title: Sonothrombolysis for intraocular fibrin formation in an animal model.
abstract: Vascular diseases such as diabetic retinopathy or retinal arterial occlusion are always associated with retinal and/or choroidal vasculopathy and intravascular thrombosis is commonly found. The ultrasound (US) therapy is a recently developed technique to accelerate fibrinolysis and it is being applied to some clinical fields. The present study was to observe the effects of extraocular US exposure on intraocular fibrin, which is a deteriorating factor in various ocular diseases. Tubes containing human blood (2 mL) in the following groups were irradiated with US; US alone, US with tissue plasminogen activator (tPA), tPA alone, and saline (control). Fibrinolysis was quantified by measuring D-dimer after 2h. In rat eyes, intracameral fibrin (fibrin formation in the anterior chamber of the eye) was induced by YAG-laser-induced iris bleeding. Then, eyes in the following groups were irradiated with US; US alone, subconjunctival tPA alone, US and subconjunctival tPA, control. Intracameral fibrin was scored on day 3 (3+ maximum to 0). The temperatures of rat eyes were measured by infrared thermography. Histologic evaluation was also performed. D-dimer was increased by US with statistical significance (p <0.05) or tPA (p <0.01). D-dimer in US with tPA group was significantly higher than either US alone or tPA alone group (p <0.01). In rat eyes, the average intracameral fibrin score on day 3 was 1.4 in control group and 1.2 in subconjunctival tPA alone group; however, it decreased significantly in the US alone group (0.75; p <0.05, vs. control), US and subconjunctival tPA group (0.71; p <0.01, vs. control). The temperature was less than 34 degrees C after US exposure. No histologic damage was observed. US irradiation from outside accelerated intracameral fibrinolysis without causing apparent tissue damage. This noninvasive method might have therapeutic value for intraocular fibrin.
authors.affiliation: Department of Ophthalmology, Kagoshima University Graduate School of Medical and Dental Sciences, Sakuragaoka, Kagoshima 890-8520, Japan.
authors.forename: Toshifumi
authors.initials: T
authors.lastname: Yamashita
authors.forename: Hiroki
authors.initials: H
authors.lastname: Ohtsuka
authors.forename: Noboru
authors.initials: N
authors.lastname: Arimura
authors.forename: Shozo
authors.initials: S
authors.lastname: Sonoda
authors.forename: Chihiro
authors.initials: C
authors.lastname: Kato
authors.forename: Kaneo
authors.initials: K
authors.lastname: Ushimaru
authors.forename: Naoko
authors.initials: N
authors.lastname: Hara
authors.forename: Katsuro
authors.initials: K
authors.lastname: Tachibana
authors.forename: Taiji
authors.initials: T
authors.lastname: Sakamoto
mesh_terms: D000818:Animals; D000867:Anterior Chamber / Q000378:metabolism*; D003131:Combined Modality Therapy; D004195:Disease Models, Animal; D005123:Eye / Q000473:pathology / Q000503:physiopathology; D005337:Fibrin / Q000378:metabolism*; D005338:Fibrin Fibrinogen Degradation Products / Q000378:metabolism; D005343:Fibrinolytic Agents / Q000008:administration & dosage / Q000627:therapeutic use; D056965:Injections, Intraocular; D008297:Male; D051381:Rats; D011914:Rats, Inbred BN; D013696:Temperature; D013817:Thermography; D015912:Thrombolytic Therapy / Q000379:methods*; D010959:Tissue Plasminogen Activator / Q000008:administration & dosage / Q000627:therapeutic use; D014464:Ultrasonic Therapy / Q000379:methods*
chemical_list: D005338:Fibrin Fibrinogen Degradation Products; D005343:Fibrinolytic Agents; C036309:fibrin fragment D; D005337:Fibrin; D010959:Tissue Plasminogen Activator