- ICH GCP
- Registr klinických studií v USA
- Klinická studie NCT00403143
Do Blue-Blocking Lenses Block Blue Colour From Our Lives?
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
Přehled studie
Detailní popis
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.
Typ studie
Zápis (Očekávaný)
Fáze
- Nelze použít
Kontakty a umístění
Studijní kontakt
- Jméno: Amynah Goawalla, BSc, MBBS MRCOphth
- Telefonní číslo: 7130 020 963
- E-mail: amynahgoawalla@nwlh.nhs.uk
Studijní místa
-
-
-
London, Spojené království, NW10 7NS
- Nábor
- North West London Hospitals NHS Trust
-
Kontakt:
- Iva Hauptmannova, BSc MA
- Telefonní číslo: 5286 020 8869
- E-mail: iva.hauptmannova@nwlh.nhs.uk
-
Vrchní vyšetřovatel:
- Gillian Vafidis, MA FRCS FRCOphth
-
Dílčí vyšetřovatel:
- Amynah Goawalla, BSc MBBS MRCOphth
-
-
Kritéria účasti
Kritéria způsobilosti
Věk způsobilý ke studiu
Přijímá zdravé dobrovolníky
Pohlaví způsobilá ke studiu
Popis
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
Studijní plán
Jak je studie koncipována?
Detaily designu
- Primární účel: Léčba
- Přidělení: Randomizované
- Intervenční model: Paralelní přiřazení
- Maskování: Singl
Co je měření studie?
Primární výstupní opatření
Měření výsledku |
---|
To objectively determine whether colour vision is reduced with a blue-light filtering
|
intraocular lens compared with a colourless intraocular implant in cataract surgery
|
Sekundární výstupní opatření
Měření výsledku |
---|
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
|
Spolupracovníci a vyšetřovatelé
Vyšetřovatelé
- Ředitel studie: Gillian Vafidis, MA FRCS FRCOphth, London North West Healthcare NHS Trust
Termíny studijních záznamů
Hlavní termíny studia
Začátek studia
Termíny zápisu do studia
První předloženo
První předloženo, které splnilo kritéria kontroly kvality
První zveřejněno (Odhad)
Aktualizace studijních záznamů
Poslední zveřejněná aktualizace (Odhad)
Odeslaná poslední aktualizace, která splnila kritéria kontroly kvality
Naposledy ověřeno
Více informací
Termíny související s touto studií
Klíčová slova
Další relevantní podmínky MeSH
Další identifikační čísla studie
- 06/Opa/23
Tyto informace byly beze změn načteny přímo z webu clinicaltrials.gov. Máte-li jakékoli požadavky na změnu, odstranění nebo aktualizaci podrobností studie, kontaktujte prosím register@clinicaltrials.gov. Jakmile bude změna implementována na clinicaltrials.gov, bude automaticky aktualizována i na našem webu .