Results of Ahmed glaucoma valve implantation in primary congenital glaucoma M. Reza Razeghinejad, MD, Saeed Kaffashan, MD, and Mohammad H. Nowroozzadeh, MD PURPOSE METHODS
RESULTS
CONCLUSIONS
To evaluate the outcome of Ahmed glaucoma valve (AGV) implantation in primary congenital glaucoma (PCG). The medical records of patients with PCG refractory to trabeculotomy and medical therapy who had undergone AGV implantation with a minimum follow-up of 6 months were retrospectively reviewed. The primary outcome measure was cumulative probability of success, defined as intraocular pressure (IOP) of 6–21 mm Hg, with or without medication, and no serious complications, additional glaucoma surgery, or loss of light perception. A total of 33 eyes of 22 children with a mean age (and standard deviation) of 2.7 3.1 years were included. The patients had a mean follow-up time of 32.6 18.3 months. The mean IOP was 32.8 7.3 mm Hg preoperatively and 16.8 4.0 mm Hg postoperatively. The number of glaucoma medications was 2.5 0.7 preoperatively and 2.2 0.7 postoperatively. The cumulative probability of success (and standard error) was 97% 3.0% in the 1st year, 85% 7.0% in the 2nd year, and 56% 14.8% in the 5th year. When only the first operated eye per patient was included, the cumulative probability of success was 96% 4.4% in the 1st and the 2nd years and 72% 15.3% in the 5th year. Major complications comprised tube–endothelial touch (3 eyes), cataract (2 eyes), shunt extrusion (1 eye), and retinal detachment (1 eye). AGV implantation in patients with PCG offers moderate success in controlling the IOP with a low rate of complications. Most continued to require medications. ( J AAPOS 2014;18:590-595)
P
rimary congenital glaucoma (PCG), the most common type of glaucoma in infancy,1 is a potentially blinding disorder. Surgical management is the mainstay of treatment in PCG,2,3 and medical therapy is often used adjunctively to control intraocular pressure (IOP).4-8 Angle surgeries such as goniotomy or trabeculotomy are the initial procedures of choice.9,10 Although these procedures have a success rate of 75%-90% in Western countries,9,11 in Middle Eastern and South Asian countries, with a higher incidence of CYP1B1-related PCG,12 the reported success rate ranges from 54% to 69%.13,14 Children with uncontrolled IOP after angle surgeries require additional measures to achieve an adequate control of IOP. The surgical options in this group of patients include trabeculectomy,15,16 nonpenetrating glaucoma surgery,17 Author affiliations: Poostchi Ophthalmology Research Center, Department of Ophthalmology, Shiraz University of Medical Sciences, Shiraz, Iran This study was funded and supported by Shiraz University of Medical Sciences (Grant 90-01-01-2769). This paper was derived from a thesis for a Medical Degree. Submitted May 4, 2014. Revision accepted August 31, 2014. Published online November 12, 2014. Correspondence: Mohammad H. Nowroozzadeh, MD, Department of Ophthalmology, Poostchi Ophthalmology Research Center, Poostchi Clinic, Zand Street, Shiraz, Iran (email: [email protected]). Copyright Ó 2014 by the American Association for Pediatric Ophthalmology and Strabismus. 1091-8531/$36.00 http://dx.doi.org/10.1016/j.jaapos.2014.08.008
590
combined trabeculotomy and trabeculectomy,18 cycloablative therapy,19,20 and glaucoma drainage devices.21-24 Trabeculectomy in a buphthalmic eye is technically challenging and is frequently unsuccessful.25 Adjunctive antifibrotics, such as mitomycin C and 5-fluorouracil, may improve the success rate, but long-term complications include bleb failure, bleb leak, and infection.1,26 Cycloablative laser therapy (either transscleral or endoscopic) has a limited success rate, a high risk of complications, and frequently necessitates retreatment in children19,20,27,28; therefore, it is usually reserved for eyes unresponsive to other interventions. The use of glaucoma drainage devices in children was first described in 1973 by Molteno,29 with a reported success rate of 67% using single-plate Molteno implants. Since then, glaucoma drainage devices have been used to treat refractory pediatric glaucoma, particularly when trabeculectomy fails or is known to have a high risk of failure (ie, significant conjunctival scarring).30,31 Several studies have evaluated different types of glaucoma drainage devices in pediatric glaucoma.21,22,32-35 The reported success rates for the Ahmed glaucoma valve (AGV) in children ranges from 58% to 93% in achieving IOPs of \21 mm Hg. The majority of these reports comprised children with a variety of pediatric glaucoma diagnoses, including primary or secondary causes.21,22,36,37 The success rate and potential complications of the AGV in the PCG are still debated.
Journal of AAPOS
Volume 18 Number 6 / December 2014 The purpose of the present study was to describe the outcome of AGV implantation in a racially homogenous group of PCG patients with uncontrolled IOP using topical medications and having undergone prior trabeculotomy. In contrast to most previous reports, the present study included only PCG patients.
Subjects and Methods This study was approved by the Ethics Committee of Shiraz University of Medical Sciences. Children with PCG who had undergone AGV implantation from March 2005 through March 2013 at a tertiary eye-care center affiliated with the Shiraz University of Medical Sciences were retrospectively reviewed. Inclusion criteria were uncontrolled IOP (.21 mm Hg) despite maximal medical therapy ($3 topical antiglaucoma medications), history of previous trabeculotomy at two sites (superonasal and inferotemporal quadrants), and a minimum of 6 months’ follow-up after AGV implantation. Children with previous ocular surgeries other than trabeculotomy, \6 months’ follow-up, and secondary diagnoses such as aphakia or pseudophakia, Sturge-Weber syndrome, uveitic glaucoma, aniridia, and anterior segment dysgenesis were excluded. All surgeries and also follow-up examinations were performed by a single glaucoma surgeon (MRR). Because of poor visualization secondary to severe corneal edema in almost all cases, trabeculotomy was the preferred primary intervention. Preoperative data included age at time of surgery, sex, laterality, IOP prior to AGV implantation, number of antiglaucoma medications (1 point was assigned for each topical antiglaucoma medication and 2 points were assigned for oral acetazolamide),38 cup:disk ratio, and corneal diameter. The following postoperative data was collected at 1 month and 6 months and at 6-month intervals thereafter through 60 months: type of AGV, IOP measurements, number of antiglaucoma medications, crystalline lens status, intra- and postoperative complications, additional surgical procedures after shunt implantation. IOPs were measured by applanation tonometry (Tonopen-XL; Mentor, Norwell, MA). The primary outcome was postoperative success, defined as IOP of 6–21 mm Hg, with a maximum of 3 antiglaucoma medications. Failure included IOP .21 mm Hg on 2 consecutive visits, loss of light perception, need for additional glaucoma surgery (except tube repositioning, scleral patch graft reinforcement for tube exposure, or bleb needling with 5-fluorouracil injection), and serious complications, such as retinal detachment, endophthalmitis, suprachoroidal hemorrhage, aqueous misdirection, or phthisis.
Razeghinejad, Kaffashan, and Nowroozzadeh
591
fixed to the sclera using a 10-0 nylon suture. A piece of donor sclera was manually trimmed and sutured over the tube using two 8-0 polyglactin 910 sutures. The conjunctiva was reposed and sutured using 8-0 polyglactin 910 sutures. A subconjunctival injection of betamethasone was given at the conclusion of surgery. Postoperatively, topical antibiotic (chloramphenicol) and steroid (betamethasone) eyedrops were prescribed and tapered over an 8-week period.
Statistical Analysis All statistical analyses were performed using SPSS version 19.0 for Windows (SPSS Inc, Chicago, IL). Kaplan-Meier survival analyses were used to assess the success rates of AGV implantation at postoperative visits. Cox proportional hazards regression analysis was used to determine the predictive factors for failure. The mean value of continuous variables are reported with standard deviations; standard errors were used to estimate success rates. A P value of \0.05 was considered statistically significant. Because of the rarity of the disorder, the eye (n 5 33) was regarded as the unit of analysis. To evaluate the consistence of findings, repeat Kaplan-Meier survival analysis was also performed with 1 eye per patient (n 5 22), using the first eye that underwent AGV implantation.
Results Data of 33 eyes of 22 patients (17 males) were compiled and analyzed. The AGV models used were the S2 (n 5 2), S3 (n5 6), FP7 (n 5 23), and FP8 (n 5 2). Eleven patients (8 males) underwent bilateral AGV implantation. The mean age at AGV implantation was 2.7 3.1 years (median, 1.0; range, 0.1-11 years). The mean interval between trabeculotomy and AGV implantation was 21.3 31.5 months (median, 6; range, 1-132 months). The mean follow-up period was 32.6 18.3 months (median, 24.0; range, 6-60 months).
Surgical Technique
Changes in IOP The mean IOP was 32.8 7.3 mm Hg before AGV implantation and 16.8 4.0 mm Hg at final last follow-up (P \ 0.001; repeated measures ANOVA, Bonferroni post hoc test). The mean decrease in IOP at the final followup compared to preoperative IOPs were 16.5 8.5 mm Hg. Of 33 eyes, 23 (70%) showed a transient early postoperative hypertensive phase at the first postoperative month that was controlled by antiglaucoma medications. Of these eyes, 18 had a successful outcome and 5 ended in failure. Alterations in the pre- and postoperative mean IOPs and number of eyes lost to follow-up are provided in Figure 1.
After applying a corneal traction suture using a 7-0 silk suture, a fornix- based conjunctival peritomy was created in the superotemporal quadrant. The AGV was primed using 1 ml of balanced salt solution and secured to the sclera, with its anterior edge 8–10 mm posterior to the limbus using two 7-0 silk sutures. A 23-gauge needle was then used to enter the anterior chamber at the surgical limbus, pointing toward the center of the pupil. The tube was trimmed bevel-up and inserted through the opening after forming the anterior chamber with a viscoelastic material. The tube was
Antiglaucoma Medications The mean number of antiglaucoma medications was 2.5 0.7 (median, 2; range, 1-5) before AGV implantation and 2.2 0.7 (median, 2; range, 0-3; P 5 0.08, paired t test) at the last follow-up examination. Preoperatively, 15 (46%) eyes were treated with 3 or more antiglaucoma medications, compared to 11 (33%) eyes at the last follow-up. Only one eye (with 36 months of follow-up) required no
Journal of AAPOS
592
Razeghinejad, Kaffashan, and Nowroozzadeh
Volume 18 Number 6 / December 2014
FIG 1. Changes in intraocular pressure. Mean intraocular pressure (IOP) profile before surgery (pre-op) and during follow-up visits in eyes with primary congenital glaucoma (PCG) that underwent Ahmed glaucoma valve (AGV) implantation.
FIG 3. Survival analysis. Kaplan-Meier cumulative probability curve of success in eyes with PCG that underwent AGV implantation. A, Survival analysis of all eyes with PCG (n 5 33). B, Survival analysis of one eye per PCG patient (n 5 22).
FIG 2. Changes in number of medications. Mean number of antiglaucoma medications used preoperatively and during follow-up visits in eyes with PCG that underwent AGV implantation.
medication for controlling IOP. Figure 2 shows the changes in mean number of antiglaucoma medications pre- and postoperatively. Surgical Success and Risk Factors for Failure AGV implantation failed in 7 (21%) eyes; the mean time to failure was 29.1 15.7 months (median, 24.0; range, 6-48). The operation was successful in 26 (79%) eyes; the mean follow-up time for eyes with successful surgery was 29.3 17.0 months (median, 24.0; range, 6-60). Of 11 patients who underwent bilateral surgery, 7 (64%) had success in both eyes, 3 (27%) had success in one eye, and 1 (9%)
had failure in both eyes. According to Kaplan-Meier survival analysis, the success rate of AGV implantation in PCG eyes (n 5 33) was 97.0% 3.0% at the 6th month, 97.0% 3.0% at the 1st year, 84.8% 7.0% at the 2nd year, and 56.3% 14.8% at the 5th year after surgery (Figure 3A). There was no significant difference for survival when one eye of each participant was used for statistical analysis, with 96% 4.4% in the 1st and the 2nd years, and 72% 15.3% in the 5th year (Figure 3B). Causes of failure are presented in Table 1. Risk factors for surgical failure after AGV implantation in refractory PCG, comparison between success and failure groups, and results from univariate Cox proportional hazards regression models are presented in e-Supplement 1 (available at jaapos.org). The observed associations of all potential risk factors were not statistically significant. Significant complications were observed in 8 eyes (24%), of which 3 (38%) ended in failure (Table 2). No patient developed isolated hypotony or loss of light perception after the first AGV implantation.
Journal of AAPOS
Volume 18 Number 6 / December 2014
Razeghinejad, Kaffashan, and Nowroozzadeh
593
Table 1. Causes to failure, characteristics, and additional procedures for eyes with failed Ahmed glaucoma valve implantation Eye 1 2 3 4 5 6 7
Cause of failure
Time to failure, months
IOP, mm Hg
Number of medicationsa
Additional intervention
Uncontrolled IOP Uncontrolled IOP Uncontrolled IOP Uncontrolled IOP Uncontrolled IOP Uncontrolled IOP Retinal detachment
36 48 48 6 18 24 24
27 26 28 28 25 34 20
3 3 3 1 3 2 3
1. Tube revision; 2. TSCPCb TSCPCc TSCPCc TSCPCc Second AGV placementd 1. Tube revision; 2. Explantatione None
AGV, Ahmed glaucoma valve; IOP, intraocular pressure; TSCPC, transscleral cyclophotocoagulation. a At the time of failure. b IOP eventually controlled (18 mm Hg) with 3 medications. c IOP could not be controlled despite maximal medical therapy. d IOP eventually controlled (16 mm Hg) with 2 medications. e IOP at final follow-up was 18 mm Hg on 3 topical medications.
Table 2. Complications after Ahmed glaucoma valve implantation in patients with primary congenital glaucoma Eyea 1
Complication
7 8
Tube-endothelial touch 1. Tube–endothelial touch; 2. Shunt extrusion Retinal detachment Cataract
9
Cataract
10 11
Tube–endothelial touch Bleb encapsulation
12
Bleb encapsulation
6
Intervention
Final outcome
Tube revision
Failure
1. Tube revision; 2. Explantation
Failure
None (lost eye)b Lensectomy and anterior vitrectomy Lensectomy and anterior vitrectomy Tube revision
Failure Success
Bleb needling and 5-FU injection Bleb needling and 5-FU injection
Success Success Success Success
5-FU, 5-fluorouracil. a Eyes 1, 6, and 7 are the same as indicated in Table 2. b According to retina specialist because of severe glaucomatous optic nerve damage no intervention was taken.
Discussion In this study the cumulative probability of success with a single AGV implant in patients with PCG was 97.0% at 1 year, which decreased to 56.3% at 5 years. Tube–endothelial touch was the most frequently encountered complication, followed by bleb encapsulation and cataract. Many studies have reported promising results in using tubes to treat pediatric glaucoma. However, because of remarkable variations in the types of devices implanted, populations studied (including ethnicity and enrollment criteria), criteria of success, and length of follow-up, direct comparison of surgical success rates is difficult. The reported shorter survival rate of AGV implantation in PCG versus other types of pediatric glaucoma is still debated.9,21 Chen and colleauges39 found a lower success rate with AGV implantation in PCG (45% [n 5 20]) compared with aphakic glaucoma (68.4% [n 5 19]). Djodeyre and colleagues36 found a lower mean survival rate for AGV
Journal of AAPOS
implantation in PCG (13.9 months [n 5 17]) compared to other diagnoses, such as Sturge-Weber syndrome, postoperative glaucoma, and so forth (35.6 months [n 5 18]). However, other studies did not report an association between surgical failure rate and glaucoma type in children.6,9,24,35 Considering only the first operated eyes (n 5 22), our 5-year success rate of 72% is comparable to the 70% result reported by O’Malley Schotthoefer and colleagues.35 Ou and colleagues40 reported the outcomes of AGV implantation in 30 eyes of 19 children with PCG. The reported cumulative probability of success with a single AGV implant was 63% at 1 year and 33% at 5 years, considerably less than our report. In their study, Hispanic ethnicity (RR 5 3.67; P 5 0.02) and female sex (RR 5 5.56; P 5 0.005) were associated with increased risk of failure. In their study of 42 eyes (28 with PCG), Almobarak and Khan41 reported that cumulative valve survival 2 years following implantation was 63.3%, less than our 85%. However, their cohort included cases other than PCG that may have had worse outcomes. Moreover, they limited their study to children #2 years of age, a population that probably has a lower success rate and higher complication rate. The most common postoperative complication in Almobarak and Khan41 was tube malpositioning (26.2%). Another study by Khan and Almobarak42 found no difference in terms of success and outcome between the two models of Ahmed valve (S2, S3). Brasil and colleagues43 compared silicone and polypropylene Ahmed valves and concluded that both valves have similar results with respect to effectiveness in controlling IOP and complication rate. We found no statistically significant difference in survival between silicone and polypropylene implants (P 5 0.27; log-rank test); however, the small sample size of the polypropylene group (n 5 8) limits the validity of these results. Previous studies were inconclusive regarding the relative superiority of specific AGV models in terms of IOP control or complications.42-44 Future studies are warranted to shed light on this issue. Postoperative hypotony is less likely with the AGV,39 whereas the risk of an early transient hypertensive phase
594
Razeghinejad, Kaffashan, and Nowroozzadeh
is greater. The incidence of a hypertensive phase after AGV implantation in adults ranges between 56 to 82%.29,45,46 Chen and colleagues39 reported a 25% risk of hypertensive phase after AGV implantation in pediatric glaucoma, less than that reported in adults. However, the current study found the risk of a hypertensive phase to be 70%. Chen and colleagues39 found that the presence of a hypertensive phase was associated with a lower success rate, whereas we found no significant association. In accordance with our results, Ou and colleagues40 reported that uncontrolled IOP (including those who required a second AGV implantation) was the primary cause of failure, and the most common complications were tube-related problems such as tube–endothelial touch and tube exposure. In the current study, the mostly performed glaucoma procedure after AGV failure was transscleral cyclophotocoagulation (TSCPC). The procedure was successful in only 1 patient (25%) in controlling IOP. A previous study reported similar rates of success and complications with TSCPC and sequential tube shunt following primary tube shunt failure in childhood glaucoma.47 Overall, the decision for the type of additional procedure in a failed shunt should be tailored to the individual and based on visual prognosis, ocular anatomy, and type of previous surgeries. This study is limited by its retrospective nature. In addition, the young age of study participants precluded acquisition of quantitative measurement of visual acuity outcomes. The study’s strengths include the uniformity in PCG population and AGV implantation and a relatively large number of eyes, considering the rarity of condition.
Acknowledgments The authors thank Narges Rousta, MSc, for her help with statistical analysis of the data. References 1. Taylor RH, Ainsworth JR, Evans AR, Levin AV. The epidemiology of pediatric glaucoma: the Toronto experience. J AAPOS 1999;3: 308-15. 2. Beck AD. Diagnosis and management of pediatric glaucoma. Ophthalmol Clin North Am 2001;14:501-12. 3. Turach ME, Aktan G, Idil A. Medical and surgical aspects of congenital glaucoma. Acta Ophthalmol Scand 1995;73:261-3. 4. Enyedi LB, Freedman SF. Latanoprost for the treatment of pediatric glaucoma. Surv Ophthalmol 2002;47(Suppl 1):S129-32. 5. Maris PJ Jr, Mandal AK, Netland PA. Medical therapy of pediatric glaucoma and glaucoma in pregnancy. Ophthalmol Clin North Am 2005;18:461-8. vii. 6. Portellos M, Buckley EG, Freedman SF. Topical versus oral carbonic anhydrase inhibitor therapy for pediatric glaucoma. J AAPOS 1998;2: 43-7. 7. Sabri K, Levin AV. The additive effect of topical dorzolamide and systemic acetazolamide in pediatric glaucoma. J AAPOS 2006;10: 464-8. 8. Zimmerman TJ, Kooner KS, Morgan KS. Safety and efficacy of timolol in pediatric glaucoma. Surv Ophthalmol 1983;(28 Suppl): 262-4.
Volume 18 Number 6 / December 2014 9. Anderson DR. Trabeculotomy compared to goniotomy for glaucoma in children. Ophthalmology 1983;90:805-6. 10. Shaffer RN. Prognosis of goniotomy in primary infantile glaucoma (trabeculodysgenesis). Trans Am Ophthalmol Soc 1982;80:321-5. 11. McPherson SD Jr, Berry DP. Goniotomy vs external trabeculotomy for developmental glaucoma. Am J Ophthalmol 1983;95:427-31. 12. Khan AO. Genetics of primary glaucoma. Curr Opin Ophthalmol 2011;22:347-55. 13. Elder MJ. Congenital glaucoma in the West Bank and Gaza Strip. Br J Ophthalmol 1993;77:413-16. 14. Debnath SC, Teichmann KD, Salamah K. Trabeculectomy versus trabeculotomy in congenital glaucoma. Br J Ophthalmol 1989;73: 608-11. 15. Fulcher T, Chan J, Lanigan B, Bowell R, O’Keefe M. Long-term follow up of primary trabeculectomy for infantile glaucoma. Br J Ophthalmol 1996;80:499-502. 16. Rodrigues AM, J unior AP, Montezano FT, de Arruda Melo PA, Prata J Jr. Comparison between results of trabeculectomy in primary congenital glaucoma with and without the use of mitomycin C. J Glaucoma 2004;13:228-32. 17. Roche O, Beby F, Parsa A, Orssaud C, Dufier JL, Parsa CF. Nonpenetrating external trabeculectomy for congenital glaucoma: a retrospective study. Ophthalmology 2007;114:1994-9. 18. Mandal AK, Gothwal VK, Bagga H, Nutheti R, Mansoori T. Outcome of surgery on infants younger than 1 month with congenital glaucoma. Ophthalmology 2003;110:1909-15. 19. al Faran MF, Tomey KF, al Mutlaq FA. Cyclocryotherapy in selected cases of congenital glaucoma. Ophthalmic Surg 1990;21:794-8. 20. Phelan MJ, Higginbotham EJ. Contact transscleral Nd:YAG laser cyclophotocoagulation for the treatment of refractory pediatric glaucoma. Ophthalmic Surg Lasers 1995;26:401-3. 21. Coleman AL, Smyth RJ, Wilson MR, Tam M. Initial clinical experience with the Ahmed Glaucoma Valve implant in pediatric patients. Arch Ophthalmol 1997;115:186-91. 22. Englert JA, Freedman SF, Cox TA. The Ahmed valve in refractory pediatric glaucoma. Am J Ophthalmol 1999;127:34-42. 23. Munoz M, Tomey KF, Traverso C, Day SH, Senft SH. Clinical experience with the Molteno implant in advanced infantile glaucoma. J Pediatr Ophthalmol Strabismus 1991;28:68-72. 24. Rodrigues AM, Corpa MV, Mello PA, de Moura CR. Results of the Susanna implant in patients with refractory primary congenital glaucoma. J AAPOS 2004;8:576-9. 25. Gressel MG, Heuer DK, Parrish RK 2nd. Trabeculectomy in young patients. Ophthalmology 1984;91:1242-6. 26. Waheed S, Ritterband DC, Greenfield DS, Liebmann JM, Sidoti PA, Ritch R. Bleb-related ocular infection in children after trabeculectomy with mitomycin C. Ophthalmology 1997;104: 2117-20. 27. Bock CJ, Freedman SF, Buckley EG, Shields MB. Transscleral diode laser cyclophotocoagulation for refractory pediatric glaucomas. J Pediatr Ophthalmol Strabismus 1997;34:235-9. 28. Alvarado JA. Endocyclophotocoagulation for pediatric glaucoma: a tale of two cities. J AAPOS 2007;11:10-11. 29. Molteno ACB. Children with advanced glaucoma treated with drainig implants. S Afr Arch Ophthalmol 1973;1:55-61. 30. Ishida K, Mandal AK, Netland PA. Glaucoma drainage implants in pediatric patients. Ophthalmol Clin North Am 2005;18: 431-42. vii. 31. Netland PA, Walton DS. Glaucoma drainage implants in pediatric patients. Ophthalmic Surg 1993;24:723-9. 32. Eid TE, Katz LJ, Spaeth GL, Augsburger JJ. Long-term effects of tube-shunt procedures on management of refractory childhood glaucoma. Ophthalmology 1997;104:1011-16. 33. Fellenbaum PS, Sidoti PA, Heuer DK, Minckler DS, Baerveldt G, Lee PP. Experience with the baerveldt implant in young patients with complicated glaucomas. J Glaucoma 1995;4:91-7.
Journal of AAPOS
Volume 18 Number 6 / December 2014 34. Hill RA, Heuer DK, Baerveldt G, Minckler DS, Martone JF. Molteno implantation for glaucoma in young patients. Ophthalmology 1991; 98:1042-6. 35. O’Malley Schotthoefer E, Yanovitch TL, Freedman SF. Aqueous drainage device surgery in refractory pediatric glaucomas: I. Longterm outcomes. J AAPOS 2008;12:33-9. 36. 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. 37. Morad Y, Donaldson CE, Kim YM, Abdolell M, Levin AV. The Ahmed drainage implant in the treatment of pediatric glaucoma. Am J Ophthalmol 2003;135:821-9. 38. Imaizumi M, Takaki Y, Yamashita H. Phacoemulsification and intraocular lens implantation for acute angle closure not treated or previously treated by laser iridotomy. J Cataract Refract Surg 2006;32:85-90. 39. Chen TC, Bhatia LS, Walton DS. Ahmed valve surgery for refractory pediatric glaucoma: a report of 52 eyes. J Pediatr Ophthalmol Strabismus 2005;42:274-83. quiz 304–5. 40. Ou Y, Yu F, Law SK, Coleman AL, Caprioli J. Outcomes of Ahmed glaucoma valve implantation in children with primary congenital glaucoma. Arch Ophthalmol 2009;127:1436-41.
Razeghinejad, Kaffashan, and Nowroozzadeh
41. Almobarak F, Khan AO. Complications and 2-year valve survival following Ahmed valve implantation during the first 2 years of life. Br J Ophthalmol 2009;93:795-8. 42. 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. 43. Brasil MV, Rockwood EJ, Smith SD. Comparison of silicone and polypropylene Ahmed Glaucoma Valve implants. J Glaucoma 2007; 16:36-41. 44. 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. 45. Ayyala RS, Zurakowski D, Smith JA, et al. A clinical study of the Ahmed glaucoma valve implant in advanced glaucoma. Ophthalmology 1998;105:1968-76. 46. Nouri-Mahdavi K, Caprioli J. Evaluation of the hypertensive phase after insertion of the Ahmed Glaucoma Valve. Am J Ophthalmol 2003;136:1001-8. 47. Sood S, Beck AD. Cyclophotocoagulation versus sequential tube shunt as a secondary intervention following primary tube shunt failure in pediatric glaucoma. J AAPOS 2009;13:379-83.
An Eye on the Arts—the Arts on the Eye
In late August Brother Wren got permission to visit Singing Cow in the guesthouse, and Aedrea Sister Clare-of-Assisi became aware that Brother Cook had a cancer eating his throat. His voice had diminished to a hoarse whisper. He called his cancer Brother Crab, and joked about it. Aedrea came up behind him as he sat and talked with his old friend, Moo. He started up as she touched him, but then settled back in his chair with a smile and let her hands explore his throat. He started again when she pressed down hard with her fingertips below his Adam’s apple. “Relax, Brother. Does it hurt?” “Not much,” Wren whispered. “What have you done? Something popped.” She continued caressing his throat for a while, then left him and went to her cell. Father Moo crossed himself. Brother Wren noticed and followed suit. “Better not tell anyone,” Singing Cow said. Within three days, Wren began to get his voice back. Word got around. Within a week, Sister Clare had healed infected blisters, a hernia, an abscessed tooth, and a probable case of gonorrhea of the eye. All of this might have been passed unnoticed, but when she cured the old librarian, Brother Obohl, of his myopia and he got a look at the beautiful woman who had laid hands on his eyes, his squawk of astonishment was followed by the joyful noise of his thanksgiving, and this fell upon the ears of Dom Abiquiu. —Walter M. Miller Jr, Saint Leibowitz and the Wild Horse Woman (Random House, 2000), 368. Contributed by Alex V. Levin, MD, MHSc, Philadelphia, Pennsylvania
Journal of AAPOS
595
RESULTS
CONCLUSIONS
To evaluate the outcome of Ahmed glaucoma valve (AGV) implantation in primary congenital glaucoma (PCG). The medical records of patients with PCG refractory to trabeculotomy and medical therapy who had undergone AGV implantation with a minimum follow-up of 6 months were retrospectively reviewed. The primary outcome measure was cumulative probability of success, defined as intraocular pressure (IOP) of 6–21 mm Hg, with or without medication, and no serious complications, additional glaucoma surgery, or loss of light perception. A total of 33 eyes of 22 children with a mean age (and standard deviation) of 2.7 3.1 years were included. The patients had a mean follow-up time of 32.6 18.3 months. The mean IOP was 32.8 7.3 mm Hg preoperatively and 16.8 4.0 mm Hg postoperatively. The number of glaucoma medications was 2.5 0.7 preoperatively and 2.2 0.7 postoperatively. The cumulative probability of success (and standard error) was 97% 3.0% in the 1st year, 85% 7.0% in the 2nd year, and 56% 14.8% in the 5th year. When only the first operated eye per patient was included, the cumulative probability of success was 96% 4.4% in the 1st and the 2nd years and 72% 15.3% in the 5th year. Major complications comprised tube–endothelial touch (3 eyes), cataract (2 eyes), shunt extrusion (1 eye), and retinal detachment (1 eye). AGV implantation in patients with PCG offers moderate success in controlling the IOP with a low rate of complications. Most continued to require medications. ( J AAPOS 2014;18:590-595)
P
rimary congenital glaucoma (PCG), the most common type of glaucoma in infancy,1 is a potentially blinding disorder. Surgical management is the mainstay of treatment in PCG,2,3 and medical therapy is often used adjunctively to control intraocular pressure (IOP).4-8 Angle surgeries such as goniotomy or trabeculotomy are the initial procedures of choice.9,10 Although these procedures have a success rate of 75%-90% in Western countries,9,11 in Middle Eastern and South Asian countries, with a higher incidence of CYP1B1-related PCG,12 the reported success rate ranges from 54% to 69%.13,14 Children with uncontrolled IOP after angle surgeries require additional measures to achieve an adequate control of IOP. The surgical options in this group of patients include trabeculectomy,15,16 nonpenetrating glaucoma surgery,17 Author affiliations: Poostchi Ophthalmology Research Center, Department of Ophthalmology, Shiraz University of Medical Sciences, Shiraz, Iran This study was funded and supported by Shiraz University of Medical Sciences (Grant 90-01-01-2769). This paper was derived from a thesis for a Medical Degree. Submitted May 4, 2014. Revision accepted August 31, 2014. Published online November 12, 2014. Correspondence: Mohammad H. Nowroozzadeh, MD, Department of Ophthalmology, Poostchi Ophthalmology Research Center, Poostchi Clinic, Zand Street, Shiraz, Iran (email: [email protected]). Copyright Ó 2014 by the American Association for Pediatric Ophthalmology and Strabismus. 1091-8531/$36.00 http://dx.doi.org/10.1016/j.jaapos.2014.08.008
590
combined trabeculotomy and trabeculectomy,18 cycloablative therapy,19,20 and glaucoma drainage devices.21-24 Trabeculectomy in a buphthalmic eye is technically challenging and is frequently unsuccessful.25 Adjunctive antifibrotics, such as mitomycin C and 5-fluorouracil, may improve the success rate, but long-term complications include bleb failure, bleb leak, and infection.1,26 Cycloablative laser therapy (either transscleral or endoscopic) has a limited success rate, a high risk of complications, and frequently necessitates retreatment in children19,20,27,28; therefore, it is usually reserved for eyes unresponsive to other interventions. The use of glaucoma drainage devices in children was first described in 1973 by Molteno,29 with a reported success rate of 67% using single-plate Molteno implants. Since then, glaucoma drainage devices have been used to treat refractory pediatric glaucoma, particularly when trabeculectomy fails or is known to have a high risk of failure (ie, significant conjunctival scarring).30,31 Several studies have evaluated different types of glaucoma drainage devices in pediatric glaucoma.21,22,32-35 The reported success rates for the Ahmed glaucoma valve (AGV) in children ranges from 58% to 93% in achieving IOPs of \21 mm Hg. The majority of these reports comprised children with a variety of pediatric glaucoma diagnoses, including primary or secondary causes.21,22,36,37 The success rate and potential complications of the AGV in the PCG are still debated.
Journal of AAPOS
Volume 18 Number 6 / December 2014 The purpose of the present study was to describe the outcome of AGV implantation in a racially homogenous group of PCG patients with uncontrolled IOP using topical medications and having undergone prior trabeculotomy. In contrast to most previous reports, the present study included only PCG patients.
Subjects and Methods This study was approved by the Ethics Committee of Shiraz University of Medical Sciences. Children with PCG who had undergone AGV implantation from March 2005 through March 2013 at a tertiary eye-care center affiliated with the Shiraz University of Medical Sciences were retrospectively reviewed. Inclusion criteria were uncontrolled IOP (.21 mm Hg) despite maximal medical therapy ($3 topical antiglaucoma medications), history of previous trabeculotomy at two sites (superonasal and inferotemporal quadrants), and a minimum of 6 months’ follow-up after AGV implantation. Children with previous ocular surgeries other than trabeculotomy, \6 months’ follow-up, and secondary diagnoses such as aphakia or pseudophakia, Sturge-Weber syndrome, uveitic glaucoma, aniridia, and anterior segment dysgenesis were excluded. All surgeries and also follow-up examinations were performed by a single glaucoma surgeon (MRR). Because of poor visualization secondary to severe corneal edema in almost all cases, trabeculotomy was the preferred primary intervention. Preoperative data included age at time of surgery, sex, laterality, IOP prior to AGV implantation, number of antiglaucoma medications (1 point was assigned for each topical antiglaucoma medication and 2 points were assigned for oral acetazolamide),38 cup:disk ratio, and corneal diameter. The following postoperative data was collected at 1 month and 6 months and at 6-month intervals thereafter through 60 months: type of AGV, IOP measurements, number of antiglaucoma medications, crystalline lens status, intra- and postoperative complications, additional surgical procedures after shunt implantation. IOPs were measured by applanation tonometry (Tonopen-XL; Mentor, Norwell, MA). The primary outcome was postoperative success, defined as IOP of 6–21 mm Hg, with a maximum of 3 antiglaucoma medications. Failure included IOP .21 mm Hg on 2 consecutive visits, loss of light perception, need for additional glaucoma surgery (except tube repositioning, scleral patch graft reinforcement for tube exposure, or bleb needling with 5-fluorouracil injection), and serious complications, such as retinal detachment, endophthalmitis, suprachoroidal hemorrhage, aqueous misdirection, or phthisis.
Razeghinejad, Kaffashan, and Nowroozzadeh
591
fixed to the sclera using a 10-0 nylon suture. A piece of donor sclera was manually trimmed and sutured over the tube using two 8-0 polyglactin 910 sutures. The conjunctiva was reposed and sutured using 8-0 polyglactin 910 sutures. A subconjunctival injection of betamethasone was given at the conclusion of surgery. Postoperatively, topical antibiotic (chloramphenicol) and steroid (betamethasone) eyedrops were prescribed and tapered over an 8-week period.
Statistical Analysis All statistical analyses were performed using SPSS version 19.0 for Windows (SPSS Inc, Chicago, IL). Kaplan-Meier survival analyses were used to assess the success rates of AGV implantation at postoperative visits. Cox proportional hazards regression analysis was used to determine the predictive factors for failure. The mean value of continuous variables are reported with standard deviations; standard errors were used to estimate success rates. A P value of \0.05 was considered statistically significant. Because of the rarity of the disorder, the eye (n 5 33) was regarded as the unit of analysis. To evaluate the consistence of findings, repeat Kaplan-Meier survival analysis was also performed with 1 eye per patient (n 5 22), using the first eye that underwent AGV implantation.
Results Data of 33 eyes of 22 patients (17 males) were compiled and analyzed. The AGV models used were the S2 (n 5 2), S3 (n5 6), FP7 (n 5 23), and FP8 (n 5 2). Eleven patients (8 males) underwent bilateral AGV implantation. The mean age at AGV implantation was 2.7 3.1 years (median, 1.0; range, 0.1-11 years). The mean interval between trabeculotomy and AGV implantation was 21.3 31.5 months (median, 6; range, 1-132 months). The mean follow-up period was 32.6 18.3 months (median, 24.0; range, 6-60 months).
Surgical Technique
Changes in IOP The mean IOP was 32.8 7.3 mm Hg before AGV implantation and 16.8 4.0 mm Hg at final last follow-up (P \ 0.001; repeated measures ANOVA, Bonferroni post hoc test). The mean decrease in IOP at the final followup compared to preoperative IOPs were 16.5 8.5 mm Hg. Of 33 eyes, 23 (70%) showed a transient early postoperative hypertensive phase at the first postoperative month that was controlled by antiglaucoma medications. Of these eyes, 18 had a successful outcome and 5 ended in failure. Alterations in the pre- and postoperative mean IOPs and number of eyes lost to follow-up are provided in Figure 1.
After applying a corneal traction suture using a 7-0 silk suture, a fornix- based conjunctival peritomy was created in the superotemporal quadrant. The AGV was primed using 1 ml of balanced salt solution and secured to the sclera, with its anterior edge 8–10 mm posterior to the limbus using two 7-0 silk sutures. A 23-gauge needle was then used to enter the anterior chamber at the surgical limbus, pointing toward the center of the pupil. The tube was trimmed bevel-up and inserted through the opening after forming the anterior chamber with a viscoelastic material. The tube was
Antiglaucoma Medications The mean number of antiglaucoma medications was 2.5 0.7 (median, 2; range, 1-5) before AGV implantation and 2.2 0.7 (median, 2; range, 0-3; P 5 0.08, paired t test) at the last follow-up examination. Preoperatively, 15 (46%) eyes were treated with 3 or more antiglaucoma medications, compared to 11 (33%) eyes at the last follow-up. Only one eye (with 36 months of follow-up) required no
Journal of AAPOS
592
Razeghinejad, Kaffashan, and Nowroozzadeh
Volume 18 Number 6 / December 2014
FIG 1. Changes in intraocular pressure. Mean intraocular pressure (IOP) profile before surgery (pre-op) and during follow-up visits in eyes with primary congenital glaucoma (PCG) that underwent Ahmed glaucoma valve (AGV) implantation.
FIG 3. Survival analysis. Kaplan-Meier cumulative probability curve of success in eyes with PCG that underwent AGV implantation. A, Survival analysis of all eyes with PCG (n 5 33). B, Survival analysis of one eye per PCG patient (n 5 22).
FIG 2. Changes in number of medications. Mean number of antiglaucoma medications used preoperatively and during follow-up visits in eyes with PCG that underwent AGV implantation.
medication for controlling IOP. Figure 2 shows the changes in mean number of antiglaucoma medications pre- and postoperatively. Surgical Success and Risk Factors for Failure AGV implantation failed in 7 (21%) eyes; the mean time to failure was 29.1 15.7 months (median, 24.0; range, 6-48). The operation was successful in 26 (79%) eyes; the mean follow-up time for eyes with successful surgery was 29.3 17.0 months (median, 24.0; range, 6-60). Of 11 patients who underwent bilateral surgery, 7 (64%) had success in both eyes, 3 (27%) had success in one eye, and 1 (9%)
had failure in both eyes. According to Kaplan-Meier survival analysis, the success rate of AGV implantation in PCG eyes (n 5 33) was 97.0% 3.0% at the 6th month, 97.0% 3.0% at the 1st year, 84.8% 7.0% at the 2nd year, and 56.3% 14.8% at the 5th year after surgery (Figure 3A). There was no significant difference for survival when one eye of each participant was used for statistical analysis, with 96% 4.4% in the 1st and the 2nd years, and 72% 15.3% in the 5th year (Figure 3B). Causes of failure are presented in Table 1. Risk factors for surgical failure after AGV implantation in refractory PCG, comparison between success and failure groups, and results from univariate Cox proportional hazards regression models are presented in e-Supplement 1 (available at jaapos.org). The observed associations of all potential risk factors were not statistically significant. Significant complications were observed in 8 eyes (24%), of which 3 (38%) ended in failure (Table 2). No patient developed isolated hypotony or loss of light perception after the first AGV implantation.
Journal of AAPOS
Volume 18 Number 6 / December 2014
Razeghinejad, Kaffashan, and Nowroozzadeh
593
Table 1. Causes to failure, characteristics, and additional procedures for eyes with failed Ahmed glaucoma valve implantation Eye 1 2 3 4 5 6 7
Cause of failure
Time to failure, months
IOP, mm Hg
Number of medicationsa
Additional intervention
Uncontrolled IOP Uncontrolled IOP Uncontrolled IOP Uncontrolled IOP Uncontrolled IOP Uncontrolled IOP Retinal detachment
36 48 48 6 18 24 24
27 26 28 28 25 34 20
3 3 3 1 3 2 3
1. Tube revision; 2. TSCPCb TSCPCc TSCPCc TSCPCc Second AGV placementd 1. Tube revision; 2. Explantatione None
AGV, Ahmed glaucoma valve; IOP, intraocular pressure; TSCPC, transscleral cyclophotocoagulation. a At the time of failure. b IOP eventually controlled (18 mm Hg) with 3 medications. c IOP could not be controlled despite maximal medical therapy. d IOP eventually controlled (16 mm Hg) with 2 medications. e IOP at final follow-up was 18 mm Hg on 3 topical medications.
Table 2. Complications after Ahmed glaucoma valve implantation in patients with primary congenital glaucoma Eyea 1
Complication
7 8
Tube-endothelial touch 1. Tube–endothelial touch; 2. Shunt extrusion Retinal detachment Cataract
9
Cataract
10 11
Tube–endothelial touch Bleb encapsulation
12
Bleb encapsulation
6
Intervention
Final outcome
Tube revision
Failure
1. Tube revision; 2. Explantation
Failure
None (lost eye)b Lensectomy and anterior vitrectomy Lensectomy and anterior vitrectomy Tube revision
Failure Success
Bleb needling and 5-FU injection Bleb needling and 5-FU injection
Success Success Success Success
5-FU, 5-fluorouracil. a Eyes 1, 6, and 7 are the same as indicated in Table 2. b According to retina specialist because of severe glaucomatous optic nerve damage no intervention was taken.
Discussion In this study the cumulative probability of success with a single AGV implant in patients with PCG was 97.0% at 1 year, which decreased to 56.3% at 5 years. Tube–endothelial touch was the most frequently encountered complication, followed by bleb encapsulation and cataract. Many studies have reported promising results in using tubes to treat pediatric glaucoma. However, because of remarkable variations in the types of devices implanted, populations studied (including ethnicity and enrollment criteria), criteria of success, and length of follow-up, direct comparison of surgical success rates is difficult. The reported shorter survival rate of AGV implantation in PCG versus other types of pediatric glaucoma is still debated.9,21 Chen and colleauges39 found a lower success rate with AGV implantation in PCG (45% [n 5 20]) compared with aphakic glaucoma (68.4% [n 5 19]). Djodeyre and colleagues36 found a lower mean survival rate for AGV
Journal of AAPOS
implantation in PCG (13.9 months [n 5 17]) compared to other diagnoses, such as Sturge-Weber syndrome, postoperative glaucoma, and so forth (35.6 months [n 5 18]). However, other studies did not report an association between surgical failure rate and glaucoma type in children.6,9,24,35 Considering only the first operated eyes (n 5 22), our 5-year success rate of 72% is comparable to the 70% result reported by O’Malley Schotthoefer and colleagues.35 Ou and colleagues40 reported the outcomes of AGV implantation in 30 eyes of 19 children with PCG. The reported cumulative probability of success with a single AGV implant was 63% at 1 year and 33% at 5 years, considerably less than our report. In their study, Hispanic ethnicity (RR 5 3.67; P 5 0.02) and female sex (RR 5 5.56; P 5 0.005) were associated with increased risk of failure. In their study of 42 eyes (28 with PCG), Almobarak and Khan41 reported that cumulative valve survival 2 years following implantation was 63.3%, less than our 85%. However, their cohort included cases other than PCG that may have had worse outcomes. Moreover, they limited their study to children #2 years of age, a population that probably has a lower success rate and higher complication rate. The most common postoperative complication in Almobarak and Khan41 was tube malpositioning (26.2%). Another study by Khan and Almobarak42 found no difference in terms of success and outcome between the two models of Ahmed valve (S2, S3). Brasil and colleagues43 compared silicone and polypropylene Ahmed valves and concluded that both valves have similar results with respect to effectiveness in controlling IOP and complication rate. We found no statistically significant difference in survival between silicone and polypropylene implants (P 5 0.27; log-rank test); however, the small sample size of the polypropylene group (n 5 8) limits the validity of these results. Previous studies were inconclusive regarding the relative superiority of specific AGV models in terms of IOP control or complications.42-44 Future studies are warranted to shed light on this issue. Postoperative hypotony is less likely with the AGV,39 whereas the risk of an early transient hypertensive phase
594
Razeghinejad, Kaffashan, and Nowroozzadeh
is greater. The incidence of a hypertensive phase after AGV implantation in adults ranges between 56 to 82%.29,45,46 Chen and colleagues39 reported a 25% risk of hypertensive phase after AGV implantation in pediatric glaucoma, less than that reported in adults. However, the current study found the risk of a hypertensive phase to be 70%. Chen and colleagues39 found that the presence of a hypertensive phase was associated with a lower success rate, whereas we found no significant association. In accordance with our results, Ou and colleagues40 reported that uncontrolled IOP (including those who required a second AGV implantation) was the primary cause of failure, and the most common complications were tube-related problems such as tube–endothelial touch and tube exposure. In the current study, the mostly performed glaucoma procedure after AGV failure was transscleral cyclophotocoagulation (TSCPC). The procedure was successful in only 1 patient (25%) in controlling IOP. A previous study reported similar rates of success and complications with TSCPC and sequential tube shunt following primary tube shunt failure in childhood glaucoma.47 Overall, the decision for the type of additional procedure in a failed shunt should be tailored to the individual and based on visual prognosis, ocular anatomy, and type of previous surgeries. This study is limited by its retrospective nature. In addition, the young age of study participants precluded acquisition of quantitative measurement of visual acuity outcomes. The study’s strengths include the uniformity in PCG population and AGV implantation and a relatively large number of eyes, considering the rarity of condition.
Acknowledgments The authors thank Narges Rousta, MSc, for her help with statistical analysis of the data. References 1. Taylor RH, Ainsworth JR, Evans AR, Levin AV. The epidemiology of pediatric glaucoma: the Toronto experience. J AAPOS 1999;3: 308-15. 2. Beck AD. Diagnosis and management of pediatric glaucoma. Ophthalmol Clin North Am 2001;14:501-12. 3. Turach ME, Aktan G, Idil A. Medical and surgical aspects of congenital glaucoma. Acta Ophthalmol Scand 1995;73:261-3. 4. Enyedi LB, Freedman SF. Latanoprost for the treatment of pediatric glaucoma. Surv Ophthalmol 2002;47(Suppl 1):S129-32. 5. Maris PJ Jr, Mandal AK, Netland PA. Medical therapy of pediatric glaucoma and glaucoma in pregnancy. Ophthalmol Clin North Am 2005;18:461-8. vii. 6. Portellos M, Buckley EG, Freedman SF. Topical versus oral carbonic anhydrase inhibitor therapy for pediatric glaucoma. J AAPOS 1998;2: 43-7. 7. Sabri K, Levin AV. The additive effect of topical dorzolamide and systemic acetazolamide in pediatric glaucoma. J AAPOS 2006;10: 464-8. 8. Zimmerman TJ, Kooner KS, Morgan KS. Safety and efficacy of timolol in pediatric glaucoma. Surv Ophthalmol 1983;(28 Suppl): 262-4.
Volume 18 Number 6 / December 2014 9. Anderson DR. Trabeculotomy compared to goniotomy for glaucoma in children. Ophthalmology 1983;90:805-6. 10. Shaffer RN. Prognosis of goniotomy in primary infantile glaucoma (trabeculodysgenesis). Trans Am Ophthalmol Soc 1982;80:321-5. 11. McPherson SD Jr, Berry DP. Goniotomy vs external trabeculotomy for developmental glaucoma. Am J Ophthalmol 1983;95:427-31. 12. Khan AO. Genetics of primary glaucoma. Curr Opin Ophthalmol 2011;22:347-55. 13. Elder MJ. Congenital glaucoma in the West Bank and Gaza Strip. Br J Ophthalmol 1993;77:413-16. 14. Debnath SC, Teichmann KD, Salamah K. Trabeculectomy versus trabeculotomy in congenital glaucoma. Br J Ophthalmol 1989;73: 608-11. 15. Fulcher T, Chan J, Lanigan B, Bowell R, O’Keefe M. Long-term follow up of primary trabeculectomy for infantile glaucoma. Br J Ophthalmol 1996;80:499-502. 16. Rodrigues AM, J unior AP, Montezano FT, de Arruda Melo PA, Prata J Jr. Comparison between results of trabeculectomy in primary congenital glaucoma with and without the use of mitomycin C. J Glaucoma 2004;13:228-32. 17. Roche O, Beby F, Parsa A, Orssaud C, Dufier JL, Parsa CF. Nonpenetrating external trabeculectomy for congenital glaucoma: a retrospective study. Ophthalmology 2007;114:1994-9. 18. Mandal AK, Gothwal VK, Bagga H, Nutheti R, Mansoori T. Outcome of surgery on infants younger than 1 month with congenital glaucoma. Ophthalmology 2003;110:1909-15. 19. al Faran MF, Tomey KF, al Mutlaq FA. Cyclocryotherapy in selected cases of congenital glaucoma. Ophthalmic Surg 1990;21:794-8. 20. Phelan MJ, Higginbotham EJ. Contact transscleral Nd:YAG laser cyclophotocoagulation for the treatment of refractory pediatric glaucoma. Ophthalmic Surg Lasers 1995;26:401-3. 21. Coleman AL, Smyth RJ, Wilson MR, Tam M. Initial clinical experience with the Ahmed Glaucoma Valve implant in pediatric patients. Arch Ophthalmol 1997;115:186-91. 22. Englert JA, Freedman SF, Cox TA. The Ahmed valve in refractory pediatric glaucoma. Am J Ophthalmol 1999;127:34-42. 23. Munoz M, Tomey KF, Traverso C, Day SH, Senft SH. Clinical experience with the Molteno implant in advanced infantile glaucoma. J Pediatr Ophthalmol Strabismus 1991;28:68-72. 24. Rodrigues AM, Corpa MV, Mello PA, de Moura CR. Results of the Susanna implant in patients with refractory primary congenital glaucoma. J AAPOS 2004;8:576-9. 25. Gressel MG, Heuer DK, Parrish RK 2nd. Trabeculectomy in young patients. Ophthalmology 1984;91:1242-6. 26. Waheed S, Ritterband DC, Greenfield DS, Liebmann JM, Sidoti PA, Ritch R. Bleb-related ocular infection in children after trabeculectomy with mitomycin C. Ophthalmology 1997;104: 2117-20. 27. Bock CJ, Freedman SF, Buckley EG, Shields MB. Transscleral diode laser cyclophotocoagulation for refractory pediatric glaucomas. J Pediatr Ophthalmol Strabismus 1997;34:235-9. 28. Alvarado JA. Endocyclophotocoagulation for pediatric glaucoma: a tale of two cities. J AAPOS 2007;11:10-11. 29. Molteno ACB. Children with advanced glaucoma treated with drainig implants. S Afr Arch Ophthalmol 1973;1:55-61. 30. Ishida K, Mandal AK, Netland PA. Glaucoma drainage implants in pediatric patients. Ophthalmol Clin North Am 2005;18: 431-42. vii. 31. Netland PA, Walton DS. Glaucoma drainage implants in pediatric patients. Ophthalmic Surg 1993;24:723-9. 32. Eid TE, Katz LJ, Spaeth GL, Augsburger JJ. Long-term effects of tube-shunt procedures on management of refractory childhood glaucoma. Ophthalmology 1997;104:1011-16. 33. Fellenbaum PS, Sidoti PA, Heuer DK, Minckler DS, Baerveldt G, Lee PP. Experience with the baerveldt implant in young patients with complicated glaucomas. J Glaucoma 1995;4:91-7.
Journal of AAPOS
Volume 18 Number 6 / December 2014 34. Hill RA, Heuer DK, Baerveldt G, Minckler DS, Martone JF. Molteno implantation for glaucoma in young patients. Ophthalmology 1991; 98:1042-6. 35. O’Malley Schotthoefer E, Yanovitch TL, Freedman SF. Aqueous drainage device surgery in refractory pediatric glaucomas: I. Longterm outcomes. J AAPOS 2008;12:33-9. 36. 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. 37. Morad Y, Donaldson CE, Kim YM, Abdolell M, Levin AV. The Ahmed drainage implant in the treatment of pediatric glaucoma. Am J Ophthalmol 2003;135:821-9. 38. Imaizumi M, Takaki Y, Yamashita H. Phacoemulsification and intraocular lens implantation for acute angle closure not treated or previously treated by laser iridotomy. J Cataract Refract Surg 2006;32:85-90. 39. Chen TC, Bhatia LS, Walton DS. Ahmed valve surgery for refractory pediatric glaucoma: a report of 52 eyes. J Pediatr Ophthalmol Strabismus 2005;42:274-83. quiz 304–5. 40. Ou Y, Yu F, Law SK, Coleman AL, Caprioli J. Outcomes of Ahmed glaucoma valve implantation in children with primary congenital glaucoma. Arch Ophthalmol 2009;127:1436-41.
Razeghinejad, Kaffashan, and Nowroozzadeh
41. Almobarak F, Khan AO. Complications and 2-year valve survival following Ahmed valve implantation during the first 2 years of life. Br J Ophthalmol 2009;93:795-8. 42. 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. 43. Brasil MV, Rockwood EJ, Smith SD. Comparison of silicone and polypropylene Ahmed Glaucoma Valve implants. J Glaucoma 2007; 16:36-41. 44. 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. 45. Ayyala RS, Zurakowski D, Smith JA, et al. A clinical study of the Ahmed glaucoma valve implant in advanced glaucoma. Ophthalmology 1998;105:1968-76. 46. Nouri-Mahdavi K, Caprioli J. Evaluation of the hypertensive phase after insertion of the Ahmed Glaucoma Valve. Am J Ophthalmol 2003;136:1001-8. 47. Sood S, Beck AD. Cyclophotocoagulation versus sequential tube shunt as a secondary intervention following primary tube shunt failure in pediatric glaucoma. J AAPOS 2009;13:379-83.
An Eye on the Arts—the Arts on the Eye
In late August Brother Wren got permission to visit Singing Cow in the guesthouse, and Aedrea Sister Clare-of-Assisi became aware that Brother Cook had a cancer eating his throat. His voice had diminished to a hoarse whisper. He called his cancer Brother Crab, and joked about it. Aedrea came up behind him as he sat and talked with his old friend, Moo. He started up as she touched him, but then settled back in his chair with a smile and let her hands explore his throat. He started again when she pressed down hard with her fingertips below his Adam’s apple. “Relax, Brother. Does it hurt?” “Not much,” Wren whispered. “What have you done? Something popped.” She continued caressing his throat for a while, then left him and went to her cell. Father Moo crossed himself. Brother Wren noticed and followed suit. “Better not tell anyone,” Singing Cow said. Within three days, Wren began to get his voice back. Word got around. Within a week, Sister Clare had healed infected blisters, a hernia, an abscessed tooth, and a probable case of gonorrhea of the eye. All of this might have been passed unnoticed, but when she cured the old librarian, Brother Obohl, of his myopia and he got a look at the beautiful woman who had laid hands on his eyes, his squawk of astonishment was followed by the joyful noise of his thanksgiving, and this fell upon the ears of Dom Abiquiu. —Walter M. Miller Jr, Saint Leibowitz and the Wild Horse Woman (Random House, 2000), 368. Contributed by Alex V. Levin, MD, MHSc, Philadelphia, Pennsylvania
Journal of AAPOS
595
