Primary trabeculotomy compared to combined trabeculectomy-trabeculotomy in congenital glaucoma: 3-year study

Primary congenital glaucoma: We are always on the way

Primary congenital glaucoma (PCG), a developmental glaucoma occurring due to angle anomaly, earns growing concerns among ophthalmologists for its vision-damaging attribute. The incidence of PCG varies among races and geographic regions and is mostly genetically associated. Theories have been posed in attempt to address the etiology of this congenital maldevelopment and in the meanwhile providing evidence for feasibility of PCG surgeries. In regard to the clinical aspects of this entity, both the clinical characteristics and general principals of management are introduced, with angle surgeries highlighted for clarifying details including their success rates, key points for a successful surgical intervention, postoperative management, and follow-up strategies. Taking patients' vision-associated quality of life into consideration, we stressed that further perceptual learning and low vision rehabilitation are momentous. However, much has yet to be elucidated in respect of the truly comprehensive pathogenesis underneath as well as means by which clinical outcomes of PCG can be further improved. We are now looking forward to innovative therapeutic approaches like gene therapy in specific genes in the future, with the hope of improving their life-long visual quality in those young patients.

Long-Term Results of Combined Trabeculotomy Trabeculectomy in Primary Congenital Glaucoma

PRCIS

Primary congenital glaucoma (PCG) in Tunisian children seems to be characterized by a high prevalence of inherited and advanced forms of the disease. Primary combined trabeculotomy trabeculectomy (CTT) allowed satisfactory long-term intraocular pressure (IOP) control and reasonable visual outcome.

PURPOSE

To report the long-term outcome of CTT as the initial glaucoma surgery in children with PCG.

METHODS

Retrospective analysis of children who underwent primary CTT for PCG between January 2010 and December 2019. The main outcome measures were IOP reduction, corneal clarity, complications, refractive errors, and visual acuity (VA). Success was defined as IOP <16 mm Hg without (complete) or with (qualified) antiglaucoma medication. The WHO criteria of vision loss were used to categorize visual impairment (VI).

RESULTS

Of 62 patients, 98 eyes were enrolled. At the last follow-up, the mean IOP was reduced from 22.7 ± 4.0 mm Hg to 9.7 ± 3.9 mm Hg ( P < 0.0001). The complete success rate was 91.6%, 88.4%, 84.7%, 71.6%, 59.7%, and 54.3%, at the first, second, fourth, sixth, eighth, and tenth year, respectively. Follow-up averaged 42.1 ± 28.4 months. Preoperatively, 72 eyes (73.5%) had significant corneal edema versus 11 eyes (11.2%) at the end of the follow-up ( P < 0.0001). Endophthalmitis was encountered in one eye. Myopia was the most common refractive error (80.6%). Data on Snellen VA were available for 53.2% of the patients; 33.3% achieved a VA ≥6/12, 21.2% had mild VI, 9.1% had moderate VI, 21.2% had severe VI, and 15.2% were blind. The failure rate was statistically correlated to the early disease onset (<3 mo) and to preoperative corneal edema ( P = 0.022 and P = 0.037, respectively).

CONCLUSION

Primary CTT seems to be a good procedure in a population with advanced PCG at presentation, problematic follow-up visits, and limited resources.

Outcome measures in childhood glaucoma: a systematic review of randomized controlled trials

PURPOSE

To synthesize the outcome measures used by randomized controlled trials (RCTs) for childhood glaucoma.

METHODS

MEDLINE, EMBASE, and Scopus were searched from inception to February 17, 2023. Randomized controlled trials and observational studies related to childhood glaucoma were included. Primary and secondary outcomes were extracted and the data was used to generate a literature review.

RESULTS

This review identified 42 unique reports pertaining to childhood glaucomas. Most of the studies originated from Egypt, India, and the USA. Intraocular pressure (IOP) outcomes were the most frequent outcomes studied, followed by clinical outcomes and safety outcomes. Clinical outcomes were the most common secondary outcomes studied, followed by IOP outcomes and safety outcomes.

CONCLUSIONS

This systematic review found heterogenous outcomes with IOP outcomes as the most studied primary outcome. As the remaining outcomes were not consistently utilized, this review highlights the need for a consensus on studies of pediatric glaucoma.

Comparative efficacies of 13 surgical interventions for primary congenital glaucoma in children: a network meta-analysis of randomized clinical trials

BACKGROUND

Timely and proper intraocular pressure (IOP) management is vital to the prevention of visual impairment in children with primary congenital glaucoma (PCG). Although various surgical interventions have been proposed, no well-founded evidence exists on their comparative efficacies. We aimed to compare the efficacies of surgical interventions for PCG.

METHODS

We searched relevant sources up to 4 April 2022. Randomized controlled trials (RCTs) entailing surgical interventions for PCG in children were identified. A network meta-analysis (NMA) was performed, comparing 13 surgical interventions: Conventional partial trabeculotomy ([CPT] control), 240-degree trabeculotomy, Illuminated microcatheter-assisted circumferential trabeculotomy (IMCT), Viscocanalostomy, Visco-circumferential-suture-trabeculotomy, Goniotomy, Laser goniotomy, Kahook dual blade ab-interno trabeculectomy, Trabeculectomy with mitomycin C, Trabeculectomy with modified scleral bed, Deep sclerectomy, Combined trabeculectomy-trabeculotomy with mitomycin C, and Baerveldt implant. The main outcomes were mean IOP reduction and surgical success rate at postoperative 6 months. The mean differences (MDs) or odds ratios (ORs) were analyzed by a random-effects model, and the efficacies were ranked by P -score. We appraised the RCTs using the Cochrane risk-of-bias (ROB) tool (PROSPERO: CRD42022313954).

RESULTS

Sixteen RCTs were eligible for NMA, including 710 eyes of 485 participants and 13 surgical interventions, which formed a network of 14 nodes comprising both single interventions and intervention combinations. IMCT was superior to CPT in both IOP reduction [MD (95% CI): -3.10 (-5.50 to -0.69)] and surgical success rate [OR (95% CI): 4.38 (1.61-11.96)]. The MD and OR comparing the other surgical interventions and intervention combinations with CPT were not statistically significant. The P -scores ranked IMCT as the most efficacious surgical intervention in terms of success rate ( P -score =0.777). Overall, the trials had a low-to-moderate ROB.

CONCLUSION

This NMA indicated that IMCT is more effective than CPT and might be the most efficacious of the 13 surgical interventions for management of PCG.

Normal intraocular pressure in Egyptian children and meta-analysis

OBJECTIVE

To determine the normal intraocular pressure in a sample of Egyptian children 0-12 years of age, and compare it to that recorded in previous studies.

METHODS

This is a prospective cross-sectional study, including 345 eyes. All children underwent complete history taking and ophthalmic examination. Any glaucomatous patients or glaucoma suspects were excluded. Intraocular pressure was measured using Haag Streit Perkins M2 handheld applanation tonometer under topical or general anaesthesia. Three readings were recorded for each eye and the average was calculated. Central corneal thickness was measured, using handheld pachymeter (Pachmate 2), whenever possible.

RESULTS

The study included 345 eyes of 187 children (101 males and 86 females), aged 2 months to 12 years (mean: 5.69 ± 3.42 years). The recorded IOP was 5-20 mm Hg (mean: 11.5 ± 2.34 mm Hg). Central corneal thickness was 469-742 μm (mean: 564.8 ± 42.72 μm). The mean recorded intraocular pressure showed positive correlation with increased age (p = 0.026) and increased central corneal thickness (p = 0.037), with a difference of 1 mm Hg for every 100-μm change in central corneal thickness. The mean IOP was significantly lower than that recorded by most previous studies. A detailed comparative analysis is presented comparing our findings with other studies including grouped analysis, by country, ethnicity and tonometers used.

CONCLUSIONS

The mean IOP in a group of normal Egyptian children was 11.5 ± 2.34 mm Hg, with positive correlation to age and central corneal thickness. This mean intraocular pressure was lower than that previously reported in any other population.

Comparison of viscocanalostomy plus suture-assisted near-360-degree trabeculotomy and viscocanalostomy plus rigid probe trabeculotomy in primary congenital glaucoma

PURPOSE

To compare the efficacy and safety of viscocanalostomy plus near-360-degree suture trabeculotomy (VST) with viscocanalostomy plus rigid probe trabeculotomy (VT) in treating primary congenital glaucoma (PCG) over a one-year follow-up.

METHODS

This consecutive retrospective study included patients with PCG confirmed within 3 years of age from March 2017 to October 2019. Efficacy was evaluated by comparing the postoperative intraocular pressure (IOP) curve and the success rate at one year after surgery. Safety was assessed by comparing the postoperative complications. The number of anti-glaucoma agents, horizontal corneal diameter (HCD) and cup-to-disc ratio (C/D) of the two surgical methods were also compared.

RESULTS

Data of 90 eyes from 61 patients were analysed. The baseline parameters of the two groups were similar. The IOP at 12 months after surgery in the VST group was 12.7 ± 4.8 mmHg, while that in the VT group was 15.8 ± 6.5 mmHg. The IOP at 6, 9 and 12 months postoperatively in the VST group was significantly lower than in the VT group (p < 0.05). Viscocanalostomy plus near-360-degree suture trabeculotomy (VST) remained a significant favourable factor for complete one-year success (93.6% versus 74.4%, p = 0.005) but not qualified one-year success (97.9% versus 88.4%, p = 0.06). The number of anti-glaucoma agents, HCD and C/D were reduced in both groups. Postoperative complications were not significantly different between the two groups.

CONCLUSIONS

In children with PCG, VST provides a more durable IOP control than VT over the one-year follow-up, with a similar safety profile.

Twenty-Years of Experience in Childhood Glaucoma Surgery

To quantify the results of childhood glaucoma treatment over time in a cohort of children with different types of childhood glaucoma. A retrospective cohort study of consecutive cases involving children with primary congenital glaucoma, primary juvenile, and secondary juvenile glaucoma at the Childhood Glaucoma Center, University Medical Center Mainz, Germany from 1995 to 2015 was conducted. The main outcome measure was the long-term development of intraocular pressure. Further parameters such as surgical success, refraction, corneal diameter, axial length, and surgical procedure in children with different types of childhood glaucoma were evaluated. Surgical success was defined as IOP < 21 mmHg in eyes without a need for further intervention for pressure reduction. A total of 93 glaucomatous eyes of 61 childhood glaucoma patients with a mean age of 3.7 ± 5.1 years were included. The overall mean intraocular pressure at first visit was 32.8 ± 10.2 mmHg and decreased to 15.5 ± 7.3 mmHg at the last visit. In the median follow-up time of 78.2 months, 271 surgical interventions were performed (130 of these were cyclophotocoagulations). Many (61.9%) of the eyes that underwent surgery achieved complete surgical success without additional medication. Qualified surgical success (with or without additional medication) was reached by 84.5% of the eyes.

Combined Trabeculotomy-Trabeculectomy Versus Trabeculectomy for Treatment of Silicone Oil-induced Ocular Hypertension

PRCIS

Combined trabeculotomy-trabeculectomy (CTT) has a significantly better hypotensive effect than trabeculectomy and a higher success rate in cases of silicone oil-induced ocular hypertension.

PURPOSE

To compare the ocular hypotensive effect of CTT with mitomycin-C (MMC) to that of trabeculectomy with MMC in cases of silicone oil-induced ocular hypertension.

PATIENTS AND METHODS

Thirty eyes of 30 patients with high intraocular pressure (IOP) after vitrectomy and silicone oil injection (followed by silicone oil removal) were randomly allocated to 2 groups in this randomized trial. Group A was composed of 15 cases who underwent combined CTT with MMC while group B cases contained 15 cases undergoing trabeculectomy with MMC. Patients were followed up for 12 months. We included patients above 18 years old, having performed vitrectomy and silicone oil injection followed by oil removal, and having IOP >21 mm Hg uncontrollable by antiglaucoma medications.

RESULTS

The postoperative IOP drop was significantly greater in group A than in group B at all follow up visits (P<0.05). Compared with preoperative IOP, both surgeries produced a significantly lower postoperative IOP at all follow-up visits (P<0.05). For group A, complete success rates (IOP≤21 mm Hg without ocular hypotensive medications) and qualified success rates (IOP≤21 mm Hg with or without ocular hypotensive medications) were both higher than for group B.

CONCLUSION

Both surgeries effectively reduce IOP in cases of silicone oil-induced ocular hypertension, but CTT has a significantly better hypotensive effect and a higher success rate on the long-term.

Changes in Intraocular Pressure and Anterior Chamber Angle After Congenital Cataract Extraction

PRECIS

Anterior chamber angle (ACA) narrowing continues to occur for at least 2 years after congenital cataract surgery. Risk factors for intraocular pressure (IOP) elevation after congenital cataract surgery were higher central corneal thickness (CCT) and surgery at <2 months.

PURPOSE

The purpose of this study was to study the changes in IOP and in the ACA during the first 2 years after pediatric cataract surgery and to determine risk factors for such changes.

PATIENTS AND METHODS

A retrospective observational study was done on infants who underwent pediatric cataract surgery in Cairo University Hospitals and completed a 1-year follow-up. Demographic and clinical characteristics were recorded including age at surgery, sex, corneal diameter, CCT pupil diameter, IOP, gonioscopic findings, presence of persistent hyperplastic primary vitreous, surgical approach, primary intraocular lens implantation, and perioperative subconjunctival steroid injection. Changes in IOP and in the ACA were recorded, and the risk factors for such changes were analyzed.

RESULTS

Postoperative IOP elevation >18 mm Hg occurred in 23 eyes of 206 eyes (11%), who completed Year 1 and in 9 (13%) of 86 eyes who completed Year 2. Risk factors for IOP elevation were larger preoperative CCT (P=0.01) in Year 1, and younger age at surgery (P=0.01), and aphakia (P=0.05) in Year 2. In multivariate analysis only younger age at surgery was a risk factor for IOP elevation in Year 2. ACA narrowing occurred in 49% and in 21% of the examined eyes in Years 1 and 2, respectively. Aphakia was not a significant risk factor of angle narrowing in Years 1 and 2 (P=0.17 and 0.42, respectively).

CONCLUSIONS

Higher preoperative CCT was a risk factor for early-onset IOP elevation. Surgery at >2 months was associated with lower susceptibility to late-onset IOP elevation.

Early Experience With Ahmed Clear Path Glaucoma Drainage Device in Childhood Glaucoma

PURPOSE

The aim was to evaluate the short-term outcomes of Ahmed clear path (ACP) valveless glaucoma drainage device in childhood glaucoma.

METHODS

Retrospective chart review of all patients 16 years or below with childhood glaucoma who had ACP implantation at Boston Children's Hospital from December 2019 to June 2020 with at least 6 months follow-up period.

RESULTS

The study included 7 eyes of 5 patients implanted by a single surgeon. The median follow-up was 12 months. The mean intraocular pressure (IOP) was reduced from 36±3.5 mm Hg on a mean of 2.7±0.6 glaucoma medications preoperatively to a mean IOP of 12.4±2.8 mm Hg (P<0.001) on a mean of 0.7±0.8 medications postoperatively at final follow-up (P=0.0009). Complete success was achieved in 4 eyes while qualified success was achieved in 3 eyes.

CONCLUSION

The ACP glaucoma drainage device provided good short-term IOP control and technical advantages for implantation for pediatric eyes were observed.

Long-term success after trabeculotomy in primary congenital glaucoma - a study with up to 35 years follow-up

PURPOSE

To evaluate the surgical success after trabeculotomy for primary congenital glaucoma (PCG) in Denmark in the last 40 years.

METHODS

Retrospective review of medical files on children who all underwent trabeculotomy as the first surgical intervention between January 1rst, 1977 and December 31, 2016. Information on diagnosis and surgical procedures were extracted. Primary outcome was surgical success was defined as intraocular pressure (IOP) < 21 mmHg without medications one year after surgery. Secondary outcome was the number of reoperations needed.

RESULTS

Out of 118 children with PCG, 96 children (144 eyes) had an ab externo trabeculotomy as primary IOP lowering procedure opening Schlemm's channel 4 clock hours into the anterior chamber. Complete surgical success at one year was achieved in 73% (106 of 144 eyes). On the long term, IOP could be controlled by one surgical procedure in 2/3 of children, eight eyes required >5 surgical procedures to control IOP. In 12.1% of children the second glaucoma procedure was performed >5 years after the initial trabeculotomy. There was a tendency towards greater risk of needing a second procedure in patients < 3 months of age at primary trabeculotomy (hazard ratio, HR, 2.01, 95% CI 0.96-4.22) and in boys (HR 2.02, 95% CI 0.97-4.18) and a lower risk of requiring a third surgery if the second surgery was trabeculectomy with MMC.

CONCLUSION

Dedicated follow-up of patients with PCG is essential as the disease may continue to progress even after years of quiescence and some children need multiple surgeries to control IOP. Additional glaucoma procedures are required in 1/3 of children and boys and younger patients seem to be at greater risk.

Ab Interno Goniotomy Combined with Ab Externo Trabeculotomy in Advanced Primary Congenital Glaucoma Patients: 2-Year Follow-Up

Introduction

Primary congenital glaucoma (PCG) is a challenging disease that needs to be surgically managed with more innovative methods. Conventional incisional surgery, such as goniotomy and trabeculotomy, has a primary high success rate, but does not seem to be a very effective treatment in advanced stages.

Design

A prospective clinical case study.

Purpose

To qualify the outcome, in terms of success rate, of goniotomy combined with trabeculotomy as a surgical option to treat eyes affected by PCG with a corneal diameter larger than 14 mm.

Patients and Methods

This study included 50 eyes of 50 patients diagnosed with PCG with corneal diameter larger than 14 mm who underwent ab interno goniotomy combined with ab externo trabeculotomy. Intraocular pressure (IOP) was measured preoperatively and 24 months postoperatively. A statistical analysis was performed to detect correlations between the success rate and corneal diameter, preoperative IOP, age of onset, axial length, and consanguinity. The main outcome was reduction in IOP; secondary outcomes were factors affecting the success rate, complications, and the need for additional surgical intervention to control IOP.

Results

The mean age of the patients was 18.86±9.94 months. Males made up 52% of cases and females 48% of cases. Positive consanguinity was present in 38% of cases. Axial length ranged between 20 and 22 mm, with a mean of 20.98±0.8 mm. Mean preoperative IOP was 29.56±3.36 mmHg, which decreased postoperatively to 12.6±2.5, 14.1±3.2, 16.8±5.5, 14.4±2.3, 14.3±1.6, 14.3±1.6, 14.3±1.6, 14.3±1.7, and 14.3±1.7 mmHg at 1, 3, 6, 9, 12, 15, 18, 21, and 24 months respectively (p˂0.001). Use of medical treatment was decreased from 2.7±0.4 preoperatively to 1.4±0.7 postoperatively (p˂0.001). Hyphema was the only complication that appeared, occurring in 47% of cases. The success rate was 94%. Complete success (IOP <21 mmHg without treatment) was achieved in 70% of cases, 24% were considered a qualified success (IOP <21 mmHg with treatment), while failure was documented in 6% of cases (IOP >21 mmHg with treatment). The success rate was significantly related to preoperative IOP, corneal diameter, axial length, consanguinity, and age of onset (p˂0.001). All cases were followed for 24 months.

Conclusion

Ab interno goniotomy combined with ab externo trabeculotomy improves the success rate of buphthalmos surgery. A significant correlation was detected between success rate and preoperative IOP, corneal diameter, axial length, consanguinity, and age of onset.

Correlation of histopathology of trabecular meshwork with clinical features in primary congenital glaucoma

PURPOSE

To correlate histopathological changes of trabecular meshwork (TM) with clinical features in primary congenital glaucoma (PCG).

METHODS

This was a prospective interventional study including 66 eyes of 39 PCG children aged ≤12 months at diagnosis. Corneal clarity, corneal diameter (CD), intraocular pressure (IOP) and cup disc ratio (C:D ratio) were assessed at baseline and at 1-year follow-up. The trabecular meshwork (TM) specimens obtained during primary combined trabeculectomy and trabeculotomy augmented with Mitomycin-C were evaluated on light microscopy to look for eosinophilic membrane (EM), status of trabecular beams and trabecular endothelial cells (TEC), presence of intervening spaces, TM thickness and TEC count which were then correlated with clinical features.

RESULTS

At 1-year follow-up, IOP reduced from 27.96±10.2 to 11.88±5.63 mm Hg, p<0.001, C:D ratio decreased from 0.65±0.34 to 0.49±0.06, p=0.036, and the bleb had a significant tendency to change from well formed (59-46) to flat type (3-6) or thin, cystic type (4-14) (p=0.014). Presence of EM on the cameral surface was associated with a lower baseline IOP. Fused trabecular beams were associated with higher baseline IOP. The TM was significantly thicker in eyes with IOP >20 mm Hg at presentation (1.86±0.7 mm vs 1.3±0.47 mm, p=0.0356). Eyes with IOP ≤14 mm Hg at final follow-up had lower TEC count than eyes with IOP >14 mm Hg (0.92±0.45 cells/mm² vs 1.00±0.74 cells/mm², p=0.0028).

CONCLUSION

A light microscopic analysis of surgical specimens may guide prognosis of PCG. However, larger studies are required to validate these results.

Surgical interventions for primary congenital glaucoma

BACKGROUND

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.

OBJECTIVES

To compare the effectiveness and safety of different surgical techniques for PCG.

SEARCH METHODS

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.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) and quasi-RCTs comparing different surgical interventions in children under five years of age with PCG.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodology.

MAIN RESULTS

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.

AUTHORS' CONCLUSIONS

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.

Rate of Complete Catheterization of Schlemm's Canal and Trabeculotomy Success in Primary and Secondary Childhood Glaucomas

PURPOSE

Despite the increasing use of microcatheters to perform 360-degree trabeculotomy, the rate of complete Schlemm's canalization in different forms of pediatric glaucoma is under-reported.

DESIGN

Retrospective institutional observational case series.

METHODS

Ocular diagnoses and surgical details of 60 pediatric patients (≤18 years old) who underwent trabeculotomy between 2013 and 2019 were collected. Surgical success was defined as an intraocular pressure (IOP) of 5-20 mm Hg and no additional IOP-lowering surgery.

RESULTS

Eighty-five eyes of 60 patients underwent trabeculotomy. For bilateral cases, the first eye to undergo surgery was included for analysis. Diagnoses included primary congenital glaucoma (PCG n = 22), juvenile open angle glaucoma (JOAG n = 16), glaucoma following cataract surgery (GFCS n = 15), and other secondary forms of glaucoma (n = 7). Canalization using a microcatheter was attempted in 52 of 60 eyes (87%) of which 21 (40%) achieved full 360-degree. Complete canalization was attained in 69% of JOAG patients, which was significantly higher than in PCG patients (22%; P = 0.007), but not GFCS (36%) and other secondary glaucoma (29%). The 5-year survival rate for all eyes was 75% with 95% confidence interval (CI), 57 to 86. Survival curves for 360-degree catheter, 270-degree to 360-degree combined catheter/Harms trabeculotome, and <180-degree Harms trabeculotome trabeculotomies were significantly different (P < 0.001) with 5-year survival rates of 100%, 69% with 95% CI, 16 to 93, and 48% with 95% CI, 29 to 64, respectively.

CONCLUSIONS

A 360-degree catheter trabeculotomy is highly effective in obtaining IOP control; however, complete canalization of Schlemm's canal is most frequently achieved in JOAG patients. Congenital anomalies or scarring from previous surgeries, which prevents full canalization, may inherently decrease success of angle surgery in other glaucoma.

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.

Characteristics of Pediatric Glaucoma in a Latin American Reference Center

Aim

To describe the clinical and epidemiological characteristics of children with pediatric glaucoma (PG) treated in an ophthalmologic national reference center.

Materials and methods

A retrospective study of patients diagnosed with PG in a national ophthalmologic reference center was made, between 2005 and 2015. Clinical findings, type of treatment, and the follow-up were evaluated.

Results

A total of 89 patients (145 eyes) were included. The median age of diagnosis was 2.0 years. The most frequent type of glaucoma was primary PG with 67.4% of affected patients, primary congenital glaucoma (PCG) being more frequent (69 eyes) than juvenile open-angle glaucoma (JOAG 36 eyes). Secondary PG accounted for 32.6% of the cases (40 eyes). At least one surgical procedure was needed in 56.6% of all studied eyes, and 10.7% of eyes had more than two surgical procedures. Even more, eyes with PCG had surgery in 88.4% of cases. On the contrary, eyes with JOAG did not require surgery. In the last assessment, the distribution of cases according visual acuity did not show differences. However, it is important to note that patients with secondary PG maintained a good vision only in 17.9% of cases.

Conclusion

Pediatric glaucoma is a heterogeneous group of diseases, and due to its low incidence, descriptive reports of large cohorts are not available. This study has a well-detailed report of PG characteristics in a national reference center. The frequency of JOAG in the present study was significantly higher than that reported in other studies. Also, clinical characteristics of all glaucoma described have some differences from data published.

Clinical significance

There are few studies that describe characteristics of PG. This study is an important tool to analyze the characteristics of PG in an effort to better know the disease.

How to cite this article

Saavedra C, Rios HA, Belalcazar S, et al. Characteristics of Pediatric Glaucoma in a Latin American Reference Center. J Curr Glaucoma Pract 2020;14(1):10–15.

Clinical Manifestations of Strabismus in Patients with Primary Congenital Glaucoma

Purpose: To determine the clinical manifestations and risk factors of developing strabismus in primary congenital glaucoma (PCG) patients who underwent glaucoma surgery. Methods: A retrospective case-series study of 54 PCG patients who were followed for at least 3 years after glaucoma surgery. The subjects were divided into 2 groups based on the occurrence of strabismus. Age at glaucoma diagnosis and surgery, visual acuity, intraocular pressure, amblyopia, cup-disc ratio, and orthoptic status were compared between the 2 groups. Results: Twenty of 54 patients (37.0%) developed strabismus after glaucoma surgery. The mean ages at the time of glaucoma diagnosis and surgery were 3.2 ± 2.7 months and 3.4 ± 2.8 months in the strabismus group and 24.3 ± 19.1 months and 26.4 ± 18.9 months in the non-strabismus group, respectively (p < .05). In addition, the mean logMAR visual acuities were 0.87 ± 0.38 in the strabismus group and 0.24 ± 0.21 in the non-strabismus group (p < .05). The proportion of patients experiencing amblyopia was 90.0% in the strabismus group. Low visual acuity and young age at glaucoma surgery were significant predictors of developing strabismus. Kaplan-Meier survival analysis demonstrated that the probability of developing strabismus after glaucoma surgery was 50.6% at 10 years post-surgery. Conclusions: PCG patients who developed strabismus after glaucoma surgery were diagnosed with glaucoma and underwent surgery at a younger age, exhibited a worse mean best corrected visual acuity, and exhibited a higher amblyopia incidence than did patients in the non-strabismus group.

Postoperative outcome of three different procedures for childhood glaucoma

Purpose

To investigate the long-term postoperative outcome of three surgical procedures for childhood glaucoma.

Patients and methods

In this retrospective study, the patients were divided into a goniotomy group, a trabeculotomy group, and a filtering surgery group, based on the initial surgical procedure. Failure was defined as an IOP ≥21 mmHg with medication at two consecutive visits. A Kaplan–Meier analysis was applied to calculate the probability of success. Additional metrics included IOP, number of additional operations, eye drop scores, and visual acuity.

Results

We studied 40 eyes of 25 patients, 21 eyes of 15 patients, and 12 eyes of 7 patients in the goniotomy, trabeculotomy, and filtering surgery groups, respectively. The 10- and 20-year probability of success was 65.2% and 65.2%, 42.2% and NA (no data for 20 years), and 91.7% and 80.2% for the goniotomy, trabeculotomy, and filtering surgery groups, respectively.

Conclusion

All three procedures maintained an IOP of less than 21 mmHg for up to 10 years in 65.2%, 42.2%, and 91.7% of childhood glaucoma cases.