The Impact of Light Conditions on the Efficacy of Multifocal Intraocular Lens Implantation in Activities of Daily Living
Condition: Presbyopia; Near Vision; Reading; Daily Activities; Multifocal Intraocular Lens; Cataract
MeSH terms: Cataract; Presbyopia
Study type: Observational [Patient Registry]

Summary: 
      Primary objective of this study is to identify the optimal task lighting conditions (in terms
      of light intensity and light temperature) for 10 activities of daily living (ADLs) that
      require near or intermediate vision acuity in a validated ADL simulation framework for a
      sample of patients who underwent presbyopic correction with bilateral multifocal intraocular
      lenses (IOLs) implantation, and to compare their capacity to perform ADLs (ADL scores)
      between three study groups (SG): SG1. patients implanted bilaterally with trifocal
      diffractive IOLs, SG2. patients implanted bilaterally with bifocal hybrid
      (diffractive-refractive) IOLs, SG3. patients implanted bilaterally with monofocal IOLs
    

Detailed description: 
      Patients who underwent presbyopic correction with bilateral implantation of multifocal IOLs
      are supposed to have sufficient uncorrected vision capacity for ADLs that require near (ie.
      book reading) or intermediate (ie. reading in a computer screen) vision acuity. However, it
      is known that light intensity and light temperature has a great impact on near/intermediate
      vision capacity, but also patients that have been implanted with multifocal IOLs are most
      likely to present completely different lighting needs than patients with their own
      crystalline lenses.

      Primary objective of this study is to identify the optimal task lighting conditions (in terms
      of light intensity and light temperature) for 10 ADLs that require near or intermediate
      vision acuity in a validated ADL simulation framework for a sample of patients who underwent
      presbyopic correction with bilateral multifocal IOLs implantation, and to compare their
      capacity to perform the ADLs (ADL scores) in 9 different lighting combinations (combinations
      of light intensity and light temperature) between three study groups: SG1. patients implanted
      bilaterally with trifocal diffractive IOLs, SG2. patients implanted bilaterally with bifocal
      hybrid (diffractive-refractive) IOLs, SG3. patients implanted bilaterally with monofocal IOLs

      The study is conducted in an experimental facility in a hospital room with a dimension of
      6.87 × 2.9 × 3 m (depth × width × height) and flat white surface walls (reflectance: 70%). Αn
      advanced light diffusion system has been installed, which consists of four linear LED
      luminaires producing low glare (unified glare rating (UGR) < 19). Light intensity (dimming /
      in foot candles - fc) and light temperature (white tuning / (in Kelvins - K) have been
      adjusted using the Casambi wireless control application (Casambi Technologies Oy Inc., Espoo,
      Finland), which uses integrated Bluetooth mesh technology and secures maximal uniformity at
      different user-defined lighting settings. The four LED luminaires have been mounted on the
      ceiling. The exact luminaire positioning and the amount of the provided luminous flux have
      been defined using the RELUX light simulation tool (version 2021.1.1.0) (Relux Informatik AG,
      Münchenstein, Switzerland) prior to the installation. The confirmation of illuminance and
      on-site adjustments have been confirmed with the Extech Lux Meter EA30 (Extech Instruments
      Corporation, Nashua, NH, United States). As regards photometric properties derived from
      lighting laboratory photometric measurements, the correlated color temperature (CCT) of the
      luminaires ranges between 2700 K and 6500 K, emitting a maximum luminous flux of 10,626 lm
      and 11,508 lm, respectively. The exact radiant flux P(λ) emitted from the selected light
      sources has been measured using a Konica Minolta CL-500A spectrum meter for the wavelength
      range of 380-780 nm using a step of 1 nm. The power of each luminaire is 106 W, resulting in
      luminous efficacy of 100.2 lm/W and 108.6 lm/W for 2700 K and 6500 K, respectively. The color
      rendering index (CRI) is 84. The wireless dimming control system enables dimming from 0% to
      100% and vice versa.

      The 9 lighting combinations (light intensity, light temperature) are the following:

      3000 K - 25 fc, 3000 K - 50 fc, 3000 K - 75 fc / 4000 K - 25 fc, 4000 K - 50 fc, 4000 K - 75
      fc / 6000 K - 25 fc, 6000 K - 50 fc, 6000 K - 75 fc

      In specific, patients address the following ten ADLs:

      1. Phone Book Search (PBS), 2. Supermarket receipt (SupRe), 3. Book reading (BR), 4. Cellular
      message (CM), 5. Cellular entry search (CES), 6. Reading computer screen (RCS), 7. Drops
      bottle reading (DR), 8. Subtitles reading (SubRe), 9. Open door test (ODT), and, 10.
      Screwdriver test (ST).

      Test-retest reliability will be assessed by calculating intraclass correlation coefficients
      (ICCs) for all ADLs at the nine combinations of light conditions in two different visits with
      an average 15-day time window to prevent memory effect.
    

Intervention name(s): ADL performance
Intervention type(s): Other
Intervention description(s): ADL performance
All study groups address the following 10 ADL tasks in 9 different combinations of light temperature and light intensity in order possible differences to be revealed among the study groups and light combinations:
1. Phone Book Search (PBS), 2. Supermarket receipt (SupRe), 3. Book reading (BR), 4. Cellular message (CM), 5. Cellular entry search (CES), 6. Reading computer screen (RCS), 7. Drops bottle reading (DR), 8. Subtitles reading (SubRe), 9. Open door test (ODT), and, 10. Screwdriver test (ST).
The 9 light combinations are the following:
3000 K - 25 fc, 3000 K - 50 fc, 3000 K - 75 fc / 4000 K - 25 fc, 4000 K - 50 fc, 4000 K - 75 fc / 6000 K - 25 fc, 6000 K - 50 fc, 6000 K - 75 fc
Observational model: Cohort
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        Patients underwent phacoemulsification and bilateral implantation of IOLs [SG1: trifocal
        diffractive IOL, SG2: bifocal hybrid (diffractive - refractive) IOL, SG3: monofocal IOL]
      
Keywords: activities of daily living; presbyopia; light temperature; light intensity; multifocal intraocular lens