Long-term Clinical Outcomes of Pars Plana Versus Anterior Chamber Placement of Glaucoma Implant Tubes

Comparison of Ahmed glaucoma drainage implant outcomes in the anterior chamber versus pars plana

OBJECTIVE

To compare long-term outcomes of eyes undergoing Ahmed glaucoma drainage implants in the anterior chamber versus the pars plana.Retrospective cohort study.

PARTICIPANTS

Operated patients were divided into anterior-chamber or pars plana groups.

METHODS

Follow-up data included intraocular pressure (IOP), need for antiglaucoma medications (AGMs), and postoperative complications. Treatment success was evaluated based on the following criteria: IOP ≤21 mm Hg and no AGM use, IOP ≤21 mm Hg with or without AGM use, IOP ≤18 mm Hg and no AGM use, IOP ≤18 mm Hg with or without AGM use, IOP ≤15 mm Hg and no AGM use, and IOP ≤15 mm Hg with or without AGM use.

RESULTS

A total of 170 eyes were selected and split into an anterior-chamber group (n = 57) and a pars plana group (n = 113). No differences between groups were found on the decrease in IOP (p = 0.612) or number of AGMs (p = 0.695) in the postoperative period. No differences regarding corneal decompensation (p = 0.554) or retinal detachment (p = 0.168) were observed between groups. The 1-year success rates for all the criteria were, respectively, 89%, 96%, 88%, 92%, 88% and 90%; the 3-year success rates for all the criteria were, respectively, 33%, 61%, 32%, 55%, 28%, and 45%; and the 5-year success rates for all the criteria were, respectively, 7%, 48%, 7%, 36%, 4% and 17%.

CONCLUSIONS

No differences between the groups were observed for long-term outcomes of IOP, AGM use, or postoperative complications. Success rates were comparable between groups, decreased along the follow-up time, and were higher when associated with AGM use.

Clinical Factors Impacting Outcomes From Failed Trabeculectomy Leading to Glaucoma Drainage Device Implantation and Subsequent Penetrating Keratoplasty

PRCIS

We evaluated the factors that impacted time from glaucoma drainage implant (GDI) surgery to penetrating keratoplasty (PK) in eyes with previously clear corneas (ie, GDI-first sequence), and that specifically underwent a trabeculectomy before GDI surgery for intraocular pressure (IOP) control.

PURPOSE

To describe through an event-triggered data collection method the clinical course and the long-term outcomes of 2 procedures that are commonly performed sequentially in complex clinical situations: GDI surgery and PK. The study investigates the clinical factors associated with the progression to PK and determines the GDI success rate and graft survival.

METHODS

A single, tertiary-care center retrospective interventional cases series including patients with a sequential history of trabeculectomy, GDI surgery, and PK from 1999 to 2009. Outcome measures included IOP, visual acuity, graft failure, GDI failure, and time from GDI to PK.

RESULTS

Of the eyes, 56% had primary open angle glaucoma. The time from the last trabeculectomy to GDI was 66.5 ± 66.7 months. Of the eyes, 84% received a Baerveldt GDI. Time from GDI to PK was 36.4 ± 28.4 months. IOP at the time of PK was between 5 mm Hg and 21 mm Hg in 90% of eyes. At the last follow-up, 48% of grafts were clear. At 5 years post-PK, 33% of corneal grafts remained clear, whereas 81% of tubes remained functional.

CONCLUSIONS

Nearly half of the corneal grafts are clear at the last long-term follow-up. Graft failure occurs at a higher rate than tube failure suggesting that IOP control is only one and possibly not the most important factor in graft survival in eyes with prior glaucoma surgery.

Tube–Iris Distance and Corneal Endothelial Cell Damage Following Ahmed Glaucoma Valve Implantation

The most significant factor for endothelial cell loss should be readily identified, since prevention is the most crucial treatment. Here, we investigate risk factors for corneal endothelial cell density (ECD) decline following Ahmed glaucoma valve (AGV) implantation and determine the optimal cut-off values. This study included 103 eyes (95 patients) with glaucoma that underwent AGV implantation between January 2006 and January 2021 at a single medical center (Severance Hospital). We conducted consecutive t-tests between two groups separated by the ECD change rate to determine the survival state of the enrolled patients. Associations were evaluated using univariable and multivariable linear regressions. Optimal cut-off values for identified risk factors were analyzed using a Cox proportional hazards model and a receiver operating characteristic (ROC) curve based on logistic regression. Mean follow-up duration was 4.09 ± 2.20 years. After implementing consecutive t-tests, only patients with an ECD change rate greater than −6.1%/year were considered to have survived. Tube–iris distance (TID) was the only statistically significant factor identified in both the univariable and multivariable linear regressions. The cut-off value determined from the consecutive Cox regression method was 0.33 mm (smallest p-value of 0.0087), and the cut-off value determined from the ROC method was 0.371 mm (area under the receiver operating characteristic curve [AUC], 0.662). Patients with short TIDs showed a better ECD prognosis following AGV surgery; we suggest optimal TID cut-off values of 0.33 mm and 0.371 mm based on the implemented Cox regression and ROC methodology, respectively.

Der Intraokulardruck nach Netzhauteingriffen

Zusammenfassung - Deutsch Netzhauteingriffe können zu einem erhöhten Augeninnendruck führen. Die Ursachen hierfür sind vielfältig und schließen mechanische aber auch pharmakologische Gründe ein. Die Therapie besteht zunächst aus einer Lokaltherapie mit drucksenkenden Augentropfen. Bei unzureichendem Ansprechen sind chirurgische Eingriffe indiziert. Summary - English Retinal surgery can lead to an elevated intraocular pressure. The causes for this are manifold and include mechanical but also pharmacological reasons. Therapy consists initially of topical therapy with pressure-lowering eye drops. In case of inadequate response, surgical interventions are indicated.

Outcomes of Anterior Chamber, Sulcus, and Pars Plana Glaucoma Drainage Device Placement in Glaucoma Patients

Purpose

To assess outcomes of anterior chamber (AC), sulcus, and pars plana (PP) glaucoma drainage device (GDD) placement in glaucoma patients. Patients and Methods. Retrospective evaluation of glaucoma patients who underwent GDD insertion in the AC, sulcus, or PP at Massachusetts Eye and Ear between November 2016 and May 2021. Patients who received AC, sulcus, and pars plana tubes were selected using simple random sampling, and the first 40 patients meeting inclusion criteria were analyzed. Main outcome measures were cumulative success probabilities from Kaplan-Meier (KM) analyses, intraocular pressure (IOP), medication burden, and complication rates.

Results

The PP group had a larger proportion of Ahmed GDDs and was younger on average with less severe glaucoma compared to patients with AC or sulcus tubes. The PP group had a higher proportion of mixed-mechanism glaucoma and lower proportion of primary open-angle glaucoma. With success defined as IOP reduction ≥20% and 5 < IOP ≤ 21 mm Hg, the Kaplan-Meier cumulative success probabilities for all three GDD locations were not significantly different. No significant differences were found in complication rates between all groups after 3 months. Patients with PP GDD had significantly lower medication burden than those with AC or sulcus GDDs up to 1.5 years postoperatively (1.7 ± 1.1, 3.0 ± 1.4, and 2.8 ± 1.2 for PP, AC, and sulcus, respectively; P=0.017).

Conclusion

PP GDDs may be more effective in lowering medication burden than AC or sulcus tubes without compromising long-term safety.

Pars plana Aurolab aqueous drainage implantation for refractory glaucoma: Outcome of a new modified technique

PURPOSE

To report the outcomes of pars plana insertion of Aurolab aqueous drainage implant (AADI) in adults with refractory glaucoma by the novel technique of making scleral tunnel instead of patch graft to cover the tube to prevent its migration.

METHODS

A retrospective study was done between April 2016 and April 2018 on patients with ≥12 months of follow-up. The main outcome measure was a surgical failure at 12 months. The failure was defined as intraocular pressure (IOP) >18 mmHg or IOP ≤5 mmHg on two consecutive follow-up visits after 3 months, reoperation for glaucoma, loss of light perception vision, or implant explantation. Alternate definitions of failure including IOP >21 and IOP >15 mmHg were also considered.

RESULTS

: The study included 32 eyes of 32 patients. The mean age was 46.2 ± 17.5 years. The most common etiology is traumatic glaucoma (12 eyes, 37.5%). The mean preoperative IOP and anti-glaucoma medications were 43.3 ± 10.3 and 3.4 ± 0.5 mmHg, respectively; both the parameters at the final follow-up were reduced to 15.2 ± 8.1 and 1.6 ± 0.5 mmHg. The Kaplan-Meier survival estimates demonstrated that the cumulative probability of failure was 15.6% (95% CI; 6.8-33.5%) at 3 months, 18.7% (95% CI; 8.9-37.0%) at 6 months, and 25.0% (95% CI; 13.4-43.8%) at 12 months.

CONCLUSION

Pars plana AADI implantation with a newer modification technique is a useful procedure in reducing IOP and the number of anti-glaucoma medications in the eyes with refractory glaucoma. The visual acuity may be stabilized with the concurrent treatment of posterior segment pathology.

Corneal endothelial cell changes and surgical results after Ahmed glaucoma valve implantation: ciliary sulcus versus anterior chamber tube placement

We compared the changes in corneal endothelial cells and surgical outcomes after Ahmed glaucoma valve (AGV) implantation with the valve tip inserted either into ciliary sulcus (CS) or anterior chamber (AC). We retrospectively reviewed the medical records of patients treated with CS AGV (n = 24) and AC AGV (n = 38). We compared the preoperative and postoperative central corneal endothelial cell density (ECD), endothelial cell coefficient of variation (CV), best-corrected visual acuity, intraocular pressure (IOP), number of glaucoma medications, and postoperative complications in the two groups. Both groups had similar baseline characteristics and follow-up period. At the last follow-up, the AC AGV group had significantly higher mean monthly ECD loss (17.47 ± 11.50 cells/mm² vs. 6.40 ± 7.69 cells/mm², p < 0.0001) and greater proportion of mean monthly ECD loss than the CS AGV group (0.84 ± 0.53 vs. 0.36 ± 0.39%, p < 0.0001). Both groups had similar mean monthly CV changes. The qualified success rates at 2 years were 83.3% and 76.3% for the CS AGV and AC AGV groups, respectively. Although similar surgical outcomes including visual acuity, IOP, number of glaucoma medications, and postoperative complications were obtained following CS AGV and AC AGV, corneal ECD loss was higher in the AC AGV group. Thus, CS AGV may be a better surgical option than AC AGV.

Combined pars plana glaucoma drainage device placement and vitrectomy using a vitrectomy sclerotomy site for tube placement: a case series

Purpose

The purpose of this study is to report the safety and efficacy of pars plana glaucoma drainage devices with pars plana vitrectomy using one of the vitrectomy sclerotomy sites for tube placement in patients with refractory glaucoma.

Methods

Retrospective case series of 28 eyes of 28 patients who underwent combined pars plana glaucoma drainage device and pars plana vitrectomy between November 2016 and September 2019 at Massachusetts Eye and Ear. Main outcome measures were intraocular pressure (IOP), glaucoma medication burden, best corrected visual acuity, and complications. Statistical tests were performed with R and included Kaplan-Meier analyses, Wilcoxon paired signed-rank tests, and Fisher tests.

Results

Mean IOP decreased from 22.8 mmHg to 11.8 mmHg at 1.5 years (p = 0.002), and mean medication burden decreased from 4.3 to 2.1 at 1.5 years (p = 0.004). Both IOP and medication burden were significantly lower at all follow-up time points. The probability of achieving 5 < IOP ≤ 18 mmHg with at least 20% IOP reduction from preoperative levels was 86.4% at 1 year and 59.8% at 1.5 years. At their last visit, three eyes (10.7%) achieved complete success with IOP reduction as above without medications, and 14 eyes (50.0%) achieved qualified success with medications. Hypotony was observed in 1 eye (3.6%) prior to 3 months postoperatively and 0 eyes after 3 months. Visual acuity was unchanged or improved in 23 eyes (82.1%) at their last follow-up. Two patients had a visual acuity decrease of > 2 lines. Two eyes required subsequent pars plana vitrectomies for tube obstruction, and one eye had transient hypotony.

Conclusions

The results of pars plana glaucoma drainage device and pars plana vitrectomy using one of the vitrectomy sclerotomy sites for tube placement are promising, resulting in significant IOP and medication-burden reductions through postoperative year 1.5 without additional risk of postoperative complications. Inserting glaucoma drainage devices into an existing vitrectomy sclerotomy site may potentially save surgical time by obviating the need to create another sclerotomy for tube placement and suture one of the vitrectomy ports.

The Effect of Tube Location on Corneal Endothelial Cells in Patients with Ahmed Glaucoma Valve

PURPOSE

To compare the effects of the Ahmed glaucoma valve (AGV; New World Medical, Rancho Cucamonga, CA) with sulcus versus anterior chamber (AC) tube placement on the corneal endothelial density and morphology over time.

DESIGN

Nonrandomized, interventional study.

PARTICIPANTS

This study included 106 eyes from 101 pseudophakic patients who had the AGV tube placed in the AC (acAGV) and 105 eyes from 94 pseudophakic patients who had the AGV tube placed in the ciliary sulcus (sAGV).

METHODS

All patients underwent preoperative specular microscopy, which was repeated postoperatively in 2019. The patients' demographic information, glaucoma diagnoses, and basic ocular information were obtained on chart review. Anterior segment OCT was conducted for patients who underwent sAGV to evaluate the sulcus tube position. Gonioscopy was performed to document peripheral anterior synechiae (PAS). Linear mixed-effects models were used to compare the different ocular and endothelial measurements between the 2 groups and to identify risk factors for endothelial cell density (ECD) loss over time.

MAIN OUTCOME MEASURES

Monthly change in corneal endothelial measurements, including ECD and coefficient of variation (CV), calculated as the difference between preoperative and postoperative measurements divided by the number of months from the time of surgery to postoperative specular microscopy.

RESULTS

The acAGV and sAGV groups were comparable in all baseline characteristics except that the acAGV group had longer follow-up (37.6 vs. 20.1 months, respectively, P < 0.001). Mean monthly loss in central ECD was significantly more in the acAGV group (mean ± standard deviation: 29.3±29.7 cells/mm²) than in the sAGV group (15.3±20.7 cells/mm², P < 0.0001). Mean monthly change in CV was similar between the 2 groups (P = 0.28). Multivariate analyses revealed that younger age and tube location in the AC were associated with faster central ECD loss (P = 0.02, P < 0.0001, respectively). For patients with sAGV, while PAS was associated with faster central ECD loss (P = 0.002), a more forward tube position tenting the iris was not (P > 0.05).

CONCLUSIONS

Compared with anterior segment placement, ciliary sulcus tube implantation may be a preferred surgery approach to reduce endothelial cell loss in pseudophakic patients.

Effects of Baerveldt Glaucoma Implant Surgery on Corneal Endothelial Cells of Patients with No History of Trabeculectomy

Purpose

Persistent corneal edema is a serious potential complication of Baerveldt glaucoma implant (BGI) surgery. A trabeculectomy reduces the density of corneal endothelial cells. We investigated the effect of BGI surgery on corneal endothelial cells of patients with no history of trabeculectomy.

Methods

We retrospectively analyzed 85 eyes of 85 patients who underwent BGI surgery and were followed-up for ≥12 months. We used new criteria for surgical failure. We defined persistent corneal edema or needed additional surgery for changing the tube position due to remarkable reduction in corneal endothelial cells as failure. We compared surgical outcomes with new criteria and the rates of corneal endothelial cell density (ECD) loss after BGI surgery between the anterior chamber insertion (AC) group (n=23) and vitreous cavity insertion (VC) group (n=63).

Results

The mean pre-operative ECD values of the AC and VC groups were not significantly different at 2309 ± 498 and 2204 ± 556 (p=0.426). The ECD reduction rate in the AC group was significantly faster than in the VC group. The mean post-operative IOP values significantly decreased in both groups. However, the VC group's surgical outcomes were significantly better than the AC group's (p=0.0241) with the new criteria.

Conclusion

The mean of ECD did not decrease significantly after BGI surgery in VC group patients with no history of trabeculectomy. BGI surgery insertion to the vitreous cavity was safe and had much less effect on the ECD decrease compared to insertion to the anterior chamber.

Comparison of pars plana with anterior chamber glaucoma drainage device implantation for glaucoma: a meta-analysis

Background

The purpose of this study was to compare the efficacy and safety of pars plana glaucoma drainage device (PP GDD) with anterior chamber glaucoma drainage device (AC GDD) for the treatment of glaucoma.

Methods

We comprehensively searched three databases, including PubMed, EMBASE, and the Cochrane Library databases, selecting the relevant studies. The continuous variables, namely, intraocular pressure (IOP) and glaucoma medications, were pooled by the weighted mean differences (WMDs), and the dichotomous outcomes, including corneal failure incidence and overall complications incidence, were pooled by the odds ratio (ORs).

Results

Four retrospective studies involving 275 eyes were evaluated, with 135 in the PP GDD group and 140 in the AC GDD group. The WMDs of the IOP reduction between the PP GDD group and the AC GDD group were − 1.01 mmHg (95% CI -4.05 to 2.03, p = 0.52). The WMDs of the glaucoma medications reduction between the PP GDD group and the AC GDD group were 0.23 (95% CI -0.11 to 0.56, p = 0.19). The pooled ORs comparing PP GDD group with AC GDD group were 1.01 (95% CI 0.03 to 40.76, p = 0.99) for corneal failure incidence and 1.19 (95% CI 0.68 to 2.09, p = 0.54) for overall complication incidence. There were no significant differences between PP GDD group and AC GDD group on these aspects.

Conclusions

Both PP GDD and AC GDD procedures had similar efficacy of reduction in the IOP and number of medications. They are also both comparable on the safety with similar incidence of corneal failure and overall complications.

Electronic supplementary material

The online version of this article (10.1186/s12886-018-0896-x) contains supplementary material, which is available to authorized users.