4 research outputs found
Evaluation of Verteporfin as a Novel Antifibrotic Agent in a Rabbit Model of Glaucoma Filtration Surgery
Purpose: Verteporfin is a benzoporphyrin derivative which is Food and Drug Administration-approved for treatment of choroidal neovascularization in conjunction with photodynamic therapy. It has been shown to prevent fibrosis and scar formation in several organs and represents a promising novel antifibrotic agent for glaucoma surgery. The goal of this study is to determine the effect of verteporfin on wound healing after glaucoma filtration surgery. Design: Preclinical study using a rabbit model of glaucoma filtration surgery. Subjects: Eight New Zealand white rabbits underwent glaucoma filtration surgery in both eyes. Methods: Eyes were randomized into 4 study groups to receive a postoperative subconjunctival injection of 1 mg/mL verteporfin (n = 4), 0.4 mg/mL mitomycin C (MMC; n = 4), 0.4 mg/mL MMC + 1 mg/mL verteporfin (n = 4), or balanced salt solution (BSS) control (n = 4). Bleb survival, vascularity, and morphology were graded using a standard scale over a 30-day period, and intraocular pressure (IOP) was monitored. At 30 days postoperative or surgical failure, histology was performed to evaluate for inflammation, local toxicity, and scarring. Main Outcome Measures: The primary outcome measure was bleb survival. Secondary outcome measures were IOP, bleb morphology, and bleb histology. Results: Compared to BSS control blebs, verteporfin-treated blebs demonstrated a trend toward increased surgical survival (mean 9.8 vs. 7.3 days, log rank P = 0.08). Mitomycin C-treated blebs survived significantly longer than verteporfin-treated blebs (log rank P = 0.009), with all but 1 MMC-treated bleb still surviving at postoperative day 30. There were no significant differences in survival between blebs treated with combination verteporfin + MMC and MMC alone. Mitomycin C-treated blebs were less vascular than verteporfin-treated blebs (mean vascularity score 0.3 ± 0.5 for MMC vs. 1.0 ± 0.0 for verteporfin, P < 0.01). Bleb histology did not reveal any significant toxicity in verteporfin-treated eyes. There were no significant differences in inflammation or scarring across groups. Conclusions: Although verteporfin remained inferior to MMC with regard to surgical survival, there was a trend toward increased survival compared with BSS control and it had an excellent safety profile. Further studies with variations in verteporfin dosage and/or application frequency are needed to assess whether this may be a useful adjunct to glaucoma surgery. Financial Disclosure(s): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article
Medidas imitanciomĂ©tricas em crianças com ausĂȘncia de emissĂ”es otoacĂșsticas Acoustic immittance in children without otoacoustic emissions
Partindo da hipĂłtese de que alteraçÔes da função de orelha mĂ©dia possam prejudicar a captação das EOAs, Ă© possĂvel que a ausĂȘncia destas, em lactentes, esteja associada a discretas alteraçÔes timpanomĂ©tricas. OBJETIVO: Verificar a associação entre resposta de EOAT e alteração imitanciomĂ©trica com a sonda de 226Hz em lactentes. MĂTODOS: Estudo de coorte contemporĂąnea com corte transversal. Foram avaliados 20 lactentes com ausĂȘncia de EOAT (grupo pesquisa) e 101 lactentes com presença de EOAT (grupo comparação), com idades variando entre o nascimento e oito meses. Os lactentes foram submetidos a: timpanometria; pesquisa dos limiares de reflexo acĂșstico contralateral com estĂmulos de 0,5k, 1k, 2k, 4kHz e ruĂdo de faixa larga; emissĂ”es otoacĂșsticas (transiente e por produtos de distorção). O potencial evocado auditivo de tronco encefĂĄlico para pesquisa do limiar de resposta foi realizado no grupo pesquisa. RESULTADOS: Observou-se diferença estatisticamente significante entre os grupos (p<0,05), caracterizada pela redução na altura timpanomĂ©trica e aumento do limiar de reflexo acĂșstico no grupo pesquisa e a ocorrĂȘncia de discreto comprometimento de orelha mĂ©dia, no grupo pesquisa, associada Ă s respostas eletrofisiolĂłgicas normais. CONCLUSĂO: O uso combinado da timpanometria e do reflexo acĂșstico, em lactentes, acrescenta precisĂŁo no diagnĂłstico de alteração de orelha mĂ©dia.<br>Considering the hypothesis that middle ear changes can impair the recording of otoacoustic emissions, it is possible that absent otoacoustic emissions in infants could be associated with a light tympanometric change. AIM: To study the association between transient otoacoustic emissions and changes in acoustic immittance measurements with 226Hz probe tone in neonates. METHODS: Cross-sectional contemporary cohort study. 20 infants with no transient otoacoustic emissions (study group) and 101 infants with transient otoacoustic emissions (control group), with ages ranged from birth to eight months, were assessed. Infants were submitted to: admittance tympanometry; contralateral acoustic reflex threshold with stimulus of 0.5, 1, 2, 4 kHz and broad band noise; transient and distortion product otoacoustic emissions. The auditory brain response was used to study the threshold in neonates without transient otoacoustic emissions. RESULTS: Significant statistical differences were observed between the groups (p < 0.005), characterized by reduction in tympanometric configuration and increase acoustic reflex thresholds in the study group. These data suggest the occurrence of middle ear mild impairment in infants without transient otoacoustic emissions associated with normal auditory brain response. CONCLUSION: tympanometry associated with acoustic reflex adds accuracy to the diagnosis of middle ear abnormalities