Aqueous shunt devices compared with trabeculectomy with mitomycin-C for children in the first two years of life

Long-term Results of Ahmed Valve Implantation With Mitomycin-C in Pediatric Glaucoma

PRECIS

Mitomycin was used with Ahmed valve implantation in 81 eyes of 63 children. After 5 years, probability of intraocular pressure (IOP) control without glaucoma medication was 35±6%; 57% achieved IOP control with topical medications after 10 years.

PURPOSE

The purpose of this study was to determine the long-term outcomes of Ahmed glaucoma valve (AGV) implantation with intraoperative application of mitomycin-C (MMC) for the treatment of childhood glaucoma.

METHODS

Retrospective review of children undergoing AGV implantation with subtenon application of MMC between 2000 and 2019. We defined surgical success as a final IOP of 5 to 21 mm Hg with no glaucoma medication, no subsequent glaucoma surgery, and no severe complication. Qualified success was defined if the above criteria were met with topical antiglaucoma medication.

RESULTS

Eighty-one eyes of 63 patients were included. The probability of complete success was 72±5% (63% to 83%) at 1 year, 58±6% (48% to 70%) at 2 years, and 35±6% (25% to 48%) at 5 years. The probability of qualified success was 92±3% (87% to 98%) at 1 year, 79±5% (70% to 89%) at 5 years, 57±7% (44% to 73%) at 10 years, and 39±9% (24% to 62%) at 14 years. The IOP was reduced by an average of 10.7±9 mm Hg from preoperative visit to the last follow-up, and the number of medications decreased from 3.0±1.4 to 1.5±1.4 after implantation.

CONCLUSIONS

A significant proportion of patients achieved long-term IOP control without glaucoma medication. The majority achieved IOP control with additional topical antiglaucoma medications. When compared with existing AGV implantation in childhood literature, the use of MMC appears to lengthen the drop-free (complete success) duration, as well as the long-term IOP control with topical medications.

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.

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.

Serial intracameral visualization of the Ahmed glaucoma valve tube by anterior segment optical coherence tomography

PURPOSE

To investigate serial changes of the Ahmed glaucoma valve (AGV) implant tube in the anterior chamber by anterior segment optical coherence tomography (AS-OCT).

METHODS

Patients who had received AGV implantation without complications (n=48) were included in this study. Each patient received follow-up examinations including AS-OCT at days 1 and 2, week 1, and months 1, 3, 6, and 12. Tube parameters were defined to measure its length and position. The intracameral length of the tube was from the tip of the bevel-edged tube to the sclerolimbal junction. The distance between the extremity of the tube and the anterior iris surface (T-I distance), and the angle between the tube and the posterior endothelial surface of the cornea (T-C angle) were defined. Factors that were related to tube parameters were analysed by multiple regression analysis.

RESULTS

The mean change in tube length was -0.20 ± 0.17 mm, indicating that the tube length shortened from the initial inserted length. The mean T-I distance change was 0.11 ± 0.07 mm and the mean T-C angle change was -6.7 ± 5.6°. Uveitic glaucoma and glaucoma following penetrating keratoplasty showed the most changes in tube parameters. By multiple regression analysis, diagnosis of glaucoma including uveitic glaucoma (P=0.049) and glaucoma following penetrating keratoplasty (P=0.008) were related to the change of intracameral tube length.

CONCLUSIONS

These results suggest that the length and position of the AGV tube changes after surgery. The change was prominent in uveitic glaucoma and glaucoma following penetrating keratoplasty.