Galilei Lens Professional vs. Predicate Devices: a Comparison Study

Study question: How does the new GALILEI Lens Professional compare to predicate devices? Study hypothesis: The GALILEI Lens Professional achieves a better precision in the postoperative, calculated target refraction with cataract surgeries than predicate devices, and it is more versatile in the measurable parameters as well as more user-friendly.

Background: An accessory to the commercially available GALILEI Dual-Scheimpflug Corneal Topographer/Keratometer with the name "EBR Accessory" was developed by the company Ziemer Ophthalmic Systems AG for the measurement of intraocular distances. The combination is called "GALILEI Lens Professional". The measurement principle is based on on short coherence interferometry/-reflectometry, which has gained wide-spread application and has been applied clinically, including one of the members of this study group, for the precise measurement of axial, intraocular distances (12.1.). Such EBR Accessory measurements, in combination with measurements by the GALILEI, may be applied to given intra-ocular lens (IOL) types and IOL equations, an permit the calculation of suggested IOLs that are implanted during cataract surgery, in order to achieve the desired vision correction. To register this accessory for sale, the precision and agreement to existing devices with similar applications ("predicate devices") must be demonstrated. One complete measurement consists of a cornea-topography/keratometry scan, followed immediately by three consecutive, axial biometry scans of the anterior segment (cornea and crystalline lens) and - after a short re-alignment - three consecutive, axial biometry scans of the retina. The measurement process is continuous, but divided in two steps. Blinking by the patient is possible in between the two steps, which increases patient comfort and, in certain cases, measurement success. Precision is evaluated by three repeated, complete measurements with the GALILEI Lens Professional and each predicate device. Two standard devices with comparable optical technology that are used in routine cataract surgery were declared as predicate devices. These two devise are typically used in combination with standard keratometers, as which the GALILEI Lens Professional may be employed as well. Goal: The comparison of the GALILEI Lens Professional to predicate devices with respect to precision in measuring postoperative, calculated target refractions in cataract patients, and versatility of measurable quantities.

Assessed parameters: Axial Length (AL; G6, IOLM, LS) Central Corneal Thickness (CCT; G6, LS)) Anterior Chamber Depth (ACD; G6, IOLM, LS) Lens Thickness (LT; G6, LS) Corneal Curvature (SimK; G6, IOLM, LS) White-to-White (WtW; G6, IOL, LS)

Assessed parameters: Axial Length (AL) Central Corneal Thickness (CCT) Anterior Chamber Depth (ACD) Lens Thickness (LT) Corneal Curvature (SimK) White-to-White (WtW)

Inclusion Criteria: spherical equivalent between -10 D and +10 D best-corrected VA of 20/100 or better. Exclusion Criteria: strabism blepharitis nystagmus amblyopia anisometropia (spherical equivalent > 1D) angle closure glaucoma seizure disorder brain damages Down syndrome trisomy 13 or 18 cerebral palsy other serious disorders of the eye or central nervous systems