title: Comparison of FP-7 and S-2 Ahmed glaucoma valve implantation in refractory glaucoma patients for short-term follow-up.
abstract: BACKGROUND
  Ahmed glaucoma valves (AGV) has been used for decades, but there is no detailed report about the efficacy of AGV in Chinese glaucoma patients. This study aimed to compare the intraocular pressure (IOP) lowering efficacy and side effects of S-2 polypropylene and PF-7 silicone AGV implantation in Chinese refractory glaucoma patients.
  
  
  METHODS
  Patients were divided into S-2 model AGV group and FP-7 model AGV group. The complete and qualified surgical success rate, change of IOP, number of anti-glaucoma medications used and postoperative complications were recorded and analyzed.
  
  
  RESULTS
  Average follow-up time was comparable between two groups. IOP was reduced from (37.9 ± 12.7) mmHg preoperatively to (17.3 ± 5.3) mmHg at the last follow-up in S-2 group and reduced from (39.9 ± 14.4) mmHg to (17.7 ± 4.9) mmHg in FP-7 group. Anti-glaucoma medications were reduced from 3.8 ± 0.2 to 1.5 ± 0.2 in S-2 group, and 3.5 ± 0.2 to 0.7 ± 0.2 in FP-7 groups. The cumulative success rates were comparable in two groups, which were 61.2% and 72.1% in S-2 group and FP-7 group respectively. When IOP reduction criteria was used, complete success rates were 30.6% and 51.2% for S-2 and FP-7 groups, and qualified success rates were 86.1% and 92.7% separately. In both groups, the major complication was hypotony, and the previous trabeculectomy of patients was the major risk factor for surgery failure.
  
  
  CONCLUSIONS
  In this short-term retrospective study, S-2 AGV is showed at least as effective as FP-7 AGV in IOP reduction, but associated with higher rate of complications. Previous trabeculectomy is a principle risk factor for AGV implantation failure. These clinical outcomes are important for converting use of the FP-7 silicon AGV in Chinese refractory glaucoma patients.
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, China.
authors.forename: Yu-jing
authors.initials: YJ
authors.lastname: Bai
authors.forename: Yi-qing
authors.initials: YQ
authors.lastname: Li
authors.forename: Fang
authors.initials: F
authors.lastname: Chai
authors.forename: Xue-jiao
authors.initials: XJ
authors.lastname: Yang
authors.forename: Yi-chong
authors.initials: YC
authors.lastname: Zhang
authors.forename: Yan-tao
authors.initials: YT
authors.lastname: Wei
authors.forename: Jing-jing
authors.initials: JJ
authors.lastname: Huang
authors.forename: Jian
authors.initials: J
authors.lastname: Ge
authors.forename: Ye-hong
authors.initials: YH
authors.lastname: Zhuo
mesh_terms: D000328:Adult; D005260:Female; D005901:Glaucoma / Q000503:physiopathology / Q000628:therapy*; D020327:Glaucoma Drainage Implants; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D008297:Male; D012189:Retrospective Studies