Decapsulation versus valve reimplantation in cases with an encysted Ahmed valve in refractory glaucoma

• Main Author: Salah M Al-Mosallamy
• Format: Article
• Language: English
• Published: Wolters Kluwer Medknow Publications 2015-01-01
• Series: Delta Journal of Ophthalmology
• Subjects: ahmed glaucoma valve; decapsulation; refractory glaucoma
• Online Access: http://www.djo.eg.net/article.asp?issn=1110-9173;year=2015;volume=16;issue=1;spage=22;epage=26;aulast=Al-Mosallamy
• ISSN: 1110-9173; 2090-4835

Purpose The aim of the study was to evaluate the efficacy and safety of decapsulation of the fibrous capsule around the valve body versus valve reimplantation in another site in refractory glaucoma cases. Patients and methods We studied 25 cases with refractory glaucoma that had been implanted with an Ahmed glaucoma valve; their intraocular pressure (IOP) was greater than 21 mmHg and had undergone additional maximum topical antiglaucoma therapy. Patients were divided into two groups according to the surgical treatment that had been performed: group I included 12 eyes that had been treated by surgical decapsulation of the cyst around the valve body without removal of the valve and group II included 13 eyes treated by removal of the valve and reimplantation in another quadrant of the eye. Results Of the 25 patients included in the study, 15 were male and 10 were female, with a mean age of 19.2 ± 9.2 years in group I and 22.1 ± 10.3 years in group II. Recurrent congenital glaucoma was the most common preoperative diagnosis in both groups (50 and 53.8% in groups I and II, respectively). There was no statistically significant difference between the two groups regarding preoperative patient demographic characteristics (P < 0.05). The surgical results revealed that the mean operation time was significantly lower in group I than in group II (30 ± 12 and 45 ± 13.5 min, respectively; P = 0.023). However, there were no statistically significant differences in the success (complete and partial) and failure rates between the two groups (P < 0.05). There was marked reduction in IOP from preoperative values in both groups but there were no significant differences in IOP levels between the two groups over the follow-up visits. Tube-related complications occurred in group II only and included corneal tube touch in one (7.7%) case and erosion of the tube covering in two (15.4%) cases. One of them developed endophthalmitis and then lost the perception of light (PL) and ended in phthisis bulbi. Recurrence of encapsulation occurred more in group I (three cases, 25%) than in group II (two cases, 15.4%), after a mean postoperative time of 23 ± 2 weeks. The incidence of valve re-encapsulation was statistically insignificant between the two groups (P = 0.09). Conclusion Both surgical techniques were effective in controlling IOP in cases with encapsulated Ahmed valve; however, the decapsulation technique was simpler with shorter operation time and no probability for tube-related complications. Although the other technique of valve reimplantation had a longer operation time and more tube-related complications, it was associated with less incidence of re-encapsulation. However, larger multicenter studies with longer follow-up are needed for validation of these treatment strategies.