title: Use of hydroxypropylmethylcellulose 2% for removing adherent silicone oil from silicone intraocular lenses.
abstract: OBJECTIVE
  To investigate the effect of hydroxypropylmethylcellulose (HPMC) on the physical interaction (contact angle) between silicone oil and a silicone intraocular lens (IOL).
  
  
  METHODS
  In vitro experiments were performed, to determine the effect of HPMC (0.5%, 1% or 2%), with or without an additional simple mechanical manoeuvre, on the contact angle of silicone oil at the surface of both silicone and acrylic (control) IOLs. A balanced salt solution chamber was used. The study group comprised 21 silicone and nine acrylic IOLs.
  
  
  RESULTS
  The median contact angle of silicone oil on silicone IOL was 99 degrees. The addition of HPMC 2% alone did not significantly alter the contact angle. HPMC 2% combined with an additional single mechanical manoeuvre increased the contact angle to 180 degrees (greater non-wetting), with complete separation of silicone oil from silicone IOL within 1 min. The manoeuvre alone, or in conjunction with a lower concentration of HPMC (0.5 or 1%), was ineffective in increasing the contact angle.
  
  
  CONCLUSIONS
  We present a novel, non-toxic technique of using hydroxypropylmethylcellulose 2% combined with a simple mechanical manoeuvre, for the removal of adherent silicone oil droplets from silicone intraocular lenses.
authors.affiliation: Vitreoretinal Department, Moorfields Eye Hospital, 162 City Road, London EC1V 2PD, UK. chien.wong@moorfields.nhs.uk
authors.forename: S C
authors.initials: SC
authors.lastname: Wong
authors.forename: Y D
authors.initials: YD
authors.lastname: Ramkissoon
authors.forename: M
authors.initials: M
authors.lastname: Lopez
authors.forename: K
authors.initials: K
authors.lastname: Page
authors.forename: I P
authors.initials: IP
authors.lastname: Parkin
authors.forename: P M
authors.initials: PM
authors.lastname: Sullivan