Preservation of corneal endothelium after pars plana tube insertion of the Ahmed glaucoma valve

Survey of the American Glaucoma Society Membership on Current Glaucoma Drainage Device Placement and Postoperative Corticosteroid Use

Purpose

To assess practice patterns and opinions of glaucoma specialists regarding glaucoma drainage device tube shunt placement and post-operative anti-inflammatory medication use. We also assess the perceived need for a randomized control trial to compare them.

Patients and Methods

An online survey was distributed to a group of glaucoma specialists from the American Glaucoma Society via the American Glaucoma Society forum from April to August 2021.

Results

One hundred and twenty-eight responses were included. Ninety percent placed tubes in the anterior chamber. Sixty-one percent reported that evidence suggested the superiority of sulcus tube placement over the anterior chamber, whereas 34% reported there was not enough evidence to suggest superiority of either in preventing endothelial cell loss. Comparing these techniques for intraocular pressure control, 49% reported evidence suggested sulcus tube placement superiority whereas 46% reported there was not enough evidence. Over 40% of respondents reported that they were either unfamiliar with literature or that there was not enough evidence to support the superiority of difluprednate 0.05% over prednisolone 1% for post-operative use in preventing endothelial cell loss and for intraocular pressure control. Ninety percent and 81% of respondents respectively would benefit from randomized control trials comparing outcomes of anterior chamber vs sulcus tube placement and post-operative corticosteroid usage.

Conclusion

Most glaucoma specialists surveyed place glaucoma drainage device tube in the anterior chamber over the sulcus. A randomized control trial to determine optimal tube placement and post-operative anti-inflammatory medication use for preventing endothelial cell loss would change current glaucoma drainage device practice patterns.

Corneal endothelial cell density loss following glaucoma surgery alone or in combination with cataract surgery: A systematic review and meta-analysis

TOPIC

Corneal endothelial cell density (ECD) loss following glaucoma surgery with or without cataract surgery.

CLINICAL RELEVANCE

Corneal ECD loss may occur due to intraoperative surgical trauma in glaucoma surgery or postoperatively with chronic endothelial cell trauma or irritation.

METHODS

Trabeculectomy, glaucoma filtration surgery or microinvasive glaucoma surgery in participants with ocular hypertension, primary and secondary open angle glaucoma, normal tension glaucoma and angle-closure glaucoma were included. Pediatric populations and participants with pre-existing corneal disease were excluded. Laser treatments and peripheral iridotomy were excluded. Electronic databases searched in December 2021 included MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), ClinicalTrials.gov and The International Prospective Register of Systematic Reviews (PROSPERO), FDA PMA and FDA 510(k).

RESULTS

39 studies were included in quantitative synthesis. 12 months following suprachoroidal MIGS mean ECD loss was 282 cells/mm² (95% Confidence Interval (CI) 220 to 345; p <0.00001; Chi² = 0.06; I² = 0%; 2 studies; very low certainty). Mean ECD loss after Schlemm's canal implantable devices was 338 cells/mm² (95% CI 185 to 491; p<0.0001; Chi² = 0.08; I² = 0%; 2 studies; low certainty) at 12 months. When compared to phacoemulsification alone, Schlemm's canal implants combined with phacoemulsification showed statistically significant mean ECD reduction at 24 months; mean difference of ECD was -19% (95% CI -37% to -2%; p=0.03; Chi² = 3.04; I² = 34%; 3 studies; low certainty). Mean ECD loss was 64 cells/mm² (95% CI 21 to 107; p=0.004; Chi² = 4.55; I² = 0%; 6 studies; low certainty) following Schlemm's canal procedures (without implantable devices) at 12 months. At 12 months the mean ECD loss after trabeculectomy was 33 cells/mm² (95% CI -38 to 105, p=0.36, Chi² = 1.17; I² = 0%; moderate certainty). At 12 months mean ECD loss was 121 cells/mm² (95% CI 53 to 189; p=0.0005; Chi² = 3.00; I² = 0%; 5 studies; low certainty) after Express implantation. When compared to control fellow eye, aqueous shunt surgery reduced ECD by 5.75% (95% CI -0.93 to 12.43; p=0.09 Chi² = 1.32; I² = 0%; low certainty) and 8.11% ECD loss (95%CI 0.06 to 16.16 p=0.05; Chi²= 1.93; I²=48%) at 12 and 24 months, respectively.

CONCLUSIONS

Overall there is low certainty evidence to suggest that glaucoma surgery involving long-term implants has a greater extent of ECD loss than glaucoma filtration surgeries without the use of implants. The results of this review support long-term follow-up (beyond 36 months) to assess ECD loss and corneal decompensation following implantation of glaucoma drainage implants.

Effect of Postoperative Trimming of the Tube Portion of Ahmed Glaucoma Valve on Corneal Endothelial Cell Loss

PRCIS

We reduced the tube length through a small limbal incision in eyes that underwent Ahmed glaucoma valve (AGV) implantation and found that the rate of corneal endothelial cell (CEC) density was markedly reduced from -12.2% per year to -3.5% per year after this simple procedure.

PURPOSE

The aim was to evaluate the effect of postoperative tube tip trimming (TT) after AGV implantation on CEC loss.

METHODS

In this retrospective cohort study, a total of 75 eyes from 67 patients (41 eyes in the AGV implantation only group (AGVG: mean follow-up, 42.2±13.8 mo) and 34 eyes in the TT after AGV implantation group (TAGVG: mean follow-up, 64.9±18.5 mo) were analyzed. TT was performed through a small limbal incision at a mean of 41 months after AGV implantation. Both groups were followed up for at least 1 year and underwent at least 2 specular microscopic examinations after AGV implantation and/or TT.

RESULTS

In the AGVG, CEC density was reduced from 2247.0±527.3 to 1665.7±643.3 cells/mm2 (P<0.001). In the TAGVG, it was reduced from 2383.1±619.4 to 1552.9±700.9 cells/mm2 before TT (mean 41 mo of follow-up) and after TT, to 1394.6±654.7 cells/mm2 (mean 26 mo of the follow-up). The reduction rate of CEC density before TT was -12.2±6.5% per year, and this rate was significantly reduced to -3.5±6.9% per year after TT in the TAGVG (P=0.002). The probability of corneal failure defined as a 15% reduction in CEC density was significantly reduced after TT in TAGVG (P=0.038).

CONCLUSIONS

Tube TT after AGV implantation markedly reduced the rate of CEC loss without serious complications in eyes with AGV implantation.

Three-year outcome of sulcus fixation of Baerveldt glaucoma implant surgery

PURPOSE

The purpose of this study was to evaluate the 3-year surgical outcome of the sulcus fixation of Baerveldt glaucoma implant (BGI), focusing on corneal damage.

METHODS

This prospective observational study included 37 patients who underwent a median of two previous glaucoma surgeries and sulcus fixation of BGI for the first time. Each patient's intraocular pressure (IOP), glaucoma drug score, corneal endothelial cell density (ECD), and logMAR-converted best-corrected visual acuity (VA) were measured preoperatively and postoperatively until 36 months after surgery. Complete success was defined as reduced IOP (5-21 mmHg and >20% rate), without corneal damage (postoperative development of decompensation, unmeasurable ECD, or reduction in ECD of >20%), without loss of light perception, and without additional surgery requirement. Qualified success was defined by excluding the corneal criteria from complete success.

RESULTS

A total of 51% (19/37) patients experienced complete treatment success, whereas 86% (32/37) had qualified success. The median IOP (glaucoma drug score) decreased from 26 mmHg (5) to 15 mmHg (2) at three years postoperatively. The median postoperative ECD (reduction rate) decreased from 1838 cells/cm² preoperatively to 1587 cells/mm² (14%) at one year, 1358 cells/mm² (26%) at two years, and 1228 cells/mm² (33%) at three years postoperatively. One month after surgery, the VA was significantly reduced from preoperative values but did not decline after that.

CONCLUSION

Sulcus fixation of BGI was effective for IOP reduction. However, ECD decreased over time.

Anterior Chamber Versus Ciliary Sulcus Ahmed Glaucoma Valve Tube Placement: Longitudinal Evaluation of Corneal Endothelial Cell Profiles

PRCIS

An Ahmed glaucoma valve (AGV) tube in the ciliary sulcus (CS) is safer for the endothelium. At 4 years of follow-up, there was a significant decrease in endothelial cell count only with anterior chamber (AC) placement.

PURPOSE

Corneal endothelium (CE) damage is one of the most feared long-term complications that can result from glaucoma drainage devices. Nonetheless, there is a lack of studies evaluating longitudinal changes in CE cells. This study aims to compare CE changes after AGV implantation in eyes with AC or CS tube placement.

MATERIALS AND METHODS

This was a retrospective, nonrandomized, longitudinal study of pseudophakic eyes with open-angle glaucoma and medically uncontrolled intraocular pressure that received an AGV. Eyes with additional glaucoma surgeries performed during follow-up were excluded. The main outcome measure was endothelial cell density (ECD), which was evaluated 1 year±2 months and 4 years±2 months postoperatively. The average endothelial cell size (AS) and the distance from the tube tip to the cornea were also evaluated.

RESULTS

Twenty-six eyes from 26 patients, with a mean age of 73±10 years, were included. The tube was placed in the AC in 15 eyes and in the CS in 11 eyes. The eyes with tube placement in the AC showed a significant AS increase (P=0.007) and ECD decrease (P=0.034), whereas eyes with tube placement in the CS had no significant AS (P=0.575) or ECD (P=0.445) change. In the eyes with tube placement in the AC, there was no correlation between DTC and ECD (P=0.260) or AS (P=0.428) changes.

CONCLUSIONS

Tube placement in the AC seems to lead to significant CE cell loss over time, compared with tube placement in the CS.

A case of chronic retinal necrosis after tube shunt surgery for secondary glaucoma associated with cytomegalovirus corneal endotheliitis

BACKGROUND

We report a case of chronic retinal necrosis (CRN) combined with cytomegalovirus (CMV) corneal endotheliitis.

CASE PRESENTATION

An 80-year old man was diagnosed with CRN that developed after tube shunt surgery with vitrectomy for secondary glaucoma associated with CMV corneal endotheliitis. After the use of oral valganciclovir and panretinal photocoagulation, the retinal lesion resolved rapidly and he has maintained visual acuity better than before the onset of CRN.

CONCLUSIONS

Use of oral valganciclovir, prophylactic panretinal photocoagulation for the non- perfusion area and vitrectomy were effective in maintaining the visual acuity for the patient with CRN.

Surgical Results of Ahmed Glaucoma Valve Implantation in One-chamber Eyes

PRECIS

Ahmed glaucoma valve (AGV) implantation in eyes with damaged iris-lens diaphragms ("1-chamber" eyes) resulted in mean intraocular pressure (IOP) and antiglaucoma medications decreases of 66% and 59% (P<0.0001 for both), respectively, at the mean 23-month follow-up.

PURPOSE

The purpose of this study was to report the results of AGV implantation with pars plana tube insertion to control IOP in glaucomatous eyes with damaged iris-lens diaphragms ("1-chamber" eyes).

METHODS

The medical records of 52 consecutive glaucomatous 1-chamber eyes (48 Japanese patients, mean age±SD, 76.0±11.2 y) were retrospectively reviewed. Other than aphakic eyes, eyes were defined as having 1 chamber if intraocular lenses (IOLs) were sclerally or intrasclerally fixated, IOLs were fixed on-the-bag due to posterior capsular defects, vitreous collapse into the anterior chamber resulted from Zinn zonular dialysis, and phacodonesis or IOL-donesis required lens/IOL explantation during AGV implantation. The data collected were preoperative/postoperative IOPs, numbers of antiglaucoma medications, visual acuity, anterior chamber flare, visual field mean deviation, corneal endothelial cell density, and surgical complications/interventions.

RESULTS

The preoperative IOP (28.5±9.4 mm Hg) and a number of antiglaucoma medications (3.2±1.2) decreased significantly (P<0.0001 for both) to 9.8±3.3 mm Hg and 1.3±1.3, respectively, at the final visit (mean follow-up, 23 mo). The success rates of IOP control (6 to 21 mm Hg and >20% reduction irrespective of medication use) were 82.5% and 79.0%, respectively, at postoperative years 1 and 2. The most common postoperative complications were macular edema (n=9, 17%), choroidal detachment (n=8, 15%), vitreous hemorrhage (n=7, 13%), and hyphema (n=7, 13%). The most common postoperative intervention was tubal repositioning/reopening (n=6, 12%). Compared with preoperative values, the visual acuity, anterior chamber flare, mean deviation, corneal endothelial cell density remained unchanged postoperatively.

CONCLUSION

Choice of pars plana AGV tube insertion with simultaneous vitrectomy is reasonable to achieve IOP reduction and minimize vision-threatening complication in glaucomatous eyes with a damaged iris-lens diaphragm.

The Effects of Glaucoma and Glaucoma Therapies on Corneal Endothelial Cell Density

A healthy corneal endothelium is required for corneal clarity. Both the glaucoma disease state and its various forms of treatment can have adverse effects on the corneal endothelium. Both the presence of glaucoma and the magnitude of intraocular pressure elevation are related to endothelial cell loss (ECL). Topical medical therapy, laser procedures, and both traditional surgeries-trabeculectomy and tube-shunts-and newer minimally invasive glaucoma surgeries have variable effects on ECL. This review will summarize the reported effects of glaucoma and its treatment on ECL. Concerns for corneal endothelial cell health should be part of the decision-making process when planning glaucoma therapy for lowering intraocular pressure, with added caution in case of planned device implantation in eyes with preexisting ECL and low endothelial cell density at high risk for corneal endothelial decompensation.

Midterm Results of Microhook ab Interno Trabeculotomy in Initial 560 Eyes with Glaucoma

All the 560 glaucomatous eyes of 375 Japanese subjects (181 men, 194 women; mean age ± standard deviation, 76.0 ± 13.2 years) who underwent microhook ab interno trabeculotomy (µLOT) alone (159 eyes, 28%) or combined µLOT and cataract surgery (401 eyes, 72%) performed by one surgeon at Matsue Red Cross Hospital between May 2015 and March 2018 to control intraocular pressure (IOP) were retrospectively assessed. Preoperative and postoperative IOPs, numbers of antiglaucoma medications, the logarithm of the minimum angle of resolution visual acuity (logMAR VA), anterior chamber (AC) flare, visual field mean deviation (MD), and corneal endothelial cell density (CECD) were compared up to 36 months. Surgical complications and required interventions were described. The duration of the follow-up was 405 ± 327 (range, 2–1326) days. The mean preoperative IOP (20.2 ± 7.0 mmHg) and number of antiglaucoma medications (2.8 ± 1.1) decreased to 13.9 ± 4.5 mmHg (31% reduction, p < 0.0001) and 2.5 ± 1.0 (11% reduction, p < 0.0001), respectively, at the final visit. After combined surgery, compared with preoperatively, the final VA improved 0.11 logMAR (p < 0.0001), AC flare increased 4.5 photon counts/msec (p = 0.0011), MD improved 0.6 decibel (p < 0.0001), and the CECD decreased 6% (p < 0.0001). Layered hyphema (172 eyes, 31%) and hyphema washout (26 eyes, 5%) were the most common postoperative complication and intervention, respectively. At the final visit, 379 (69%) eyes achieved successful IOP control of ≤18 mmHg and ≥20% IOP reduction, and 349 (64%) eyes achieved successful IOP control of ≤15 mmHg and ≥20% IOP reduction. Older age, steroid-induced glaucoma, developmental glaucoma, and the absence of postoperative complications were associated with lower final IOP; exfoliation glaucoma, other types of glaucoma, and higher preoperative IOP were associated with higher final IOP. µLOT has a significant IOP-lowering potential in patients with glaucoma, and improves visual function when combined with cataract surgery.

Corneal Parameters after Tube-Shunt Implantation through the Ciliary Sulcus

PURPOSE

To monitor bilateral corneal parameters after unilateral Baerveldt 350 tube-shunt implantation (Advanced Medical Optics, Santa Ana, CA) through the ciliary sulcus.

DESIGN

Retrospective, interventional case series.

PARTICIPANTS

Patients from 1 private glaucoma practice with severe uncontrolled glaucoma treated with sulcus tube-shunt implantation in 1 pseudophakic eye.

METHODS

Specular microscopy data were collected before and after unilateral sulcus tube-shunt implantation from the surgical and the glaucomatous fellow eyes.

MAIN OUTCOME MEASURES

Central corneal endothelial cell density (CECD), coefficient of variation (CV), percent of hexagonal cells, central corneal thickness (CCT), intraocular pressure (IOP), IOP-lowering medications, visual acuity, and complications.

RESULTS

Forty-six patients (mean age, 69.9 years; standard deviation [SD], 4.6 years; range, 20-88 years; male gender, 41.3%) were identified. After surgery, IOP and the number of IOP-lowering medications decreased significantly by 42.3% (P < 0.0001) and 32.1% (P < 0.0001), respectively, in the surgical eye group. Preoperative CECD measured 1807 cells/mm² (SD, 172 cells/mm²) and 1825 cells/mm² (SD, 172 cells/mm²) in the surgical and fellow eyes, respectively (P = 0.92), and compared with baseline, it decreased by 8.6% (P = 0.17) and 3.1% (P = 0.65), respectively, by 24 months. Preoperative CV, percent of hexagonal cells, and CCT were similar in both groups and remained stable. All corneal parameters remained unchanged in a subgroup of 15 patients with low preoperative CECD (1273 cells/mm²; SD, 99 cells/mm²). Best-corrected visual acuity remained stable in both groups. Hyphema occurred in 23.9% of the surgical eyes and resolved with no intervention. We found no sight-threatening complications or corneal failures during follow-up.

CONCLUSIONS

Tube-shunt implantation through the ciliary sulcus in pseudophakic eyes appears relatively safe to the corneal endothelium, demonstrating a small and nonsignificant decline in central CECD compared with baseline and with glaucomatous fellow eyes. No significant disruption to corneal endothelial cell morphologic features, increased corneal thickness, or corneal failures were found during the 24-month follow-up period. A prospective head-to-head comparison to assess the effects of the various methods of tube-shunt implantation on the corneal endothelium is needed.

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.

Baerveldt or Ahmed glaucoma valve implantation with pars plana tube insertion in Japanese eyes with neovascular glaucoma: 1-year outcomes

Purpose

To describe the 1-year surgical outcomes of both Baerveldt glaucoma implant (BGI) and the Ahmed glaucoma valve (AGV) implant with pars plana tube insertion in Japanese eyes with neovascular glaucoma (NVG).

Patients and methods

This was a retrospective study of 21 eyes of 18 patients who had undergone BGI (10 eyes) or AGV (11 eyes) implantation. The 1-year surgical outcomes in the two groups were compared. Surgical success was defined as an intraocular pressure (IOP) of 6–21 mmHg (criterion A) or 6–18 mmHg (criterion B) with >20% reduction regardless of the use of antiglaucoma medications.

Results

The mean preoperative IOP was 33.9±6.6 mmHg in the BGI group and 30.9±5.3 mmHg in the AGV group (P=0.31). The IOP at 1-year was lower in the BGI group at 10.3±5.9 mmHg than in the AGV group at 14.8±3.3 mmHg (P=0.044). The mean number of glaucoma medications at 1 year was 1.0±1.3 in the BGI group and 1.4±1.4 in the AGV group (P=0.57). The incidence of postoperative complications during the 1-year follow-up was not statistically different between the two groups; however, one eye in the BGI group lost light perception after additional surgery for Hoffman elbow exposure. The 1-year success rates of the BGI group was 60.0% and that in the AGV group was 90.9% based on criterion A (P=0.095), and 50.0% and 81.8% based on criterion B (P=0.074).

Conclusions

Significant reductions of the IOP and number of glaucoma medications were achieved at 1 year after both types of implants in Japanese eyes with NVG.

Risk Factors for Endothelial Decompensation after Penetrating Keratoplasty and Its Novel Therapeutic Strategies

Purpose

To review the risk factors and pathogenesis of endothelial decompensation after penetrating keratoplasty (PKP) and its novel therapeutic strategies.

Methods

Literature review.

Results

As the major cause of graft failure in PKP, endothelial decompensation of corneal allograft is considered an irreversible decrease in endothelial cell density and endothelial dysfunction. Various risk factors, including donor status and operative and recipient factors, have been found to be associated with this pathological process. Operative factors like graft size and recipient factors such as indications, glaucoma, or glaucoma surgery history are highly associated with the occurrence of endothelial decompensation, while others are still under investigation. Although the mechanism of these risk factors remains unclear, pathogenesis can be summarized as an acute and chronic loss of endothelium, and cell exchange between donor and recipient is at the core of chronic cell loss. Endothelial keratoplasty has been a useful alternative to repeat standard PKP in eyes with failed grafts. Descemet stripping automated endothelial keratoplasty (DSAEK) and Descemet's membrane endothelial keratoplasty (DMEK) following failed PKP provide more rapid visual recovery and achieve better rates of graft survival than those of a second PKP.

Conclusions

Any direct or indirect damage to the endothelium could cause the loss, morphological changes, and dysfunction of endothelial cells. Graft size, indications, and recipient glaucoma or glaucoma surgery history are risk factors for endothelial decompensation. DSAEK and DMEK are novel therapeutic strategies for failed PKP grafts and have potential superiorities compared with repeat PKP.

Surgical management of raised intra-ocular tension in the hostile ocular surface - recurrent tube erosion in a patient with systemic sclerosis: a case report

Background

The surgical management of patients with uncontrolled glaucoma and scleroderma is challenging, as the hostile ocular surface poses a challenge to surgery. A serious complication is tube erosion, with the risk of subsequent endophthalmitis. Here, we present a novel technique of harvesting autologous tissue to successfully manage recurrent tube extrusion.

Case presentation

MG is a 60-year-old Arabic lady diagnosed with scleroderma, that was previously managed with systemic corticosteroids. She has chronic open angle glaucoma, with a failed left eye trabeculectomy, which was then managed by a Baerveldt tube (BVT) insertion. Eight months after this primary surgery, she developed an anterior uveitis. This was further complicated by conjunctival erosion, tube exposure, leak around the sclerostomy site and hypotony. The erosion was likely secondary to her tight eyelids as a result of her scleroderma. She was taken back to theatre for tube revision, with single layer amniotic membrane transplant (AMT) over the exposed area, but the tube was eroding again after 2 months. She eventually underwent tube extraction, pars plana tube plate stabilisation, pars plana vitrectomy (PPV), pars plana tube insertion, phacoemulsification and intra-ocular lens insertion, jointly with the vitreo-retinal surgeons and with high dose prednisolone cover both pre- and post-operatively. We harvested the capsule which had grown over the end plate of the original tube. We sutured this over the new tube, specifically over a single layer of tutoplast prior to conjunctival closure. Almost a year on, the pars plana tube remains in place with no complications.

Conclusions

This case highlights the role of a pars plana tube in cases of cicatricial disease, with the use autologous tissue instead of grafts wherever possible. In patients with systemic disease such as scleroderma, pre-operative immunosuppression helps to reduce the of erosion in difficult cases.

Baerveldt surgery outcomes: anterior chamber insertion versus vitreous cavity insertion

PURPOSE

We compared the outcomes of Baerveldt glaucoma implant (BGI) surgery between vitreous cavity and anterior chamber insertion.

METHODS

We retrospectively analyzed a total of 105 consecutive eyes that underwent BGI surgery and were followed up for ≥ 12 months. BGI surgery was performed via the anterior chamber (AC group 48 eyes) or the pars plana into the vitreous cavity (VC group 57 eyes). Patients' data were examined at 3, 6, and 12 months, and then every 6 months after surgery. We compared the groups' intraocular pressure (IOP), success ratio, visual acuity, number of glaucoma medications, central corneal endothelial cell density (CCECD), reduction ratio of CCECD, and postoperative complications.

RESULTS

The mean preoperative and postoperative IOP values were not significantly different between the two groups. In the Kaplan-Meier survival plots, there was no significant between-group difference in the success rate (p = 0.333). The postoperative mean CCECD decreased significantly faster in the AC group than the VC group at all time points. The cases of postoperative corneal edema were 12.5% in AC group and 1.8% in VC group. The risk of postoperative corneal edema was significantly higher in the AC group (p = 0.0136). Risk factors for the rapid reduction of CCECD were "history of trabeculectomy" (p = 0.00283), "insertion into the anterior chamber" (p = 0.001), and "shorter distance between the tube and corneal endothelium" (p = 0.0137).

CONCLUSION

There was no significant between-group difference in postoperative IOP, medications, or success rate. Considering the reduction of corneal endothelial cells, insertion into the vitreous cavity seems safer than insertion into the anterior chamber.

Prospective cohort study of corneal endothelial cell loss after Baerveldt glaucoma implantation

Purpose

To evaluate corneal endothelial cell loss after Baerveldt glaucoma implantation.

Methods

We prospectively evaluated changes in endothelial cell density (ECD) in the cornea of 59 patients (59 eyes) who underwent Baerveldt glaucoma implantation. Tubes were inserted into the anterior chamber in 45 eyes and pars plana in 14 eyes. The primary outcome measure was the change in corneal ECD after Baerveldt glaucoma implantation. Secondary outcome measures included relationships between corneal ECD and optical coherence tomography images of tube parameters (tube–cornea distance and tube–cornea angle) and prognostic factors for corneal ECD loss.

Results

Corneal ECD decreased significantly by 9.2% at 12 months after surgery (P = 0.001). In the anterior chamber Baerveldt glaucoma implantation group, corneal ECD at the tube insertion quadrant decreased significantly by 9.6% at 3 months (P = <0.001), 10.7% at 6 months (P = <0.001), and 13.1% at 12 months (P = <0.001). Corneal ECD at the center decreased significantly at 6 months after surgery (7.2% loss; P = 0.012) and at 12 months after surgery (12.1% loss; P = 0.001). Corneal ECD at the contralateral quadrant decreased significantly at 12 months after surgery only (10.3% loss; P = 0.004). In the pars plana Baerveldt glaucoma implantation group, no significant loss of corneal ECD was found in any corneal areas at any post-surgery follow-up visits. Tube-cornea angle was negatively correlated with the rate of corneal ECD loss at the tube insertion quadrant; r = −0.55 (P = 0.0013). In multivariable analyses, exfoliation glaucoma and narrower tube–cornea angle were significant prognostic factors for severe corneal ECD loss (P = 0.0068 and P = 0.046, respectively).

Conclusions

Anterior chamber Baerveldt glaucoma implantation causes corneal endothelial cell loss. Corneal endothelial cell loss starts at the tube insertion quadrant. Exfoliation glaucoma and narrower tube-corneal angle are associated with severe loss of corneal endothelial cells.

Effectiveness and safety of combined cataract surgery and microhook ab interno trabeculotomy in Japanese eyes with glaucoma: report of an initial case series

PURPOSE

To report the early postoperative results and safety profile of ab interno microhook trabeculotomy (μLOT) combined with cataract surgery.

PATIENTS AND METHODS

This retrospective observational case series included 68 consecutive glaucomatous eyes of 23 Japanese men and 25 Japanese women [mean (SD) age, 76.0 ± 8.5 years] who underwent μLOT for intraocular pressure (IOP) and visually relevant cataracts. The LOT site/extent, perioperative complications, and complication treatments were collected from the medical and surgical records. The preoperative and postoperative IOP, numbers of antiglaucoma medications, logarithm of the minimum angle of resolution visual acuity (VA), anterior chamber (AC) flare, and corneal endothelial cell density (CECD) were compared.

RESULTS

After small incisional cataract surgery, the trabecular meshwork was incised in the nasal (6 eyes, 3.6 ± 0.5 clock hours), temporal (6 eyes, 3.8 ± 0.8 clock hours), or both nasal and temporal (56 eyes, 6.5 ± 0.6 clock hours) angles. The mean preoperative IOP (16.4 ± 2.9 mmHg) and number of antiglaucoma medications (2.4 ± 1.2) decreased significantly (P < 0.0001 and P = 0.0039, respectively) to 11.8 ± 4.5 and 2.1 ± 1.0 mmHg at 9.5 months postoperatively. Compared with the preoperative conditions, the final VA improved (P = 0.0002), the AC flare increased by 6.3 pc/ms (P = 0.0157), and the CECD decreased by 6% (P = 0.0005). Hyphema with niveau formation (28 eyes, 41%) and hyphema washout (6 eyes, 9%) were the most common postoperative complication and intervention, respectively. At the final visit, 54 eyes (79%) had achieved successful IOP control of 15 mmHg or less and IOP reduction of 15% or greater.

CONCLUSION

Combined μLOT and cataract surgery improves IOP and VA during the early postoperative period in patients with glaucoma and cataract.

Assessment of Filtration Bleb and Endplate Positioning Using Magnetic Resonance Imaging in Eyes Implanted with Long-Tube Glaucoma Drainage Devices

Background

To evaluate ocular fluid filtration and endplate positioning in glaucomatous eyes with long-tube glaucoma drainage devices (GDDs) using magnetic resonance imaging (MRI) and the effects of various factors on postoperative intraocular pressure (IOP).

Methods

This observational case series included 27 consecutive glaucomatous eyes (18 men, 7 women; mean age ± standard error, 63.0±2.0 years) who underwent GDD implantation (n = 8 Ahmed Glaucoma Valves [AGV] and n = 19 Baerveldt Glaucoma Implants [BGI]). Tubes were inserted into the pars plana in 23 eyes and anterior chamber in 4 eyes. Six months postoperatively, high-resolution orbital images were obtained using 3-Tesla MRI with head-array coils, and the filtering bleb volume, bleb height, and distances between the anterior endplate edge and corneal center or limbus or between the endplate and orbital wall were measured.

Results

In MR images obtained by three-dimensional fast imaging employing steady-state acquisition (3D-FIESTA) sequences, the shunt endplate was identified as low-intensity signal, and the filtering bleb was identified as high-intensity signals above and below the endplate in all eyes. The 6-month-postoperative IOP level was correlated negatively with bleb volume (r = -0.4510, P = 0.0182) and bleb height (r = -0.3954, P = 0.0412). The postoperative IOP was significantly (P = 0.0026) lower in BGI-implanted eyes (12.2±0.7 mmHg) than AGV-implanted eyes (16.7±1.2 mmHg); bleb volume was significantly (P = 0.0093) larger in BGI-implanted eyes (478.8±84.2 mm³) than AGV-implanted eyes (161.1±52.3 mm³). Other parameters did not differ.

Conclusions

The presence of intraorbital/periocular accumulation of ocular fluid affects postoperative IOP levels in eyes implanted with long-tube GDDs. Larger filtering blebs after BGI than AGI implantations explain lower postoperative IOP levels achieved with BGI than AGV. The findings will contribute to better understanding of IOP reducing mechanism of long-tube GDDs.

A Comparison of Endothelial Cell Loss in Combined Cataract and MIGS (Hydrus) Procedure to Phacoemulsification Alone: 6-Month Results

Purpose. To compare the corneal endothelial cell loss after phacoemulsification, alone or combined with microinvasive glaucoma surgery (MIGS), in nonglaucomatous versus primary open angle glaucoma (POAG) eyes affected by age-related cataract. Methods. 62 eyes of 62 patients were divided into group 1 (n = 25, affected by age-related cataract) and group 2 (n = 37, affected by age-related cataract and POAG). All patients underwent cataract surgery. Group 2 was divided into subgroups A (n = 19, cataract surgery alone) and B (n = 18, cataract surgery and MIGS). Prior to and 6 months after surgery the patients' endothelium was studied. Main outcomes were CD (cell density), SD (standard deviation), CV (coefficient of variation), and 6A (hexagonality coefficient) variations after surgeries. Results. There were no significant differences among the groups concerning preoperative endothelial parameters. The differences in CD before and after surgery were significant in all groups: 9.1% in group 1, 17.24% in group 2A, and 11.71% in group 2B. All endothelial parameters did not significantly change after surgery. Conclusions. Phacoemulsification determined a loss of endothelial cells in all groups. After surgery the change in endothelial parameters after MIGS was comparable to the ones of patients who underwent cataract surgery alone.

Comparison of the changes in corneal endothelial cells after pars plana and anterior chamber ahmed valve implant

Purpose. To compare the changes in corneal endothelial cells after pars plana Ahmed glaucoma valve (AGV) implantation with those after the anterior chamber AGV implantation for refractory glaucoma. Methods. The medical records of 18 eyes with pars plana implantation of AGV (ppAGV) were reviewed retrospectively and were compared with 18 eyes with the anterior chamber AGV (acAGV) implant. The preoperative and postoperative endothelial cells, intraocular pressure (IOP), and postoperative complications during the follow-up in both groups were compared. Results. The average follow-up was 18 months. The postoperative endothelial cells in the ppAGV and acAGV groups were 2044 ± 303 and 1904 ± 324, respectively (P = 0.25). The average percentage decrease in the endothelial cells in the ppAGV and acAGV groups at 18 months was 12.5% and 18.4%, respectively, and showed significant difference between the 2 groups (P = 0.01). No difference in IOP control and the number of postoperative glaucoma medications was observed between the 2 groups. Conclusions. Endothelial cell damage in the ppAGV group for refractory glaucoma appeared to be lower than that in the acAGV group. Therefore, pars plana implantation of AGV may be preferred as it may have lower level of endothelial cell damage while maintaining similar level of IOP control.