clinical study - es 900 - 2020-1

Conditions: Cataract

Summary: eyestar 900 is a device developed by haag-streit which utilises 3d oct for quantitative measurements of the geometry of the entire eye, including ocular biometry and corneal topography. it is the most recent in a series of successful biometry devices by haag-streit (hs pachymeter, lenstar ls 900, ls 900 t-cone and ls 900 aps) and also allows for advanced corneal tomography examinations. the eyestar 900 is ce marked. these measurement results of this device are used for the planning of the medical treatment of patients. depending on the application, the benefits of this device may include improved visual acuity (after cataract surgery), reduced risk of complications (after refractive surgery or implant of a phakic intraocular lens), early identification of pathological deformations of the cornea (keratoconus detection). the primary objective of this clinical trial is to assess the clinical performance of the investigational device in dense cataracts. to that end, for each measurand, the in-vivo repeatability will be quantified, as well as limits of agreement and the mean measurement deviation, with respect to the current gold standard device. as a secondary objective of the study, raw measurement data will be collected to allow for the improvement of existing algorithms, development of additional measurands and for retrospective analysis. no diseases are studied.

the eyestar 900 is a non-contact device for measuring the human eye, consisting of a swept source oct sub-unit (oct: optical coherence tomography, a measurement method to acquire tomographic images by optical interferometry) and an imaging system sub-unit. the oct sub-unit performs a three-dimensional measurement of all refractive ocular structures in the anterior eye segment (curvatures and locations of the anterior corneal surface, posterior corneal surface, the anterior crystalline lens surface, posterior crystalline lens surface), as well as a one-dimensional measurement of axial eye length. it also generates cross-sectional images of the anterior eye section and the central retina. the measurement is implemented by scanning the eye with a low-power near-infrared laser beam and measuring the light which is back-reflected to the device. the imaging system sub-unit is used to obtain photographic images of the eye. based on these images, the keratometry (anterior corneal curvature of the steepest and flattest meridian), the white-to-white distance and the pupil diameter are measured. additionally, these images can serve to document the locations of special landmarks on the eye, such as blood vessels. the imaging system sub-unit is based on conventional digital photography technology. illumination for imaging is provided by infrared and white-light leds (light emitting diodes). measurement of keratometry additionally requires measuring the distance to the eye using the oct sub-unit. the eyestar 900 is designed as standalone-device with integrated pc (personal computer) and display for device operation, measurement acquisition and processing, and presentation of the measurement results. after a patient is placed in front of the device and the chin rest is adjusted, the device can perform the remaining positioning procedures and acquire the measurements in a fully automated manner. position information is derived from the oct and digital camera system sub-units. both implemented measuring methods, optical coherence tomography (oct), as well as digital photography are non-invasive, contactless methods. oct uses a laser beam of λ=1060nm central wavelength and less than 2 mw optical power, which is focussed to a beam diameter of approximately 80µm at the anterior lens plane, and is continuously scanned in the lateral direction. digital photography uses diffuse illumination of the eye by white-light leds (425nm ≤ λ ≤ 725nm) and infrared leds with central wavelength λ=850nm. all light sources emit levels that comply with iso 15004-2 ("ophthalmic instruments - fundamental requirements and test methods - part 2: light hazard protection"), under normal operating conditions as well as in case of a single fault condition. the main application of this device is to acquire biometric measurements of cataractous eyes which are used to calculate suitable intraocular lens power and dimension. the patient population must be capable of sitting up straight and keeping their head still and their eyes opened. they must be physically and mentally able to cooperate and mentally capable of following the examination. patients must be at least 18 years old. the target device user is an ophthalmologist or a trained specialist. the investigational device eyestar 900 is developed and manufactured by haag-streit ag, koeniz (switzerland). for the duration of the examination (approximately 1-2 minutes), the patient is in contact with the device at following applied parts: 1. the chin rest shell (edistir rk451 g naturally coated with haeratex aqua 2k-structural coater bw89 10k ral 9005); 2. the forehead rest band (saxamid 126-n001 uncoated pa6 white fk 6659 pa); 3. (depending on the subject's requirements) the patient handles (aluminium en aw-6060 (almgsi 0.5) colourless anodized class 20 with sealing chemically polished and sandblasted). no other contact with body tissues or fluids takes place. no critical biocompatibility issues were identified.

Eligibility criteria:
inclusion criteria: * voluntary participation * informed consent * 35 years of age or older exclusion criteria: * ineligibility for cataract surgery for any reason, e.g., aphakia * disqualifying pathologies: * keratoconus * corneal astigmatism of more than 3.5 d * history of recurrent inflammation or infection of the eye * disqualifying corneal conditions: * comorbidities, * deformations, * lesions, or * scarring of the cornea * acute inflammation or infection of the eye * disqualifying treatments: * previous refractive surgeries, including prk and lasik * previous corneal surgeries * previous corneal transplants * previous intraocular surgeries * disqualifying outcomes: * failed iol implantation into the capsular bag

Keywords: optical biometry corneal topography