Ahmed glaucoma valve in children: A review

Glaucoma in retinopathy of prematurity: A review

Glaucoma in retinopathy of prematurity (ROP) is a challenge. It is typically secondary, though it may be associated with primary congenital glaucoma. Secondary causes are multifactorial, with mechanisms and severity potentially linked to the stage of ROP, time of presentation, or interventions for its treatment. Anecdotal reports of glaucoma following anti-vascular endothelial growth factor injection exist, but conclusive evidence is lacking. The most important cause of glaucoma in ROP is secondary angle closure in patients with stage 5 ROP. Clinical features such as corneal clouding and increased corneal diameters are clues to diagnosing glaucoma; however, glaucoma may present much later in life as well, therefore, life-long follow-up of these patients is essential. Appropriate control of intraocular pressure (IOP) becomes imperative in infants with ROP as these eyes tend to enlarge quickly with raised IOP. Management strategies consist of medical therapy, angle-based surgery, filtration surgery, glaucoma drainage devices and cyclo-ablation. The choice of therapy is individualized according to the age, presentation of glaucoma, and visual potential. We review the epidemiology, etiology, natural history, risk factors, clinical features, investigations, differential diagnosis, management and outcomes of glaucoma in ROP.

Long-term outcomes of Ahmed glaucoma drainage device capsulectomies in pediatric glaucoma patients

PURPOSE

To investigate the long-term outcomes associated with Ahmed glaucoma device capsulectomy in pediatric patients at a single institution over a period of nearly 10 years, from 2011 to 2021.

METHODS

We retrospectively reviewed the medical records of pediatric glaucoma patients with FP-7 Ahmed glaucoma device capsulectomies performed by three surgeons. Surgical success was defined as post-capsulectomy IOP of <21 mm Hg at most recent follow-up without need for additional procedures, regardless of topical medications.

RESULTS

A total of 22 capsulectomies of 22 eyes of 18 patients aged 1-17 years were reviewed. Median post-capsulectomy follow-up was 5.8 years. Etiologies of glaucoma were primary congenital glaucoma (50%), anterior segment dysgenesis (32%), Sturge-Weber syndrome (14%), and angle recession (5%). Pre-capsulectomy IOP was 30 ± 6.2 mm Hg, with first postoperative IOP of 15 ± 8.0 mm Hg. Surgical success was achieved with 5 capsulectomies (23%), with follow-up of 1.5-5.9 years. Post-capsulectomy complications included short-term hypotony in 1 eye (5%) and macular edema in 1 eye (5%). Eleven of 22 eyes (50%) had at least one repeat placement of Ahmed glaucoma device, with median time to repeat surgery of 80 months.

CONCLUSIONS

In pediatric glaucoma patients with glaucoma drainage device encapsulation, capsulectomy likely does not prevent additional surgery in most children over the long term, but may serve as a temporizing measure before other interventions.

Glaucoma drainage devices in children: an updated review

Implantation of glaucoma drainage devices is a valuable therapeutic option, particularly in children with glaucoma refractory to primary surgical treatment. Glaucoma drainage devices are typically used when conjunctival scarring hampers filtration surgery or prior angle procedures are not effective in controlling intraocular pressure. Despite known complications, the use of glaucoma drainage devices in children has increased in recent years, even as the primary surgical option. In this review, we evaluate the results of recent studies involving the implantation of glaucoma drainage devices in children, discussing new advances, and comparing the success rates and complications of different devices.

The PAUL® glaucoma implant: 1-year results of a novel glaucoma drainage device in a paediatric cohort

PURPOSE

The PAUL® glaucoma implant (PGI) is a novel glaucoma drainage device, which has not been previously reported in paediatric glaucoma management. This study aims to evaluate the safety and effectiveness of the PGI in a paediatric cohort.

METHODS

A retrospective evaluation of 25 cases of paediatric PGI surgery (age 8 months to 16 years) was performed at Manchester Royal Eye Hospital between September 2019 and July 2020. Primary outcome measures included failure (intraocular pressure (IOP) > 21 mmHg or < 20% reduction of IOP, removal of the implant, further glaucoma intervention or visual loss. Secondary outcomes included mean IOP, mean number of medications, logMAR visual acuity and complications.

RESULTS

Eleven eyes (48%) had a complete success and achieved an unmedicated IOP < 21 mmHg, and 21 eyes (84%) had a qualified success (with or without medications). Four failures were observed, 2 due to hypotony and 2 underwent further surgery (gonioscopy-assisted transluminal trabeculotomy). The mean preop IOP was 30.9 ± 5.9 mmHg (n = 25), falling to 13.5 ± 6.8 mmHg at 1 month, 17.9 ± 7.2 mmHg at 3 months, 13.4 ± 5.1 mmHg at 6 months, 13.2 ± 4.9 mmHg at 12 months and 11.8 ± 4.6 mmHg at 24 months. The mean change in IOP from the preoperative visit to the last visit was a reduction of 19.1 ± 7.7 mmHg. A significant reduction in the number of medications and IOP was demonstrated after PGI (p < 0.0001). Nine patients required removal of the intraluminal Prolene stent from the PGI for further pressure lowering.

CONCLUSION

The one- to two-year results demonstrate paediatric PGI has high qualified success rates and effectively reduces IOP and the need for glaucoma medical therapy.

Pediatric Glaucoma-From Screening, Early Detection to Management

Pediatric glaucoma (PG) covers a rare and heterogeneous group of diseases with variable causes and presentations. Delayed diagnosis of PG could lead to blindness, bringing emotional and psychological burdens to patients' caregivers. Recent genetic studies identified novel causative genes, which may provide new insight into the etiology of PG. More effective screening strategies could be beneficial for timely diagnosis and treatment. New findings on clinical characteristics and the latest examination instruments have provided additional evidence for diagnosing PG. In addition to IOP-lowering therapy, managing concomitant amblyopia and other associated ocular pathologies is essential to achieve a better visual outcome. Surgical treatment is usually required although medication is often used before surgery. These include angle surgeries, filtering surgeries, minimally invasive glaucoma surgeries, cyclophotocoagulation, and deep sclerectomy. Several advanced surgical therapies have been developed to increase success rates and decrease postoperative complications. Here, we review the classification and diagnosis, etiology, screening, clinical characteristics, examinations, and management of PG.

Risk Factors for Glaucoma Drainage Device Exposure in Children: A Case-Control Study

PURPOSE

To identify the risk factors for glaucoma drainage device (GDD) exposure in children.

DESIGN

Retrospective case-control study.

METHODS

The study population comprised children (one eye each) who presented with a history of GDD exposure to a tertiary care eye hospital over the period January 2014 to January 2020. Consecutive children (age <18 years) were included. A control group from the same time period (children without GDD exposure) were included in the ratio of 5 controls to every 1 case of exposure. The main outcome measures included risk factors for exposure (univariate and multivariate analysis).

RESULTS

A total of 21 eyes (of 21 children with implant exposure) and 115 eyes (of 115 children without exposure) were included in this study. During the same study period, a total of 494 eyes had undergone GDD implantation, giving an estimated incidence of exposure of 4.25%). In the bivariate analysis, GDD exposure was associated with multiple previous ocular surgeries (P = .001), longer follow-up duration (P < .001), combined procedure at the time of primary implantation (P = .002), and a younger age at the time of primary implantation (P = .006). The former 3 risk factors continued to prove a statistically significant association on multivariable regression analysis. Postoperative use of eye lubricants was more common among children in the control group (P = .007).

CONCLUSION

In pediatric glaucoma patients, younger age and combined procedure at the time of primary GDD implantation, in addition to multiple previous ocular surgeries, were associated with greater risk of implant exposure. Postoperative use of eye lubricants may be protective.

Early weaning versus prolonged administration of aqueous suppressants for prevention of hyperencapsulation in paediatric Ahmed glaucoma valve

PURPOSE

To investigate the role of early and prolonged administration of aqueous suppressants in reduction of hyperencapsulation and intraocular pressure (IOP) control after paediatric Ahmed glaucoma valve (AGV) implantation.

METHODS

A prospective randomized interventional study recruited children who had AGV implantation for paediatric glaucoma. All patients received postoperative Timolol 0.5% for either 12 months (Group A) or 3 months (Group B). Additional IOP-reducing medications were added if IOP exceeded 21 mmHg or hyperencapsulation developed in either group. Primary outcome measures were rate of hyperencapsulation and reduction of IOP.

RESULTS

Eighty sex children completed the 12-month follow-up visits. Baseline IOP was significantly reduced from 31.95 ± 9.1 to 16.94 ± 3.4 mmHg at 12 months in Group A and from 32.7 ± 7.4 to 19.85 ± 6.9 mmHg at 12 months in Group B. IOP was significantly lower in Group A than B at 6-, 9- and 12-month follow-up visits. In the first 4 months, the hyperencapsulation rate was similar in both Group A (six eyes, 13.3%) and Group B (seven eyes, 17.1%). However, the hyperencapsulation rate was significantly lower in Group A than B at both 6 months (22.5% versus 36.6%) and 12 months (31.1% versus 46.3%). Anti-glaucoma medications were significantly lower in Group A than B at both 6 months (1.3 versus 3.2 drugs) and 12 months (1.5 versus 3.6 drugs).

CONCLUSION

Early and prolonged use of aqueous suppressants significantly reduced the rate of hyperencapsulation and provided better IOP control after paediatric AGV implantation.

Update in Genetics and Surgical Management of Primary Congenital Glaucoma

Primary congenital glaucoma (PCG) continues to be an important cause of visual impairment in children despite advances in medical and surgical treatment options. The progressive and blinding nature of the disease, together with the long lifespan of the affected population, necessitates a thorough understanding of the pathophysiology of PCG and the development of long-lasting treatment options. The first part of this review discusses the genetic features and makeup of this disorder, including all currently identified genetic loci (GLC3A, GLC3B, GLC3C and GLC3D) and relevant protein targets important for trabecular and Schlemm canal dysgenesis. These target molecules primarily include CYP1B1, LTBP2, and TEK/Tie2 proteins. Their potential roles in PCG pathogenesis are discussed with the purpose of bringing the readers up to date on the molecular genetics aspect of this disorder. Special emphasis is placed on functional implications of reported genetic mutations in the setting of PCG. The second part of the review focuses on various modifications and refinements to the traditional surgical approaches performed to treat PCG, including advances in goniotomy and trabeculotomy ab externo techniques, glaucoma drainage implant surgery and cyclodiode photocoagulation techniques that ultimately provide safer surgical approaches and more effective intraocular pressure control in the 21st century.

Choroidal detachment with exudative retinal detachment following Ahmed valve implantation in Sturge-Weber syndrome

Ahmed glaucoma valve implant appears to be a relatively useful drainage device in eyes with glaucoma secondary to Sturge-Weber syndrome (SWS). However, early postoperative choroidal and exudative retinal detachment may occur from a rapid expansion of the choroidal hemangioma with effusion of fluid into the suprachoroidal and subretinal spaces. We report the case of a ten-year-old boy who had SWS with choroidal haemangioma and secondary glaucoma. He had Ahmed glaucoma valve implantation on account of the secondary glaucoma which had been refractory to both conventional medical and surgical managements. He developed choroidal and exudative retinal detachment postoperatively. However, he responded to conservative treatment and further surgical management was not required. Ahmed glaucoma valve in the treatment of glaucoma secondary to SWS is useful, but the risk of choroidal effusion with exudative retinal detachment is still present. Surgeons should be alert to this likely complication and be prepared for prompt management.

Cataract extraction in patients with primary congenital glaucoma

OBJECTIVE

To assess incidence and risk factors of cataract extraction in patients with primary congenital glaucoma, surgical outcome, and complications.

MATERIAL AND METHOD

Retrospective cohort study, in which 108 patients with primary congenital glaucoma were included. Data collected were need for cataract extraction and at what age, intraocular pressure at diagnosis of primary congenital glaucoma, required antiglaucomatous surgeries, possible mutation in the CYP1B1 gene, and final visual acuity. Among the patients who required cataract extraction were visual acuity, intraocular pressure, and complications, evaluated preoperatively and postoperatively. The data were analysed with STATA.

RESULTS

A total of 198 eyes of 108 patients were included, with a median follow-up of 8 years (range: 5-53). In all, 32 eyes (16.2%) of 24 patients (22%) required cataract extraction. The median age for cataract extraction was 12.94 years (interquartile range: 2.42-22). The main identified risk factors associated with cataract extraction were antiglaucomatous surgeries (hazard ratio 1.48, p < 0.001) and valvular implant (hazard ratio 2.78, p < 0.001). Lens was implanted in 30/32 eyes and the main complications were intraocular pressure decontrol (n = 13), capsular fibrosis (n = 7), corneal decompensation (n = 4), lens subluxation (n = 4), and endophthalmitis (n = 1). Visual acuity improvement was observed after cataract extraction in 66.67% of eyes.

CONCLUSIONS

There is a high incidence of cataract surgery in patients with primary congenital glaucoma, but generally outside of pediatric age. A greater risk of cataract extraction was identified in those patients with a greater number of antiglaucomatous surgeries, especially after valvular implantation. Despite the high rate of complications related to cataract extraction in primary congenital glaucoma, good visual improvement was observed after surgery.

Ahmed valve implantation in childhood glaucoma associated with Sturge-Weber syndrome: our experience

PURPOSE

To evaluate the efficacy and safety of Ahmed valve implantation in childhood glaucoma associated with Sturge-Weber syndrome (SWS).

METHODS

A retrospective chart review of patients who underwent primary Ahmed valve implantation in childhood glaucoma associated with SWS. The outcome measures were success rate (Intraocular pressure (IOP) >5 and <21 mm Hg without additional surgical maneuver), and operative complications.

RESULTS

Twenty-four eyes of 18 patients were analyzed. Mean IOP (26.21 ± 3.52 to 12.27 ± 1.27 mm Hg) and mean number of anti-glaucoma medicines (3.92 ± 0.28 to 1.5 ± 1) reduced significantly after the surgery at the mean follow-up of 2.12 ± 0.87 years (P = < 0.05). The cumulative probability of success rate was 75% (Confidence Interval 95%, 60 to 100%) by Kaplan-Meier survival curve analysis. Failed eyes [6 (25%)], hyphema [4 (16.67%)], hypotony [3 (12.5%)], choroidal detachment [3 (12.5%)], tube-cornea touch [2 (8.33%), and visually significant cataract [4 (16.67%)] were the complications observed in post-operative period.

CONCLUSION

Primary Ahmed valve implantation may provide a safe and effective option in the management of childhood glaucoma associated with SWS.

Short- to long-term results of Ahmed glaucoma valve in the management of elevated intraocular pressure in patients with pediatric uveitis

OBJECTIVE

The aim of this study was to evaluate the long-term outcome of Ahmed glaucoma valve (AGV) implant for elevated intraocular pressure (IOP) in pediatric patients with uveitis.

DESIGN

This was a retrospective chart review.

PARTICIPANTS

The study included 16 eyes (11 children) with uveitis.

METHODS

Success was defined as having IOP between 6 and 21 mm Hg with (qualified success) or without (complete success) antiglaucoma medications and without the need for further glaucoma or tube extraction surgery.

RESULTS

Mean age of patients at the time of AGV implantation was 14.19 ± 3.25 years. AGV implantation was the first glaucoma surgical procedure in 12 eyes (75%). Average postoperative follow-up period was 64.46 ± 33.56 months. Mean preoperative IOP was 33.50 ± 7.30 mm Hg versus 12.69 ± 3.20 mm Hg at the last follow-up visit (p < 0.001). Three eyes (18.7%) were determined as cases of "failure" because of tube removal in 2 eyes and a second AGV implantation in 1 eye. The cumulative probability of complete success was 68.8% at 6 months, 56.3% at 12 months, 49.2% at 36 months, 42.2% at 48 months, and 35.2% at 84 months, and the cumulative probability of eyes without complication was 75.0% at 6 months, 66.7% at 24 months, 58.3% at 36 months, 48.6% at 48 months and 24.3% at 108 months based on Kaplan-Meier survival analysis.

CONCLUSIONS

Although AGV implant is an effective choice in the management of elevated IOP in pediatric uveitis, antiglaucoma medications are frequently needed for control of IOP. Tube exposure is an important complication in the long term. Differential diagnosis between relapse of uveitis and endophthalmitis is important in patients who received AGV implantation.

Pediatric Glaucoma: A Literature's Review and Analysis of Surgical Results

The purpose of this paper is to review the surgical options available for the management of pediatric glaucoma, to evaluate their advantages and disadvantages together with their long-term efficacy, all with the intent to give guidelines to physicians on which elements are to be considered when taking a surgical decision. Currently there is a range of surgical procedures that are being used for the management of pediatric glaucoma. Within these, some are completely new approaches, while others are improvements of the more traditional procedures. Throughout this vast range of surgical options, angle surgery remains the first choice in mild cases and both goniotomy and trabeculotomy have good success rates. Trabeculectomy with or without mitomycin C (MMC) is preferred in refractory cases, in aphakic eyes, and in older children. GDIs have a good success rate in aphakic eyes. Nonpenetrating deep sclerectomy is still rarely used; nevertheless the results of ongoing studies are encouraging. The different clinical situations should always be weighed against the risks associated with the procedures for the individual patients. Glaucomatous progression can occur many years after its stabilization and at any time during the follow-up period; for this reason life-long assessment is necessary.

Complications of glaucoma drainage device surgery: a review

PURPOSE

To review current literature on the complications of the use of glaucoma drainage device surgery.

SUMMARY

The use of glaucoma drainage devices has increased significantly in recent years for both primary treatment of glaucoma and refractory glaucoma. The efficacy and safety of glaucoma drainage devices has been well established, so they are a viable surgical option in patients who fail medical therapy. With the increased use of these devices, understanding their complications is essential in managing these patients. The prevention and management of complications associated with glaucoma drainage device insertion has some similarities to that of a trabeculectomy. The glaucoma drainage devices have additional complications associated with the fact that hardware is left within the eye. There have been no definitive answers as to the perfect surgical technique to prevent complications but careful surgical performance, tube placement and use of a double-layered graft over the tube are likely to lead to a better outcome. The rate of complications also dictates careful follow up to identify these complications early in their process as early intervention will likely lead to better outcomes.

Childhood glaucoma surgery in the 21st century

Most children with glaucoma will require surgery in their lifetime, often in their childhood years. The surgical management of childhood glaucoma is however challenging, largely because of its greater potential for failure and complications as compared with surgery in adults. The available surgical repertoire for childhood glaucoma has remained relatively unchanged for many years with most progress owing to modifications to existing surgery. Although the surgical approach to childhood glaucoma varies around the world, angle surgery remains the preferred initial surgery for primary congenital glaucoma and a major advance has been the concept of incising the whole of the angle (circumferential trabeculotomy). Simple modifications to the trabeculectomy technique have been shown to considerably minimise complications. Glaucoma drainage devices maintain a vital role for certain types of glaucoma including those refractory to other surgery. Cyclodestruction continues to have a role mainly for patients following failed drainage/filtering surgery. Although the prognosis for childhood glaucoma has improved significantly since the introduction of angle surgery, there is still considerable progress to be made to ensure a sighted lifetime for children with glaucoma all over the world. Collaborative approaches to researching and delivering this care are required, and this paper highlights the need for more high-quality prospective surgical trials in the management of the childhood glaucoma.

Current surgical options for the management of pediatric glaucoma

Currently, there are numerous choices for the treatment of pediatric glaucoma depending on the type of glaucoma, the age of the patient, and other particularities of the condition discussed in this review. Traditionally, goniotomy and trabeculotomy ab externo have been the preferred choices of treatment for congenital glaucoma, and a variety of adult procedures adapted to children have been utilized for other types of pediatric glaucoma with variable results and complications. More recently, seton implantations of different types have become more popular to use in children, and newer techniques have become available including visualized cannulation and opening of Schlemm's canal, deep sclerectomy, trabectome, and milder more directed cyclodestructive procedures such as endolaser and transcleral diode laser cyclophotocoagulation. This paper reviews the different surgical techniques currently available, their indications, results, and most common complications to allow the surgeon treating these conditions to make a more informed choice in each particular case. Although the outcome of surgical treatment in pediatric glaucoma has improved significantly, its treatment remains challenging.