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1.
Cornea ; 34(2): 228-34, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25522222

RESUMO

PURPOSE: The aim of this study was to evaluate the clarity of gamma-irradiated sterile corneal donor lenticules. METHODS: Broadband UV, visible, and near-infrared (200-850 nm) light transmission was measured through gamma-irradiated, sterile partial-thickness, and full-thickness donor lenticules and fresh corneal tissues and compared with standard acrylic intraocular lens (IOL) implants using a conventional spectrophotometer technique. RESULTS: All tissues had high light transmission (≥ 90%) in the visible and near-infrared regions and very low (<2%) transmission below 290 nm. Differences in light transmission between irradiated and fresh cornea types were observed between 300 and 450 nm, which mirrored differences in light transmission through their respective storage solutions. Light transmission through partial-thickness irradiated donor lenticules was greatest across all wavelengths. All corneal tissues exhibited higher transmission than acrylic IOL implant across all wavelengths. CONCLUSIONS: Gamma-irradiated donor lenticules are comparable with fresh corneas regarding light transmission, with both partial-thickness and full-thickness lenticules having greater transmission than standard IOL. We would expect the optical performance of gamma-irradiated donor lenticules to be comparable to fresh cornea if used for lamellar corneal procedures that do not require a viable endothelium.


Assuntos
Córnea/fisiologia , Córnea/efeitos da radiação , Raios gama , Raios Infravermelhos , Luz , Raios Ultravioleta , Humanos , Preservação de Órgãos , Espectrofotometria Ultravioleta , Espectroscopia de Luz Próxima ao Infravermelho , Esterilização/métodos , Doadores de Tecidos
2.
Rev Sci Instrum ; 84(8): 084301, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24007081

RESUMO

We developed and validated a versatile test method for precise quantification of phase retardation in corneal tissues using a femtosecond laser. It is based on an experimental system for direct measurement of corneal phase rotation due to corneal birefringence effects using a dual-polarizer, computer-controlled, femtosecond laser design. It also includes a comprehensive analytical model using Jones matrices. The test method presented is used for quantification of phase retardation in corneal tissues by employing the experimental data obtained from corneal phase rotation measurements and using analytical model assessments. The experimental and theoretical results obtained, and thus, the system's high accuracy and repeatability potential for assessing the corneal phase retardation are validated using control phase retardation evaluation.


Assuntos
Córnea/citologia , Lasers , Fenômenos Ópticos , Animais , Bovinos , Reprodutibilidade dos Testes
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