Combined trabeculotomy-trabeculectomy using the modified Safer Surgery System augmented with MMC: its long-term outcomes of glaucoma treatment in Asian children

Current surgical techniques for the management of pediatric glaucoma: A literature review

Pediatric glaucoma surgery is challenging due to its diverse and complex pathophysiology, altered anterior segment anatomy, greater potential for failure, and complications compared to adult patients. Moreover, numerous challenges are associated with long-term postoperative management. Thus, when dealing with childhood glaucoma, it is important to consider the potential complications in addition to the benefits of each intervention. The purpose of this article is to review recently published literature to shed light on the most recent surgical techniques for the safe and effective treatment of childhood glaucoma. Current literature shows that goniotomy and trabeculotomy are the first choices for the management of primary congenital glaucoma. Although older children with phakic eyes seem to benefit from trabeculectomy with adjunctive mitomycin C, it carries a long-term risk of bleb-related endophthalmitis. Glaucoma drainage devices may be preferred for patients with secondary or refractory glaucoma. However, hypotony or tube-related complications are common and encountered more often in children than in adults. Cyclodestructive procedures are also an option for cases in which filtering surgery has failed, but they can also be used as a temporizing measure to reduce the rate of complications in high-risk patients. However, their outcomes can be unpredictable, in terms of efficiency and complications. Finally, minimally invasive glaucoma surgery (MIGS) as the sole alternative treatment or as an adjunctive surgical procedure is a relatively new path for pediatric patients.

Combined trabeculotomy-trabeculectomy with and without augmentation in primary congenital glaucoma: triple-armed randomized controlled trial

PURPOSE

To evaluate the efficacy and safety of using Mitomycin-C (MMC) or Ologen implant as an adjunct to combined trabeculotomy-trabeculectomy (CTT) surgery relative to non-augmented CTT surgery in achieving higher success rates in patients with primary congenital glaucoma (PCG).

STUDY DESIGN

A prospective triple-armed randomized controlled clinical trial was conducted in the period between April 2019 and May 2021, targeting 75 eyes of patients with PCG over one year, with patients being followed up for at least one whole year.

PATIENTS AND METHODS

The study included 75 eyes; only 70 fulfilled the inclusion criteria and were randomly assigned to one of the three study groups using a computer program to generate random number list. Eyes were treated by either CTT without augmentation, CTT augmented with MMC, or CTT augmented with Ologen implant. Only 63 eyes completed one year of follow-up and were evenly distributed among the three study groups; with 21 eyes in each group were statistically analyzed.

OUTCOME MEASURES

Our primary outcome measure is to report and compare the percentage of patients who demonstrated complete success with intraocular pressure (IOP) controlled and maintained below 21 mmHg without the use of antiglaucoma medications or additional glaucoma surgery over a one-year follow-up. Secondary outcome measures include reporting failure, intra- and postoperative complications of the three surgical modalities, postoperative corneal diameter, clearance of corneal edema, and postoperative cup/disk (C/D) ratio.

RESULTS

Complete success was achieved in 17 eyes (81.0%) in CTT group, 18 eyes (85.7%) in MMC group, and 17 eyes (81.0%) in Ologen group. Qualified success (IOP < 21 with or without antiglaucoma medications) was achieved in 18 eyes (85.7%) in both the CTT and the Ologen groups, with 19 eyes (90.5%) in the MMC group. Failure was observed in three eyes (14.3%) in both CTT and Ologen groups and two eyes (9.5%) in the MMC group. Based on survival analysis, CTT group had a cumulative success probability of 95.2% at three months, which dropped to 85.7% at six months and remained at that level for the 9th and 12th months of follow-up. With respect to the MMC group, the cumulative success probability at three months was 95.2%, dropped to 90.5% at six months, and remained at that level for the 9th and 12th months of follow-up. While in the Ologen group, the cumulative success probability at three months was 85.7% and remained at the same level during the 6th, 9th, and 12th months of follow-up, with p value = 0.862 using the logrank test.

CONCLUSION

CTT is a safe and effective primary surgical intervention in patients with PCG without the need for augmentation while preserving the augmented procedure's use for recurrent cases.

ZD6474 attenuates TGF-β1-induced fibrosis in human Tenon fibroblasts and inhibits neovascularization via AKT-mTOR signaling pathway

PURPOSE

To investigate the anti-fibrotic effect of ZD6474 (a novel inhibitor of VEGF and EGF) in TGF-β1 stimulated human Tenon's capsule fibroblasts (HTFs) and the anti-angiogenetic role in HUVECs, compared to that of mitomycin C (MMC).

METHODS

The effects of ZD6474 on cell proliferation or migration in TGF-β1-stimulated HTFs and HUVECs were determined, using CCK8 or wound healing assay, respectively. The typical markers of fibrosis in TGF-β1-stimuated HTFs were detected, vimentin by immunofluorescence, α-SMA and snail by western blot. Tube formation was applied to validate the anti-angiogenesis effect in HUVECs following ZD6474 treatment. Furthermore, phosphorylated AKT and mTOR (p-AKT and p-mTOR) were evaluated, compared to the standardized total AKT and mTOR, using western blot.

RESULTS

There was almost no decreased cell viability in HTFs following ZD6474 (≤ 1 μM/mL) treatment, but MMC (> 50 μg/mL) significantly impaired cell viability. ZD6474 significantly inhibited TGF-β1-stimulated proliferation and migration in HTFs, compared to control group (**P < 0.01). ZD6474 also significantly attenuated the TGF-β1-stimulated expression of vimentin, α-SMA and snail in HTFs. Tube formation was notably interrupted in HUVECs following ZD6474 treatment (**P < 0.01). P-AKT and p-mTOR were significantly decreased in response to ZD6474 treatment in TGF-β1- induced HTFs and HUVECs.

CONCLUSIONS

ZD6474 exerts anti-proliferation and anti-fibrotic effects in TGF-β1-stimulated HTFs perhaps via regulating AKT-mTOR signaling pathway. ZD6474 also inhibited proliferation, migration and tube formation in HUVECs via the same signaling pathway. We concluded that ZD6474 may be potentially a novel agent in preventing bleb dysfunction following glaucoma filtration surgery (GFS).

Clinical Analysis of Pediatric Glaucoma in Central China

Purpose

We aimed to describe the characteristics, epidemiology, management, and outcomes of glaucoma in pediatric patients in central China.

Methods

This study retrospectively analyzed inpatients with pediatric glaucoma at Henan Provincial People's Hospital, Henan Eye Institute, and Henan Eye Hospital between 2017 and 2020.

Results

Overall, 239 cases (276 eyes) of pediatric glaucoma in patients, comprising 87 girls (36.40%) and 152 boys (63.60%) were analyzed. The mean age was 6.65 ± 4.46, and 2.93% of the patients had a family history of glaucoma. Primary congenital glaucoma (PCG) was the most common type of glaucoma, followed by traumatic glaucoma in 8.33% of the patients, which was considered secondary glaucoma. The most common signs and symptoms were elevated intraocular pressure (IOP) and eye pain. Trabeculotomy (Trab) and microcatheter-assisted 360° trabeculotomy (MAT) combined with Trab were the most commonly performed surgeries. The IOP of patients with PCG, juvenile open-angle glaucoma (JOAG), and secondary glaucoma were 15.27 ± 7.48 mmHg, 17.16 ± 10.05, and 18.65 ± 8.55, respectively, at the final follow up. The rate of re-operations in patients with PCG, JOAG, and secondary glaucoma were 9.15%, 6.78%, and 4.69%, respectively. The mean visual acuity of the eyes with PCG, JOAG, and secondary glaucoma was 0.79 ± 0.68, 0.51 ± 0.48, and 0.53 ± 0.50, respectively.

Conclusion

PCG, JOAG, and traumatic glaucoma were the most prevalent subtypes in patients with pediatric glaucoma in central China. Trab and MAT combined with Trab were the most common interventions used in this study. Pediatric amblyopia might require full attention during the entire treatment, especially after glaucoma surgery. Effective preventive measures and more public education on glaucoma prevention and the importance of early diagnosis and treatment is necessary.

Results of childhood glaucoma surgery over a long-term period

PURPOSE

To evaluate long-term results of glaucoma surgery in newborn and infants with glaucoma.

METHODS

Seventy-nine eyes of 52 children (age: 3 weeks-15.3 years) with primary congenital or secondary glaucoma treated between 2015 and 2017 were included. The median follow-up time was 3.9 years. Conventional probe trabeculotomy, 360° catheter-assisted trabeculotomy, filtering and cyclodestructive surgery were compared. Strict criteria for surgical success were applied: Complete surgical success (IOP below target IOP, no further surgery) and incomplete surgical success (additional surgery allowed) were analyzed, and IOP at baseline and last follow-up was compared.

RESULTS

Intraocular pressure (IOP) was significantly reduced in primary congenital (preoperative IOP: 27.8 ± 7.5 mmHg vs. postoperative IOP: 14.2 ± 4.5 mmHg) and secondary glaucoma (preoperative IOP: 29.2 ± 9.1 mmHg vs. postoperative IOP: 16.6 ± 4.7 mmHg). 90% of all eyes reached target IOP with or without medication allowing for additional surgeries. As first surgery, 360° catheter-assisted trabeculotomy had a tendency to higher surgical success than other surgical approaches, while cyclodestructive procedures had lowest.

CONCLUSIONS

We found very promising surgical results in our childhood glaucoma patient group. Surgical success in both congenital and secondary glaucoma was high.

Visual evoked potentials changes with surgery in primary congenital glaucoma: a pilot study

OBJECTIVE

To report the flash visual evoked potential (VEP) findings in children with primary congenital glaucoma (PCG) before and after successful surgical control of the intraocular pressure (IOP).

METHODS

The study enrolled children presenting with PCG to the Ophthalmology Department of Alexandria Main University Hospital in the period between June and December 2019. All study participants were subjected to a standard protocol of examination, to confirm the diagnosis of PCG. The child was then referred for flash VEP testing. Peaks were designated as negative and positive waves in a numerical sequence (N1, P1, N2, P2, N3 and P3). The child was then scheduled for surgery within 1 week of presentation. Postoperative VEP testing was scheduled as soon as feasible and was conducted in the same way as the preoperative VEP testing.

RESULTS

The study was conducted on 11 (four right) eyes of eight (five males) children. The mean ± standard deviation of the age of the study children at presentation and at postoperative VEP testing was 3.5 ± 1.6 and 5.1 ± 3.0 months, respectively. The study eyes mean ± standard deviation IOP at presentation and at postoperative VEP testing was 23.0 ± 6.7 and 8.3 ± 2.4 mmHg, respectively (p < 0.0001). There were a statistically insignificant reduction in P2 implicit time (p = 0.235) and a statistically insignificant increase in each of N1-P1 (p = 0.15) and N2-P2 (p = 0.67) amplitudes postoperatively than preoperatively.

CONCLUSIONS

IOP elevation in PCG adversely affects the optic nerve function, but, at least in the short term, has no permanent detrimental effect on the optic nerve function as evidenced by the improvement in the VEP parameters.

Retrospective analysis of paediatric glaucoma at a tertiary referral centre in Hong Kong

PURPOSE

To evaluate the epidemiological features, clinical interventions, and outcomes of paediatric glaucoma in Hong Kong.

STUDY DESIGN

Retrospective chart review.

METHODS

Clinical data from the medical records of all patients under 18 years of age diagnosed with glaucoma from January 2008 to December 2017 at a university-affiliated, tertiary referral centre were collected. The patients' demographics, etiological distribution, clinical interventions, and outcomes were analysed.

RESULTS

A total of 33 subjects (53 eyes) were identified, 30 (49 eyes) of whom were Chinese. Primary glaucoma accounted for 21.2% of subjects, while 78.8% were diagnosed with secondary glaucoma. The most common subtype was juvenile-onset open angle glaucoma, followed by Sturge-Weber Syndrome related glaucoma. The most commonly performed surgical interventions were tube-shunt surgery (Ahmed Glaucoma Valve) and transscleral cyclophotocoagulation. Most eyes had significant reduction in intraocular pressure after medical or surgical intervention, but deterioration of visual acuity remained common.

CONCLUSION

Most cases of childhood glaucoma in Hong Kong are secondary rather than primary, similar to other regions with low incidence of parental consanguinity. The large proportion of secondary glaucoma which generally has poorer prognosis, is reflected by the frequency of multiple surgery, and a high incidence of visual deterioration despite significant intraocular pressure reduction in most eyes.

Trabeculotomy versus combined trabeculotomy-trabeculectomy for primary congenital glaucoma: study protocol of a randomised controlled trial

INTRODUCTION

Trabeculotomy and combined trabeculotomy-trabeculectomy (CTT) are major surgical options for primary congenital glaucoma (PCG). However, it is unclear which of these two surgical procedures should be recommended as the optimum first-line treatment for PCG. This trial aims to determine whether the outcomes of trabeculotomy are non-inferior to those of CTT in moderate PCG with a horizontal corneal diameter (HCD) of 12-14 mm.

METHODS AND ANALYSIS

This is a 3-year, non-inferiority, prospective, randomised controlled trial. We plan to recruite 248 participants (aged ≤3 years) with PCG with an HCD of 12-14 mm from the Department of Glaucoma, Zhongshan Ophthalmic Center, Guangzhou, China. One eye per participant will be randomly (1:1) assigned to receive trabeculotomy or CTT. The primary outcome is the 3-year postoperative success rate in lowering intraocular pressure (IOP), and the secondary clinical outcomes will include IOP reduction, visual acuity, HCD, central corneal thickness, axial length, cup-disc ratio, refractive error and postoperative complications. Data will be analysed by the intention-to-treat principle.

ETHICAL APPROVAL AND DISSEMINATION

The study protocol has been approved by the ethics committee of Zhongshan Ophthalmic Center (2014MEKY023) and the '5010 Plan' evaluation committee at Sun Yat-Sen University, Guangzhou, China. The results will be disseminated in international academic meetings and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

Chinese Clinical Trial Registry, ChiCTR-IOR-14005588; Date registered: 20 November 2014.

Contemporary management of refractory pediatric glaucoma

PURPOSE OF REVIEW

The management of pediatric glaucoma poses a unique challenge in terms of maintaining lifelong vision and combating an aggressive scarring response from surgery. Contemporary literature regarding the surgical management of children with pediatric glaucoma who fail, or are at a high risk of failure, from conventional surgery is limited. The aim of this review is to highlight recent developments in relation to the current opinion regarding the management of children with refractory pediatric glaucoma.

RECENT FINDINGS

Some studies have reported impressive success rates with circumferential trabeculotomy, even in eyes with previous failed surgery. Early results of deep sclerectomy in populations which may not respond well to conventional angle surgery are encouraging but data is limited for the pediatric age group. In compliant patients in whom multiple postoperative examinations under anesthesia are possible, trabeculectomy remains an effective procedure. Multiple recent studies have demonstrated that glaucoma drainage device (GDD) surgery is associated with 5-year success rates of over 70% in primary childhood glaucomas.

SUMMARY

Glaucoma drainage device surgery is likely to remain a mainstay of surgical management for refractory glaucoma in older children. More prospective data are needed on the success of circumferential trabeculotomy, deep sclerectomy and micropulse laser in pediatric eyes with previous failed surgery. VIDEO ABSTRACT: http://links.lww.com/COOP/A34.