Outcomes of using a sutureless bovine pericardial patch graft for Ahmed glaucoma valve implantation

Long scleral tunnel technique for prevention of drainage tube-related complications during Ahmed glaucoma valve implantation

To evaluate the safety and efficacy of modified Ahmed glaucoma valve (AGV) implantation (long scleral tunnel technique) in the treatment of neovascularization glaucoma (NVG). This retrospective observational case series included 23 patients (23 eyes) diagnosed with NVG secondary to proliferative diabetic retinopathy from January 2020 to June 2021. All 23 cases received anti-vascular endothelial growth factor treatment. Then, after 3 to 7 days, these cases were treated with modified AGV implantation (long scleral tunnel technique) and were followed up for at least 6 months. The best corrected visual acuity, intraocular pressure, numbers of antiglaucoma medications used, and postoperative complications were observed at 1 week and 1, 3, and 6 months after treatment. With treatment, the mean best corrected visual acuity improved significantly (P < .001) from 1.62 ± 0.52 logMAR preoperatively to 1.29 ± 0.36 logMAR at the 6-month follow-up. The mean postoperative intraocular pressure was significantly lower than that before modified AGV implantation during follow-up period, decreasing from 45.48 ± 7.86 mm Hg preoperatively to 14.87 ± 1.96 mm Hg at 1 week, 18.39 ± 2.25 mm Hg at 1 month, 16.61 ± 1.47 mm Hg at 3 months, and 17.48 ± 1.38 mm Hg at 6 months (F = 256.646, P < .001). The median number of antiglaucoma medications used by patients also significantly decreased from 3 (3-4) preoperatively to 0 (0-1) at the 6-month follow-up after surgery (Z = -4.248, P < .001). Postoperative complications included hyphema in 2 cases and vitreous hemorrhage in 1 case, and all 3 patients achieved satisfactory recovery with treatment. No drainage tube-related complications occurred among our patients. Long scleral tunnel technique is a safe and effective surgical treatment for NVG with fewer drainage tube-related complications.

Glaucoma Drainage Device Implantation, Outcomes, and Complications

Glaucoma drainage device (GDD) surgery has gained popularity as a treatment strategy for patients with medically uncontrolled glaucoma. Glaucoma is the leading cause of irreversible blindness in the world and continues to be a major public health issue. While our understanding of glaucoma continues to evolve, the primary treatment for glaucoma continues to be intraocular pressure (IOP) control. When medical treatment fails, glaucoma surgery is considered. GDD implantation is one of the most commonly performed incisional glaucoma surgeries. GDD was originally designed for patients with secondary glaucoma and/or patients who are at an increased risk of failure after trabeculectomy. More recently, its application has been extended to primary glaucoma as the first choice of incisional surgery. This manuscript summarizes recent GDD types, implantation, clinical outcome and complications.

Assessing patient cosmetic satisfaction after glaucoma drainage device surgery for different patch grafts

BACKGROUND

The use of a tissue patch graft is common practice with a glaucoma drainage device (GDD). Patch grafts can be visible in the palpebral fissure and may be cosmetically displeasing for some patients. The aim of this study was to report the cosmetic satisfaction of pericardial, scleral, and corneal patch grafts related to superior GDD surgery.

METHODS

Baseline clinical data were collected for consecutive patients with glaucoma operated between 2014 and 2019 at two tertiary eye care institutions (for superiorly-placed) Ahmad glaucoma valve implant using sclera, cornea and pericardium patch graft. A patient questionnaire that contained 4 concise questions, with a Likert-scale grading relating to cosmetic satisfaction was administered by a telephone-based interview. Responses and scores for each question were compared across patients who received the three different types of graft. A binominal logistic regression analysis was used to assess the effects of age, gender, type of graft, number of previous ocular surgeries, and final visual acuity to explain differences.

RESULTS

We included 92 patients who met our inclusion criteria (24 patients received a corneal patch graft, 30 who received sclera and 38 who received pericardium). The mean (±SD) age was 50 (±17.5) years, and the average follow up was 20.7 (± 18.6) months. Regardless of the type of patch graft, most (67-84%) of patients were satisfied with the appearance of their eyes. Patients who received cornea or sclera were more likely to report that their eye looked 'abnormal' by others. Younger age was significantly associated with the response to this question.

CONCLUSION

Patients are generally satisfied with the appearance of their eye following GDD surgery with each of the patch grafts for superiorly-placed GDDs. Younger patients with cornea or sclera were more likely to report that their eyes looked abnormal.

Clinical outcomes of Ahmed glaucoma valve implantation without fixation of a plate: The free plate technique

OBJECTIVE

This study compared surgical outcomes between free plate Ahmed glaucoma valve (FPAGV) implantation without plate fixation and conventional Ahmed glaucoma valve (CAGV) implantation with plate fixation.

METHODS

A retrospective, comparative case series study. Patients with refractory glaucoma who underwent FPAGV or CAGV implantation and were followed >1 year were enrolled consecutively. We reviewed medical records, including data on postoperative intraocular pressure (IOP) and postoperative complications. The success rate and early postoperative hypertensive phase were compared between groups.

RESULTS

A total of 74 patients with CAGV implantations and 36 patients with FPAGV implantations were studied. The average follow-up periods were 23.3 ± 2.6 months (CAGV) and 22.8 ± 2.8 months (FPAGV; p = 0.424). The surgery time was significantly shorter in the FPAGV group than in the CAGV group (42.6 ± 4.1 vs. 47.3 ± 5.4 min; p < 0.001). Postoperative IOP at 1 week and 1 month were significantly lower in the FPAGV group than in the CAGV group (11.8 ± 3.6 and 14.0 ± 5.3 mmHg vs. 18.7 ± 5.5 and 22.2 ± 5.2 mmHg; p = 0.012 and p = 0.002, respectively). An early postoperative hypertensive phase occurred in 62 eyes, and the frequency was greater in the CAGV group (50 eyes) than the FPAGV group (12 eyes; p = 0.001). There was no significant difference in postoperative complications between the two groups (p = 0.735). The success rate was 84.2% in the FPAGV group and 80.6% in the CAGV group 24 months after surgery (p = 0.367).

CONCLUSION

FPAGV implantation was associated with a shorter surgery time, without any change in the extent of IOP reduction or complication rate. This procedure may be considered a good alternative for CAGV implantation in patients with refractory glaucoma.

Tendon elongation with bovine pericardium in strabismus surgery-indications beyond Graves' orbitopathy

BACKGROUND

For some patients with complex ocular motility disorders, conventional strabismus surgery is insufficient. Surgery with tendon elongation allows correction of larger angles and maintains a sufficient arc of contact for rectus muscles. This study reports results for tendon elongation with bovine pericardium (Tutopatch®) in indications other than Graves' orbitopathy in which it is already widely used.

METHODS

We reviewed the records of all patients who underwent surgery with Tutopatch® in our institution. Angles of squint and head postures were analyzed preoperatively, on the first postoperative day, and in the long term (median 9 weeks after the operation). Patients with Graves' orbitopathy were excluded.

RESULTS

From 2011 to 2018, the procedures on 58 eyes of 54 patients (35 females, median age 35 years (3-75)) met the inclusion criteria. Horizontal rectus muscle surgery (53 eyes) was conducted on patients with residual strabismus (13), Duane's retraction syndrome with eso- (type I: 16)/exodeviation (type II: 2, type III: 1), 6th (7)/3rd nerve palsy (7), Möbius syndrome (2), congenital fibrosis of the extraocular muscles type 3A (CFEOM3A, TUBB3 mutation) (4), and orbital apex syndrome (1). Vertical rectus muscle surgery (5 eyes) was conducted on patients with myasthenia (1), vertical tropia after orbital floor fracture (1), CFEOM1 (2), and Parry-Romberg syndrome (1). 42 eyes had prior eye muscle surgery (1-5 procedures, median 1). Out of 45 patients with postoperative long-term data, 43 showed an angle reduction. Fifty-one percent had an angle of 10Δ (prism diopter) or less, one had a significant over-effect, and 10 had revision surgery. For the heterogeneous group of residual eso- and exotropias, the median absolute horizontal angle was reduced from 35Δ (16 to 45Δ) to 9Δ (0 to 40Δ), for Duane's retraction syndrome from 27.5Δ (9 to 40Δ) to 7Δ (0 to 40Δ), and for sixth and third nerve palsies from 43Δ (20 to 75Δ) to 18Δ (4 to 40Δ). For 3 patients with vertical rectus muscle surgery, the median absolute vertical angle was reduced from 30Δ (20 to 45Δ) to 4Δ (1 to 22Δ). The motility range was shifted in the direction contrary to the elongated muscle in all subgroups. A considerable reduction of the excursion into the field of action of the elongated muscle had to be registered.

CONCLUSIONS

Strabismus surgery with bovine pericardium introduces new surgical options for complicated revisions and for rare and complex oculomotor dysfunctions. Yet, it has to be recognized that this type of surgery aiming at maximum effects, despite preservation or restitution of the arc of contact, leads to reduction of the excursion into the field of action of the elongated muscle. Furthermore, dose finding can be difficult depending on the underlying pathology and more than one intervention might be necessary for optimal results.

Tenon Capsule Grafting versus Autologous Scleral Graft in Ahmed Glaucoma Valve Surgery

Objective

To compare between the surgical outcomes of Tenon capsule grafting and autologous scleral graft in Ahmed glaucoma valve (AGV) surgery in the management of refractory glaucoma and prevention of tube exposure. Patients and Methods. This prospective randomised study included 30 eyes of 30 patients with refractory glaucoma, who were aged between 46 and 58 years and diagnosed with refractory glaucoma. This study was conducted in Menofia University Hospital between July 2018 and December 2019. Informed patient consent was obtained. The studied eyes were divided into two groups: the first group included 15 eyes for which AGV with Tenon capsule grafting was performed, while the second group included 15 eyes for which AGV with autologous scleral graft was performed. All patients were followed up for one year after the surgery. The outcomes were evaluated according to intraocular pressure (IOP) and the number of postoperative glaucoma medications. Visual acuity, visual field, number of postoperative glaucoma medications, and postoperative complications were followed throughout the 1-year follow-up period.

Results

There was a significant reduction in IOP in both groups, with more reduction in the Tenon graft group where the mean IOP after one year was 11.66 ± 0.89 mmHg, whereas in the scleral graft group, the mean IOP was 14.20 ± 4.0 mmHg (p value < 0.001). However, the difference between the 2 groups in lowering IOP was insignificant. Regarding postoperative complications, tube exposure was observed in one case in the scleral graft group with associated scleral melting and hypotony, postoperative hypotony was more in the scleral graft group with 3 cases (20%), and in the Tenon graft group, hypotony occurred only in 1 case (6.67%). In addition, less vascular blebs were seen in most cases in the Tenon graft group, while most blebs seen in the scleral graft group were vascular blebs. In addition, both groups showed stability in terms of visual acuity and visual field.

Conclusion

Tenon capsule grafting and autologous scleral grafting might be effective and safe techniques when applied with AGV in the management of refractory glaucoma. Tenon capsule resection with grafting showed relatively low incidence of tube exposure and hypertensive phase.

Safety and Efficacy of Ahmed Valve on Intractable Glaucoma in Saudi Population

PURPOSE

The study aims to assess the efficacy and safety of Ahmed glaucoma valve implant in eyes with intractable glaucoma and to evaluate the risk factors for failure.

METHODS

A retrospective evaluation of 83 patients (117 eyes) with intractable glaucoma who underwent silicone Ahmed glaucoma valve implant was done in a tertiary care center in Riyadh, Saudi Arabia, between January 2014 and December 2016. Complete success was defined as intraocular pressure (IOP) ≤21 mmHg without medication after a minimum follow-up of 6 months.

RESULTS

Eighty-three patients (117 eyes) with intractable glaucoma were evaluated. After a mean follow-up duration of 20.8 ± 3.1 (12-24) months, the overall success rate was achieved in 104 eyes (88.9%). Thirty-six eyes (30.8%) had a complete success rate, whereas 68 eyes (58.1%) had a qualified success rate. Thirteen eyes (11.1%) failed to achieve controlled IOP. The postoperative probability to fail was found to be increasing with time from 0.9% (0.9) in the 1^st month to 11.1% (9.9) after 1 year. Complications included a hypertensive phase in 25 eyes (21.4%), encapsulation in 10 eyes (8.5%), hyphema in 7 eyes (6%), hypotony in 2 eyes (1.7%), and blood clots in the implanted tube in 2 eyes (1.7%). The presence of hyphema, scleral patch, and coronary heart diseases was found to increase the risk of failure after Ahmed valve implantation (P = 0.006, 0.040, and 0.014, respectively).

CONCLUSIONS

Ahmed glaucoma valve implant was safe and effective in treating cases of intractable glaucoma.

Managing Ahmed Glaucoma Valve tube exposure: Surgical technique

PURPOSE

To describe a new surgical technique for managing Ahmed Glaucoma Valve tube exposure. The technique is simple, safe, easy to perform and may be an interesting alternative to conventional covering of the tube. This technique allows unlike the classical ones to act on the cause and not only on the complication of extrusion.

MATERIALS AND METHODS

This study was a retrospective case series that included four eyes of four patients who presented with an Ahmed Glaucoma Valve tube exposure.

RESULTS

Surgery was uneventful in all cases and we did not observe any intraoperative or postoperative complications. After at least 1-year follow-up, no case of tube re-exposure was detected.

CONCLUSIONS

Many techniques have been proposed in order to cover the extruded tubes, and different materials may be used to reinforce the coverage, but re-exposure of the tube is a possible scenario. Indeed, our technique attempts not only to cover the exposed tube but also to solve the cause of the extrusion.

Mammalian Pericardium-Based Bioprosthetic Materials in Xenotransplantation and Tissue Engineering

Bioprosthetic materials based on mammalian pericardium tissue are the gold standard in reconstructive surgery. Their application range covers repair of rectovaginal septum defects, abdominoplastics, urethroplasty, duraplastics, maxillofacial, ophthalmic, thoracic and cardiovascular reconstruction, etc. However, a number of factors contribute to the success of their integration into the host tissue including structural organization, mechanical strength, biocompatibility, immunogenicity, surface chemistry, and biodegradability. In order to improve the material's properties, various strategies are developed, such as decellularization, crosslinking, and detoxification. In this review, the existing issues and long-term achievements in the development of bioprosthetic materials based on the mammalian pericardium tissue, aimed at a wide-spectrum application in reconstructive surgery are analyzed. The basic technical approaches to preparation of biocompatible forms providing continuous functioning, optimization of biomechanical and functional properties, and clinical applicability are described.

Multiparametric Optical Bioimaging Reveals the Fate of Epoxy Crosslinked Biomeshes in the Mouse Subcutaneous Implantation Model

Biomeshes based on decellularized bovine pericardium (DBP) are widely used in reconstructive surgery due to their wide availability and the attractive biomechanical properties. However, their efficacy in clinical applications is often affected by the uncontrolled immunogenicity and proteolytic degradation. To address this issue, we present here in vivo multiparametric imaging analysis of epoxy crosslinked DBPs to reveal their fate after implantation. We first analyzed the structure of the crosslinked DBP using scanning electron microscopy and evaluated proteolytic stability and cytotoxicity. Next, using combination of fluorescence and hypoxia imaging, X-ray computed microtomography and histology techniques we studied the fate of DBPs after subcutaneous implantation in animals. Our approach revealed high resistance to biodegradation, gradual remodeling of a surrounding tissue forming the connective tissue capsule and calcification of crosslinked DBPs. These changes were concomitant to the development of hypoxia in the samples within 3 weeks after implantation and subsequent induction of angiogenesis and vascularization. Collectively, presented approach provides new insights on the transplantation of the epoxy crosslinked biomeshes, the risks associated with its applications in soft-tissue reconstruction and can be transferred to studies of other types of implants.

Efficacy and Safety of the Ab-interno Xen Gel Stent After Failed Trabeculectomy

AIMS

To assess the efficacy and safety of the Xen gel stent in reducing intraocular pressure (IOP) in eyes with prior failed trabeculectomy and to determine the frequency of complications and further intervention.

METHODS

Retrospective case note review of all patients with prior trabeculectomy undergoing Xen surgery across 5 centers from August 2015 to May 2017.

RESULTS

In total, 17 surgeries were reviewed. IOP reduced from 21.5 (±2.4) mm Hg preoperatively to 13.6 (±3.4) mm Hg at month 12 (P<0.05). Medication usage reduced from 2.8 (±0.6) preoperatively to 1.0 (±1.3) at month 12 (P<0.05). Adverse events included: numerical hypotony (IOP<6 mm Hg) in 4 cases (23.5%) that all resolved spontaneously, IOP spike of ≥30 mm Hg in 2 (11.8%) cases and transient occlusion of the implant by iris in 1 (5.9%) case. Secondary filtration surgery (Baerveldt tube implantation) was required in 2 (11.8%) cases. Postoperative bleb intervention was required in 9 cases (52.9%), usually in the first month after surgery.

CONCLUSIONS

Xen reduces IOP and number of medications in eyes with failed trabeculectomy. Detailed preoperative conjunctival assessment and targeted stent placement is required. Prospective data and follow-up beyond 12 months are required but Xen seems a viable, effective, and safe option after failed trabeculectomy.

Long-Term Functional Outcomes of Glaucoma Tube Shunt Revision Surgery

PURPOSE

To characterize long-term outcomes of tube shunt revision surgeries and identify factors associated with their failure.

DESIGN

Retrospective chart review.

PARTICIPANTS

One eye from each of 179 patients who underwent tube shunt revision surgery at the Wilmer Eye Institute between 2004 and 2015 with a minimum follow-up of 6 weeks.

METHODS

Eligible eyes were identified from billing records and data related to their care were extracted from electronic medical records. Eyes were analyzed in aggregate and by indication for revision, including hypotony, high intraocular pressure (IOP), tube reposition, and tube exposure.

MAIN OUTCOME MEASURES

Surgical failure, defined as a need for further tube shunt revision or other glaucoma surgery, unsatisfactory IOP at last follow-up, or both. Secondary outcomes included postoperative infection and functional visual impairment.

RESULTS

With a median follow-up of 4.2 years, 126 failures occurred among 179 eyes. By Kaplan-Meier analysis, the cumulative rates of surgical failure at 1, 2, and 5 years after revision were 49%, 59%, and 74%, respectively. Most revision failures (105/126) were the result of the need for additional surgery, whereas 11 eyes showed IOP above target levels and 10 eyes showed dysfunctionally low IOP at the last follow-up. Factors associated with failure in a stepwise regression model were revision for hypotony (hazard ratio [HR], 6.79; P = 0.002), different surgeons performing the original and revision surgeries (HR, 2.80; P = 0.002), longer duration of symptoms before revision (P = 0.01), revision of a right eye (HR, 1.92; P = 0.03), and presumed preoperative infection (HR, 2.47; P = 0.04). In univariate analysis, success varied significantly by prior surgeon (P = 0.01), but not by revision surgeon. There was a 16% cumulative incidence of postoperative infection, with the highest risk in those with presumed preoperative infections (P = 0.01) and in persons of non-African, non-European derivation (P = 0.03).

CONCLUSIONS

The estimated rate of failure of tube shunt revision is 75% by 5 years, most often because of a need for further surgery. The major potentially modifiable feature associated with success is tube shunt revision being performed by the original surgeon.

Surgical outcomes associated with a sutureless drainage valve implantation procedure in patients with refractory glaucoma

Purpose

To evaluate the safety and efficacy profile of a sutureless procedure for drainage valve implantation with combined cataract removal and/or endoscopic cyclophotocoagulation (ECP).

Materials and methods

A retrospective case series study of consecutive surgeries for Ahmed glaucoma valve (AGV; New World Medical) implantation in a 1-year period was analyzed. The surgery was performed using a Tisseel fibrin sealant (Baxter Healthcare Corporation) in place of sutures. Some subsets within the case series also included a cataract extraction with intraocular lens (CEIOL) insertion and/or ECP (Endo Optiks) within the same procedure. Primary outcomes for this study including efficacy (IOP change, reduction in medications) and safety (complications and reoperations) were measured out to 3 years. Comparisons between subsets were made using ANOVA with post hoc Tukey’s pairwise tests.

Results

One hundred twenty-two eyes of 99 patients underwent sutureless AGV implantation surgery. Of the 122, 18 had an AGV implantation only, 46 had an AGV + CEIOL, 35 had an AGV + ECP, and 23 had an AGV + CEIOL + ECP. In total, there was a significant decrease in IOP (P<0.0001) and number of glaucoma medications (P≤0.0054) at each postoperative visit. In a one-way ANOVA, there were no significant differences in mean IOP between the different subsets of surgeries (P>0.05); 10.7% and 14.8% of eyes required a reoperation either for a complication or for uncontrolled glaucoma, respectively.

Conclusion

Sutureless valve implantation is associated with a significant reduction in IOP percentage and medication use after the procedure with a safety profile comparable with other glaucoma surgeries.

A novel surgical technique for prevention of Ahmed glaucoma valve tube exposure: long scleral flap augmented with Tenon advancement and duplication

Background

To describe a new technique and present its long-term outcome for prevention of Ahmed glaucoma valve (AGV) tube exposure in patients with refractory glaucoma.

Methods

Twenty-seven eyes of 24 patients (mean age, 50 years; age range, 16–78 years; 8 females, 16 males) with refractory glaucoma who had the AGV implant were retrospectively reviewed. For AGV implantation, a long scleral flap combined with Tenon advancement and duplication was used. In this technique, a long scleral flap is created to completely cover the extraocular part of valve’s tube, and the flap surface is covered with duplicated Tenon’s tissue. The average follow-up after AGV implantation was 21.7 months (range, 12–36 months).

Results

The mean intraocular pressure before the operation, which was 44.1 mmHg (range, 26–62 mmHg), decreased to 14.2 mmHg (range, 8–20 mmHg) at the last follow-up visit, showing 67% reduction with AGV implantation. The mean number of antiglaucomatous medications was 4.1 before the AGV implantation and decreased to 0.9 after the operation, showing 88% reduction. In 14 eyes (51.9%), there was no change in the best corrected visual acuity (BCVA), and in 11 eyes (40.7%), the BCVA increased by 2 lines on the Snellen chart postoperatively. No patient developed postoperative hypotony, flat anterior chamber, diplopia, strabismus, erosion or exposure of the tube, or tube/plate migration.

Conclusions

The long scleral flap augmented with Tenon advancement and duplication is an effective and safe surgical technique for the implantation of AGV and preventing tube exposure in cases of refractory glaucoma.

Long-term outcomes of uveitic glaucoma treated with Ahmed valve implant in a series of Chinese patients

AIM

To report long-term outcomes of secondary glaucoma due to uveitis treated with Ahmed glaucoma valve (AGV) implantation in a series of Chinese patients.

METHODS

The retrospective study included 67 eyes from 56 patients with uveitic glaucoma who underwent AGV implantation. Success of the treatment was defined as patients achieving intraocular pressure (IOP) levels between 6 and 21 mm Hg with or without additional anti-glaucoma medications and/or a minimum of 20% reduction from baseline IOP. The main outcome measurements included IOP, the number of glaucoma medications at 1, 3, 6, 12, 24, 36, 48 and 60mo after surgery, surgical complications, final best-corrected vision acuity (BCVA), visual field (VF) and retinal nerve fiber layer (RNFL).

RESULTS

The mean follow-up was 53.3±8.5 (range 48 to 60)mo. The cumulative probability of success rate was 98.5%, 95.5%, 89.6%, 83.6%, 76.1%, 70.1%, 65.7% and 61.2% at 1, 3, 6, 12, 24, 36, 48 and 60mo, respectively. IOP was reduced from a baseline of 30.8±6.8 to 9.9±4.1, 10.1±4.2, 10.9±3.7, 12.9±4.6, 13.8±3.9, 13.2±4.6, 12.3±3.5 and 13.1±3.7 mm Hg at 1, 3, 6, 12, 24, 36, 48 and 60mo, respectively (P<0.01). The number of postoperative glaucoma medications was significantly decreased compared with baseline at all time points during the study period (P<0.05). There was no significant difference between preoperative and postoperative BCVA. Remarkable surgical complications were not found after surgery. The VF and RNFL of the patients were stable after the surgery.

CONCLUSION

AGV implantation is safe and effect in terms of reducing IOP, decreasing the number of glaucoma medications, and preserving vision for patients with uveitic glaucoma.

Single long scleral tunnel technique for prevention of Ahmed valve tube exposure

Purpose:

To evaluate the outcome of single long scleral tunnel technique for the prevention of conjunctival erosions caused by the Ahmed glaucoma valve.

Methods:

This study was a retrospective case series that included 30 eyes of 30 patients who underwent glaucoma valve implantation surgery by the single long scleral tunnel technique.

Results:

The mean age of patients at the time of surgery was 52 ± 21.6 years (range: 10–90 years). The mean visual acuity was 1.5 ± 0.81 logMAR preoperatively. The intraocular pressure was 40.7 ± 9.18 mm Hg (range: 25–58) before surgery that decreased significantly to 19.7 ± 3.1 mm Hg (range: 14–25; p < 0.0001) after a mean follow-up of 37.2 ± 5.9 months. During follow-up, no case of tube exposure was detected in patients.

Conclusion:

Single long scleral technique was efficacious with no occurrence of tube exposure in relatively long period of follow-up. In this method, there is no need to harvest any additional material, and in situations with limited access to patch grafts, it is performable with the minimal facilities.

Long-term results of Ahmed glaucoma valve implantation in Egyptian population

AIM

To evaluate the long-term results and complications of Ahmed glaucoma valve (AGV) implantation in a cohort of Egyptian patients.

METHODS

A retrospective study of 124 eyes of 99 patients with refractory glaucoma who underwent AGV implantation and had a minimum follow-up of 5y was performed. All patients underwent complete ophthalmic examination and intraocular pressure (IOP) measurement before surgery and at 1d, weekly for the 1^st month, 3, 6mo, and 1y after surgery and yearly afterward for 5y. IOP was measured by Goldmann applanation tonometry and/or Tono-Pen. Complications and the number of anti-glaucoma medications needed were recorded. Success was defined as IOP less than 21 mm Hg with or without anti-glaucoma medication and without additional glaucoma surgery.

RESULTS

Mean age was 23.1±19.9y. All eyes had at least one prior glaucoma surgery. IOP was reduced from a mean of 37.2±6.8 to 19.2±5.2 mm Hg after 5y follow-up with a reduced number of medications from 2.64±0.59 to 1.81±0.4. Complete and qualified success rates were 31.5% and 46.0% respectively at the end of follow-up. The most common complications were encapsulated cyst formation in 51 eyes (41.1%), complicated cataract in 9 eyes (7.25%), recessed tube in 8 eyes (6.45%), tube exposure in 6 eyes (4.8%) and corneal touch in 6 eyes (4.8%). Other complications included extruded AGV, endophthalmitis and persistent hypotony. Each of them was recorded in only 2 eyes (1.6%).

CONCLUSION

Although refractory glaucoma is a difficult problem to manage, AGV is effective and relatively safe procedure in treating refractory glaucoma in Egyptian patients with long-term follow-up. Encapsulated cyst formation was the most common complication, which limits successful IOP control after AGV implantation. However, effective complications management can improve the rate of success.

Aqueous Drainage Device Erosion: A Review of Rates, Risks, Prevention, and Repair

Aqueous drainage device tube erosions require prompt intervention to prevent endophthalmitis. As the use of drainage devices in glaucoma surgery continues to increase, recognizing and managing tube erosions is a pertinent issue. This review provides a comprehensive overview of tube erosions, including the rates of erosion with various types of patch grafts, the risk factors associated with erosion, and approaches to repair in order to counsel and treat our patients to prevent endophthalmitis.

A Review of the Ahmed Glaucoma Valve Implant and Comparison with Other Surgical Operations

The Ahmed glaucoma valve (AGV) is a popular glaucoma drainage implant used for the control of intraocular pressure in patients with glaucoma. While in the past AGV implantation was reserved for glaucoma patients poorly controlled after one or more filtration procedures, mounting evidence has recently encouraged its use as a primary surgery in selected cases. AGV has been demonstrated to be safe and effective in reducing intraocular pressure in patients with primary or secondary refractory glaucoma. Compared to other glaucoma surgeries, AGV implantation has shown favorable efficacy and safety. The aim of this article is to review the results of studies directly comparing AGV with other surgical procedures in patients with glaucoma.

Ahmed glaucoma valve implant: surgical technique and complications

Implantation of Ahmed glaucoma valve is an effective surgical technique to reduce intraocular pressure in patients affected with glaucoma. While in the past, the use of this device was reserved to glaucoma refractory to multiple filtration surgical procedures, up-to-date mounting experience has encouraged its use also as a primary surgery for selected cases. Implantation of Ahmed glaucoma valve can be challenging for the surgeon, especially in patients who already underwent previous multiple surgeries. Several tips have to be acquired by the surgeon, and a long learning curve is always needed. Although the valve mechanism embedded in the Ahmed glaucoma valve decreases the risk of postoperative hypotony-related complications, it does not avoid the need of a careful follow-up. Complications related to this type of surgery include early and late postoperative hypotony, excessive capsule fibrosis around the plate, erosion of the tube or plate edge, and very rarely infection. The aim of this review is to describe surgical technique for Ahmed glaucoma valve implantation and to report related complications.

Needle Revision With 5-fluorouracil for the Treatment of Ahmed Glaucoma Valve Filtering Blebs: 5-Fluoruracil Needling Revision can be a Useful and Safe Tool in the Management of Failing Ahmed Glaucoma Valve Filtering Blebs

PURPOSE

To determine the outcome of needling with adjunctive 5-fluorouracil (5-FU) in patients with a failing Ahmed glaucoma valve (AGV) implant, and to identify predictors of long-term intraocular pressure (IOP) control.

METHODS

A prospective observational study was performed on consecutive patients with medically uncontrolled primary open-angle glaucoma (POAG) with AGV encapsulation or fibrosis and inadequate IOP control. Bleb needling with 5-FU injection (0.1 mL of 50 mg/mL) was performed at the slit-lamp. Patients were examined 1 week following the needling, and then at months 1, 3, and 6. Subsequent follow-up visits were scheduled at 6-month intervals for at least 2 years. Needling with 5-FU was repeated no more than twice during the first 3 months of the follow-up. Procedure outcome was determined on the basis of the recorded IOP levels.

RESULTS

Thirty-six patients with an encapsulated or fibrotic AGV underwent 67procedures (mean 1.86 ± 0.83). Complete success, defined as IOP ≤ 18 mm Hg without medications, was obtained in 25% at 24 months of observation. The cumulative proportion of cases achieving either qualified (ie, IOP ≤ 18 mm Hg with medications) or complete success at 24 months of observation was 72.2%. In a univariate Cox proportional hazards model, age was the only variable that independently influenced the risk of failing 5-FU needling revision. Fourteen eyes (38.8%) had a documented complication.

CONCLUSIONS

Needling over the plate of an AGV supplemented with 5-FU is an effective and safe choice in a significant proportion of POAG patients with elevated IOP due to encapsulation or fibrosis.

The Results of the Use of Ahmed Valve in Refractory Glaucoma Surgery

The treatment of refractory glaucoma (RG) is challenging. The commonly adopted strategy in RG treatment is a glaucoma drainage device (GDD) implantation, which despite its radical nature may not always provide the desired intraocular pressure (IOP) levels for a long term. This review is based on the scientific literature on Ahmed glaucoma valve (AGV) implantation for refractory glaucoma. The technique of AGV implantation is described and data for both the types, FP7 and FP8 performance are presented. The outcome with adjunct antimetabolite and anti-VEGF drugs are also highlighted. An insight is given about experimental and histological examinations of the filtering bleb encapsulation. The article also describes various complications and measures to prevent them.

How to cite this article: Bikbov MM, Khusnitdinov II. The Results of the Use of Ahmed Valve in Refractory Glaucoma Surgery. J Curr Glaucoma Pract 2015;9(3):86-91.

Outcomes of Ahmed valve surgery for refractory glaucoma in Dhahran, Saudi Arabia

AIM

To evaluate the outcomes of Ahmed glaucoma valve (AGV) implantation surgery for refractory glaucoma.

METHODS

This one-armed historical cohort study was conducted in 2011. Refractory glaucoma was defined as eyes with an intraocular pressure (IOP) greater than 21 mm Hg with maximally tolerated glaucoma medications, failed surgeries, or both. For all eyes with refractory glaucoma that underwent AGV implantation, data were collected on IOP, the best corrected visual acuity (BCVA) and glaucoma medications preoperatively and 4, 6, 12, 24 and 56wk postoperatively. Logarithm values of IOP were calculated and compared.

RESULTS

The study group was comprised of 30 patients (30 eyes, 16 males and 14 females) with refractory glaucoma. Mean preoperative IOP was 39.3±13.8 mm Hg. Postoperative mean IOP was 15.7±7.1 mm Hg, 19.6±12.8 mm Hg and 13.9±14.2 mm Hg at 12, 24 and 56wk respectively. BCVA was ≥ 6/60 in 11 eyes preoperatively, and five eyes had BCVA≥6/60 at 56wk postoperatively. Preoperatively, more than four medications were used to treat glaucoma in 21 eyes. At 12wk postoperatively, no medications were required to control IOP in 20 eyes. At 56wk postoperatively, at least one medication was required to control IOP in 10 eyes. Over the entire follow up period, four eyes were treated with yttrium aluminium garnet (YAG) laser and 14 eyes required a second surgery. The AGV was removed in four eyes.

CONCLUSION

AGV implantation reduced IOP and the number of medications required to control refractory glaucoma. However, there was a higher risk of decreased vision. Long-term follow up and prompt intervention are recommended.

Surgical results of Ahmed valve implantation combined with intravitreal triamcinolone acetonide injection for preventing choroidal detachment

Background

To investigate the surgical results of Ahmed valve implantation with intravitreal triamcinolone acetonide injection (IVTA) in patients with aphakic or pseudophakic glaucoma.

Methods

Fifty-nine patients who underwent Ahmed valve implantation were consecutively recruited from November 2005 to August 2011 at the Beijing Tongren Hospital. In the IVTA group (29 eyes), 4 mg of TA was injected into the vitreous cavity during Ahmed valve implantation was performed. In the control group (30 eyes), only Ahmed valve implantation was performed. The primary outcome was intraocular pressure (IOP). The visual acuity (VA), supplemental medical therapy and complications were evaluated as secondary outcomes.

Results

The IVTA and control groups were followed up for a mean of 22.7 and 31.4 months, respectively. IOP decreased in both groups at 1 day, 1 week, 1 month and the final follow-up points after the surgery. However, there was no significant difference between 2 groups at all intervals (P > 0.05). The rate of shallow anterior chamber and choroidal detachment in IVTA group was significantly lower than control group (6.9% vs. 40%, P = 0.007; 0% vs. 26.7%, P = 0.009).

Conclusions

Ahmed valve implantation combined IVTA seems to be effective to reduce the incidence of complications for treatment of aphakic or pseudophakic glaucoma.

Hypertensive phase and early complications after Ahmed glaucoma valve implantation with intraoperative subtenon triamcinolone acetonide

Objective

To evaluate intraoperative subtenon triamcinolone acetonide (TA) as an adjunct to Ahmed glaucoma valve (AGV) implantation.

Design

Retrospective comparative case series.

Participants

Forty-two consecutive cases of uncontrolled glaucoma undergoing AGV implantation: 19 eyes receiving intraoperative subtenon TA and 23 eyes that did not receive TA.

Methods

A retrospective chart review was performed on consecutive pseudophakic adult patients with uncontrolled glaucoma undergoing AGV with and without intraoperative subtenon TA injection by a single surgeon. Clinical data were collected from 42 eyes and analyzed for the first 6 months after surgery.

Main outcome measures

Primary outcomes included intraocular pressure (IOP) and number of glaucoma medications prior to and after AGV implantation. The hypertensive phase (HP) was defined as an IOP measurement of greater than 21 mmHg (with or without medications) during the 6-month postoperative period that was not a result of tube obstruction, retraction, or malfunction. Postoperative complications and visual acuity were analyzed as secondary outcome measures.

Results

Five out of 19 (26%) TA cases and 12 out of 23 (52%) non-TA cases developed the HP (P=0.027). Mean IOP (14.2±4.6 in TA cases versus [vs] 14.7±5.0 mmHg in non-TA cases; P=0.78), and number of glaucoma medications needed (1.8±1.3 in TA cases vs 1.6±1.1 in the comparison group; P=0.65) were similar between both groups at 6 months. Although rates of serious complications did not differ between the groups (13% in the TA group vs 16% in the non-TA group), early tube erosion (n=1) and bacterial endophthalmitis (n=1) were noted with TA but not in the non-TA group.

Conclusions

Subtenon TA injection during AGV implantation may decrease the occurrence of the HP but does not alter the ultimate IOP outcome and may pose increased risk of serious complications within the first 6 months of surgery.

Evaluation of the tightness of contact between limbal sclera tunnel and tube following Ahmed glaucoma valve implantation

PURPOSE

To investigate whether the tightness of contact between the tube and the limbal sclera tunnel can be evaluated with high-magnification anterior segment optical coherence tomography (OCT) imaging following Ahmed glaucoma valve implantation.

METHODS

Tightness between the tube and the limbal sclera tunnel was investigated with the CAM-L cornea lens adapter of the Optovue Fourier-domain OCT (RTVue-OCT) for 21 uncomplicated Ahmed glaucoma valves implanted in 20 eyes of 19 patients with glaucoma. Nineteen valves were implanted 4 to 124 months earlier (late postoperative cases) and 2 valves 1 day prior to the imaging (early postoperative cases). All valves were introduced into the anterior chamber via a limbal sclera tunnel.

RESULTS

The limbal intratunnel part of the tube was successfully imaged in all but 2 cases where an additional full-thickness sclera patch was used. In 14 cases, the contact was tight without tube compression. In 
5 cases, the tube was partially compressed but remained open in the limbal sclera tunnel, and redilated behind the limbus. No case with loose contact or peritubular filtration was seen. The posterior run of the tube was successfully imaged in all 19 cases without a full-thickness sclera patch.

CONCLUSION

High-magnification imaging with the CAM- L anterior segment adapter of the RTVue-OCT allows detailed examination of the limbal insertion area of tubes in both the early and late postoperative periods. Therefore this method may potentially be applied for detection of complications related to tube insertion after glaucoma drainage device surgery.