Postoperative Hypotony Research Articles

Same-site trabeculectomy with mitomycin and Ologen™ following failed non-penetrating deep sclerectomy.

To assess the effectiveness and safety of same-site trabeculectomy (TRAB) with mitomycin C (MMC) and Ologen™ (Aeon Astron Europe BV. Leiden, The Netherlands) in patients with a failed non-penetrating deep sclerectomy (NPDS). A retrospective study of 24 consecutive eyes (22 patients) undergoing reintervention by same-site TRAB with at least one-year follow-up after failed NPDS. Mean visual acuity (VA), intraocular pressure (IOP) and use of glaucoma medications were compared before and one year after surgery. Early and late postoperative complications were registered. Kaplan-Meier survival analysis was performed according to four levels of success criteria. Overall the mean IOP reduced significantly (24.9 ± 7.1 vs. 14.4 ± 4.5 mmHg; p < 0.001), and the number of glaucoma medications (2.80 ± 1.01 vs. 0.55 ± 0.94; p < 0.001) significantly decreased, one year after surgery. The mean VA remained stable one year after surgery (p = 0.516). Hypotony, defined as IOP ≤ 5 mmHg, in the early postoperative period was observed in 62.5% of eyes, but only in 2 patients (8.33%) in the long term. The mean survival time ranged from 10 months (CI 95% 5-15) to 29 months (CI 95%: 26-32) according to the most stringent and lenient success criteria respectively. Same-site TRAB augmented with MMC and Ologen™ may provide an effective, safe and lasting alternative following failed NPDS, especially when sparing of the conjunctiva is highly desirable. Postoperative hypotony is the most common postoperative complication.

Socioeconomic disadvantage and impact on visual outcomes in patients with viral retinitis and retinal detachment

While socioeconomic disparities impact clinical care and patient outcomes, their impact on the anatomic and visual outcomes of retinal detachment in patients with viral retinitis is unstudied. This case series included 18 eyes in 18 patients from a single academic institution between January 1, 2008 and December 31, 2018. Patient characteristics including age, sex, race, ethnicity, insurance, immunosuppression, viral retinitis, retinal detachment, retinal detachment repair, visual and anatomic outcomes, missed appointments, and Area Deprivation Index [ADI] were collected. The low-ADI group, indicating less socioeconomic disadvantage, was comprised of twelve patients with national ADIs less than 38, and the high-ADI group of six patients with national ADIs greater than 38. High-ADI patients tended to be younger (average age 38.0 versus 51.3; P = 0.06), of female sex (P = 0.03), and had more missed appointments (median 11.0 vs 0; P = 0.002). A similar number of patients in both the high-ADI and low-ADI groups underwent pars plana vitrectomy alone or pars plana vitrectomy with scleral buckle. Visual acuity was similar in the high-ADI group than in the low-ADI group at baseline, but worse at the final follow-up visit (P = 0.004). Post-operative and final visit ocular hypotony were more common in the high-ADI group (P = 0.02). In our series, socioeconomic disadvantage negatively affects the visual outcomes in patients with viral retinitis associated-retinal detachments. These factors should be considered by ophthalmologists when treating these patients.

First clinical results with the PAUL® Glaucoma Implant at the University Eye Hospital Bonn

Glaucoma drainage devices (GDD) are an invasive procedure for the treatment of glaucoma. The PAUL® Glaucoma Implant (PGI) has been developed as anew, innovative therapeutic procedure. The PGI differs from previous GDD with regard to the smaller size of the drainage tube. This study analyses 6‑months results of the PGI in terms of effectiveness and safety. Adatabase of patients treated with the PGI at the University Eye Hospital Bonn was created and continuously updated based on follow-up controls. Statistical analysis was performed using SPSS Statistics for Windows (IBM Corp., Armonk, NY, USA). Atotal of 53eyes of the first 51consecutive patients treated with the PGI were included in this study. Mean intraocular pressure was 26.62 mmHg (7-48 mmHg) preoperatively and reduced to 12.20 mmHg (3-22 mmHg) after 6months. Local pressure-lowering therapy was reduced from 3.37 agents preoperatively to 0.30 agents after 6months. The complication rate was low; only 3patients (5.8%) had persistent hypotony. In 16patients, the intraluminal prolene stent was removed in the postoperative course after an average of 2.9months. Thereafter, these patients experienced areduction of intraocular pressure from 22.21 to 11.07 mmHg. The PAUL® Glaucoma Implant is asafe treatment modality that can successfully reduce intraocular pressure to alow level and reduce pressure-lowering local therapy. It has alow complication rate, particularly regarding postoperative hypotony.

Novel Surgical Techniques to Control Flow With PreserFlo MicroShunt for Late Hypotony After Baerveldt Drainage Device Implantation.

We report a new surgical technique for controlling flow with a PreserFlo MicroShunt, in patients with late postoperative hypotony, following a Baerveldt glaucoma drainage device implantation. We present 2 cases with late postoperative hypotony after Baerveldt-shunt implantations. In both cases, the outflow resistance of the Baerveldt tube was modulated by the insertion of a PreserFlo MicroShunt into the lumen of the Baerveldt tube. In the first case, the Microshunt was inserted through the distal opening of the tube in the anterior chamber. In the second case, an end plate, sided approach was chosen after opening the conjunctiva. In both cases, the hypotony was successfully treated. The intraocular pressure rose immediately after the procedure, and it remained well controlled within the targeted range during the first postoperative months without additional pressure-lowering medication. This novel surgical technique provided predictable flow reductions, according to the Hagen-Poiseuille equation. This approach offers a valuable alternative to permanent tube ligation.

POSTERIOR VITREOUS DETACHMENT STATUS AS A PREDICTIVE FACTOR FOR OUTCOMES OF VITRECTOMY FOR DIABETIC VITREOUS HEMORRHAGE.

The purpose of this study was to evaluate the prognostic utility of the degree of vitreous attachment for predicting outcomes of vitrectomy for nonclearing vitreous hemorrhage associated with proliferative diabetic retinopathy. Medical records of patients who underwent primary vitrectomy for dense nonclearing vitreous hemorrhage secondary to proliferative diabetic retinopathy were examined retrospectively. Eyes were divided into four groups based on the intraoperatively assessed stage of posterior vitreous detachment (PVD), ranging from Stage 0/1 (complete or near-complete vitreoretinal adhesion) to Stage 4 (complete PVD). Overall, 136 eyes (117 patients) were included. In comparison with eyes with a partial or complete PVD (Stages 2-4), eyes with no PVD (Stage 0/1) had a higher incidence of postoperative hypotony (8%, P = 0.03) and traction retinal detachment (27%, P = 0.002), an increased rate of repeat vitrectomy (49%, P = 0.04), and poorer best-corrected visual acuity at 6 months and 1 year postoperatively (P = 0.04 and P = 0.01, respectively). Presence of a complete PVD at baseline was independently associated with improved postoperative vision at 6 months (P = 0.04). More extensive vitreoretinal adhesion is associated with higher rates of reoperation and poorer visual outcomes after vitrectomy for dense nonclearing vitreous hemorrhage associated with proliferative diabetic retinopathy. Preoperative determination of PVD status using B-scan ultrasonography may be useful for predicting anatomical and functional outcomes after vitrectomy in these patients.

Posterior segment complications of Ahmed valve implantation

BackgroundTo assess the time, incidence, and outcome of posterior segment complications of Ahmed valve implantation (AVI).Methods248 eyes that underwent AVI were reviewed retrospectively. Visual acuity, preoperative characteristics, and postoperative posterior segment complications were assessed.ResultsThe incidence of posterior segment complications of AVI was 31.4% (78/248). The mean follow-up period was 97.4 ± 53.5 months. The mean time to occur posterior segment complication was 1.5 months. The most common posterior segment complication was choroidal detachment (17.7%) and others included ocular decompression retinopathy (3.2%), hypotonic maculopathy (2.8%), vitreous hemorrhage (2.0%), retinal detachment (1.2%), endophthalmitis (1.2%), suprachoroidal hemorrhage (1.2%), epiretinal membrane (0.8%), cystoid macular edema (0.8%), and proliferative vitreoretinopathy (0.4%). Older age, hypertension, and postoperative hypotony had an increased risk of posterior segment complications of AVI.ConclusionsThe overall incidence of posterior segment complications of AVI was 31.4%. Older age, hypertension, and postoperative hypotony were significantly associated with posterior segment complications of AVI.

Multipiece posterior chamber intraocular lens as sutureless, glueless scleral fixated intraocular lens.

PURPOSE:The purpose of the study is to report the outcomes of sutureless, glueless multipiece posterior chamber intraocular lens (PCIOL) as scleral fixated intraocular lens (SFIOL) implantation in patients with poor or no posterior capsular support.METHODS:Medical records of 45 eyes of 42 patients who underwent SFIOL implantation where no suture or glue was used to fixate intraocular lens (IOL) to the sclera from November 2016 to October 2017, with minimum 18 months of follow-up were retrospectively analyzed. The best-corrected visual acuity, indication of surgery, other significant eye examination findings, and complications were analyzed.RESULTS:Out of 42 patients, 62% were males and 38% were females. Mean age of subjects was 48.5 ± 16.5 years (range 13–79 years). Mean preoperative and postoperative visual acuity was 1.48 ± 0.6 Logarithm of the Minimum Angle of Resolution (logMAR) units and 0.6 ± 0.3 logMAR units, respectively. Most common complication was vitreous hemorrhage six eyes (13.3%) followed by postoperative hypotony in five eyes (11.11%). Other complications such as transient postoperative intraocular pressure rise, hyphema, tilted IOL, cystoid macular edema, retinal detachment were also noted.CONCLUSION:Multipiece PCIOL used as SFIOL without any sutures and glue is a viable, cost-effective method of IOL implantation in eyes with aphakia following surgical complication or trauma, with comparable outcome to other techniques of SFIOL implantation.

One-Year Efficacy and Safety of the PAUL Glaucoma Implant Using a Standardized Surgical Protocol.

The PAUL Glaucoma Implant is an effective intraocular pressure (IOP)-lowering device with an acceptable safety profile. Its design as a nonvalved device with a small tube diameter using a vicryl ligation suture around the tube that is posteriorly reabsorbed instead of an ab luminal stent makes it an option in cases selected for glaucoma drainage device implantation. The aim was to determine the 1-year efficacy and safety of PAUL Glaucoma Implant using a uniform, standardized surgical procedure. Retrospective, cohort study. Patient charts were screened between December 2018 and January 2020, with inclusion requiring a minimum follow-up of 12 months. Primary outcome was IOP-lowering at 12 months, with surgical success defined as ≤18 mm Hg and at least 30% reduction and higher than 5 mm Hg. Absolute success was achieved if no IOP-lowering medication was needed and qualified success if otherwise. Safety outcomes were also analyzed. A standardized protocol was followed in all cases, which included mitomycin C application and 1 vicryl ligation of the tube. A total of 24 eyes from 21 patients fulfilled inclusion criteria. Median patient age at time of surgery was 42 years (range: 1 to 76 y). IOP decreased from 31.4 (10.0) mm Hg in preoperative period to 12.5 (4.3) mm Hg in the last follow-up (P<0.001). Qualified success criteria were fulfilled by 75% of cases, while absolute success was 33%. The mean number of IOP-lowering drugs used before surgery was 3.0 and 0.9 at the 12-month visit (P<0.001). No postoperative hypotony requiring intervention was recorded. PAUL Glaucoma Implant appears to be a safe and effective glaucoma drainage implant for the treatment of moderate and advanced glaucoma.

Intraluminal stenting versus external ligation of Ahmed glaucoma valve in prevention of postoperative hypotony.

To compare intraluminal stenting and external ligation of Ahmed glaucoma valves (AGV) for refractory glaucoma management and postoperative hypotony prevention. This randomized prospective blind study included 30 eyes of 25 patients (age range: 44-56y) with refractory glaucoma. This study was conducted from September 2018 to January 2020. The study included two groups, AGV with intraluminal stenting group (n=15 eyes) and AGV with external ligation group (n=15 eyes). Follow-up period was one year postoperatively. The primary outcome was intraocular pressure (IOP) and its association with the number of postoperative glaucoma medications. IOP≤21 mm Hg without medications indicated complete success while IOP≤21 mm Hg with medications indicated qualified success; and IOP<6 mm Hg was defined as hypotony. After a year of follow-up, IOP was significantly reduced in the intraluminal stenting group than in the external ligation group (11.67±0.89 vs 14.2±4.0 mm Hg, respectively, P=0.024). Postoperative hypotony was more common in the external ligation group (2 cases, 13.33%) than in the intraluminal stenting group (1 case, 6.67%). Application of intraluminal stenting or external ligation during AGV surgery usually prevents postoperative hypotony (transient and persistent) that occurs in conventional AGV surgery.

Intraocular Pressure Changes in the Contralateral Eye After Glaucoma Surgery.

Glaucoma surgery in 1 eye can result in significant intraocular pressure (IOP) elevation in the fellow eye in a significant percentage of subjects. This effect is more pronounced following glaucoma drainage device implantation and in subjects developing postoperative hypotony in the first eye. The aim was to investigate the course and magnitude of IOP changes in contralateral eyes following glaucoma surgery. We studied 131 glaucoma patients undergoing surgery. IOP changes in fellow eyes and the number of glaucoma medications were recorded for 6 months. Both normal and glaucomatous fellow eyes were included. Patients on preoperative acetazolamide were analyzed separately. IOP change ≥4 mm Hg or 20% increase from baseline values was considered significant. Baseline IOP in fellow eyes was 13.1±3.3 mm Hg which increased significantly at all-time points with a peak at 1 week (mean increase: 3.1±3.2 mm Hg) gradually decreasing up to 6 months (mean increase 0.9±2.1 mm Hg). The number of fellow eyes with clinically significant IOP elevation at 1 day, 1 week, and 1, 3. and 6 months was 47, 76, 47, 31, and 37 showing mean IOP rise of 4.5±2.3 (38.5%), 5.4±1.8 (48.5%), 4.8±1.6 (44.2%), 3.7±1.3 (36.5%), and 3.2±1.3 (32.6%) mm Hg, respectively. Medications were added to 18 fellow eyes (including 10 initially "normal" eyes) while 7 other fellow eyes required surgery.Significant IOP elevation in fellow eyes was associated with tube shunt surgery (P<0.008 at all-time points), a diagnosis of glaucoma following cataract surgery, IOP ≤5 mm Hg on the first postoperative day (P=0.002) and use of preoperative acetazolamide. Glaucoma surgery was associated with IOP elevation in fellow eyes in a significant number of subjects and suggests that IOP in the unoperated eye should also be checked at postoperative visits.

Implantation of XEN After Failed Trabeculectomy: an Efficient Therapy?

Trabeculectomy (TE) has been the standard procedure in glaucoma surgery for a long time. This study examined the efficacy and safety profile of XEN45 Gel Stent (XEN) after failed and/or scarred trabeculectomy. We analysed all files of patients, who received a XEN after insufficient TE and examined changes in intraocular pressure (IOP), IOP-lowering medication, best corrected visual acuity, visual field tests as well as the intra- and postoperative complications recorded within a 12-month follow-up period. 31 eyes of 28 patients were analysed in our study (mean age: 66,2 ± 13,4 years; 39% female; 48% right eye; mean follow-up after TE: 70,3 ± 64,9 months). The mean IOP decreased from 23,5 ± 6,5 to 18,0 ± 5,3 mmHg (- 23,5% compared to baseline-IOP; p = 0,01) while the mean IOP-lowering medication could be reduced from 2,8 ± 1,1 to 1,1 ± 1,5 (p < 0,01) 12 months after XEN-implantation. The mean visual acuity did not change significantly (pre-op: 0,5 ± 0,6 logMAR; 12 months post-op: 0,5 ± 0,6 logMAR). The most common complications postoperatively were choroideal detachment due to postoperative hypotony in 4 eyes (13%), a needling procedure in 9 eyes (29%), a Re-XEN-Implantation in 4 eyes (13%), an open revision of the conjunctiva in 3 eyes (10%), and a Re-TE in 1 eye (3%) as well as an Ahmed-Valve implantation in 2 eyes (6%). Overall, neither needling procedure nor further glaucoma surgery was necessary in 19 eyes (61%). In 10 of 22 evaluable eyes (45%) an IOP reduction of > 20% was achieved 12 months after XEN implantation. XEN could be an effective method to reduce IOP after failed TE. The rate of complications seems to be low and the rate of needling procedures and/or revisions is acceptable.

Parallel Suture: A Simple Approach to Enable Early Laser Suture Lysis and Prevent Hypotony after Trabeculectomy

ABSTRACT Purpose To define a modified flap suture approach and evaluate its effectiveness. Methods Clinical data of patients undergoing trabeculectomy with modified parallel suture technique (Group 1, N = 38 eyes) were compared to patients operated with classical flap suture technique (Group 2, N = 42 eyes). In the modified technique, two parallel sutures (one tight and one loose) are placed simultaneously in one of the flap corners with the aim of obtaining a safety stitch when the tight one needs to be cut. Data from preoperative and postoperative visits at day 1, week 1, months 1, 3, 6 and year 1 were recorded from patient charts and compared between the groups. Results In Group 1, seven eyes underwent laser suture lysis (LSL) between postoperative days 2 to 8 and in Group 2 two eyes at days 29 and 37. No complication related to LSL was observed. Rate of postoperative hypotony decreased with the parallel suture approach (P= .002). Number of eyes experiencing any of the complications related to hypotony was lower in Group 1 (P= .004). No significant difference was noted in the mean IOP between the groups (P> .05 for all). Conclusion The modified approach with parallel suture technique was found to be effective and safe. By enabling early LSL, it provided more precise IOP modulation in the early postoperative period. Thus, in our series, the rate of hypotony and hypotony-related complications decreased, while the success of the surgery was preserved.

The SWISS IOL Technique (Small-Width Incision Scleral Suture): A Mini-Invasive Technique.

Purpose To evaluate the outcomes and safety of a minimally invasive technique for sutured IOL scleral fixation in case of compromised capsular and iris support. Materials and Methods In this retrospective study, we explain our mini-invasive technique and assess the outcomes in terms of visual acuity, pre- or postoperative complications, and IOL position (Sensar AR40e, AMO) in a case series of three patients. Results The expected best corrected visual acuity could be achieved after one month. Surgeries were uneventful with a stable eye. No postoperative complications occurred except for one patient who had a conjunctival disinsertion. Neither postoperative hypotony nor raised IOP was found. Additionally, no patient experienced corneal edema at one week control, IOL dislocation, vitreous hemorrhage, or new pupil's irregularity. Conclusions In conclusion, each scleral technique has its own advantages and its inherent postoperative complications. To date, there is no evidence of superiority of any single technique. By improving our scleral sutured lens techniques, we could improve peroperative ocular stability, potentially decrease postoperative complication rate, and offer a rapid recovery with a stable visual acuity within a month.

Long-term Outcomes of Fibrin Glue-Assisted Intrascleral Haptic Fixation of Posterior Chamber Intraocular Lenses in Children.

To evaluate the long-term outcomes of intrascleral haptic fixation of posterior chamber intraocular lens (PCIOL) with fibrin glue in children. This is a retrospective case study conducted in a tertiary eye institute in North India. A total of 118 eyes of 82 children who underwent glued intrascleral haptic fixation of PCIOLs were retrospectively analyzed. Detailed analysis of the indication for surgery and ocular and systemic associations was performed. The outcome measures included intraoperative complications, final visual and refractive outcomes, and postoperative complications. The mean age of the patients was 10.16±3.94 years. Fifty-one patients (62.2%) were male and 31 (37.8%) were female. The mean follow-up period was 31.28±13.22 months. The mean preoperative corrected distance visual acuity was 1.18±0.63 Logarithm of Mean angle of resolution (logMAR) which improved to 0.60±0.58 logMAR postoperatively at 6 weeks (P<0.001). The mean preoperative and 6 weeks postoperative endothelial cell density were 3,176.08±318.6 and 2,936±289.9 cells/mm2, respectively (P=0.23). In the immediate postoperative period, corneal edema (19 eyes; 16.1%), decentered IOL/tilt (3 eyes; 2.54%), vitreous hemorrhage (3 eyes; 2.54%), optic capture (4 eyes; 3.38%), and hypotony (2 eyes; 1.69%) were seen. In the late postoperative period (>6 weeks), retinal detachment was observed in two eyes that had associated Marfan syndrome. Cystoid macular edema was seen in four eyes (3.38%), and glaucoma was seen in five eyes (4.23%). Fibrin glue-assisted intrascleral haptic fixation of a PCIOL is a safe and effective method to manage aphakia with inadequate capsular support in children.

Comparison of Surgical Outcomes of Sponge Application versus Subconjunctival Injection of Mitomycin-C during Combined Phacoemulsification and Trabeculectomy Surgery in Asian Eyes.

Purpose:To compare the outcomes of combined phacoemulsification–trabeculectomy surgery with intraoperative sponge-applied versus subconjunctival injection of mitomycin-C (MMC) in Asian eyes.Methods:This was a retrospective review of 95 eyes that consecutively underwent combined phacoemulsification–trabeculectomy surgery in a tertiary eye center in Singapore from January 2013 to June 2014. Data collected included intraocular pressure (IOP), best corrected visual acuity, and number of glaucoma medications. Outcome measures included postoperative IOP and complications at various timepoints up to 12 months after surgery.Results:Twenty eyes (21.1%) received 0.2 mg/ml subconjunctival MMC injection (“Group 1”) and 75 (78.9%) received 0.4 mg/ml sponge-applied MMC (“Group 2”). There was no difference between groups in demographics, IOP, and number of glaucoma medications preoperatively. There was a reduction in IOP at postoperative month (POM) 1, 6, and 12 in both the groups (POM12: Group 1, −2.8 ± 5.36 mmHg, P < 0.001; Group 2, −5.8 ± 6.29 mmHg, P = 0.054). At POM1, Group 2 showed a trend toward greater IOP reduction (−5.89 ± 7.67 mmHg vs. −1.55 ± 5.68 mmHg, P = 0.061). However, at both POM6 and POM12, there was no statistically significant difference in IOP reduction between the two groups. At POM12, complete success, defined as achieving an IOP of between 6 and 15 mmHg without the use of antiglaucoma medications, was achieved in 11 (55%) eyes in Group 1 and 48 (64%) in Group 2 (P = 0.9). There was a lower rate of postoperative hypotony in the Group 1 (0%) compared to Group 2 (8%) (P = 0.34).Conclusion:Combined phacoemulsification–trabeculectomy with subconjunctival MMC injection has comparable outcomes to that with sponge-applied MMC, with a similar reduction in IOP at 1, 6, and 12 months postoperatively and a lower postoperative complication rate.

Assessing risk factors for postoperative hypotony in Ahmed glaucoma valve implantation surgery.

To assess the risk factors associated with the development of hypotony after Ahmed glaucoma valve (AGV) implantation. One hundred and ninety-three eyes of 177 patients with various types of glaucoma that were treated with AGV implantation were retrospectively evaluated. Intraocular pressure lower than 6mmHg related to the surgery is defined as postoperative hypotony. Patients' demographic characteristics, type of glaucoma, preoperative and postoperative visual acuity, necessity of antiglaucoma treatments, lens status, previous ocular surgeries, intraocular pressure (IOP) measurements before and after surgeries, the need for additional procedures and postoperative complications were recorded from the patients' charts. Hypotony was seen in 68 of 193 eyes (35.2%) postoperatively. In 45 eyes (23.3%), it has occurred in first postoperative day and in 23 eyes (11.9%) after the first day within the first week. There was no difference in intraocular pressures between two groups in the first year follow-up. Pre- and postoperative best-corrected visual acuities, age and gender were not statistically different between hypotony and no hypotony groups (p > 0.05). Also, lens status, history of previous ocular surgery, type of glaucoma and number of preoperative glaucoma medication usage were not found to be different between groups (p > 0.05). Potential risk factors such as age, sex, lens status, history of previous ocular surgeries, preoperative glaucoma medication usage or glaucoma type are not found to influence upon postoperative hypotony prevalence for AGV surgery. Surgery type and personal ocular factors, which could not be determined beforehand, could be more important than demographic features.

Er:YAG laser-assisted filtration surgery: initial results in rabbits

BackgroundGlaucoma is a leading cause of global blindness, especially preventable blindness. The increased prevalence of glaucoma has led to a growing demand for newer, safer, more rapid, and simpler treatments for the reduction of intraocular pressure (IOP). In this study, we evaluated the safety and feasibility of performing filtration glaucoma surgery with an Ab-Interno Er:YAG laser in rabbits.MethodsNine New Zealand White rabbits age 16 weeks were studied. After subconjunctival injection of mitomycin C (MMC), a novel Ab-Interno Er:YAG laser probe was inserted into the anterior chamber (AC) through a clear corneal 1 mm paracentesis and directed at the trabecular meshwork adjacent to the MMC injection area. A pulsed laser beam was applied to create a patent sclerostomy connecting the AC to the subconjuctival space, resulting in a filtering bleb. The laser system used was the Er:YAG laser system - LAS25-FCU, (Pantec Biosolutions AG, Liechtenstein). Parameters used: Wave lengh: 2940 nm, Pulse length: 100–400 μsec,frequency: 250 Hz. Average laser power in accordance to the fiber tip diameter: 0.85 W(range 0.8–0.92 W). Complete ocular exams, including IOP measurements, were performed on 1, 7, 14, and 23 days postoperatively. Three rabbits were sacrificed on days 1, 14, and 23, and histological examinations were performed on all nine eyes.ResultsAll procedures resulted in a functional medium-large superior bleb without significant complications. The bleb was sustained in all rabbits by day 14 and in one of the three rabbits that reached the last follow-up at 23 days. No cases of postoperative hypotony were observed. There was a transient significant reduction in mean IOP on postoperative days 5 and 7 (P = 0.028). Histopathological analysis revealed a patent full-thickness scleral tunnel with only a minor degree of surrounding coagulation necrosis.ConclusionsThe Ab-Interno laser sclerostomy procedure is potentially safe and effective based on initial experience in an in-vivo rabbit animal model.

Double versus single suture stenting to manage hypertensive spikes after glaucoma drainage device implantation.

To evaluate the safety and efficacy of double compared to single intraluminal suture stenting in reducing early postoperative hypertensive spikes (HS) and hypotony after Baerveldt glaucoma implant surgery. For this retrospective study, we reviewed the medical charts of 60 patients (60 eyes) who underwent Baerveldt drainage device surgery between 2017 and 2019. Two groups were formed according to whether a single suture stent was placed within the tube (5-0 polypropylene, 30 eyes, group 1) or a double suture (5-0 and 6-0 polypropylene, 30 eyes, group 2). Intraocular pressure (IOP) was measured at baseline, at 6 h, and on postoperative days 1, 2, 5, 7, 14, 21, 30, 60, 90, 180. The occurrence of HS (IOP ⩾ 30 mmHg), anterior chamber reformation, decompressive paracentesis, anti-glaucoma medication, and adverse events were recorded. There was a greater decrease in IOP from baseline at days 1, 2, and 21 (p < 0.05) and number of HS at 6 h (p = 0.006) and postoperative day 1 (p < 0.001) in group 2. The mean number of decompressive paracentesis, anterior chamber reformation procedures, and topical anti-glaucoma medications was the same in both groups; the need for oral acetazolamide was significantly lower in group 2 at days 1, 21, and 30 (p < 0.05). While both stenting methods provide a gradual, controlled decrease in IOP, the double stenting technique was associated with a sooner and greater postoperative reduction in IOP and a good safety profile thanks to fewer HS in the early postoperative period and less need for oral acetazolamide.

Ahmed glaucoma valve in vitrectomized eyes: An implantation technique to minimize early postoperative fluid-loss hypotony.

To describe the application of a modified Ahmed glaucoma valve (AGV) surgical implantation technique in vitrectomized eyes, in order to minimize the risk of early postoperative hypotony, which leads to hemorrhagic complications. Data of patients implanted with AGV using the surgical technique described were retrospectively reviewed. Inclusion criterion: glaucomatous eyes with previous history of pars plana vitrectomy. Intraocular pressure (IOP) measurement and ophthalmic examination were performed preoperatively and postoperatively weekly for 1 month for the detection of early hypotony, choroidal effusion/detachment, intraocular hemorrhage. The surgical technique consisted in creating a 5 mm long scleral tunnel with a 23 G needle reaching the anterior chamber at the iridocorneal angle, in which the Ahmed glaucoma valve tube was inserted. Ten eyes of 10 patients were included. Median preoperative IOP was 30.5 mmHg [interquartile range (IQR) 28.3-33.0]; median postoperative IOP was 12.0 mmHg (IQR 9.3-13.0) at 1 week, and 12.5 mmHg (IQR 11.0-15.0) at 1 month. In no cases postoperative IOP was <8 mmHg. On the first postoperative day, five (50%) eyes showed few blood clots in the anterior chamber. On the second-week appointment, moderate choroidal effusion was observed in two eyes (20%). No hemorrhagic complications were observed. The creation of a long intrascleral tunnel with a 23 G needle for AGV implantation in vitrectomized eyes could be effective in decreasing leakage through the space between the valve tube and the sclerocorneal tissue. This technique is safe, easy to perform, feasible and fast. Due to its advantages and good postoperative results, it could also be adopted in non-vitrectomized eyes.

Intraluminal Stent Optimization for the Baerveldt Glaucoma Implant: An Experimental Study.

Our laboratory study determined the approximate suture diameter for use in intraluminal stenting of the Baerveldt glaucoma implant (BGI) to prevent postoperative hypotony. Commercial 3-0 monofilament nylon sutures which are commonly used may vary significantly outside of this diameter. Postoperative hypotony is a complication of surgical treatment of glaucoma using the BGI. One method utilized to prevent early postoperative hypotony is intraluminal stenting of the implant with monofilament sutures. The present study attempted to determine optimal stent diameter in microns for 3-0 monofilament sutures to reduce outflow and thereby reduce the risk of postoperative hypotony using the BGI. A laboratory bench model of the anterior chamber was utilized to measure the outflow rate of balanced salt solution through the BGI at pressures of 20 and 40 mm Hg while utilizing commercially available 3-0 monofilament nylon stents of various diameters. The BGI tube has an inner diameter of 300 µm. In addition, 3-0 nylon sutures were studied for variability by measuring the diameters at 10 equally spaced points along the length of each sample using a digital micrometer. Average experimental flow rates decreased with increasing intraluminal stent diameter and increased with increasing pressure. An intraluminal stent diameter of 250 µm yielded a flow rate of 40 µL/min at a nominal pressure of 20 mm Hg. Diameters of the tested 3-0 monofilament nylon sutures were all within the United States Pharmacopeia diameter range of 200 to 250 µm, but diameters varied significantly depending on the manufacturer. In our laboratory model, the optimal stent diameter to reduce aqueous flow to a level approaching the normal aqueous production is at least 250 µm. Secondarily, commercially available 3-0 monofilament nylon suture materials showed variable diameters within the United States Pharmacopeia diameter range.