Conventional Trabeculotomy Research Articles

Conventional Trabeculotomy versus Gonioscopy-Assisted Transluminal Trabeculotomy: A Retrospective Cohort Study.

Background: Conventional trabeculotomy (CT) is performed in an ab-externo manner with at most 120 degrees of incision area of Schlemm’s canal (SC). Recently, gonioscopy-assisted transluminal trabeculotomy (GATT), which makes possible a 360-degree incision area of SC in an ab-interno manner, is introduced. The purpose of this study was to compare surgical outcomes for CT and GATT with and without simultaneous phacoemulsification over 24 months and to identify factors associated with surgical success. Results: Patients’ baseline characteristics were not significantly different between two groups. The surgical success rate in CT and GATT with phacoemulsification groups were 40.4% and 96.6% and were significantly higher in the GATT group than in the CT group (p < 0.001). However, the surgical success rate in CT and GATT without phacoemulsification groups were 40.8% and 54.2%, and there were no significant differences between two groups without phacoemulsification (p = 0.55). Similarly, the postoperative IOP was significantly lower in the GATT group than in the CT group only in eyes with simultaneous phacoemulsification. There were no significant differences in the numbers of glaucoma medications between the two groups. Additional glaucoma surgery was needed in 13.2% and 25.9% of patients in the GATT and CT groups, respectively (p = 0.157). The multivariate logistic regression analysis revealed that the surgical success of trabeculotomy was significantly associated with combined phacoemulsification and the type of glaucoma surgery (GATT). Conclusion: Although both groups without phacoemulsification had a similar surgical success and IOP-lowering effect, GATT combined with phacoemulsification had a higher surgical success rate and a greater IOP-lowering effect compared with combined CT and phacoemulsification. Multivariate logistic regression analysis showed that the factors associated with higher surgical success at one year and two years postoperatively were the combined phacoemulsification procedure and the GATT.

Microcatheter-Assisted Circumferential Trabeculotomy versus Conventional Trabeculotomy for the Treatment of Childhood Glaucoma: A Meta-analysis.

Background The aim of the current meta-analysis was to compare the efficacy of microcatheter-assisted circumferential trabeculotomy (Group 1) with that of conventional trabeculotomy (Group 2) for the treatment of childhood glaucoma. Methods Published studies were systematically searched via the Web of Science, PubMed, Embase, and Cochrane Library databases. Odds ratios and 95% confidence intervals were calculated for dichotomous variables. Mean ± the standard deviation, mean difference, and 95% confidence intervals were calculated for continuous variables. Heterogeneity was assessed. Random effects modeling and RevMan version 5.30 were used to analyze the data. Results Five eligible studies were included in the meta-analysis. Mean postoperative intraocular pressures were significantly lower in Group 1 than in Group 2 at 3 months (P = 0.03), 6 months (P = 0.03), and 12 months (P = 0.007) postoperatively. The complete success rates were higher in Group 1 than in Group 2 at 3 months (P = 0.008), 6 months (P = 0.01), and 12 months (P = 0.004) postoperatively, as were the respective qualified success rates (P = 0.04, P = 0.0007, and P = 0.001). The pooled estimate indicated lower antiglaucoma medication use in Group 1, especially at 1 month postoperatively (P = 0.003). Conclusions Microcatheter-assisted circumferential trabeculotomy resulted in excellent intraocular pressure control, higher success rates, and the utilization of less medication than conventional trabeculotomy for childhood glaucoma. Therefore, microcatheter-assisted circumferential trabeculotomy may be recommended as the initial procedure for the treatment of childhood glaucoma.

Therapy of congenital glaucoma

The primary therapy of all forms of primary and secondary congenital glaucoma is surgical. In the last few decades, the options for customized surgical approach to different types of childhood glaucoma have significantly developed. In particular, circumferential trabeculotomy has shown some superiority over conventional trabeculotomy and is now also used to treat secondary congenital glaucoma. Goniotomy is still a valid alternative. Tube implants in childhood glaucoma still need improvements.

Surgical interventions for primary congenital glaucoma.

Primary congenital glaucoma (PCG) is an optic neuropathy with high intraocular pressure (IOP) that manifests within the first few years of a child's life and is not associated with other systemic or ocular abnormalities. PCG results in considerable morbidity even in high-income countries. To compare the effectiveness and safety of different surgical techniques for PCG. We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2020, Issue 4); Ovid MEDLINE; Embase.com; PubMed; metaRegister of Controlled Trials (mRCT) (last searched 23 June 2014); ClinicalTrials.gov; and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). We did not use any date or language restrictions in the electronic search. We last searched the electronic databases on 27 April 2020. We included randomized controlled trials (RCTs) and quasi-RCTs comparing different surgical interventions in children under five years of age with PCG. We used standard Cochrane methodology. We included 16 trials (13 RCTs and three quasi-RCTs) with 587 eyes in 446 children. Eleven (69%) trials were conducted in Egypt and the Middle East, three in India, and two in the USA. All included trials involved children younger than five years of age, with follow-up ranging from six to 80 months. The interventions compared varied across trials. Three trials (on 68 children) compared combined trabeculotomy and trabeculectomy (CTT) with trabeculotomy. Meta-analysis of these trials suggests there may be little to no evidence of a difference between groups in mean IOP (mean difference (MD) 0.27 mmHg, 95% confidence interval (CI) -0.74 to 1.29; 88 eyes; 2 studies) and surgical success (risk ratio (RR) 1.01, 95% CI 0.90 to 1.14; 102 eyes; 3 studies) at one year postoperatively. We assessed the certainty of evidence as very low for these outcomes, downgrading for risk of bias (-1) and imprecision (-2). Hyphema was the most common adverse outcome in both groups (no meta-analysis due to considerable heterogeneity; I2 = 83%). Two trials (on 39 children) compared viscotrabeculotomy to conventional trabeculotomy. Meta-analysis of 42 eyes suggests there is no evidence of between groups difference in mean IOP (MD -1.64, 95% CI -5.94 to 2.66) and surgical success (RR 1.11, 95% CI 0.70 to 1.78) at six months postoperatively. We assessed the certainty of evidence as very low, downgrading for risk of bias and imprecision due to small sample size. Hyphema was the most common adverse outcome (38% in viscotrabeculotomy and 28% in conventional trabeculotomy), with no evidence of difference difference (RR 1.33, 95% CI 0.63 to 2.83). Two trials (on 95 children) compared microcatheter-assisted 360-degree circumferential trabeculotomy to conventional trabeculotomy. Meta-analysis of two trials suggests that mean IOP may be lower in the microcatheter group at six months (MD -2.44, 95% CI -3.69 to -1.19; 100 eyes) and at 12 months (MD -1.77, 95% CI -2.92 to -0.63; 99 eyes); and surgical success was more likely to be achieved in the microcatheter group compared to the conventional trabeculotomy group (RR 1.59, 95% CI 1.14 to 2.21; 60 eyes; 1 trial at 6 months; RR 1.54, 95% CI 1.20 to 1.97; 99 eyes; 2 trials at 12 months). We assessed the certainty of evidence for these outcomes as moderate due to small sample size. Hyphema was the most common adverse outcome (40% in the microcatheter group and 17% in the conventional trabeculotomy group), with greater likelihood of occurring in the microcatheter group (RR 2.25, 95% CI 1.25 to 4.04); the evidence was of moderate certainty due to small sample size (-1). Of the nine remaining trials, no two trials compared the same two surgical interventions: one trial compared CTT versus CTT with sclerectomy; three trials compared various suturing techniques and adjuvant use including mitomycin C, collagen implant in CTT; one trial compared CTT versus Ahmed valve implant in previously failed surgeries; one trial compared CTT with trabeculectomy; one trial compared trabeculotomy to goniotomy; and two trials compared different types of goniotomy. No trials reported quality of life or economic data. Many of the included trials had limitations in study design, implementation, and reporting, therefore the reliability and applicability of the evidence remains unclear. The evidence suggests that there may be little to no evidence of difference between CTT and routine conventional trabeculotomy, or between viscotrabeculotomy and routine conventional trabeculotomy. A 360-degree circumferential trabeculotomy may show greater surgical success than conventional trabeculotomy. Considering the rarity of the disease, future research would benefit from a multicenter, possibly international trial, involving parents of children with PCG and with a follow-up of at least one year.

Comparison of 360° circumferential trabeculotomy and conventional trabeculotomy in primary pediatric glaucoma surgery: complications, reinterventions and preoperative predictive risk factors.

To quantify the postoperative complications and the need of re-operation after a single circumferential trabeculotomy versus a single conventional trabeculotomy, in 5years follow-up, in patients who underwent primary pediatric glaucoma surgery. For each complication and each re-operation case, we calculate the risk of appearance pointing out the possible preoperative risk factors by establishing a statistical connection between the result and the values of preoperative IOP, corneal diameter, or axial length. This was a retrospective study of patients aged 1day to 3years who underwent primary pediatric glaucoma surgery. A total of 45 patients (79 eyes) were followed up for at least 5years. There were two groups: the 360° circumferential trabeculotomy with illuminated catheter group and the conventional trabeculotomy group. Hyphema was the most common post-operative complication occurring in 64 eyes (81.01%) 30 (78.95%) in the conventional group and 34 (82.93%) in the circumferential group. There have been 5 eyes (6.3%) that needed re-operation: 1 case of hypotony (7mmHg) and 4 cases of postop hypertension, 1 case (2.43%) in the circumferential group and the rest of 4 cases (10.53%) in the conventional group. A preop IOP of 25mmHg or more in the conventional group is statistically significant predictive (p = 0.023) for postop hyphema, as well as a preop IOP of 28mmHg or more is predictive (p = 0.02) for the need of reintervention. Circumferential trabeculotomy has better results in time, similar complications and lower failure rates meaning less eyes requiring re-operation than conventional trabeculotomy.

Clinical practice preferences for glaucoma surgery in Japan: a survey of Japan Glaucoma Society specialists

This study evaluated the surgical practice patterns of glaucoma management followed by glaucoma specialists in Japan. A survey was administered to 50 glaucoma specialists who were councilors in the Japan Glaucoma Society about surgical preferences and postoperative glaucoma care. All 50 glaucoma specialists participated in the survey. Results show that, in 2019, compared to conventional trabeculotomy (4.6%), the frequency of minimally invasive glaucoma surgery (MIGS), combined with phacoemulsification, remarkably increased (79.0%) for non-operated eyes with mild open-angle glaucoma associated with cataract. Tube-shunt surgery was performed more often for open-angle glaucoma with previously twice failed trabeculectomy (65.8%) and neovascular glaucoma with previously once failed trabeculectomy (63.4%). In addition, during one year post-operatively, MIGS required less frequent follow-up visits compared to filtering surgery. Although glaucoma specialists in the Japan Glaucoma Society usually prefer trabeculectomy, in the past decade they have selected tube-shunt surgery more often to treat refractory glaucoma. MIGS is increasing remarkably as the choice primary glaucoma surgery.

Five-year results of viscotrabeculotomy versus conventional trabeculotomy in primary congenital glaucoma: A randomized controlled study.

To assess the long-term results of viscotrabeculotomy in infants with primary congenital glaucoma and to compare its outcome with conventional trabeculotomy. A prospective randomized comparative study included infants with primary congenital glaucoma younger than 2 years. Patients were divided into two groups: viscotrabeculotomy group and conventional trabeculotomy group. Preoperative and postoperative intraocular pressures, corneal diameter, intraoperative and postoperative complications, and success rates were compared between two groups. All the patients were followed up for 5 years. The study included 154 eyes of 92 infants distributed randomly among the two groups; 78 and 76 eyes in viscotrabeculotomy and conventional trabeculotomy groups, respectively. In both groups, there was a statistically significant intraocular pressure reduction at all time points of the follow-up periods compared to the preoperative values (p < 0.0001). At 5 years, viscotrabeculotomy group showed significant reduction of the mean postoperative intraocular pressure (49.47%) than conventional trabeculotomy group (48.64%) (p < 0.0001). Intraocular pressure was statistically lower in viscotrabeculotomy starting from 12th month and till the end of the follow-up. At 5 years, the total success rate of viscotrabeculotomy group was 89.74% compared to 85.53% in conventional trabeculotomy group without significant difference (p = 0.487). The postoperative mean values of the cup/disk ratio in viscotrabeculotomy group showed statistically lower values compared to conventional trabeculotomy group (p = 0.019). Postoperative hyphema was statistically higher in conventional trabeculotomy group (p < 0.0001). All eyes that underwent a reoperation before 5 years follow-up were excluded from the statistical workup of the study after reoperation, except for calculation of success/failure. Viscotrabeculotomy and conventional trabeculotomy proved to be effective in cases of primary congenital glaucoma. Viscotrabeculotomy appeared to have prolonged stability in controlling the intraocular pressure with higher success rates and lower complications.

Ab-interno trabeculotomy-related glaucoma surgeries.

Reductions of intraocular pressure during trabeculotomy result from relieving the resistance to aqueous flow by cleavage of the trabecular meshwork and inner walls of Schlemm's canal at the point of outflow resistance of the aqueous humor. Since trabeculotomy does not result in bleb formation, development of late-onset sight-threatening complications, such as hypotony maculopathy and endophthalmitis, that are associated occasionally with trabeculectomy develop less frequently after trabeculotomy. The ab-interno approach is used in several new procedures, including the Trabectome, Kahook Dual Blade, microhook abinterno trabeculotomy, and 360° suture trabeculotomy, instead of the ab-externo approach as in conventional trabeculotomy. These newly developed novel, minimally invasive, and trabeculotomy-related glaucoma surgeries can be good options for certain glaucoma cases, including early-stage open-angle glaucoma, developmental glaucoma, and glaucoma in elderly patients.

Long-term surgical outcome of conventional trabeculotomy for childhood glaucoma.

To investigate the long-term surgical outcomes of conventional trabeculotomy in eyes with childhood glaucoma in a Japanese population. In this retrospective observational study, we enrolled Japanese patients with childhood glaucoma who underwent a conventional trabeculotomy at least once before age 3years from 1986 to 2014 in our hospital. One hundred seven eyes of 64 patients (24 girls, 40 boys; mean age, 2.8±5.1months) were included. Sixty-eight (64%) eyes had primary childhood glaucoma (PCG) and 39 (36%) eyes had secondary childhood glaucoma (SCG). The average numbers of surgical operations performed to treat the two glaucoma types that resulted in significantly (p<0.001) different surgical success rates were 1.4±0.7 and 2.1±0.8. Statistical analysis showed that eyes with PCG, compared with those with SCG, were successfully treated by one trabeculotomy and up to three trabeculotomies (hazard ratios 6.66 and 4.02, respectively). Age, gender, systemic complications, corneal diameter, corneal edema, and preoperative intraocular pressure did not significantly affect the surgical outcomes. Most eyes with PCG are treatable with a maximum of three trabeculotomies. However, SCG usually is refractory to trabeculotomy, and a more promising surgery must be designed.

A comparative study between trabeculotomy with deroofing of Schlemm′s canal augmented with Ologen implant and conventional trabeculotomy in primary congenital glaucoma

Purpose The aim of the study was to evaluate the efficacy and safety of Schlemm's canal deroofing augmented by Ologen to enhance the success of trabeculotomy for primary congenital glaucoma (PCG). Patients and methods Thirty-two eyes of 21 patients were included in this prospective study, classified into two equal groups: the study group and the control group. The study group underwent trabeculotomy with Schlemm's canal deroofing and subconjunctival Ologen implantation, and the control group underwent trabeculotomy alone for infants affected by PCG. The participants were followed up for 6 months. Results According to the definitions for success, qualified success, and failure, the study group had 13/16 (81.25%) cases of success and 3/16 (18.75%) cases of qualified success. The control group reported 10/16 cases (62.50%) of success, 2/16 cases (12.50%) of qualified success, and 4/16 cases (25%) of failure. Conclusion Success and qualified success were higher in the study group (trabeculotomy augmented with deroofing of Schlemm's canal and Ologen implant) than in the control group after 6 months of follow-up for cases of PCG.

Pneumatic trabecular bypass versus trabeculotomy in the management of primary congenital glaucoma

The optimal surgical management in primary congenital glaucoma (PCG) remains a subject of debate. The aim of this study was to assess efficacy of pneumatic trabecular bypass (PTB) in comparison to conventional trabeculotomy (T) in the treatment of PCG. In a prospective comparative experimental study, one eye per child suffering from PCG underwent either PTB or T. Complete examinations were performed before surgery, postoperatively at one and seven days, then monthly for a minimum of six months. The main outcome measures were the IOP, number of IOP-lowering medications, change in cup/disc ratio, and corneal clarity. Seventeen eyes (patients) were operated on for PTB compared to 25 eyes (patients) in the T group. The mean (±SD, range) preoperative IOP in the PTB and T groups was 34.7 (6.4, 26-48) mmHg and 26.4 (6.6, 18-44) mmHg, respectively, and these dropped at six months of follow-up to 14.9 (3.6, 11-24) mmHg and 18.8 (8.0, 6-34) mmHg, respectively. The mean reductions of IOP were 55.87%(±11) and 28.4%(±28.8), (p = 0.001), where those for cup/disc ratio were 39.0%(±29) and 17.5%(±39.7) (p = 0.088) in the PTB and T groups, respectively. The number of IOP-lowering medications had dropped from 1.7 ± 0.5 to 0.7 ± 1.0 in PTB patients, compared to an insignificant change in the T group (0.64 ± 0.9 & 0.62 ± 0.9 pre- and post-operatively respectively). Corneal clarity improved in 13 eyes (76.5%) in the PTB group, while three eyes (12%) had worsened in the T group. Total cumulative chances for success were 88.2% (15 out of 17 eyes), compared to 56% (14 out of 25 eyes), in the PTB and T groups, respectively (p = 0.027). PTB is a promising surgical technique for the control of primary congenital glaucoma. A randomized controlled trial with a longer follow-up is recommended.

Trabeculotomy without scleral flap for the treatment of pediatric glaucoma

Introduction: The purpose of this report is to describe a modification of the conventional trabeculotomy procedure. This retrospective, case series review examines 14 cases of trabeculotomy surgery performed without a scleral flap. In these cases, the radial scleral incision was initiated into full-thickness sclera and dissected posteriorly until Schlemm's canal was located. The scleral incision was then secured with 10-0 vicryl suture.

False Passage: A Complication of 360° Suture Trabeculotomy

F c s t he use of suture material to perform trabeculotomy as first described by Smith in 1960. The technique as subsequently refined by Beck and Lynch in 1995 hen they presented a series of 26 eyes undergoing 60° trabeculotomy using a single length of 6-O olypropylene suture. In this new modification, a suure fragment is passed through the entire length of chlemm’s canal via a partial thickness scleral flap. nce passed, the 2 free ends of the suture are pulled, pening all 360° of the angle as the suture tears into he anterior chamber. The potential advantage of this echnique is the ability to open the entire angle hrough only one incision during a single surgical rocedure. By contrast, conventional trabeculotomy ith metal trabeculotomes is only able to open onehird to one-half of the angle circumference at a single ession and would require at least 2 separate incisions o complete for 360° angle surgery. This report decribes a potential complication of suture trabecuotomy; false passage into the subscleral (suprachoroial) space.

Mitomycin C-augmented Trabeculectomy in Refractory Congenital Glaucoma

Objective: The purpose of the study is to determine the safety and efficacy of mitomycin C-augmented trabeculectomy in children with developmental glaucoma treated previously by conventional procedures.Design: Retrospective review of all cases of developmental glaucoma with previously failed conventional procedures that underwent mitomycin C-augmented trabeculectomy between January 1992 and December 1994.Participants: A total of 19 eyes of 13 patients were included in the study. Nineteen eyes included primary congenital glaucoma (15 eyes) with documented failure of primary trabeculotomy, Axenfeld-Reiger syndrome (2 eyes) and aniridia (2 eyes).Intervention: Mitomycin C-augmented (0.4 mg/ml for 3 minutes) trabeculectomy was the chosen intervention.Main outcome measures: Preoperative and postoperative intraocular pressures (IOPs), visual acuities, success rate, bleb characteristics, time of surgical failure, and complications were the main outcome measures.Results: The mean IOP was reduced from a preoperative level of 33.74 ± 10.70 mmHg to 11.89 ± 1.33 mmHg (P < 0.0001) with the percentage reduction in IOP being 64.75. The mean follow-up was 19.52 ± 2.65 months. Visual acuity was maintained in all the cases after surgery. Complete success as defined in the authors' study was achieved in 18 eyes (94.74%). Only one patient was classified as a qualified success. The bleb was characterized by its large elevated, avascular, transparent appearance in all the eyes. The only significant complication was retinal detachment in an eye with buphthalmos, aphakia, and large axial length. However, the retina was reattached successfully by retinal reattachment surgery, and visual acuity improved to the preoperative level of 20/200. It was not possible to determine the cause of retinal detachment or to assess the possible role of mitomycin C in this complication.Conclusions: Mitomycin C-augmented trabeculectomy is a viable option in eyes with failed conventional trabeculotomy surgery.