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Completed

NCT Number: NCT01686308

The Effect of Cataract on Photoentrainment of the Circadian Rhythm in Humans

Cataract is globally the most common cause of blindness and in Denmark the operation with - 50.000 treatments per year - is the most common eye operation. The cause of cataract is growth and denaturation of the lens proteins. This leads to an increased absorption of blue light and increased light scatter. This may affect newly discovered cells in the retina that are involved in the regulation of the circadian rhythm. When the internal circadian rhythm is not synchronized with the external day and night a phase-shift occurs. Most people know of this discomfort as jet-lag, but the consequences may be much more severe such as heighten risk of cancer and cardiovascular disease.

The goal of this project is to study how the circadian regulating cells of the retina is affected by cataract and by the operation. Cataract patients are studied before and after the operation with questionnaires, hormone and activity measurements and with a specialized pupil measurement that measures the indirect response of the circadian regulating cells to blue light.

Results from this study aim to shed light on the regulatory mechanisms of the eye on the circadian rhythm and how these are affected by cataract. Furthermore, choice of intraocular lens is evaluated. This may have impact on clinical practise especially with regard to choice of intraocular lens and widened indications for cataract surgery.

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Key information

Conditions

Cataract Eye Diseases Lens Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Glostrup University Hospital

Glostrup Municipality, DK-2600, Denmark

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Age related/senile bilateral cataract
  • Eligible for phaco-emulsification on both eyes

Exclusion criteria

  • Known eye disease other than cataract.
  • Known systemic disease, which may affect the retina (untreated hypertension, DM etc.)
  • Known systemic disease, which may affect the lens.
  • Known psychiatric disease.
  • Known sleep or circadian rhythm disorder, not caused by lowered blue light transmission by the lens.
  • Per- and post operative complications
  • Use of drugs that may affect the sleep.

For a subpopulation also:

  • Poor cooperation.
  • Severe refraction abnormalities.
  • Previous eye surgery
  • Nystagmus
  • Congenital or acquired abnormalities of: eye lids and eye area, cornea or iris.
  • Use of medicine that may affect the pupillary response.
  • Use of drugs that may affect the pupillary response.

Treatment and study plan

Yellow Intra Ocular Lens (IOL)

Procedure

Standard operation with blue light filter Yellow IOL implantation

Conventional Intra Ocular Lens (IOL)

Procedure

Standard operation with conventional IOL implantation

Primary outcomes

  1. Pupillary response to blue light

    Time frame: 1 year/1month

    Measurement of the consensual light response to red (630 nm) and blue (470 nm)

Secondary outcomes

  1. Questionnaire

    Time frame: 1year/1month

    Pittsburgh Sleep Quality Index and the Morningness Eveningness Questionnaire

  2. Questionnaire

    Time frame: 1 year/1 month

    Morningness-eveningness questionnaire

  3. Melatonin day variety analysis

    Time frame: 1year/1month

    Salivary samples collected with 4 hour interval during 24 hours. Analyzed for melatonin concentration with Radio Immuno Assay (RIA).

  4. Actigraphy

    Time frame: 1year/1month

    Activity measured during 7 days and 7 nights with the Spectrum Actiwatch, Respironics, Philips

Sponsors and collaborators

Lead sponsor

Glostrup University Hospital, Copenhagen

Other

Registry information

Acronym: CIRCAT

Important dates

Study start
2011
Primary completion
2014
Study completion
2014
First posted
Sep 18, 2012
Registry last updated
Feb 10, 2015

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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