Deep sclerectomy with bevacizumab and mitomycin C: a comparative study

Hypotony Failure Criteria in Glaucoma Surgical Studies and Their Influence on Surgery Success

PURPOSE

Review hypotony failure criteria used in glaucoma surgical outcome studies and evaluate their impact on success rates.

DESIGN

Systematic literature review and application of hypotony failure criteria to 2 retrospective cohorts.

PARTICIPANTS

A total of 934 eyes and 1765 eyes undergoing trabeculectomy and deep sclerectomy (DS) with a median follow-up of 41.4 and 45.4 months, respectively.

METHODS

Literature-based hypotony failure criteria were applied to patient cohorts. Intraocular pressure (IOP)-related success was defined as follows: (A) IOP ≤ 21 mmHg with ≥ 20% IOP reduction; (B) IOP ≤ 18 mmHg with ≥ 20% reduction; (C) IOP ≤ 15 mmHg with ≥ 25% reduction; and (D) IOP ≤ 12 mmHg with ≥ 30% reduction. Failure was defined as IOP exceeding these criteria in 2 consecutive visits > 3 months after surgery, loss of light perception, additional IOP-lowering surgery, or hypotony. Cox regression estimated failure risk for different hypotony criteria, using no hypotony as a reference. Analyses were conducted for each criterion and hypotony type (i.e., numerical [IOP threshold], clinical [clinical manifestations], and mixed [combination of numerical or clinical criteria]).

MAIN OUTCOME MEASURES

Hazard ratio (HR) for failure risk.

RESULTS

Of 2503 studies found, 278 were eligible, with 99 studies (35.6%) lacking hypotony failure criteria. Numerical hypotony was predominant (157 studies [56.5%]). Few studies used clinical hypotony (3 isolated [1.1%]; 19 combined with low IOP [6.8%]). Forty-nine different criteria were found, with IOP < 6 mmHg, IOP < 6 mmHg on ≥ 2 consecutive visits after 3 months, and IOP < 5 mmHg being the most common (41 [14.7%], 38 [13.7%], and 13 [4.7%] studies, respectively). In both cohorts, numerical hypotony posed the highest risk of failure (HR, 1.51-1.21 for criteria A to D; P < 0.001), followed by mixed hypotony (HR, 1.41-1.20 for criteria A to D; P < 0.001), and clinical hypotony (HR, 1.12-1.04; P < 0.001). Failure risk varied greatly with various hypotony definitions, with the HR ranging from 1.02 to 10.79 for trabeculectomy and 1.00 to 8.36 for DS.

CONCLUSIONS

Hypotony failure criteria are highly heterogenous in the glaucoma literature, with few studies focusing on clinical manifestations. Numerical hypotony yields higher failure rates than clinical hypotony and can underestimate glaucoma surgery success rates. Standardizing failure criteria with an emphasis on clinically relevant hypotony manifestations is needed.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Hypotony-associated Complications After Deep Sclerectomy: Incidence, Risk Factors, and Long-term Outcomes

PRECIS

Chronic hypotony is not uncommon following deep sclerectomy (DS), but only a minor proportion of patients develop hypotony-associated complications. Numerical hypotony does not affect the visual outcomes. This study identifies factors associated with hypotony.

PURPOSE

To investigate the incidence and risk factors of hypotony and hypotony-associated complications after DS.

METHODS

Retrospective cohort study of 1765 eyes (1385 patients) undergoing DS with or without cataract extraction between 2001 and 2020 in 2 UK centers. Chronic hypotony was defined as intraocular pressure (IOP) ≤5 mm Hg in ≥2 consecutive visits lasting >90 days or as any IOP ≤5 mm Hg associated with hypotony-related complications or requiring surgical intervention. Clinical hypotony was defined as the presence of: serous or hemorrhagic choroidal detachment, hypotony maculopathy, flat anterior chamber requiring reformation, decompression retinopathy. The incidence of hypotony was calculated with Kaplan-Meier statistics, and Cox regression was used to identify risk factors.

RESULTS

The median (interquartile range) age and follow-up were 76 (67 to 82) years and 45.4 (20.9 to 79.8) months, respectively. The incidence (95% confidence interval) of chronic and clinical hypotony at 5 years was 13.4% (11.5%-15.3%) and 5.6% (4.3%-6.9%), respectively. Sixteen eyes (15.7%) with hypotony-associated complications had IOP >5 mm Hg. Male sex (hazard ratio [HR]: 1.89, P=0.018), non-Caucasian ethnicity (HR: 2.49, P=0.046), intraoperative bevacizumab (HR: 3.96, P=0.01), pigmentary glaucoma (HR: 3.59, P=0.048), previous vitreoretinal surgery (HR: 5.70, P=0.009), intraoperative microperforation (HR: 4.17, P<0.001) and macroperforation (HR: 20.76, P<0.001), and avascular bleb (HR: 1.80, P=0.036) were associated with clinical hypotony.

DISCUSSION

Chronic hypotony is not uncommon following DS, but clinical hypotony is infrequent. Hypotony associated-complications can occur in eyes without statistical hypotony.

Five-year results of non-penetrating deep sclerectomy with demineralized cancellous bone xenogenically derived collagen glaucoma implant

PURPOSE

To investigate the long-term effectiveness of non-penetrating deep sclerectomy (NPDS) with xenogenically derived cancellous bone collagen glaucoma implant (XCB-CGI) implantation in patients with primary open-angle glaucoma (POAG).

MATERIALS AND METHODS

Retrospective chart review of patients with POAG stages 2 and 3 was treated with NPDS and XCB-CGI. Follow-up was at 6 months, 1, 2, 3, 4 and 5 years after surgery. Main outcomes were intraocular pressure (IOP) and medication burden. Secondary outcomes were visual acuity, corneal hysteresis (CH), visual field (VF) and optical coherence tomography (OCT) parameter analysis.

RESULTS

Among 71 patients (71 eyes), the mean age was 72.7 ± 9.8. Average initial IOP was 27.7 ± 7.9 and average initial med load was 2.36 ± 0.99. At 6 months, 1, 2, 3, 4 and 5 years, the average IOP was 14.9 ± 3.3 mm Hg (46.2% reduction), 15.3 ± 4.0 mm Hg (44.7% reduction), 14.2 ± 3.8 mm Hg (48.7% reduction), 15.2 ± 3.3 mm Hg (45.0% reduction), 15.5 ± 3.3 mm Hg (44.0% reduction) and 14.2 ± 2.8 mm Hg (48.7% reduction), respectively. In 5 years, the success rate was 34% and 67%, without, and with medications (1.8 ± 0.8 meds required), respectively. Visual acuity was not significantly different (P > .05) at all follow-up visits from baseline. Mean CH increased by 2.1 ± 0.8 (P = .05). No glaucomatous deterioration of the VF and OCT parameters was detected in 56 eyes at the 5-year follow-up.

CONCLUSION

NPDS with XCB-CGI implantation is an effective procedure to normalize the level of IOP, stabilize glaucomatous changes and decrease the number of meds needed for glaucoma control.

Impact of early and delayed Nd:YAG laser goniopuncture on results of deep sclerectomy (5-years follow up period)

Purpose:

To report on impact of Nd:YAG laser goniopuncture (LGP) timing on hypotensive efficacy of deep sclerectomy (DS) for open-angle glaucoma (OAG) patients.

Methods:

228 patients who underwent DS followed by Nd:YAG LGP between January 2010 and December 2013, (follow up – 5 years) were enrolled into a single-center, retrospective, non-randomized, consecutive study. Subjects were divided into two groups (1 – delayed LGP, n = 116; 2 – early LGP, n = 112). Demographic variables, preoperative glaucoma medications, preceding surgeries and glaucoma severity were analyzed. Intraoperative and postoperative complications, intraocular pressure (IOP), ultrasound biomicroscopy (UBM) values were recorded. Success rate was analyzed using Kaplan-Meier curve. UBM data were the criteria for early or delayed LGP.

Results:

LGP was performed 3.46 ± 1.9 (1.5–6.7) months after DS in group 1, 1.12 ± 0.08 (0.9–1.5) months in group 2 ( p = 0.0001). Mean IOP before LGP in group 1 was 18.5 ± 4.7 (11.2–22.9) mm Hg; 15.7 ± 4.1 (9.1–18.5) mm Hg in group 2 ( p = 0.001). Choroidal effusion occurred in 8.6% of group 1 and 3.5% of group 2 ( p = 0.0001). Postoperative IOP: 15.6 ± 4.6 (group 1) and 15.7 ± 4.3 mm Hg (group 2) at 12 months ( p = 0.98), 16.7 ± 4.3 and 14.9 ± 1.6 mm Hg at 24 months ( p = 0.004), 16.8 ± 3.9 and 14.5 ± 3.2 mm Hg at 60 months, respectively ( p = 0.0001). Complete success rates: 68.07% and 92.59% at 12 months, 40.7% and 75.8% at 24 months, 15.2% and 48.93% at 36, 48, 60 months in groups respectively ( p = 0.0001).

Conclusion:

Early LGP after DS excludes TDM influence on further formation of intrascleral canal cavity and outflow pathways demonstrating pronounced hypotensive success in a long-term follow-up.

[Nd:YAG laser goniopuncture as a mandatory adjuvant procedure after non-penetrating deep sclerectomy (long-term observation results)]

Today, Nd:YAG laser goniopuncture (LGP) is considered a mandatory non-penetrating deep sclerectomy adjuvant procedure. However, its indications and timing remain debatable.

PURPOSE

To evaluate the effect of Nd:YAG laser goniopuncture on the long-term hypotensive effectiveness of non-penetrating deep sclerectomy.

MATERIAL AND METHODS

The study included 114 patients after non-penetrating deep sclerectomy (NPDS). In the control group (n=58), Nd:YAG laser goniopuncture was performed within 3.4±1.9 (1.5-6.7) months, and in the main group (n=56) - within 1.12±0.08 (0.9-1.5) months after the surgery. Ultrasound biomicroscopy (UBM) was used to evaluate the semiotics of trabecular-Descemet's membrane (TDM), intrascleral canal (ISC) and filtering bleb. The follow-up period was 5 years.

RESULTS

According to UBM data, the thickness (0.10±0.009 mm) and density (50±6%) of TDM (p=0.0001) increased before LGP in the control group, the height of ISC decreased to 0.49±0.19 (0.20-0.40) (p=0.03), the height of UBM scan - to 1.49±0.05 (1.41-2.9) (p=0.0001); IOP (P₀) was 18.48±4.7 (11.2-22.9) mmHg (p=0.001). In the main group before LGP, TDM thickness was 0.08±0.006 mm, density was 40±5%, and IOP (P₀) was 15.7±4.1 (9.1-18.5) mm Hg. Complete hypotensive success was achieved in 83.6% of cases in the control group and 96.2% in the main group in 6 months; 68.07% and 92.59% in 12 months; 41.3% and 75.8% in 24 months; 15.25% and 48.93% in 36; 15% and 34.8% in 60 months after the surgery, respectively (p=0.0001, 95% confidence interval).

CONCLUSION

TDM is an additional level of retention of aqueous humor and plays key role in the formation of outflow pathways after NPDS. Performing LGP in the early postoperative period is an effective and safe adjuvant option, which excludes the influence of TDM on the formation of aqueous humor outflow pathways and significantly increases the long-term hypotensive efficacy of non-penetrating deep sclerectomy.

Comparison of the effect of mitomycin C and bevacizumab-methylcellulose mixture on combined phacoemulsification and non-penetrating deep sclerectomy surgery on the intraocular pressure (a clinical trial study)

PURPOSE

Comparison of the effect of mitomycin C (MMC) versus bevacizumab-methylcellulose mixture (BMM) on combined phacoemulsification and non-penetrating deep sclerectomy surgery on the intraocular pressure in patients with open-angle glaucoma was made.

METHODS

The current study is a controlled, randomized, double-blind clinical trial. Thirty-eight patients were enrolled, with a total of 40 eyes, and underwent a combined phacoemulsification and non-penetrating deep sclerectomy surgery from 2016 to 2017. MMC with concentration of 0.2 mg/mL for 2 min was used for 20 eyes before separating the scleral flap, and 0.3 mL of BMM (bevacizumab 1.25 mg incorporated into 2% methylcellulose) was injected subconjunctivally following surgery. The success rate of surgery was categorized as complete, relative and failure. Fisher's exact, Mann-Whitney U and Chi-square tests were employed to data analysis. A p value < 0.05 was supposed significant.

RESULTS

Patients had the same distribution in terms of age, sex, type of glaucoma and type of cataract. Patients were followed up for a mean of 6 months. The mean intraocular pressure before surgery in the MMC group was 24.85 ± 2.83 mmHg with 3.2 ± 0.523 anti-glaucoma drugs, which reached 13.75 ± 3.552 mmHg with 0.15 ± 0.489 anti-glaucoma drugs at the latest visit. The average intraocular pressure before surgery in the BMM group was 24.45 ± 2.48 mmHg with 2.9 ± 0.641 anti-glaucoma drugs, which reached 15.40 ± 3.267 mmHg with 0.25 ± 0.55 anti-glaucoma drug at the last follow-up. The intraocular pressure was notably lower in the MMC group than BMM group 6 months after surgery. There was not a significant difference from the aspect of success rate and failure rate among the two groups at the 6-month follow-up (p = 0.135).

DISCUSSION

Based on the results of this study, MMC and bevacizumab-methylcellulose both seem to be effective in the success of combined phacoemulsification and non-penetrating deep sclerectomy surgery, but MMC decreases intraocular pressure in patients at 6 months post-surgery.

Deep sclerectomy for uveitic glaucoma: long-term outcomes

PurposeTo report long-term outcomes of deep sclerectomy (DS) in eyes with raised intraocular pressure (IOP) and glaucoma secondary to uveitis.Patients and methodsRetrospective consecutive case series of 43 eyes of 43 patients with uveitic glaucoma. Mitomycin C (MMC) 0.2-0.4 mg/ml was applied sub-conjunctivally prior to scleral flap dissection for 2-3 min in 35 eyes (81%). Combined phacoemulsification and DS was done in 4 cases (9%).ResultsMean follow-up was 68.5±33.5 months. In total, 23 eyes (53.5%) had previous intraocular surgery. Pre-operative IOP was 33.6±12.0 mm Hg. Mean IOP at one, three and five years after surgery was 15.5±5.0 mm Hg, 16.9±6.7 mm Hg and 16.4±5.2 mm Hg, respectively.The probability of IOP <22 and <19 mm Hg was 69 and 62% at 3 years and 60 and 51% at 5 years, respectively. This included eyes that had undergone needle revision and/or laser goniopuncture within that period but had not needed glaucoma medication or further glaucoma procedures. The overall number of glaucoma medications decreased from 3.0±1.2 to 0.8±1.2 by last follow-up (P<0.001). Serious complications included hypotony with macular folds in two eyes and occlusion of the trabeculo-Descemet's membrane (TDM) by iris in two eyes. Recurrence of uveitis was observed in 16 eyes. Seven eyes (16.3%) had subsequent procedures including trabeculectomy with MMC in one eye, DS with MMC in two eyes and Baerveldt tube implantation in five eyes.ConclusionsDS is a safe and effective procedure to lower IOP in uveitic glaucoma. However, as with other glaucoma procedures, a significant proportion of patients will require another IOP-lowering procedure in the long-term.

Anti-vascular endothelial growth factor for control of wound healing in glaucoma surgery

BACKGROUND

Trabeculectomy is performed as a treatment for glaucoma to lower intraocular pressure (IOP). The surgical procedure involves creating a channel through the wall of the eye. However scarring during wound healing can block this channel which will lead to the operation failing. Anti-vascular endothelial growth factor (VEGF) agents have been proposed to slow down healing response and scar formation.

OBJECTIVES

To assess the effectiveness of anti-VEGF therapies administered by subconjunctival injection for the outcome of trabeculectomy at 12 months follow-up and to examine the balance of benefit and harms when compared to any other anti-scarring agents or no additional anti-scarring agents.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2015, Issue 10), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to November 2015), EMBASE (January 1980 to November 2015), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 12 November 2015.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of anti-VEGF therapies administered by subconjunctival injection compared to any other anti-scarring agents or no additional anti-scarring agents (no treatment or placebo) in trabeculectomy surgery.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Our primary outcome was successful trabeculectomy at 12 months after surgery which was defined as achieving a target IOP (usually no more than 21 mm Hg) without any additional intervention. Other outcomes included: qualified success (achieving target IOP with or without additional intervention), mean IOP and adverse events.

MAIN RESULTS

We included five RCTs (175 participants, 177 eyes) that met the inclusion criteria in this review.One trial conducted in Iran (37 participants, 37 eyes) compared anti-VEGF (bevacizumab 0.2 mg) versus control (sham injection) in people with refractory glaucoma. We judged this study to be at low risk of bias.The primary outcome of this review was not reported; mean IOP at three months was 15.1 mm Hg (standard deviation 1.0) in both anti-VEGF and control groups.Four trials compared anti-VEGF to mitomycin C (MMC) (138 particpants, 140 eyes). These studies were conducted in India, Iran, Turkey and the USA. The anti-VEGF agent used in these four trials was bevacizumab 2.5 mg (two trials), bevacizumab 1.25 mg three times and ranibizumab 0.5 mg. Two trials were at high risk of bias in two domains and one trial was at high risk of bias in four domains.Only one of these trials reported the primary outcome of this review (42 participants, 42 eyes). Low quality evidence from this trial showed that people receiving bevacizumab 2.5 mg during primary trabeculectomy were less likely to achieve complete success at 12 months compared to people receiving MMC but the confidence interval (CI) was wide and compatible with increased chance of complete success for anti-VEGF (risk ratio (RR) 0.71, 95% CI 0.46 to 1.08), Assuming that approximately 81% of people receiving MMC achieve complete success, the anticipated success using anti-VEGF agents would be between 37.2% and 87.4%. The same trial suggested no evidence for any difference in qualified success between bevacizumab and MMC (RR 1.00, 95% CI 0.87 to 1.14, moderate quality evidence). Two trials of primary trabeculectomy provided data on mean IOP at 12 months; one trial of bevacizumab 2.5 mg and one trial of ranibizumab 0.5 mg. Mean IOP was 1.86 mm Hg higher (95% CI 0.15 to 3.57) in the anti-VEGF groups compared to the MMC groups (66 people, low quality evidence). Data were reported on wound leak, hypotony, shallow anterior chamber and endophthalmitis, but these events occurred rarely and currently there are not enough data available to detect any differences, if any, between the two treatments.

AUTHORS' CONCLUSIONS

The evidence is currently of low quality which is insufficient to refute or support anti-VEGF subconjunctival injection for control of wound healing in glaucoma surgery. The effect on IOP control of anti-VEGF agents in glaucoma patients undergoing trabeculectomy is still uncertain, compared to MMC.Further RCTs of anti-VEGF subconjunctival injection in glaucoma surgery are required, particularly compared to sham treatment with at least 12 months follow-up.

Baerveldt tube implantation following failed deep sclerectomy versus repeat deep sclerectomy

PURPOSE

To compare the surgical outcomes of repeat deep sclerectomy (DS) and the Baerveldt glaucoma implant (BGI) in eyes with failed primary deep sclerectomy.

DESIGN

A retrospective comparative case-control study.

METHODS

Fifty-eight eyes of 56 glaucoma patients with previously failed DS underwent BGI (group BGI) and 58 eyes of 55 patients underwent repeat DS (group DS) at a tertiary referral centre. Visual acuity, intraocular pressure (IOP), number of glaucoma medications, surgical failure rates and complication rates were compared between groups. Surgical failure was defined as loss of IOP control, loss of light perception, or need for further glaucoma surgery.

RESULTS

Baseline demographics were similar between groups. Preoperatively, median IOP was lower in the DS than the BGI group (19 mmHg versus 21 mmHg, p = 0.10). Postoperatively at year 1, median IOP was significantly higher in the DS than BGI group (14 mmHg versus 11 mmHg, p = 0.02). There were no differences between the DS and BGI groups in mean number of medications preoperatively (2.3 versus 2.6) or postoperatively (1.3 versus 1.1). Complication rates were significantly higher in the DS group [41 % (n = 24) versus 14 % (n = 8); p = 0.01]. The failure rate at 1 year was higher in eyes with repeat DS than in eyes with BGI (30 vs. 21 %, respectively; p = 0.07).

CONCLUSIONS

Baerveldt implants were more effective in lowering IOP and resulted in significantly fewer complications than repeat deep sclerectomy in eyes with previously failed deep sclerectomy.

Complementary effects of bevacizumab and MMC in the improvement of surgical outcome after glaucoma filtration surgery

PURPOSE

To determine the optimum administration route of bevacizumab after glaucoma filtering surgery (GFS) and to investigate whether a reduced dose of mitomycin-C (MMC) in combination with bevacizumab could improve surgical outcome with a reduced incidence of side-effects.

METHODS

Plasma levels of bevacizumab were determined via ELISA after intracameral (IC), subconjunctival (SC) and intravitreal (IV) injections in mice, subjected to a mouse model of GFS. Application of MMC was compared to bevacizumab (SC, 25 μg) and to the combined use of both adjuvants. Surgical sponges soaked in MMC 0.02% or 0.01% were exposed to the sclera for 1 or 2 min. Treatment outcome was studied by bleb investigation.

RESULTS

The three administration routes of bevacizumab equally improved surgical outcome. The VEGF antibody was detected at relatively high levels in plasma shortly after IV injection, whereas it was minimally absorbed after IC and SC injections. Both bevacizumab (SC) and MMC 0.02% (2 min) similarly increased bleb area. As compared to MMC, the combined injection with bevacizumab induced an additional effect on surgical outcome. Exposure of MMC 0.02% for 1 or 2 min together with bevacizumab equally improved surgical outcome, but 2 min application induced corneal toxicity. The combined use of bevacizumab and 1-min MMC 0.01% also improved surgical outcome compared to monotherapy, although to a lesser extent than the combination with 1-min MMC 0.02%.

CONCLUSIONS

Adjunctive bevacizumab not only enhances the beneficial effect of MMC on surgical outcome, but also allows reducing the administration time of MMC 0.02%, thereby eliminating its toxic effects on the cornea.

Improving patient outcomes following glaucoma surgery: state of the art and future perspectives

Of all the treatments currently used to lower intraocular pressure in glaucoma patients, filtration surgery is known to be the most effective. However, in a significant percentage of cases, the constructed channel closes due to excessive scar formation, resulting in surgical failure. The process of postoperative wound healing is characterized by the coagulative and inflammatory phase, followed by the proliferative and repair phase, and finally the remodeling phase. Perioperative antimitotic agents, such as mitomycin C and 5-fluorouracil, are known to modulate the process of wound healing and to improve surgical outcome, but they carry a risk of vision-threatening complications. New alternative strategies to prevent filtration failure, such as inhibition of transforming growth factor-β, vascular endothelial growth factor, and placental growth factor, have shown promising results in the improvement of surgical success. However, it remains necessary to broaden the therapeutic approach by focusing on combined therapies and on extended drug delivery.