GII (49.1±28.8 vs. 38.8±30.1%, P=0.02). GI underwent fewer MP3 procedures than GII (1.2±0.5 vs. 1.5±0.8, P=0.002). No hypotony or phthisis bulbi was observed in GI (1 and 2 in GII, respectively). Procedural success was noted in 92.9% of the cases in GI and 87.1% in GII. CONCLUSIONS: Double-session MP3 therapy could be considered as a safe and effective procedure to treat glaucoma in eyes that have not undergone any previous glaucoma surgery. Primary eyes achieved a success-rate similar to those with refractory glaucoma with fewer MP3 procedures and fewer glaucoma medications.

EyeWatch Rescue of Refractory Hypotony After Baerveldt Drainage Device Implantation: Description of a New Technique.

The most effective way to control glaucoma is by lowering intraocular pressure (IOP) in order to prevent the progression of the disease. Glaucoma drainage devices (GDDs) are surgical option reserved for refractory cases and have been designed to address known complications of conventional filtering surgery. They are, however, associated with a higher rate of complications related to early hypotony and late corneal decompensation. In the case of the commonly used Baerveldt Glaucoma Implant (BGI), techniques exist in an attempt to prevent early postoperative hypotony but can be highly variable and surgeon dependent. Moreover, the additional steps required can result in unstable IOP in the immediate postoperative period. In 2014, Villamarin and colleagues described for the first time an adjustable GDD, called the eyeWatch implant, designed to better control IOP fluctuations and avoid hypotony during the early postoperative period via magnetic control of the device tube lumen. This innovation provides the possibility to adjust the amount of aqueous humor outflow after device implantation in a noninvasive manner. We report the case of an 83-year-old patient with advanced pseudoexfoliative glaucoma, referred to our tertiary center because of disease progression despite topical therapy and having undergone deep sclerectomy. First, a BGI was implanted but was unfortunately complicated by a 3-month chronic refractory hypotony from day 8, and choroidal detachment despite medical management, choroidal drainage, and viscoelastic injections. After 3 months, the decision was made to rescue the situation with an eyeWatch adjunction to the BGI. Postoperatively, the IOP was successfully controlled through fine adjustments of the eyeWatch opening position, until the last visit 8 months after the rescue, with complete resolution of the choroidal detachment and without any medications. This demonstrates that the eyeWatch may offer an answer not only to the immediate postoperative hypotonic phase of the GDD surgery but also to the later cystic bleb hypertonic phase.

Características clínicas y OCT-SA de pacientes con síndrome de tracción iridiana asociado a desprendimiento de retina regmatógeno. Reporte de tres casos / Clinical features and AS-OCT of patients with iris retraction syndrome following rhegmatogenous retinal detachment. Report of three cases

Introducción: se presenta una serie de 3 casos de síndrome de retracción iridiana (SRI) asociados a desprendimiento de retina regmatógeno (DRR) y desprendimiento coroideo. Objetivo: dar a conocer las características clínicas y tomográficas de tres pacientes con SRI asociado a desprendimiento de retina regmatógeno. Diseño del estudio: serie de casos. Resumen del caso: tres pacientes que presentaron DRR asociado a SRI. El tiempo de evolución promedio fue de 21 días (15-30 días), 2 de los 3 pacientes tuvieron resolución del SRI posterior al inicio de midriáticos y antes de ser intervenidos por el desprendimiento de retina, y 2 tuvieron presencia de proliferación vitreoretiniana (PVR) a pesar del corto tiempo de evolución. Adicionalmente estos 2 pacientes cursaron con desprendimientos coroideos. Todos los pacientes tuvieron un buen resultado estructural, AV menor o igual a 20/400, no redesprendimientos ni recurrencias de SRI durante el seguimiento. Conclusión: ante un paciente con SRI en el cual no sea posible valorar polo posterior, se debe tener en cuenta el diagnóstico de desprendimiento de retina regmatógeno. El SRI puede considerarse como un factor de mal pronóstico en pacientes con desprendimiento de retina regmatógeno.

Background: to report a 3 cases series of patients with iris retraction syndrome (IRS). Objective: introduce the clinical and tomographic features of tree patients with IRS following RRD. Study design: case series. Case summary: three patients presented IRS following RRD. They presented with an average evolution of 21 days (15 to 30 days), 2 patients had resolution of the IRS after mydriatics and before receiving surgical treatment for retinal detacthment, and 2 had vitreoretinal proliferation despite the short time. Besides, these 2 patients had choroidal detachments discovered in the operating room. All patients had good structural outcomes, visual acuity less or equal than 20/400, no re-detachment of the retina and no recurrence of IRS during follow up. Conclusion: the presence of a retinal detachment should be suspected in a patient with IRS in which it´s not possible to assess the posterior pole, and it should be considered a bad prognostic factor if present.

Downsizing a Baerveldt Glaucoma Implant For the Management of Persistent Postoperative Hypotony: A Case Series.

PURPOSE: The purpose of this study was to describe a surgical technique for treating persistent hypotony after Baerveldt glaucoma implant (BGI) surgery. MATERIALS AND METHODS: The medical records of 10 patients with persistent postoperative hypotony who underwent truncation of one or both wings of a previously placed BGI, combined with external ligation of the tube using a polypropylene suture, were retrospectively reviewed. RESULTS: All 10 eyes that underwent BGI truncation and placement of a single, external, nonabsorbable (polypropylene) tube ligature exhibited resolution of hypotony within 24 hours and resolution of choroidal effusions within the first 2 postoperative weeks. The median time interval between primary BGI surgery and truncation was 5 months (range, 1.5 mo to 8 y). Median postrevision follow-up time was 12 months (range, 5 mo to 16.2 y). The mean preoperative intraocular pressure (IOP) was 2.1±1.0 mm Hg, and the mean IOP rose to 29.2±13.9 mm Hg on postoperative day 1. Mean IOP at week 1, month 1, and month 3 was 20.5±10.4, 19.7±11.8, and 18.0±8.2 mm Hg, respectively, using an average of 1.4±1.4 glaucoma medications at postoperative month 3. Ligature release after BGI revision was performed in 9 (90%) of the 10 patients. The median time to ligature release was 1.5 months (range, 3 wk to 4 y). There was no recurrence of hypotony in any of these patients. At most recent follow-up, the mean IOP was 12.9±6.0 mm Hg on an average of 1.5±1.3 glaucoma medications. Five patients demonstrated improvement in visual acuity from their prerevision best-corrected visual acuity. CONCLUSIONS: Truncation of one or both wings of a BGI and complete closure of the tube with nonabsorbable, but releasable, suture ligature is an effective and safe method for reversing persistent postoperative hypotony while maintaining IOP control.

Dexamethasone Intravitreal Implant Injection in Eyes with Comorbid Hypotony.

PURPOSE: To evaluate outcomes in patients with hypotony treated with intravitreal dexamethasone implant (Ozurdex). DESIGN: Retrospective cohort study. PARTICIPANTS: Thirteen patients (15 eyes) that received a total of 99 dexamethasone implant injections on occasions at which the intraocular pressure was low, meeting the definition of statistical hypotony. METHODS: The medical records of 13 patients (15 consecutive eyes) receiving 1 or more intravitreal dexamethasone implants between December 2014 and April 2017 were reviewed retrospectively. Hypotony was defined as intraocular pressure less than 6.5 mmHg. The indications for intravitreal dexamethasone implant injection were intermediate or posterior uveitis (86.7%), diabetic macular edema (13.3%), and/or cystoid macular edema (6.7%). MAIN OUTCOME MEASURES: The primary outcome measures were safety outcomes and best visual acuity within 6 months of the final intravitreal dexamethasone implant injection in a hypotonous eye. RESULTS: In 15 eyes (13 patients), 99 injections were administered to eyes under circumstances of hypotony. Uveitic cystoid macular edema or diabetic macular edema was reduced after treatment in all cases. No complications were noted during the injection procedure. Three complications were noted in 2 patients after injection. Pseudophakodonesis and mild vitreous hemorrhage immediately after injection were noted in 1 patient, and a case of delayed-onset vitreous hemorrhage with pigment release was noted in another. All 3 complications resolved without intervention. The primary end point of this study-mean visual acuity-was stable over the follow-up period. In patients with hypotony whose intraocular pressure normalized during the follow-up period, this was attributable to management of glaucoma surgery-related complications rather than an effect of the intravitreal dexamethasone implant. CONCLUSIONS: Intravitreal dexamethasone implant injection is a reasonable treatment option for patients with comorbid hypotony in whom clinical findings warrant treatment with a sustained-delivery intravitreal steroid implant. Further studies, including imaging of zonules before and after intravitreal dexamethasone implant injection in a hypotonous eye, could help define risks to intraocular lens stability with this procedure.

Ab interno tube ligation for refractory hypotony following non-valved glaucoma drainage device implantation.

PURPOSE: To report the 2-year outcomes of a novel surgical technique allowing reduction of the intraluminal diameter of the tube without total tube occlusion in order to allow enough increase in outflow resistance to permit resolution of hypotony whilst also achieving adequate IOP control. METHODS: This was a single-surgeon retrospective case note review of all non-valved GDD cases over an 8-year period (2008-2015) that underwent ab interno ligation of the drainage tube in order to manage post-operative hypotony (Baerveldt or Molteno). Twelve eyes of 12 patients (4.4%) developing refractory hypotony that did not respond to multiple intracameral ophthalmic viscoelastic device (OVD) injections were included in this retrospective case series and were treated with our ab interno tube ligation technique. The post-ligation management algorithm consisted of re-instating topical anti-glaucoma agents, laser suture lysis (LSL), or further ab interno ligation. RESULTS: Mean IOP increased from 2.8 mmHg at baseline to 7.8 mmHg, 7.1 mmHg, 9.0 mmHg, 13.6 mmHg, 10.9 mmHg, 13.9 mmHg and 13.6 mmHg at day 1, week 1, month 1, month 3, month 6, year 1 and year 2 respectively, with or without additional topical anti-glaucoma medications. Although hypotony resolution following our technique was achieved in all eyes at 2 years, 8.3% of cases required reinstatement of topical medications to maintain IOP control within the target range. CONCLUSIONS: We propose ab interno partial tube tying as an effective surgical option to achieve an immediate, predictable and sustained IOP elevation either as a primary procedure or when traditional methods have failed to resolve hypotony in eyes with non-valved GDDs.

Efficacy and Safety of Trabeculectomy Versus Nonpenetrating Surgeries in Open-angle Glaucoma: A Meta-analysis.

PURPOSE: The purpose of this study was to conduct a meta-analysis on the efficacy and safety of trabeculectomy (TE) and nonpenetrating glaucoma surgery (NPGS) techniques in patients with primary open-angle glaucoma, pseudoexfoliation glaucoma, pigmentary glaucoma, and normal-tension glaucoma. METHODS: All studies were identified by searching electronic sources (PubMed, Medline, Scopus, and Embase) until February 5, 2018. Primary outcome was mean intraocular pressure (IOP) reduction at 6, 12, and 24 months. Complications, number of antiglaucomatous medications, and visual outcomes were also evaluated. RESULTS: Twenty-one studies were included. Ten studies compared TE with deep sclerectomy (DS), 5 with viscocanalostomy (VC), 1 study with both DS and VC, and 5 with canaloplasty (CP). TE was superior to DS, VC, and CP in reducing IOP at 6 and 12 months, and to DS at 24 months. When comparing TE to VC and to CP at 24 months, there was no significant difference in IOP reduction. Hypotony, choroidals, anterior chamber shallowing or flattening, and cataract formation or progression were more associated with TE than with NPGSs. TE was more effective in reducing antiglaucomatous medications than VC and CP. CONCLUSIONS: TE is more effective in reducing IOP. TE presents a higher risk of complications as compared with NPGS, except for hyphema.