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

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

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT01686308
Acronym
CIRCAT
Enrollment
76
Registered
2012-09-18
Start date
2011-02-28
Completion date
2014-12-31
Last updated
2015-02-10

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Cataract

Keywords

cataract, circadian rhythm, pupillometry, blue light transmission, questionnaire, sleep

Brief summary

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.

Interventions

PROCEDUREYellow Intra Ocular Lens (IOL)

Standard operation with blue light filter Yellow IOL implantation

PROCEDUREConventional Intra Ocular Lens (IOL)

Standard operation with conventional IOL implantation

Sponsors

Glostrup University Hospital, Copenhagen
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
DOUBLE (Subject, Investigator)

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No

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.

Design outcomes

Primary

MeasureTime frameDescription
Pupillary response to blue light1 year/1monthMeasurement of the consensual light response to red (630 nm) and blue (470 nm)

Secondary

MeasureTime frameDescription
Questionnaire1year/1monthPittsburgh Sleep Quality Index and the Morningness Eveningness Questionnaire
Melatonin day variety analysis1year/1monthSalivary samples collected with 4 hour interval during 24 hours. Analyzed for melatonin concentration with Radio Immuno Assay (RIA).
Actigraphy1year/1monthActivity measured during 7 days and 7 nights with the Spectrum Actiwatch, Respironics, Philips

Countries

Denmark

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026