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Do Blue-Blocking Lenses Block Blue Colour From Our Lives?

11 de mayo de 2007 actualizado por: London North West Healthcare NHS Trust

Do Blue-Blocking Lenses Block Colour From Our Lives? A Randomised Controlled Study Measuring Colour Vision Using the Gold Standard Colour Vision Test (an Anomaloscope)in Patients With Blue Light Filtering Intraocular Lenses (Tinted Yellow) and Comparing This With Patients Inserted With Clear, Non Blue Light Filtering Intraocular Lenses During Cataract Surgery

To measure colour vision in patients with a blue light filtering lens implant in one eye and non-tinted implant in the other eye (and compared this group with a control group with bilateral non-tinted implants) and to determine whether blue light filtering lenses limit colour vision

Descripción general del estudio

Estado

Desconocido

Condiciones

Intervención / Tratamiento

Descripción detallada

As we all age, the natural lens inside our eyes becomes denser, hazy and more yellow in colour. In other words, cataracts develop. In order to enable clear vision again, cataract surgery is performed. This involves removing the natural lens from the eye and replacing it with a synthetic lens implant inside the eye. Cataract surgery with insertion of a lens implant was first done in 1948 but didn't become routine until the early 1980s. Around this time, awareness about the harmful effects of UV light were raised and by 1986, lens implants routinely had a UV filter incorporated into them.1 As early as 1992, a study examining patients who had had a high occupational exposure to blue and visible light, concluded that there is a positive association between long term exposure to visible light and age related wear and tear change at the back of the eye, termed age related macular degeneration (AMD).2 This theory was supported by several studies which have reported an increased rate of progression of AMD in patients after cataract surgery with a clear lens implant (It is known that clear lens implants transmit more blue light to the back of the eye compared with the natural aging lens).3 Laboratory studies in 2000 showed that blue light causes damage to aging retinal cells (the nerve cells at the back of the eye which are important in enabling us to see), more so than green light or white light.4 Experimental studies with rats also showed that exposure to blue light was 30 times more damaging to retinal cells compared with yellow light.5 A further laboratory study in 2004 confirmed that by protecting aging retinal cells with a blue light filtering lens, damage caused by blue light is prevented.6 Yellow tinted, blue light filtering lens implants have been in production since 1991, first by Hoya in Tokyo and now by Alcon as well. Alcon produce the Acrysof Natural lens implant which has been designed to mimic the 53 year old natural lens and which received FDA and CE approval in 2003. To date, over 2 million of these lenses have been implanted in patients world wide.7 Although these lens implants are sometimes used in patients having cataract surgery in the UK, this is not yet routine. One of the concerns about them is whether or not they limit colour vision in any way. There have been some studies examining this and so far, none of them have found a statistically significant difference in the colour vision between patients with non-tinted lens implants and blue-filtering lens implants.8,9,10 However, none of the studies thus far, have employed colour vision testing with an anomaloscope (which is considered to be the gold standard colour vision test).11 In addition, none of them have taken into account the level of capsular opacification (the capsule is a cling film bag-like structure that supports the lens implant inside the eye and can over a period of time, become thickened and hazy following cataract surgery) and the level of macular pigment (yellow pigment which we have on the centre part of the back of our eyes which is thought to contribute towards filtering blue light) in patients' eyes.

Age related macular degeneration is already the commonest cause of blindness in the UK. It is a growing problem, particularly with our aging population and increasing levels of ambient light which we are exposed to in our daily lives. Although the evidence is strongly in favour of filtering blue light and the need for protective measures against AMD are pressing, we need to be satisfied that there are no adverse effects of blocking blue from our lives.

Tipo de estudio

Intervencionista

Inscripción (Anticipado)

40

Fase

  • No aplica

Contactos y Ubicaciones

Esta sección proporciona los datos de contacto de quienes realizan el estudio e información sobre dónde se lleva a cabo este estudio.

Estudio Contacto

Ubicaciones de estudio

      • London, Reino Unido, NW10 7NS
        • Reclutamiento
        • North West London Hospitals NHS Trust
        • Contacto:
        • Investigador principal:
          • Gillian Vafidis, MA FRCS FRCOphth
        • Sub-Investigador:
          • Amynah Goawalla, BSc MBBS MRCOphth

Criterios de participación

Los investigadores buscan personas que se ajusten a una determinada descripción, denominada criterio de elegibilidad. Algunos ejemplos de estos criterios son el estado de salud general de una persona o tratamientos previos.

Criterio de elegibilidad

Edades elegibles para estudiar

18 años y mayores (Adulto, Adulto Mayor)

Acepta Voluntarios Saludables

No

Géneros elegibles para el estudio

Todos

Descripción

Inclusion Criteria:

  • patients who have had uncomplicated cataract surgery in one eye and have a cataract in the other eye
  • patients who are over 18 years of age
  • patients who are fully able to independently give consent to have surgery

Exclusion Criteria:

  • patients who have any other ocular co-morbidity that may account for reduction in vision in either eye (as this may confound the condition)
  • patients who are colour blind
  • patients who suffered previous post-operative complications
  • patients under 18

Plan de estudios

Esta sección proporciona detalles del plan de estudio, incluido cómo está diseñado el estudio y qué mide el estudio.

¿Cómo está diseñado el estudio?

Detalles de diseño

  • Propósito principal: Tratamiento
  • Asignación: Aleatorizado
  • Modelo Intervencionista: Asignación paralela
  • Enmascaramiento: Único

¿Qué mide el estudio?

Medidas de resultado primarias

Medida de resultado
To objectively determine whether colour vision is reduced with a blue-light filtering
intraocular lens compared with a colourless intraocular implant in cataract surgery

Medidas de resultado secundarias

Medida de resultado
To determine whether patients subjectively are able to tell whether they have been
implanted with yellow tinted intraocular lens during their cataract surgery or colourless one

Colaboradores e Investigadores

Aquí es donde encontrará personas y organizaciones involucradas en este estudio.

Investigadores

  • Director de estudio: Gillian Vafidis, MA FRCS FRCOphth, London North West Healthcare NHS Trust

Fechas de registro del estudio

Estas fechas rastrean el progreso del registro del estudio y los envíos de resultados resumidos a ClinicalTrials.gov. Los registros del estudio y los resultados informados son revisados ​​por la Biblioteca Nacional de Medicina (NLM) para asegurarse de que cumplan con los estándares de control de calidad específicos antes de publicarlos en el sitio web público.

Fechas importantes del estudio

Inicio del estudio

1 de octubre de 2006

Fechas de registro del estudio

Enviado por primera vez

22 de noviembre de 2006

Primero enviado que cumplió con los criterios de control de calidad

22 de noviembre de 2006

Publicado por primera vez (Estimar)

23 de noviembre de 2006

Actualizaciones de registros de estudio

Última actualización publicada (Estimar)

14 de mayo de 2007

Última actualización enviada que cumplió con los criterios de control de calidad

11 de mayo de 2007

Última verificación

1 de mayo de 2007

Más información

Términos relacionados con este estudio

Esta información se obtuvo directamente del sitio web clinicaltrials.gov sin cambios. Si tiene alguna solicitud para cambiar, eliminar o actualizar los detalles de su estudio, comuníquese con register@clinicaltrials.gov. Tan pronto como se implemente un cambio en clinicaltrials.gov, también se actualizará automáticamente en nuestro sitio web. .

Ensayos clínicos sobre cirugía de cataratas

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