title: Suction loss during femtosecond laser-assisted small-incision lenticule extraction: Incidence and analysis of risk factors.
abstract: OBJECTIVE
  To determine the incidence of and analyze risk factors for suction loss during femtosecond laser-assisted small incision lenticule extraction in the management of myopia or myopic astigmatism.
  
  
  METHODS
  Roayah Vision Correction Center, Alexandria, Egypt.
  
  
  METHODS
  Retrospective comparative case-control study.
  
  
  METHODS
  All eyes that had femtosecond laser-assisted small-incision lenticule extraction for the correction of myopia and myopic astigmatism performed between August 2010 and April 2014 were included. Eyes that developed suction loss were identified. Their characteristics, including demographic data (age and sex), eye laterality, manifest refraction, flat keratometry (K) reading, steep K reading, K astigmatism, optical zone, central corneal thickness, and corneal cap diameter and thickness, were compared with those in randomly selected control eyes to determine the risk factors for developing suction loss.
  
  
  RESULTS
  Of the 3376 eyes that had femtosecond laser-assisted small-incision lenticule extraction during the study, 70 (2.1%) developed loss of suction. The incidence decreased with surgical experience (5.06% in 2010, 3.59% in 2011, 3.41% in 2012, 2.32% in 2013, and 1.84% in 2014), suggesting a learning curve. A multivariate logistic regression model showed that eyes with a larger cap diameter were significantly more likely to develop suction loss (P = .023; odds ratio, 9.60).
  
  
  CONCLUSIONS
  Surgical experience significantly decreased the risk for suction loss during femtosecond laser-assisted small incision lenticule extraction for the correction of myopia or myopic astigmatism but did not eliminate it. A larger cap diameter significantly increased the risk for developing the suction loss.
  
  
  BACKGROUND
  No author has a financial or proprietary interest in any material or method mentioned.
authors.affiliation: From the Department of Ophthalmology (Osman, Awad, Shousha), Faculty of Medicine, University of Alexandria, Egypt; the Bascom Palmer Eye Institute (Shi, Shousha), University of Miami, Miller School of Medicine, Miami, Florida, USA. Electronic address: osmanehab@yahoo.com.
authors.forename: Ihab M
authors.initials: IM
authors.lastname: Osman
authors.affiliation: From the Department of Ophthalmology (Osman, Awad, Shousha), Faculty of Medicine, University of Alexandria, Egypt; the Bascom Palmer Eye Institute (Shi, Shousha), University of Miami, Miller School of Medicine, Miami, Florida, USA.
authors.forename: Ramy
authors.initials: R
authors.lastname: Awad
authors.affiliation: From the Department of Ophthalmology (Osman, Awad, Shousha), Faculty of Medicine, University of Alexandria, Egypt; the Bascom Palmer Eye Institute (Shi, Shousha), University of Miami, Miller School of Medicine, Miami, Florida, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Shi
authors.affiliation: From the Department of Ophthalmology (Osman, Awad, Shousha), Faculty of Medicine, University of Alexandria, Egypt; the Bascom Palmer Eye Institute (Shi, Shousha), University of Miami, Miller School of Medicine, Miami, Florida, USA.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Abou Shousha
mesh_terms: D000293:Adolescent; D000328:Adult; D001251:Astigmatism / Q000601:surgery; D016022:Case-Control Studies; D063171:Corneal Pachymetry; D003319:Corneal Stroma / Q000601:surgery*; D004534:Egypt / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D007431:Intraoperative Complications / Q000453:epidemiology; D054018:Lasers, Excimer; D059032:Learning Curve; D008297:Male; D008866:Microsurgery / Q000379:methods; D008875:Middle Aged; D009216:Myopia / Q000601:surgery*; D012189:Retrospective Studies; D012307:Risk Factors; D013396:Suction; D055815:Young Adult