title: Polylactic acid for visualizing the vitreous body during vitrectomy.
abstract: OBJECTIVE
  To investigate the possibility of using polylactic acid (PLA) as a surgical adjuvant for visualizing the vitreous body during vitrectomy.
  
  
  METHODS
  After a core vitrectomy, 1 mL of PLA suspension was injected into the rabbit vitreous in two groups: group A, 2.5% PLA (n = 5), and group B, 1% PLA (n = 9). Vehicle injection instead of PLA was used as a control (group C, n = 5). The clinical signs and electroretinogram (ERG) were evaluated for 28 days, and histologic findings were evaluated on day 28. Next, intraocular pressure (IOP) after intracameral injection of a PLA suspension was evaluated in the rabbits (n = 6). Last, the visualization of the vitreous body by PLA suspension was evaluated during vitrectomy in monkey eyes (n = 4).
  
  
  RESULTS
  The white granules of PLA disappeared from the vitreous cavity in 10 eyes within 3 weeks; however, a small amount of PLA remained in four eyes for 4 weeks. Mild inflammation of the anterior chamber was observed in one eye in group B and 1 eye in group C. No cataract or retinal hemorrhage was found in any eyes. The amplitude of ERG on each time point did not differ between the groups. IOP remained within normal range except for the initial spike. Retinal structure was well preserved histologically. During vitrectomy in monkey eyes, the vitreous body was well visualized, and the posterior vitreous separation was performed easily and safely.
  
  
  CONCLUSIONS
  PLA can be a new surgical adjuvant to visualize the vitreous body during vitrectomy.
authors.affiliation: Department of Ophthalmology, Kagoshima University Medical and Dental School, Sakuragaoka, Kagoshima, Japan.
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Yamashita
authors.forename: Taiji
authors.initials: T
authors.lastname: Sakamoto
authors.forename: Keita
authors.initials: K
authors.lastname: Yamakiri
authors.forename: Muneki
authors.initials: M
authors.lastname: Miura
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Enaida
authors.forename: Akifumi
authors.initials: A
authors.lastname: Ueno
authors.forename: Ikuyo
authors.initials: I
authors.lastname: Atsumi
authors.forename: Keiichi
authors.initials: K
authors.lastname: Matsuhisa
authors.forename: Yuji
authors.initials: Y
authors.lastname: Sakamoto
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Kida
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Ishibashi
mesh_terms: D000818:Animals; D000869:Anterior Eye Segment / Q000187:drug effects / Q000473:pathology; D003287:Contrast Media; D004596:Electroretinography / Q000187:drug effects; D007267:Injections; D007429:Intraocular Pressure / Q000187:drug effects; D019344:Lactic Acid / Q000633:toxicity; D008252:Macaca fascicularis; D008297:Male; D011091:Polyesters; D011108:Polymers / Q000633:toxicity; D011817:Rabbits; D012160:Retina / Q000187:drug effects / Q000473:pathology; D013535:Suspensions; D014821:Vitrectomy; D014822:Vitreous Body / Q000473:pathology*
chemical_list: D003287:Contrast Media; D011091:Polyesters; D011108:Polymers; D013535:Suspensions; D019344:Lactic Acid; C033616:poly(lactide)