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Made available in DSpace on 2020-12-10T20:12:33Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-02-01 Background: This in vivo study assessed and compared the effectiveness of an aqueous indocyanine green (ICG) formulation (R-ICG) and a lipid ICG formulation (L-ICG) in occluding the rabbit choriocapillaris, and determined the singlet oxygen quantum yields and aggregation properties of both formulations in vitro. Methods: Singlet oxygen production and aggregation were compared. The eye fundus of 30 albino rabbits was irradiated 0-15 min after dye injection using an 810 nm diode laser. Fluorescein angiography and light microscopy were used to evaluate the safety and efficacy of R-ICG and L-ICG. Results: L-ICG decreased the dimerisation constant and the tendency of ICG to form aggregates, and increased the efficiency of ICG in generating singlet oxygen (R-ICG, Phi Delta= 0.120 and L-ICG, Phi Delta= 0.210). Using a 10 mg/kg dose, choriocapillaris occlusion was achieved at a light dose of 35.8 J/cm(2) with L-ICG and 71.6 J/cm(2) with R-ICG with minimal damage to the neurosensory retina. Conclusion: Restrictions to the use of ICG in aqueous solution, low singlet oxygen quantum yields and high aggregation tendency, were overcome with L-ICG. The lower laser irradiance required to obtain choriocapillaris occlusion may suggest that L-ICG is a more potent and selective photosensitiser than R-ICG. Hosp Olhos Araraquara, Retinal Diagnost & Treatment Div, BR-14802530 Araraquara, SP, Brazil Univ Fed Sao Paulo, Paulista Sch Med, Dept Ophthalmol, Sao Paulo, Brazil State Univ Sao Paulo USP Ribeirao Preto, Dept Chem, Riberir Preto, Brazil Univ Calif Irvine, Dept Ophthalmol, Irvine, CA USA State Univ Sao Paulo USP Ribeirao Preto, Dept Chem, Riberir Preto, Brazil

Background/aims: To determine the potential of an intravitreal sustained release naproxen and 5-fluorouracil (NA/5-FU) codrug for the treatment of experimental proliferative vitreoretinopathy (PVR) in a model for trauma associated tractional retinal detachment (TRD). Methods: Sustained release pellets were prepared by covalently linking naproxen to 5-fluorouracil. Drug release was tested in vitro and toxic effects were evaluated by electroretinography and light microscopy. Traumatic PVR was induced in pigmented rabbits by performing a scleral laceration, followed by repair and intravitreal injection of 0.4 ml of autologous blood. Thirty six eyes were treated with a sustained release implant containing 1.5 mg NA/5-FU as a codrug and 36 control eyes were submitted to surgery alone. Eyes were evaluated for TRD by serial indirect ophthalmoscope examination at different time points followed by postmortem fundus evaluation of the enucleated eye Results: The NA/5-FU pellets were found to provide linear release of 5-FU and naproxen over the 30 day duration of the in vitro release test. Both the severity of PVR grade and the percentage of eyes with moderate or worse tractional detachment were significantly lower in eyes treated with the codrug pellet. There were no drug related toxic effects evident on histopathological or electroretinograph examination of eyes containing the NA/5-FU pellet. Conclusions: The results suggest that this NA/5-FU codrug device effectively inhibits the progression of PVR in a rabbit trauma model that closely resembles PVR in humans. Additional studies to add knowledge to these initial findings and to clarify the potential of the codrug device for the treatment of human PVR are warranted.

We read with interest the article by Schumann et al ,1 who have reported the ultrastructural analyses of internal limiting membrane (ILM) specimens after staining with new dye Brilliant Blue G (BBG). In their study, morphological analyses failed to reveal any adverse effects possibly related to BBG. However, they stated that ultrastructural analyses alone may not be sufficient to allow definite conclusions on the safety of a vital dye used for macular surgery. Here we report the effects of accidental subretinal migration of BBG for ILM identification during vitrectomy for epiretinal membrane (ERM). A 56-year-old man had decreased visual acuity and metamorphopsia. He had an idiopathic ERM, and the best-corrected visual acuity (BCVA) measured by the Early Treatment Diabetic Retinopathy Study chart was 1.0 logMAR (Snellen equivalent 6/60). Pars plana vitrectomy and ERM peeling …