title: Histological evaluation of phthalocyanine mediated photodynamic occlusion of corneal neovascularization enhanced by hyperbaric oxygenation.
abstract: OBJECTIVE
  We evaluated the effective irradiation parameters for photodynamic thrombosis of experimental corneal neovascularization enhanced by simultaneous hyperbaric oxygenation.
  
  
  METHODS
  Neovascularization was provoked in both eyes of each of 35 albino rabbit corneas using the intracorneal suture technique. The lasered animals were divided in 3 groups. Group 1 (10 rabbits) was treated under hyperbaric conditions (28 atm for 25 min.); group 2 (5 rabbits) was treated breathing pure oxygen delivered by a face mask; group 3 (10 rabbits) was treated breathing room air. The fourth group (10 rabbits) was used for control. Animals were anaesthetized, and irradiation of new corneal vessels was carried out 30 minutes after the injection of 5 mg/kg chloroaluminum sulfonated phthalocyanine. A 670 nm diode laser with a power 4 mW and a spot diameter 350 mm was used. Exposure times necessary for vascular occlusion were registered. Histological examination was carried out at the end of the follow-up time.
  
  
  RESULTS
  Exposure times were significantly lower in groups 1 and 2 as compared to group 3 (1.75 +/- 0.15 min., 3.1 +/- 0.4 min., and 4.75 +/- 0.15 min. respectively). Total light dose averaged 490 J/cm,2 870 J/cm,2 and 1330 J/cm,2 respectively. Histological examination revealed thrombus formation in the targeted vessels of all three investigated groups.
  
  
  CONCLUSIONS
  Combination of PDT with hyperbaric oxygenation results in an acceleration of the photodynamic process and provides for a possibility of significant reduction of photodynamic dose.
authors.affiliation: Vardinoyannion Eye Institute of Crete, Department of Ophthalmology, University of Crete Medical School, Heraklion-Crete, Greece.
authors.forename: I G
authors.initials: IG
authors.lastname: Pallikaris
authors.forename: V N
authors.initials: VN
authors.lastname: Margaritis
authors.forename: I I
authors.initials: II
authors.lastname: Naoumidi
authors.forename: L P
authors.initials: LP
authors.lastname: Naoumidis
authors.forename: M K
authors.initials: MK
authors.lastname: Tsilimbaris
authors.forename: J A
authors.initials: JA
authors.lastname: Panagopoulos
authors.forename: I C
authors.initials: IC
authors.lastname: Tsamparlakis
mesh_terms: D000818:Animals; D002196:Capillaries / Q000473:pathology; D016510:Corneal Neovascularization / Q000473:pathology / Q000628:therapy*; D006931:Hyperbaric Oxygenation; D007211:Indoles; D054833:Isoindoles; D010778:Photochemotherapy; D011817:Rabbits; D011838:Radiation-Sensitizing Agents
chemical_list: D007211:Indoles; D054833:Isoindoles; D011838:Radiation-Sensitizing Agents; C013647:phthalocyanine