The Influence of Trabectome Surgery on Corneal Endothelial Cells

Comparison of corneal endothelial cell density reduction between primary open-angle glaucoma and pseudo-exfoliation glaucoma patients at 3 years after Ex-Press® surgery

PURPOSE

We compared corneal endothelial cell (CED) loss after Ex-Press (EXP) surgery between patients with primary open-angle glaucoma (POAG) and pseudo-exfoliation glaucoma (PEX).

PATIENTS AND METHODS

This was a single-facility retrospective study. We included glaucoma patients who had undergone EXP surgery and were followed up > 3 years. We measured the CED before and after (at 12, 24, and 36 months) EXP surgery by noncontact specular microscopy and compared the means of the CED values and CED survival ratios after EXP surgery by paired t-test.

RESULTS

We included 119 eyes that underwent EXP surgery, including 60 POAG eyes and 59 PEX eyes. In the POAG group, the mean CED decreased from 2389 ± 321 at baseline to 2230 ± 424 cells/mm2 after 3 years. In the PEX group, the mean CED decreased from 2111 ± 510 at baseline to 1845 ± 628 cells/mm2 after 3 years. At the 3-year follow-up, the CED survival ratio was 93.3 ± 12.5% in the POAG group and significantly lower, at 85.0 ± 19.5%, in the PEX group (p = 0.0064). Two cases in the PEX group developed bullous keratopathy.

CONCLUSIONS

EXP surgery decreased the corneal endothelial cell populations in PEX patients faster than POAG patients.

Corneal endothelial cell loss after EX-PRESS surgery depends on site of insertion, cornea or trabecular meshwork

PURPOSE

Previously, we reported that the Ex-press® shunt (EXP) was associated with more rapid reduction in corneal endothelial cells when inserted into the cornea rather than the trabecular meshwork (TM). We compared the reduction rate of corneal endothelial cells between the corneal insertion group and TM insertion group.

METHODS

This was a retrospective study. We included patients who had undergone EXP surgery and were followed for > 5 years. We analyzed the corneal endothelial cell density (ECD) before and after EXP implantation.

RESULTS

We included 25 patients in the corneal insertion group and 53 patients in the TM insertion group. One patient in the corneal insertion group developed bullous keratopathy. The ECD decreased significantly more rapidly in the corneal insertion group (p < 0.0001), in whom the mean ECD decreased from 2227 ± 443 to 1415 ± 573 cells/mm2 at 5 years with a mean 5-year survival rate of 64.9 ± 21.9%. By contrast, in the TM insertion group, the mean ECD decreased from 2356 ± 364 to 2124 ± 579 cells/mm2 at 5 years, and the mean 5-year survival rate was 89.3 ± 18.0%. The decrease rate of ECD was calculated as 8.3%/year in the corneal insertion group and 2.2%/year in the TM insertion group.

CONCLUSIONS

Insertion into cornea is a risk factor for rapid ECD loss. The EXP should be inserted into the TM to preserve the corneal endothelial cells.

Improvement of the loss of corneal endothelial cells by relocating the tip of the Baerveldt® implant tube from the anterior chamber to the vitreous cavity

PURPOSE

It has been reported that corneal endothelial cells (CEC) decrease faster when the tip of the Baerveldt glaucoma implant (BGI) tube is inserted into the anterior chamber than into the vitreous cavity. We investigated whether surgically relocating the tip of the BGI tube from the anterior chamber to the vitreous cavity could reduce CEC loss.

PATIENTS AND METHODS

This was a single facility retrospective cohort study. The inclusion criteria were the CEC density less than 1500 cells/mm2 and the CEC reduction ratio was greater than 10%/year. The subjects were 11 consecutive patients that could be followed > 12 months after relocation surgery. All patients were undergone vitrectomy, and the tip of tube was inserted into the vitreous cavity from the anterior chamber. We compared the intraocular pressure (IOP), reduction slope of CEC density and annual reduction rate of CEC density before and after relocation surgery. We calculated the annual reduction ratio in comparison with the preoperative CEC density (%/year).

RESULTS

The mean of period between the Baeveldt with anterior chamber insertion surgery and the relocation surgery was 33.8 ± 15.0 months. The mean of follow-up after relocation surgery was 21.8 ± 9.8 months. The relocation surgery did not significantly change IOP (p = 0.974). The mean preoperative and postoperative IOP were 13.1 ± 4.5 and 13.6 ± 4.3 mmHg. The reduction ratio of the CEC density was 15.4 ± 6.7 (%/year) before relocation surgery and significantly slower at 8.3 ± 6.5 (%/year) after relocation surgery (p = 0.024). Two patients resulted in bullous keratopathy after relocation surgery.

CONCLUSIONS

Relocating the tip of BGI tube from the anterior chamber to the vitreous cavity could reduce CEC loss.

Corneal Endothelial Cell Loss in Patients After Minimally Invasive Glaucoma Surgery: Current Perspectives

Minimally invasive glaucoma surgery (MIGS) is a rapidly expanding category of surgical glaucoma treatment options that offer a superior safety profile compared with traditional approaches for reducing intraocular pressure. However, MIGS may cause corneal endothelial cell loss; therefore, it has been receiving increasing attention. This systematic review aimed to evaluate and compare the rate and degree of corneal endothelial loss after MIGS. First, this paper presents an overview of the theoretical effectiveness of MIGS, the fundamental aspects regarding the roles of endothelial cells, and the effect of cataract surgery on the quality and count of endothelial cells. Further, we detail the various surgical techniques involved in MIGS, the development of these techniques over the time, and clinical aspects to consider with respect to the endothelial cell count. We discuss in detail the COMPASS-XT study, which was based on data collected over 5 years, reported that withdrawal of the CyPass Micro-Stent (Alcon Laboratories) yielded increased corneal endothelial cell loss. Generally, MIGS procedures are considered safe, with the incidence of complications ranging from 1% to 20% depending on the surgery type; however, there is still need for studies with longer follow-up. Thus, an adequate count of endothelial cells in the central cornea portion is recommended as necessary for candidate patients for MIGS.

Endothelial cell loss associated with minimally invasive glaucoma surgery

PURPOSE OF REVIEW

Minimally invasive glaucoma surgery (MIGS) represents a safer, albeit moderately effective surgical option for intraocular pressure control. However, the CyPass Micro-Stent (Alcon Laboratories) was withdrawn from the market in 2018 as the COMPASS-XT study demonstrated greater cornea endothelial cell (CEC) loss in patients who received the CyPass Micro-Stent with phacoemulsification compared with phacoemulsification alone. This led to the increased attention on MIGS-associated CEC loss and thus, this review will summarise the recent, available evidence on MIGS-associated CEC loss.

RECENT FINDINGS

Prospective clinical trials and retrospective observational studies published between 2011 and 2021 reported a wide range of 12 month CEC loss from 'insignificant', and up to 14.6%, for phacoemulsification combined with various MIGS procedures. Recent clinical trials over the same time period reported CEC loss of 12.8-15.2% associated with phacoemulsification alone.

SUMMARY

Apart from the CyPass Micro-Stent clinical trial, no other studies on combined phacoemulsification with MIGS that is 'phaco-plus' procedures have reported a higher short-term CEC loss compared with phacoemulsification alone. However, studies that specifically examine postprocedural CEC loss following phacoemulsification compared to 'phaco-plus' procedures over a longer follow-up period are required.

Corneal Endothelial Cell Loss in Glaucoma and Glaucoma Surgery and the Utility of Management with Descemet Membrane Endothelial Keratoplasty (DMEK)

The corneal endothelium has a crucial role in maintaining a clear and healthy cornea. Corneal endothelial cell loss occurs naturally with age; however, a diagnosis of glaucoma and surgical intervention for glaucoma can exacerbate a decline in cell number and impairment in morphology. In glaucoma, the mechanisms for this are not well understood and this accelerated cell loss can result in corneal decompensation. Given the high prevalence of glaucoma worldwide, this review aims to explore the abnormalities observed in the corneal endothelium in differing glaucoma phenotypes and glaucoma therapies (medical or surgical including with new generation microinvasive glaucoma surgeries). Descemet membrane endothelial keratoplasty (DMEK) is increasingly being used to manage corneal endothelial failure for glaucoma patients and we aim to review the recent literature evaluating the use of this technique in this clinical scenario.

Twenty-Four-Month Outcome of Gonioscopy-Assisted Transluminal Trabeculotomy (GATT) in Eyes With Prior Corneal Transplant Surgery

PURPOSE

Glaucoma is a well-known sequelae of corneal transplant surgery and is a leading cause of visual loss in this patient group. We evaluated the performance and safety of gonioscopy-assisted transluminal trabeculotomy (GATT) in this population.

DESIGN

Noncomparative retrospective case series.

PARTICIPANTS

Consecutive eyes of patients receiving the GATT procedure for uncontrolled intraocular pressure (IOP) following corneal transplant surgery from 2016 to 2019.

METHODS

Retrospective analysis of eyes with a history of prior corneal transplant undergoing GATT at Glaucoma Associates of Texas between 2016 and 2019 was performed. Data included IOP, patient demographics, preoperative and postoperative medications, preoperative and postoperative corneal procedures, complications, and need for reoperation for IOP control.

MAIN OUTCOME MEASURES

IOP reduction and medication use following the procedure.

RESULTS

Thirty-nine eyes of 32 patients with prior corneal transplant surgery underwent a GATT procedure. Prior corneal surgery included penetrating keratoplasty (59.0%), Descemet's stripping endothelial keratoplasty (35.9%), Descemet's membrane endothelial keratoplasty (2.6%), and deep anterior lamellar keratoplasty (2.6%). Patient age ranged from 24 to 94 years (mean 68.0 y) with 44% female and 81% Caucasian. The majority of patients had secondary open angle glaucoma (64.1%). There was a significant reduction in IOP and number of medications at all postoperative time points after censoring patients requiring reoperation to control IOP (P<0.001). At 24 months the pressure decreased from baseline of 30.9±11.5 to 13.9±4.7 mm Hg. Medications decreased from 4.2±1.0 medications at baseline to 0.6±1.0 at 24 months. Visual acuities decreased significantly over the first postsurgical month (all P<0.05), but these recovered at subsequent follow-up visits with 2-Snellen line improvements exceeding losses from month 3 to 36. Seven eyes required reoperation for uncontrolled glaucoma at a median of 8.5 months (range: 1.6 to 16.2 mo) after GATT. The cumulative proportion of eyes undergoing repeat cornea surgery was 2.6%, 2.6%, and 14.3% at 12, 24, and 36 months post-GATT, respectively.

CONCLUSIONS

This case series describes a group of glaucoma patients, with a history of prior corneal surgery, that were safely and successfully treated with GATT. While classically traditional glaucoma surgeries are considered the standard of care for eyes following corneal transplant surgery, GATT should be considered as a reasonable, safe and effective alternative for surgically lowering IOP.

A comparison of long-term results after Baerveldt 250 implantation in advanced uveitic vs. other forms of glaucoma

INTRODUCTION

Uveitic glaucoma remains challenging despite medical and surgical advancements and can potentially lead to blindness if left uncontrolled. Conservative alternatives as well as microinvasive surgeries can postpone the necessity of a highly invasive intervention. However, such procedures are still necessary to treat some refractive glaucoma cases. Since previous studies have reported excellent results following the primary implantation of glaucoma drainage devices, it was our study's aim to evaluate long-term results following a Baerveldt 250 implantation in highly complex and surgically burdened uveitic glaucoma eyes (UG) and compare these to a similar population suffering from other forms of glaucoma (OFG).

MATERIAL AND METHODS

We performed a retrospective analysis of all eyes (UG vs. OFG) following a Baerveldt 250 implant between 2013 and 2019. Efficacy parameters as well as post-operative complication data were extracted from our electronic data system for statistical analysis.

RESULTS

A total of 62 eyes were included in our study (24 UG and 38 OFG). UG baseline mean IOP was 35.04 mmHg (± 11.85 mmHg) with 3.08 (± 1.13) topical agents, and OFG was 32.63 mmHg (± 7.74 mmHg) with 2.68 (± 1.28) topical agents. A majority of eyes also required systemic acetazolamide (UG: 79% OFG: 87%) and had undergone at least one glaucoma-related operation prior to the Baerveldt 250 implant ((UG: 1.21 (± 0.66)), OFG: 1.74 (± 1.33)). At the median follow-up period (UG 592, OFG 764 days), 52.5%/32.5% of UG/OFG cases showed qualified success (IOP below 21 mmHg with either topical or/and systemic medication), 15%/30% no longer required topical medication, and 47.5% /47.5% were free of acetazolamide systemically. Moreover, 75%/72.5% of eyes experienced no further pressure-related surgical event. Although sight-threatening complications such as corneal and macular edema were reported in both groups, most either maintained or improved their visual acuity at the last follow-up (58.33%/57.89%).

CONCLUSION

The Baerveldt 250 implant is shown to be both effective and safe for advanced glaucoma cases in uveitis and other forms. No further glaucoma-related surgery is required in the majority of eyes in either group within a follow-up period of almost 2 years. Despite sight-threatening complications such as macular and corneal edema, visual acuity can be either maintained or improved in most eyes.

Effect of Preoperative Intraocular Pressure in Patients with and without Intolerance to Their IOP-Lowering Medication on the Outcome of Trabectome Surgery

Purpose

This study aimed to compare the effect of trabectome surgery in patients with and without intolerance to their medication and with preoperatively sufficiently controlled, insufficiently controlled, and uncontrolled intraocular pressure (IOP) on the surgical outcome.

Patients and Methods

A total of 155 eyes (133 patients) with different forms of open angle glaucoma with or without intolerance to their glaucoma medication undergoing trabectome surgery alone (AIT) or combined with phacoemulsification (phaco-AIT) were included in this retrospective monocentric study. Patients were corresponding to IOP ≤ 18 mmHg (controlled but glaucoma progression or intolerance, group 1), 19–26 mmHg (insufficiently controlled, group 2), and ≥ 26 mmHg (not controlled, group 3), respectively. Pre- and postoperative IOP and the number of IOP-lowering medications were registered over 12 months. Surgical success was defined as a postoperative IOP of ≤18mmHg and/or reduction of the topical treatment demand after 1 year.

Results

Of the 155 included eyes, 79 received AIT and 76 received phaco-AIT. Sixty-nine eyes had a preoperatively sufficiently controlled IOP, 63 had an insufficiently controlled IOP, and 23 had an uncontrolled IOP. In all groups, the IOP significantly dropped by 6 and 12 months after surgery (p < 0.001). Surgical success war similar in all groups [47.8% (group 1), 38.1 (group 2) and 34.8% (group 3); p= 0.47]. The effect of AIT on IOP and glaucoma medication independent of intolerance to the anti-glaucoma medication and type of surgery (AIT/phaco-AIT).

Conclusion

Independently of the preoperative IOP, a satisfying surgical success was achieved using AIT. In instances that do not qualify for filtrating surgery, trabectome surgery alone or in combination with phacoemulsification thus represents a safe and effective minimally invasive glaucoma surgery technique regardless of an intolerance to the topical medication.

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.

Safety profile of minimally invasive glaucoma surgery

PURPOSE OF REVIEW

This article reviews the safety profile of trabecular meshwork/Schlemm's canal-based, subconjunctival, and suprachoroidal minimally invasive glaucoma surgery (MIGS).

RECENT FINDINGS

Prospective randomized clinical trials and metaanalyses published during the 2019-2020 review period provided important data regarding the safety profile of trabecular meshwork/Schlemm's canal-based MIGS. Transient hyphema and intraocular pressure spikes are among the most common complications associated with this category of MIGS, but more serious adverse events such as cyclodialysis cleft formation may also occur. Trabecular bypass microstents and the intracanalicular scaffold are further subject to device-related complications, including malposition and obstruction. Recent case reports and retrospective case series have further characterized the safety profile of the subconjunctival gel stent, with adverse events ranging from self-limited hypotony to visually devastating endophthalmitis and suprachoroidal hemorrhage. Five-year results of the COMPASS XT study demonstrated significantly greater endothelial cell loss in patients randomized to receive CyPass Micro-Stent (Alcon Laboratories, Fort Worth, TX, USA) in combination with cataract surgery versus those who underwent cataract surgery alone, and ultimately led to a Food and Drug Administration Class I recall of the device.

SUMMARY

Trabecular meshwork/Schlemm's canal-based procedures are generally among the safest MIGS, with mostly self-limited and nonvision-threatening complications. Subconjunctival gel stent insertion is associated with both bleb-related and stent-specific adverse events, which are similar to those observed with trabeculectomy and tube shunt surgery, respectively. Removal of the CyPass Micro-Stent from the market underscores the need for high-quality, long-term safety data regarding MIGS.

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 Endothelial Cell Changes After Phacoemulsification Combined with Excisional Goniotomy with the Kahook Dual Blade or iStent: A Prospective Fellow-Eye Comparison

Purpose

To characterize changes in endothelial cell density and morphology following phacoemulsification combined with either excisional goniotomy with the Kahook Dual Blade (KDB-phaco) or first-generation iStent trabecular microbypass implantation (iStent-phaco).

Setting

A single clinical practice.

Methods

Twenty-one adult subjects from one center with visually significant cataract and mild-moderate open-angle glaucoma underwent KDB-phaco or iStent-phaco in one eye and the alternate procedure in the fellow eye as part of a prospective, multicenter, randomized trial. Specular microscopy and pachymetry were performed before and 6–29 months after surgery. Parameters analyzed included change from baseline of endothelial cell density (ECD), the coefficient of variation (CV), the percent of hexagonal cells (%HEX), and central corneal thickness (CCT).

Results

Baseline ECD, CV, %HEX, and CCT were similar between groups. A mean (standard deviation) of 18.2 (5.8) months postoperatively (range 12.5–28.7 months), the change from baseline in ECD was −90 ± 226 cells/mm² (−3.4%) in KDB-phaco eyes (p=0.083) and −239 ± 247 cells/mm² (−9.0%) in iStent-phaco eyes (p<0.001); the change in iStent-phaco eyes was significantly greater than in KDB-phaco eyes (p=0.013). The magnitude of Endothelial Cell Loss (ECL) was not correlated with length of postoperative follow-up time in either group. No significant differences in change from baseline in CV, %HEX, or CCT were noted with the exception of a decrease in %HEX in iStent-phaco eyes (p=0.017). No eyes manifested corneal edema, decompensation, or other cornea-related complications.

Conclusion

Both KDB-phaco and iStent-phaco are associated with postoperative ECL, with iStent-phaco producing significantly greater ECL than KDB-phaco. The clinical significance of these findings is unclear, and future studies are warranted to more robustly characterize long-term effects of glaucoma surgical procedures—with and without permanent implants—on ECD and corneal health and to develop evidence-based guidelines for the pre- and post-operative evaluation of corneal health in eyes undergoing glaucoma surgery.

Effectiveness and limitations of minimally invasive glaucoma surgery targeting Schlemm's canal

Glaucoma surgery is performed to lower intraocular pressure (IOP); ideally, the IOP reduction is safely maintained for an extended period of time. Although trabeculectomy was considered the gold standard for glaucoma surgery for many years because of its effective IOP reduction, yet now it is considered unsafe because of serious complications. In recent years, minimally invasive glaucoma surgery (MIGS), which emphasizes safety and can be performed rapidly, has become widespread. Because MIGS does not involve conjunctival incisions, patients can undergo future trabeculectomy. If IOP reduction can be maintained safely, the number of anti-glaucoma drops can be reduced and visual function maintained, good outcomes for patients with glaucoma. Currently, many types of MIGS approved in Japan are reported to yield relatively good results, with targets of approximately 15-19 mmHg. However, the IOP-lowering effects of MIGS are limited. In procedures targeting Schlemm's canal, it is difficult to lower IOP beyond episcleral venous pressure. In some instances, a beneficial effect cannot be achieved if function is reduced beyond the collector channel. There are many unclear aspects regarding long-term outcomes following MIGS. Notably, investigation is ongoing to determine which patients are likely to benefit most from surgery. Based on previous reports, this review describes the characteristics and results of MIGS, approved in Japan, as well as underlying factors that affect the preoperative predictions and outcomes of the surgical procedure.

Impact of Phacoemulsification Combined with XEN Gel Stent Implantation on Corneal Endothelial Cell Density: 2-Year Results

INTRODUCTION

Corneal integrity has long been a preoccupation of glaucoma surgeons considering glaucoma drainage device surgery or antimetabolite-enhanced trabeculectomy. Despite having demonstrated a good safety profile and significant intraocular pressure-lowering capacities, the impact of XEN gel stents on endothelial density was never specifically investigated. The purpose of this study is to assess the effect of XEN gel stents on central endothelial cell density (ECD) over 24 months. To achieve this, we compared the effect on ECD of combined XEN surgery with that of a standard phacoemulsification procedure.

METHODS

This was an investigator-initiated, retrospective study, conducted at a single tertiary glaucoma center. Patients with primary or secondary open-angle glaucoma who underwent XEN implantation combined with phacoemulsification between January 2015 and June 2016 were retrospectively enrolled. Patients who had undergone standalone phacoemulsification over the same period of time were enrolled to form the control group of this comparative study. The primary outcome measure was the ECD. Patients who had undergone standalone XEN implantation and patients for whom both a baseline and 24-month ECD could not be obtained were excluded from the analysis. Percentages of ECD reductions were calculated for each studied eye, and the mean of ECD reductions was calculated for each group as well as for subgroups.

RESULTS

Thirty-two eyes of 23 patients (mean age=76.0±7.9 y, 60% female) underwent standalone phacoemulsification (n=15) or combined XEN surgery (n=17) and had an ECD both at baseline and 24-month postoperatively. Mean baseline ECDs were 2568±491 versus 2379±335 cells/mm, respectively (P=0.21). In the combined XEN surgery group, 58.8% of eyes (n=10) required at least 1 mitomycin C (MMC)-enhanced needling revision to maintain their target intraocular pressure. In the standalone phacoemulsification group, ECD decreased by a mean 14.5%, from 2567.7±491.2 to 2196.1±591.9 cell/mm (P=0.072). In the combined XEN surgery group, ECD decreased by a mean 14.3%, from 2378.8±334.7 to 2039.6±451.1 cell/mm (P=0.018). The difference in percentage reduction of ECD between the 2 groups was not statistically significant (P=0.226). Within the combined XEN surgery group, the ECD decreased by a mean of 15.4% in patients who did not undergo needling revisions and by 13.1% in patients who underwent the MMC-augmented procedure (P=0.485). In the 3 patients who underwent >1 needling revision, a 21.3% reduction in ECD was observed, but the difference was not statistically significant (P=0.653). Neither the time of the first needling (P=0.452), the patients' age (P=0.285), or sex (P=0.308) was statistically associated with ECD loss.

DISCUSSION

The present study demonstrated that the XEN gel implant combined with phacoemulsification produces 24-month ECD loss of a similar magnitude to that observed following standalone phacoemulsification. MMC-augmented needling revisions do not appear to have an impact on ECD.

Ab Interno Trabeculotomy: Key Prognostic Factors

PRéCIS:: The preoperative factors associated with a decreased survival rate of ab interno trabeculotomy (AbIT) perfomed using a Trabectome in open-angle glaucoma were selective laser trabeculoplasty (SLT) performed previously and axial length (AL) over 23.82 mm.

PURPOSE

The purpose of this study was to find preoperative factors that predict outcomes of AbIT by a Trabectome.

MATERIALS AND METHODS

This retrospective single-center cohort study involved consecutive patients with primary open-angle glaucoma and exfoliation glaucoma treated at Helsinki University Hospital with AbIT with preoperative intraocular pressure (IOP) ≥18 mm Hg and follow-up of at least 1 year. Success was defined as lowering of their IOP by at least 20% from baseline or reduction in glaucoma medications without any rise in IOP above baseline, and no subsequent glaucoma surgery.

RESULTS

Of the total 72 eyes of 67 patients, 51 eyes had exfoliation glaucoma and 21 had primary open-angle glaucoma. Mean preoperative IOP was 25.2±5.3 mm Hg, with a mean of 3.2±1.2 glaucoma medications. In the multivariable model, a history of preoperative SLT and higher preoperative AL had hazard ratios of 2.99 [95% confidence interval (CI): 1.26-7.10] and 1.53 (95% CI: 1.12-2.09) with statistical significance (P=0.013 and 0.007). The statistically significant cutoff point was 23.82 mm in AL in relation to the success rate, with success times taken into account (P<0.001). AL over 23.82 mm had hazard ratio of 5.75 (95% CI: 2.57-12.87, P<0.001).

CONCLUSION

Previous SLT and AL over 23.82 mm reduce survival after AbIT.

Factors influencing the reduction in corneal endothelial cells after Ex-Press® surgery

PURPOSE

We investigated the factors that influence the reduction in corneal endothelial cells after Ex-Press^® surgery.

METHODS

This was a retrospective study. We included patients who had undergone Ex-Press surgery and were followed up for > 2. We analyzed the corneal endothelial cell density (ECD) before and after Ex-Press surgery. We investigated the insertion position (Ex-Press device was inserted into cornea or trabecular meshwork (TM)), Ex-Press-iris touch, cornea-iris touch, peripheral anterior synechiae, history of trabeculotomy, history of selective laser trabeculoplasty, type of glaucoma, and simultaneous cataract surgery as influencing factors. We used multivariate analysis to determine the factors influencing the reduction rate of ECD.

RESULTS

We included 129 eyes. The mean of ECD had decreased 7.0% at 2 years. Ex-Press surgeries significantly decreased the ECD after 2 years (p = 0.0118). As a result of the multivariate analysis, the factor that led to a significantly faster reduction in ECD was the insertion position of the Ex-Press (p < 0.0001). The reduction rate of ECD after 2 years in cases of insertion into the cornea (27 eyes) was 15.1 ± 3.6%, and in cases of insertion into a TM (102 eyes), it was 5.2 ± 1.4%.

CONCLUSIONS

Insertion into the cornea was a risk factor for rapid ECD loss. The Ex-Press should be inserted into a TM for long-term protection of the corneal endothelial cells.

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.