Comparison of Premium Monovision and Bilateral Implantation of Trifocal Diffractive Intraocular Lenses
Condition: Presbyopia; Refractive Errors; Cataract
MeSH terms: Cataract; Presbyopia; Refractive Errors
Study type: Observational [Patient Registry]

Summary: 
      Primary objective of this study is to compare two presbyopia correction surgical techniques,
      specificaly premium monovision, in which the dominant eye is corrected with an extended depth
      of field intraocular lens and the non-dominant eye with a trifocal diffractive intraocular
      lens, and the bilateral implantation of trifocal diffractive intraocular lenses.
    

Detailed description: 
      Two study groups will be formed. The first group will include patients who undergone premium
      monovision and the second will include patients who undergone bilateral implantation of
      trifocal diffractive intraocular lenses. Patients who have undergone one of the
      aforementioned categories of presbyopia correction surgery will be selected in order to
      compare the effectiveness of these techniques by evaluating uncorrected near, intermediate
      and distant visual acuity, uncorrected Critical Print Size (CPS) in near and intermediate
      distance, dysphotopic phenomena (glare, halos) through a 4-level severity scale by patients,
      contrast sensitivity, the need of use glasses for all distances or separately for activities
      requiring near or distant vision as well as the degree of subjective satisfaction of patient
      via interview (NEI-VFQ 25). The purpose of measuring these parameters is to calculate,
      through a mathematical model, the relative effectiveness of each method.
    

Intervention name(s): bUDVA, bUIRA, bUNRA, bUICPS, bUNCPS; Contrast sensitivity
Intervention type(s): Diagnostic Test; Diagnostic Test
Intervention description(s): All participants will be assessed on the following clinical indexes:
Binocular uncorrected distant visual acuity (bUDVA) at four meters distance
Binocular uncorrected intermediate reading acuity (bUIRA) at 60 cm
Binocular uncorrected near reading acuity (bUNVA) at 40 cm
Binocular uncorrected intermediate Critical Print Size (bUICPS) at 60 cm
Binocular uncorrected near Critical Print Size (bUNCPS) at 40 cm
All the above parameters are obtained using the Democritus Digital Acuity & Reading Test (DDART).; Contrast sensitivity is assessed with the Pelli-Robson test.
Observational model: Cohort
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        Patients who were examined at the outpatient of the Department of Ophthalmology of the
        University General Hospital of Alexandroupolis with the diagnosis of cataract with stage 2
        (according to LOCS III) and underwent one of the following presbyopia correction surguries:

          1. Bilateral implantation of trifocal diffractive intraocular lenses

          2. Premium monovision with implantation of an extended depth of focus intraocular lens in
             the dominant eye and a trifocal diffractive intraocular lens in the non-dominant eye
      
Keywords: pseudophakic presbyopic correction; premium monovision; trifocal diffractive intraocular lenses; extended depth of field intraocular lenses