title: Posterior optic buttonholing prevents intraocular pressure peaks after cataract surgery with primary posterior capsulorhexis.
abstract: BACKGROUND
  The performance of a primary posterior capsulorhexis (PPC) with and without posterior optic buttonholing (POBH) may significantly influence the intraocular pressure (IOP) after cataract surgery in age-related cataract patients.
  
  
  METHODS
  The prospective randomized clinical study was performed at the department of Ophthalmology, Medical University of Vienna, Austria. Thirty consecutive cataract patients with bilateral same-day cataract surgery (60 eyes) under topical anesthesia were enrolled. In randomized order, cataract surgery with combined PPC/POBH was performed in one eye; in the other eye, cataract surgery was performed with PPC and in-the-bag implantation of the intraocular lens (IOL). Standardized IOP measurements by Goldmann applanation tonometry were performed preoperatively, 1, 2, 4, 6, 8 and 24 hours postoperatively, as well as 1 week and 1 month postoperatively.
  
  
  RESULTS
  During the first 24 hours after surgery, all IOP measurements were significantly lower in eyes with combined PPC/POBH when compared to eyes with solitary PPC (p < 0.001). No IOP peaks of more than 27 mmHg were observed with combined PPC/POBH. In contrast, in eyes with PPC and in-the-bag IOL implantation, seven patients had an IOP peak of more than 27 mmHg and four IOP peaks of more than 30 mmHg. One week and 1 month postoperatively, IOP measurements were statistically comparable, and no significant differences could be observed between the two groups (p > 0.05).
  
  
  CONCLUSIONS
  Postoperative IOP peaks after cataract surgery with sole PPC can be effectively prevented by the buttonholing of the IOL through the posterior capsulorhexis.
authors.affiliation: Department of Ophthalmology and Optometry, Medical University of Vienna, Austria, Waehringer Guertel 18-20, A-1090, Vienna, Austria.
authors.forename: Eva
authors.initials: E
authors.lastname: Stifter
authors.forename: Rupert
authors.initials: R
authors.lastname: Menapace
authors.forename: Katharina
authors.initials: K
authors.lastname: Kriechbaum
authors.forename: Alexandra
authors.initials: A
authors.lastname: Luksch
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001699:Biometry; D019923:Capsulorhexis; D005260:Female; D006068:Gonioscopy; D006801:Humans; D007429:Intraocular Pressure; D007903:Lens Capsule, Crystalline / Q000601:surgery*; D019654:Lens Implantation, Intraocular; D008297:Male; D018918:Phacoemulsification; D011183:Postoperative Complications / Q000517:prevention & control*; D011446:Prospective Studies; D011677:Punctures; D014065:Tonometry, Ocular; D014792:Visual Acuity / Q000502:physiology