a comparison of two devices for taking measurements of the eye to assist in lens selection for cataract surgery

Conditions: Cataract

Summary: the purpose of this study is to compare the ziemer ophthalmic systems ag galilei g6 lens professional to the oculus pentacam® axl for taking images and measurements of the anterior segment of the eye, including the cornea, pupil, anterior chamber and lens, to assist in determining the power of the intraocular lens for implantation.

a corneal topographer/biometer named galilei g6 lens professional was developed by ziemer ophthalmic systems ag for the measurement of anterior segment geometry and axial intraocular distances. the measurement principle of the corneal topographer corresponds to that of the commercially available galilei g4 dual scheimpflug analyzer, whereas the measurement principle of the biometer is based on low coherence interferometry/reflectometry, which has been widely used and applied clinically by a number of predicate devices. one complete measurement consists of a corneal topography/ tomography scan followed by three consecutive, axial biometry scans of the anterior segment (cornea and crystalline lens) and three consecutive, axial biometry scans of the retina. the measurement process is continuous but divided into three alignment-click-steps. such measurements can be applied to given intra ocular lens (iol) types and iol equations, to permit the calculation of recommended iols to be implanted during cataract surgery in order to achieve the desired vision correction. the primary objectives of this clinical study are to: 1) evaluate the inter-device repeatability, inter-operator repeatability and reproducibility of the galilei g6 lens professional in repeated measurements of anterior segment geometry and axial intraocular distances and, 2) demonstrate substantial equivalence through examining agreement of the galilei measurements to those of the predicate device, the pentacam® axl.

Eligibility criteria:
inclusion criteria: * satisfies one of the subject group categories and the enrollment quota for that category has not been reached: 1. normal eyes (phakic eyes without cataracts or corneal disease, refraction ≥ -5.5 d or ≤ +5.0 d) 2. eyes having undergone previous refractive surgery (lasik or prk) 3. eyes with cataracts (locs iii grading with grades 2-6 in any or all of the posterior subcapsular (p2-p5), nuclear (n2-n5) and cortical (c2-c5), assessed by slit lamp examination; no other known ocular pathology) 4. eyes with severe myopia (≤ -6 d according to the american academy of ophthalmology) 5. eyes with severe hyperopia (≥ +5.25 d according to the american academy of ophthalmology) 6. eyes with previous cross-linking and eyes with advanced keratoconus * manifest refraction sspherical eequivalent refraction (mrser) between -10dpt and +10dpt as measured by cycloplegic autorefraction assessed less than 12 months prior to enrollment * best corrected visual acuity (bcva) of logmar 0.2 or better exclusion criteria: * strabismus, nystagmus, amblyopia, anisometropia (difference in mrser\>3d) * angle closure glaucoma * seizure disorder, brain damage, down syndrome, trisomy 13 or 18, cerebral palsy or other serious ophthalmic or central nervous system disorders * severe dry eye * severe corneal scarring * inability to hold gaze * inability to see fixation target