Dealing with pediatric glaucoma: from medical to surgical management—a narrative review

Introduction

Pediatric glaucoma is one of the most challenging condition physician have to deal with. This is because of the patient is a child, with a long life expectancy, the disease is potentially sigh-threatening and because treatment, especially surgery, is often disappointing.

The term pediatric glaucoma includes a variety of conditions. Primary congenital glaucoma is the most common form (1,2) and is considered the second cause of preventable blindness in children (3,4).

Among the other forms of pediatric glaucoma we can remember the juvenile glaucoma, with an onset ranging from 4 to 16 years, and the secondary forms of glaucoma including the pseudophakic glaucoma, occurring in children who underwent surgery for pediatric cataract, the glaucoma due to systemic disease, like in the Sturge Weber patients, the glaucoma due to ocular anomalies, like in aniridia and Peter’s anomaly, and the glaucoma associated with acquired conditions like the steroid, the traumatic, and the uveitic glaucoma (5).

Intraocular pressure elevation (IOP), increase in axial length and optic nerve cupping and corneal changes, including corneal edema and Haab striae are the clinical hallmark of pediatric glaucoma. As a consequence of the IOP elevation, loss of retinal ganglion cells occurs.

The diagnosis of pediatric glaucoma, depending on the age of the patient, is made by under sedation examination (commonly in children younger than 4 years) or during a slit lamp exam (children older than 4–6 years).

The treatment of the pediatric glaucoma is a step-by-step approach, starting with drugs and often ending up with surgery. We discussed here the algorithm treatment of the childhood glaucoma, from the medical to the surgical management. We present the following article in accordance with Narrative Review reporting checklist (available at http://dx.doi.org/10.21037/aes-21-5).

Methods

Search strategy and trials selection

For this non-systematic review, we conducted a systematic search of peer-reviewed literature in PubMed and Cochrane Library through April 3, 2020. We limited the search to clinical studies and reviews.

We used the following keywords for the computerized search: pediatric glaucoma, glaucoma children, childhood glaucoma, anti-glaucoma medication, angle surgery, trabeculotomy, goniotomy, trabeculectomy, glaucoma drainage device (GDD), glaucoma valve, glaucoma tube valve, glaucoma shunt, Ahmed valve, Baerveltd valve, Molteno valve, aqueous shunt device.

We included in our work: review; retrospective or prospective clinical study carried out with patients with glaucoma younger than 18 years under medical therapy or who underwent angle surgery, trabeculectomy, or aqueous shunt surgery.

The search was limited to papers in the English language published since 1980. We also considered the references of relevant papers for the analysis.

Discussion

Medication

It is well known that primary congenital glaucoma is handled by surgery, as well as glaucoma due to ocular anomalies. However, the role of anti-glaucoma drugs is crucial for the management of children with glaucoma. Patients with juvenile glaucoma can be primarily treated with medications, and children with glaucoma due to acquired secondary forms. In addition, anti-glaucoma drugs can be used preoperatively to lower IOP while waiting for surgery and postoperatively to optimize the IOP control after partially successful glaucoma surgery. A large trial carried-out in children who underwent glaucoma surgery showed that the percentage of patients achieving a target IOP increased from 60% to 94% when patients started to use anti-glaucoma drugs (6).

Large, randomized, controlled clinical trials (RCTs) carried out in adults in the last two decades showed the efficacy and safety of glaucoma medical management in adults. IOP lowering approach has been proven to be effective in reducing the risk of glaucoma development in subjects with ocular hypertension (7) and the rate of disease worsening in subjects with glaucoma (8-11).

The results of these RCTs have been reported in two meta-analyses (12,13).

Active agents commonly used in adults have been widely used to manage pediatric glaucoma; however, data about safety and efficacy largely went from small and retrospective studies (14-27).

It was not until the study by Ott and coauthors was performed in 2005 that we had the first RCT investigating the safety and efficacy of medical therapy in children with glaucoma (28). In this study, the authors compared the efficacy and safety of dorzolamide with 0.5% timolol gel. Three years later, Whitson and coauthors published a RCT comparing brinzolamide with 0.5% levobetaxolol (29).

Three different beta-blockers were compared in the RCT by Plager and colleagues (0.25% betaxolol, 0.25% timolol gel, and 0.5% timolol gel) (30). Latanoprost and 0.50% timolol were compared in the RCT published by Maeda-Chubachi and coauthors (31), and travoprost and 0.50% timolol were compared in the RCT by El Roy Dixon (32).

We have gathered the results of these 5 RCTs in a recent review on the role of medical treatment of pediatric glaucoma (33).

The IOP lowering efficacy of the active agents, as reported in these 5 RCTs, was comparable with the known efficacy in adults, being up to 23% for carbonic anhydrase inhibitors, to 36% for beta-blockers, and to 27% for prostaglandins analogs (33).

The percentage of patients with an IOP lowering effect greater than 20% (responders) was 50% for carbonic anhydrase inhibitors, ranging from 38% to 74% and from 60% to 83% for beta-blockers and prostaglandins, respectively (33).

The safety profile of prostaglandins analogues was excellent, as none of the young patients assuming this class of drug experienced systemic adverse events.

Conversely, two medical records reported serious systemic events occurred in children under timolol, one who experienced bradycardia and one pneumonia.

It is known that beta-blockers can lead to a potentially serious event as bradycardia, systemic hypotension, and bronchospasm. The caregiver of a pediatric subject under beta-blockers should be aware of timolol, even as eye drops can lead to systemic events.

Taking into account the potential systemic effects of beta-blockers, it is worth knowing that systemic absorption of drugs can be reduced using the lowest dose of medication (0.25% timolol rather than 0.50% is recommended in children), as well as a gel formulation. To decrease the systemic exposure of the anti-glaucoma drug, a temporarily lacrimal punctum occlusion can also be considered (34).

Surgery

Surgery is the first-line approach for the management of congenital glaucoma and is the mainstay in the childhood glaucoma treatment algorithm in patients showing an uncontrolled IOP despite medical therapy and progressive disease, despite an apparently controlled IOP.

Angle surgery is generally the first choice for the management of primary congenital glaucoma. The goal of this approach is to overcome the increased resistance to aqueous outflow due to trabecular dysgenesis. Angle surgery includes goniotomy and trabeculotomy. The former technique aims to open the trabecular meshwork by an ab interno approach. The latter aims to open the angle structures getting through the Schlemm canal by an ab externo approach.

The success rate of goniotomy and trabeculotomy are comparable, ranging from 70–90% (35).

After unsuccessful angle surgery, trabeculectomy, cyclodestructive procedures, or GDD can be considered (36,37).

Trabeculectomy is considered the gold standard surgical procedure in the adult population (38); however, trabeculectomy prognosis can be disappointing in a pediatric population.

Moreover, in pediatric patients who underwent trabeculectomy, mitomycin C (MMC) can increase the rate of complications, including avascular, thin blebs, and endophthalmitis reported with a rate as high as 6.7% (39).

Although the implantation of GDD in children is more challenging than in adults (40), GDD can be a suitable option for the control of IOP in children, especially when the initial angle surgery has failed (41) and can be considered a viable alternative to trabeculectomy.

The valved Ahmed GDD (42-59) is more commonly used than the non-valved Baerveldt GDD (36,37,60-62) for the management of pediatric glaucoma.

Both Ahmed and Baerveldt GDD effectively reduce IOP, with a final IOP ranging from 12.27 to 21.3 (42-59) and 13.8–18 (36,37,60-62) in studies carried out with Ahmed and Baerveldt GDD, respectively. At one year, the success rate has been reported to range from 50% to 94.7% (42-59) and from 72% to 94.5% (36,37,60-62) with Ahmed and Baerveldt GDD, respectively.

Although GDDs are considered the best options for the management of refractory, uncontrolled pediatric glaucoma, it is worth knowing that they can lead to several complications (36,37,42-62).

Among the complications to be aware of, hypotony is the more common. Children are more prone to hypotony because of a more elastic scleral tissue compared to adults (36,42,43,45,55). In addition to the complications commonly related to filtering surgery, including cataract development (42,48,61), endophthalmitis (42,43,49,58), hemorrhagic choroidal detachment (45,54), and retinal detachment (36,49,60-62), GDD can lead to tube-related complications, as tube exposure and malpositioning, tube obstruction by vitreous or iris, corneal decompensation and to valve plate-related complication as strabismus (36,37,42-55,60-62). Interestingly only in a few studies, MMC was used intraoperatively (44,45,46,49,50). Al-Mobarak and colleagues compared 16 eyes who underwent an Ahmed valve augmented with MMC with 15 eyes treated with a non-augmented Ahmed valve. The final IOP and the rate of failure were higher in the MMC group (46). As no conclusive data are coming from randomized trials comparing the safety and efficacy of the intraoperative use of MMC during GDD surgery, the use of MMC is not recommended so far, and it remains at the surgeon’s discretion.

Mini-invasive glaucoma surgery (MIGS) is a broad term, first used in 2012 (63) and referred to glaucoma surgery techniques requiring a lesser degree of tissue manipulation, faster recovery, and greater safety profile than traditional, major filtering surgery.

MIGS with subconjunctival drainage have been used in pediatric glaucoma. In a case series of three pediatric patients, Smith and colleagues reported the XEN gel implant outcome in one patient with glaucoma following congenital cataract surgery, one patient with congenital glaucoma, and one patient with pediatric glaucoma secondary to retinopathy of prematurity (64).

Although this small case series reported a good outcome after XEN gel implant and studies carried out in the adult population also reported good outcome and safety profile after this subconjunctival device, more data coming from randomized, large, and controlled studies in adults and hopefully in the pediatric population are needed before recommending this mini-invasive approach for the treatment of pediatric glaucoma (65).

Pediatric glaucoma outcome and rehabilitation

Pediatric glaucoma is considered one of the primary causes of childhood blindness. In a recent cross-sectional survey, more than half of the patients had a vision in the better eye lower than 20/60, and 30% were lower than 20/200 (66).

Pediatric patients with glaucoma are known to have a low vision-related quality of life than healthy children (67). The ultimate goal of glaucoma treatment is to maintain the visual function and the vision-related quality of life.

Studies reported that a higher visual acuity is associated with higher vision-related quality of life (66,68). In light of that, after elevated IOP has been controlled by therapy (including drugs, surgery, and laser), any efforts should be made to minimize the amblyopia by correcting any ametropia, using patching (34) and low vision aids (69,70) in order to improve the final visual function of the patients.

Conclusions

In conclusion, pediatric glaucoma includes a wide range of clinical entities, ranging from the most common congenital glaucoma to the secondary and syndromic ones.

We want to stress that topical medical therapy is of great importance in pediatric glaucoma treatment algorithm (6,28,71): in a percentage of children medical approach will be the first-line step, and a relevant proportion of children will eventually need medical therapy after a partially successful surgery (20,71,72).

Angle surgery is often the first surgical approach. In case of angle surgery failure, the pediatric ophthalmologist should be aware of the bleb-related complications following trabeculectomy, and that tube can be used to handle uncontrolled childhood glaucoma in order to minimize the MMC and bled related complications.

Finally, it is worth that ophthalmologist, parents, and caregiver know that pediatric glaucoma is one of the most challenging ocular disorder, requiring a step-by-step approach, several examinations, often multiple surgeries, and lifelong care. We believe that a strong alliance between eye care staff and family is of paramount importance in this challenging but also rewarding journey.

Acknowledgments

Funding: None.

Footnote

Reporting Checklist: The authors have completed the Narrative Review reporting checklist (available at http://dx.doi.org/10.21037/aes-21-5).

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form. The authors have no conflicts of interest to declare (available at http://dx.doi.org/10.21037/aes-21-5). All authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest (such as honoraria; educational grants; participation in speakers’ bureaus; membership, employment, consultancies, stock ownership, or other equity interest; and expert testimony or patent-licensing arrangements), or non-financial interest (such as personal or professional relationships, affiliations, knowledge or beliefs) in the subject matter or materials discussed in this manuscript. MS serves as an unpaid editorial board member of Annals of Eye Science from Jun 2020 to May 2022. The other authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. Qiao CY, Wang LH, Tang X, et al. Epidemiology of hospitalized pediatric glaucoma patients in Beijing Tongren Hospital. Chin Med J (Engl) 2009;122:1162-6. [PubMed]
2. Taylor RH, Ainsworth JR, Evans AR, et al. The epidemiology of pediatric glaucoma: the Toronto experience. J AAPOS 1999;3:308-15. [Crossref] [PubMed]
3. de Verdier K, Ulla E, Löfgren S, et al. Children with blindness - major causes, developmental outcomes and implications for habilitation and educational support: a two-decade, Swedish population-based study. Acta Ophthalmologica 2018;96:295-300. [Crossref] [PubMed]
4. Gudlavalleti VSM. Magnitude and Temporal Trends in Avoidable Blindness in Children (ABC) in India. Indian J Pediatr 2017;84:924-9. [Crossref] [PubMed]
5. Thau A, Lloyd M, Freedman S, et al. New classification system for pediatric glaucoma: implications for clinical care and a research registry. Curr Opin Ophthalmol 2018;29:385-94. [Crossref] [PubMed]
6. Papadopoulos M, Cable N, Rahi J, et al. The British Infantile and Childhood Glaucoma (BIG) Eye Study. Invest Ophthalmol Vis Sci 2007;48:4100-6. [Crossref] [PubMed]
7. Kass MA, Heuer DK, Higginbotham EJ, et al. The ocular hypertension treatment study: a randomized trial determines that topical ocular hypotensive medication delays or prevents the onset of primary open-angle glaucoma. Arch Ophthalmol 2002;120:701-13. [Crossref] [PubMed]
8. Heijl A, Leske MC, Bengtsson B, et al. Early manifest glaucoma trial group. Reduction of intraocular pressure and glaucoma progression: results from the early manifest glaucoma trial. Arch Ophthalmol 2002;120:1268-79. [Crossref] [PubMed]
9. The AGIS Investigators. The Advanced Glaucoma Intervention Study (AGIS): 7. The relationship between control of intraocular pressure and visual field deterioration. Am J Ophthalmol 2000;130:429-40. [Crossref] [PubMed]
10. Chauhan BC, Mikelberg FS, Artes PH, et al. Canadian glaucoma study group. Canadian glaucoma study: 3. Impact of risk factors and intraocular pressure reduction on the rates of visual field change. Arch Ophthalmol 2010;128:1249-55. [Crossref] [PubMed]
11. . Comparison of glaucomatous progression between untreated patients with normal-tension glaucoma and patients with therapeutically reduced intraocular pressures. Collaborative Normal-Tension Glaucoma Study Group. Am J Ophthalmol 1998;126:487-97. [Crossref] [PubMed]
12. van der Valk R, Webers CA, Schouten JS, et al. Intraocular pressure-lowering effects of all commonly used glaucoma drugs: a meta-analysis of randomized clinical trials. Ophthalmology 2005;112:1177-85. [Crossref] [PubMed]
13. Cheng JW, Cheng SW, Gao LD, et al. Intraocular pressure-lowering effects of commonly used fixed-combination drugs with timolol: a systematic review and meta-analysis. PLoS One 2012;7:e45079 [Crossref] [PubMed]
14. Black AC, Jones S, Yanovitch TL, et al. Latanoprost in pediatric glaucoma—pediatric exposure over a decade. J AAPOS 2009;13:558-62. [Crossref] [PubMed]
15. Enyedi LB, Freedman SF, Buckley EG. The effectiveness of latanoprost for the treatment of pediatric glaucoma. J AAPOS 1999;3:33-9. [Crossref] [PubMed]
16. Enyedi LB, Freedman SF. Latanoprost for the treatment of pediatric glaucoma. Surv Ophthalmol 2002;47:S129-32. [Crossref] [PubMed]
17. Yang CB, Freedman SF, Myers JS, et al. Use of latanoprost in the treatment of glaucoma associated with Sturge-Weber syndrome. Am J Ophthalmol 1998;126:600-2. [Crossref] [PubMed]
18. Altuna JC, Greenfield DS, Wand M, et al. Latanoprost in glaucoma associated with Sturge-Weber syndrome: benefits and side-effects. J Glaucoma 1999;8:199-203. [Crossref] [PubMed]
19. Ong T, Chia A, Nischal KK. Latanoprost in port wine stain related paediatric glaucoma. Br J Ophthalmol 2003;87:1091-3. [Crossref] [PubMed]
20. Quaranta L, Biagioli E, Riva I, et al. The Glaucoma Italian Pediatric Study (GIPSy): 3-Year Results. J Glaucoma 2018;27:856-63. [Crossref] [PubMed]
21. Donohue EK, Wilensky JT. Dorzolamide: A review. Semin Ophthalmol 1997;12:119-26. [Crossref]
22. Portellos M, Buckley EG, Freedman SF. Topical versus oral carbonic anhydrase inhibitor therapy for pediatric glaucoma. J AAPOS 1998;2:43-7. [Crossref] [PubMed]
23. Donohue EK, Wilensky JT. Therapeutics and techniques: Trusopt, a topical carbonic anhydrase inhibitor. J Glaucoma 1996;5:68-74. [Crossref] [PubMed]
24. Boger WP, Walton DS. Timolol in uncontrolled childhood glaucomas. Ophthalmology 1981;88:253-8. [Crossref] [PubMed]
25. McMahon CD, Hetherington J Jr, Hoskins HD Jr, et al. Timolol and pediatric glaucomas. Ophthalmology 1981;88:249-52. [Crossref] [PubMed]
26. Hoskins HD Jr, Hetherington J Jr, Magee SD, et al. Clinical experience with timolol in childhood glaucoma. Arch Ophthalmol 1985;103:1163-5. [Crossref] [PubMed]
27. Kanner EM, Netland PA. Medical therapy of pediatric glaucoma. Contemp Ophthalmol 2008;7:1-8.
28. Ott EZ, Mills MD, Arango S, et al. A randomized trial assessing dorzolamide in patients with glaucoma who are younger than 6years. Arch Ophthalmol 2005;123:1177-86. [Crossref] [PubMed]
29. Whitson JT, Roarty JD, Vijaya L, et al. Efficacy of brinzolamide and levobetaxolol in pediatric glaucomas: a randomized clinical trial. J AAPOS 2008;12:239-46.e3. [Crossref] [PubMed]
30. Plager DA, Whitson JT, Netland PA, et al. Betaxolol hydrochloride ophthalmic suspension 0.25% and timolol gel-forming solution 0.25% and 0.5% in pediatric glaucoma: a randomized clinical trial. J AAPOS 2009;13:384-90. [Crossref] [PubMed]
31. Maeda-Chubachi T, Chi-Burris K, Simons BD, et al. Comparison of latanoprost and timolol in pediatric glaucoma: a phase 3, 12-week, randomized, double-masked multicenter study. Ophthalmology 2011;118:2014-21. [Crossref] [PubMed]
32. Dixon ER, Landry T, Venkataraman S, et al. A 3-month Safety and Efficacy Study of Travoprost 0.004% Ophthalmic Solution Compared With Timolol in Pediatric Patients With Glaucoma or Ocular Hypertension. J AAPOS 2017;21:370-374.e1. [Crossref] [PubMed]
33. Sacchi M, Lizzio RAU, Villani E, et al. Medical management of pediatric glaucoma: lessons learned from randomized clinical trials. Graefes Arch Clin Exp Ophthalmol 2020;258:1579-86. [Crossref] [PubMed]
34. Papadopoulos M, Khaw PT. Advances in the management of paediatric glaucoma. Eye 2007;21:1319-25. [Crossref] [PubMed]
35. Meyer G, Schwenn O, Pfeiffer N, et al. Trabeculotomy in congenital glaucoma. Graefes Arch Clin Exp Ophthalmol 2000;238:207-13. [Crossref] [PubMed]
36. van Overdam KA, de Faber JT, Lemij HG, et al. Baerveldt glaucoma implant in paediatric patients. Br J Ophthalmol 2006;90:328-32. [Crossref] [PubMed]
37. Banitt MR, Sidoti PA, Gentile RC, et al. Pars plana Baerveldt implantation for refractory childhood glaucomas. J Glaucoma 2009;18:412-7. [Crossref] [PubMed]
38. Kirwan JF, Lockwood AJ, Shah P, et al. Trabeculectomy in the 21st century: a multicenter analysis. Ophthalmology 2013;120:2532-9. [Crossref] [PubMed]
39. Chen TC, Chen PP, Francis BA, et al. Pediatric glaucoma surgery: a report by the American Academy Of Ophthalmology. Ophthalmology 2014;121:2107-15. [Crossref] [PubMed]
40. Mandalos A, Sung V. Glaucoma drainage device surgery in children and adults: a comparative study of outcomes and complications. Graefes Arch Clin Exp Ophthalmol 2017;255:1003-11. [Crossref] [PubMed]
41. Giangiacomo A, Beck A. Pediatric glaucoma: review of recent literature. Curr Opin Ophthalmol 2017;28:199-203. [Crossref] [PubMed]
42. Djodeyre MR, Peralta Calvo J, Abelairas Gomez J. Clinical evaluation and risk factors of time to failure of Ahmed Glaucoma Valve implant in pediatric patients. Ophthalmology 2001;108:614-20. [Crossref] [PubMed]
43. Morad Y, Donaldson CE, Kim YM, et al. The Ahmed drainage implant in the treatment of pediatric glaucoma. Am J Ophthalmol 2003;135:821-9. [Crossref] [PubMed]
44. Kirwan C, O'Keefe M, Lanigan B, et al. Ahmed valve drainage implant surgery in the management of paediatric aphakic glaucoma. Br J Ophthalmol 2005;89:855-8. [Crossref] [PubMed]
45. Pakravan M, Homayoon N, Shahin Y, et al. Trabeculectomy with mitomycin C versus Ahmed glaucoma implant with mitomycin C for treatment of pediatric aphakic glaucoma. J Glaucoma 2007;16:631-6. [Crossref] [PubMed]
46. Al-Mobarak F, Khan AO. Two-year survival of Ahmed valve implantation in the first 2 years of life with and without intraoperative mitomycin-C. Ophthalmology 2009;116:1862-5. [Crossref] [PubMed]
47. Yang HK, Park KH. Clinical outcomes after Ahmed valve implantation in refractory paediatric glaucoma. Eye (Lond) 2009;23:1427-35. [Crossref] [PubMed]
48. Ou Y, Yu F, Law SK, et al. Outcomes of Ahmed glaucoma valve implantation in children with primary congenital glaucoma. Arch Ophthalmol 2009;127:1436-41. [Crossref] [PubMed]
49. Khan AO, Almobarak FA. Comparison of polypropylene and silicone Ahmed valve survival 2 years following implantation in the first 2 years of life. Br J Ophthalmol 2009;93:791-4. [Crossref] [PubMed]
50. El Sayed Y, Awadein A. Polypropylene vs silicone Ahmed valve with adjunctive mitomycin C in paediatric age group: a prospective controlled study. Eye (Lond) 2013;27:728-34. [Crossref] [PubMed]
51. Chen A, Yu F, Law SK, et al. Valved Glaucoma Drainage Devices in Pediatric Glaucoma: Retrospective Long-term Outcomes. JAMA Ophthalmol 2015;133:1030-5. [Crossref] [PubMed]
52. Elhefney EM, Al-Sharkawy HT, Kishk HM. Supra-Tenon Capsule Implantation of the Ahmed Glaucoma Valve in Refractory Pediatric Glaucoma. J Glaucoma 2016;25:732-7. [Crossref] [PubMed]
53. Lee N, Ma KT, Bae HW, et al. Surgical results of trabeculectomy and Ahmed valve implantation following a previous failed trabeculectomy in primary congenital glaucoma patients. Korean J Ophthalmol 2015;29:109-14. [Crossref] [PubMed]
54. Novak-Lauš K, Škunca Herman J, Šimić Prskalo M, et al. Initial Clinical Experience with Ahmed Valve Implantation in Refractory Pediatric Glaucoma. Acta Clin Croat 2016;55:555-9. [Crossref] [PubMed]
55. Eksioglu U, Yakin M, Sungur G. Short- to long-term results of Ahmed glaucoma valve in the management of elevated intraocular pressure in patients with pediatric uveitis. Can J Ophthalmol 2017;52:295-301. [Crossref] [PubMed]
56. Al-Haddad C, Al-Salem K, Ismail K. Long-term outcomes of Ahmed tube implantation in pediatric glaucoma after multiple surgeries. Int Ophthalmol 2018;38:2649-52. [Crossref] [PubMed]
57. Kaushik J, Parihar JKS, Jain VK, et al. Ahmed valve implantation in childhood glaucoma associated with Sturge-Weber syndrome: our experience. Eye (Lond) 2019;33:464-8. [Crossref] [PubMed]
58. Senthil S, Turaga K, Mohammed HA, et al. Outcomes of Silicone Ahmed Glaucoma Valve Implantation in Refractory Pediatric Glaucoma. J Glaucoma 2018;27:769-75. [Crossref] [PubMed]
59. Pakravan M, Esfandiari H, Yazdani S, et al. Clinical outcomes of Ahmed glaucoma valve implantation in pediatric glaucoma. Eur J Ophthalmol 2019;29:44-51. [Crossref] [PubMed]
60. Budenz DL, Gedde SJ, Brandt JD, et al. Baerveldt glaucoma implant in the management of refractory childhood glaucomas. Ophthalmology 2004;111:2204-10. [Crossref] [PubMed]
61. Rolim de Moura C, Fraser-Bell S, Stout A, et al. Experience with the baerveldt glaucoma implant in the management of pediatric glaucoma. Am J Ophthalmol 2005;139:847-54. [Crossref] [PubMed]
62. Vinod K, Panarelli JF, Gentile RC, et al. Long-term Outcomes and Complications of Pars Plana Baerveldt Implantation in Children. J Glaucoma 2017;26:266-71. [Crossref] [PubMed]
63. Saheb H, Ahmed II. Micro-invasive glaucoma surgery: current perspectives and future directions. Curr Opin Ophthalmol 2012;23:96-104. [Crossref] [PubMed]
64. Smith OU, Grover DS, Emanuel ME, et al. XEN Gel Stent in Pediatric Glaucoma. J Glaucoma 2020;29:e19-e22. [Crossref] [PubMed]
65. Mohamed-Noriega J, Gizzi C, Brookes J. Angle Surgery is the Best Surgical Option for New Patients With Primary Congenital Glaucoma and Not Xen Stent. J Glaucoma 2020;29:e96 [Crossref] [PubMed]
66. AlDarrab A, Al Qurashi M, Al Thiabi S, et al. Functional Visual Ability and Quality of Life in Children With Glaucoma. Am J Ophthalmol 2019;200:95-9. [Crossref] [PubMed]
67. Dahlmann-Noor A, Tailor V, Bunce C, et al. Quality of life and functional vision in children with glaucoma. Ophthalmology 2017;124:1048-55. [Crossref] [PubMed]
68. Freedman BL, Jones SK, Lin A, et al. Vision-related quality of life in children with glaucoma. J AAPOS 2014;18:95-8. [Crossref] [PubMed]
69. Gao G, Yu M, Dai J, et al. Demographic and clinical characteristics of a paediatric low vision population in a low vision clinic in China. Clin Exp Optom 2016;99:274-9. [Crossref] [PubMed]
70. Haddad MA, Sampaio MW, Oltrogge EW, et al. Visual impairment secondary to congenital glaucoma in children: visual responses, optical correction and use of low vision AIDS. Clinics (Sao Paulo) 2009;64:725-30. [Crossref] [PubMed]
71. Chang L, Ong EL, Bunce C, et al. A review of the medical treatment of pediatric glaucomas at Moorfields Eye Hospital. J Glaucoma 2013;22:601-7. [Crossref] [PubMed]
72. Tanimoto SA, Brandt JD. Options in pediatric glaucoma after angle surgery has failed. Curr Opin Ophthalmol 2006;17:132-7. [Crossref] [PubMed]