title: In vitro videographic comparison of argon and Nd:YAG laser iridotomy.
abstract: We used an in vitro technique with high-magnification video recording to evaluate from the posterior side of the iris the immediate sequence of events during argon and Nd:YAG laser peripheral iridotomy. The observed effects differed strikingly. The argon laser caused a gradual mounding up of iris pigment epithelium with each successive energy application before final penetration. This effect was reduced but not eliminated with higher power levels. The Nd:YAG laser caused complete disruption and dispersal of the pigment epithelium with a single pulse of energy. Additionally, a multiple focal point configuration of the Nd:YAG laser was observed to produce a significantly larger iridotomy than a single focal point configuration for comparable energy settings. These observations may in part explain the observed clinical advantage of the Nd:YAG laser over the argon laser for creation of a patent iridotomy.
authors.affiliation: Department of Ophthalmology, Duke University Eye Center, Durham, North Carolina 27710.
authors.forename: B E
authors.initials: BE
authors.lastname: Prum
authors.forename: S R
authors.initials: SR
authors.lastname: Shields
authors.forename: M B
authors.initials: MB
authors.lastname: Shields
authors.forename: D
authors.initials: D
authors.lastname: Hickingbotham
authors.forename: D B
authors.initials: DB
authors.lastname: Chandler
mesh_terms: D006801:Humans; D007498:Iris / Q000473:pathology / Q000601:surgery*; D053685:Laser Therapy; D010857:Pigment Epithelium of Eye / Q000473:pathology / Q000601:surgery; D014741:Video Recording