title: Bleb failure and intraocular pressure rise following Nd: Yag laser capsulotomy.
abstract: BACKGROUND
  To report the negative effect of Nd: Yag (Neodymium-doped: Yttrium Aluminium Garnet) laser capsulotomy on the intraocular pressure (IOP) and the trabeculectomy bleb integrity, in a small series of eyes, both trabeculectomised and pseudophakic, following the laser application for the management of posterior capsular opacification (PCO).
  
  
  METHODS
  This is a retrospective, non-comparative interventional case series study, in which 20 trabeculectomised and pseudophakic eyes from 15 patients, with otherwise well functioning blebs, were presented with uncontrolled IOP, in a variable distance of time following the application of YAG laser capsulotomy. Student paired t-test confirmed a statistically significant difference (P < 0.05) between IOP before Nd: YAG laser capsulotomy (16 mmHg ± 3 mmHg) and the respective one, 2 to 6 months after Nd: Yag capsulotomy (34.5 ± 11 mmHg).
  
  
  RESULTS
  All of the cases failed to respond to conservative treatment and were successfully managed with the implantation of Ahmed drainage devices. All patients showed flat filtering bleb and uncontrolled IOP (34.5 ± 11 mmHg), under maximum topical treatment, in a period of 2 to 6 months following Nd: YAG laser caspulotomy. The implantation of Ahmed valve proved to be effective treatment for these patients (IOP < 21 mmHg).
  
  
  CONCLUSIONS
  Although Nd: Yag laser capsulotomy is considered a safe surgical procedure and usually is done without second thought, in this series of eyes, it is postulated that it may be responsible for the deregulation of the filtering bleb and subsequent loss of IOP control. We consider that laser capsulotomy should be performed with caution, especially in eyes with previous trabeculectomy. Also close monitoring of the intraocular pressure and assessment of eventual bleb morphology variations in the follow-up period is mandatory. Further studies are needed in order to confirm our findings.
authors.affiliation: Athens A' University Eye Clinic, "Georgios Gennimatas" General Hospital, Athens, Greece. andreasdi@hotmail.com.
authors.forename: Andreas
authors.identifier: http://orcid.org/0000-0001-7548-0449
authors.initials: A
authors.lastname: Diagourtas
authors.affiliation: Athens A' University Eye Clinic, "Georgios Gennimatas" General Hospital, Athens, Greece.
authors.forename: Petros
authors.initials: P
authors.lastname: Petrou
authors.affiliation: Athens A' University Eye Clinic, "Georgios Gennimatas" General Hospital, Athens, Greece.
authors.forename: Ilias
authors.initials: I
authors.lastname: Georgalas
authors.affiliation: Athens A' University Eye Clinic, "Georgios Gennimatas" General Hospital, Athens, Greece.
authors.forename: Kostantinos
authors.initials: K
authors.lastname: Oikonomakis
authors.affiliation: Athens A' University Eye Clinic, "Georgios Gennimatas" General Hospital, Athens, Greece.
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Giannakouras
authors.affiliation: Athens A' University Eye Clinic, "Georgios Gennimatas" General Hospital, Athens, Greece.
authors.forename: Athanasios
authors.initials: A
authors.lastname: Vergados
authors.affiliation: Athens A' University Eye Clinic, "Georgios Gennimatas" General Hospital, Athens, Greece.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Papaconstantinou
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D058442:Capsule Opacification / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D053685:Laser Therapy / Q000009:adverse effects*; D053844:Lasers, Solid-State / Q000627:therapeutic use*; D007910:Lenses, Intraocular; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000209:etiology* / Q000503:physiopathology; D011183:Postoperative Complications / Q000209:etiology* / Q000503:physiopathology; D012189:Retrospective Studies; D014792:Visual Acuity; D055815:Young Adult
keywords: Capsulotomy; Case series; Drainage device; Intraocular pressure; Trabeculectomy