Purpose To estimate the repeatability of biometric parameters obtained with a new swept-source biometer and to compare agreement that partial coherence interferometry (PCI) optical low-coherence reflectometry (OLCR). Setting Department Ophthalmology, Helios Hospital Erfurt, Julius-Maximilians University, Würzburg, Philipps Marburg, Germany. Design Prospective comparative multicenter clinical study. Methods Biometry was taken use 3 different biometers: IOLMaster 700 biometer, PCI-based 500,...

Purpose To compare crystalline lens tilt in eyes before and intraocular (IOL) after cataract surgery using swept-source optical coherence tomography (SS-OCT) (IOLMaster 700). Setting Hanusch Hospital, Vienna, Austria. Design Prospective case series. Methods Patients' were scanned 1 week 2 months with IOL implantation an SS-OCT device. This device performs B-scans along 6 meridians (0, 30, 60, 90, 120, 150 degrees) to determine tilt. Results Sixty-two (62 patients) included the analysis. The...

To investigate the effects of eyelid pressure on corneal shape and aberrations during reading.Twenty young subjects with normal ocular health were recruited for study. The experiment was conducted early in morning, instructed not to perform any prolonged reading before experiment. Corneal topography one eye measured a videokeratoscope then again after 60-min task. natural position eyelids photographed primary gaze task.Twelve 20 corneas showed significant changes central immediately reading....

Purpose. Videokeratoscopes provide a wealth of information about the topography ocular surface. Although there have been numerous studies accuracy and precision videokeratoscopes with inanimate test objects, little exists on their (repeatability) for real eyes. Methods. To investigate stability surface in inter-blink period, 10 patients were recruited videokeratoscopy. Tear break-up time was measured videokeratographs acquired immediately post-blink again at 4, 8, 12 seconds post-blink....

To investigate whether there are significant changes in corneal topography during accommodation normal corneas and that pathologically thinner due to keratoconus.A videokeratoscope was modified present an stimulus coaxial with the instrument's measurement axis. Six subjects four keratoconus were studied. Eighteen measurements of one eye each subject taken at 0 diopter (D) demand six for both 4 D 9 demand. The effects ocular micromovements on multiple maps minimized using software algorithms....

Abstract. Purpose: To compare lid‐induced changes in corneal optics following reading, microscopy and computer work. Methods: Nine subjects with normal ocular health were recruited for the study. Five myopic, two emmetropic, one was astigmatic hyperopic. Corneal topography measured before after 60 mins of reading a novel, performing blood cell counting task on microscope Internet searching. data used to derive wavefront Zernike coefficients up fourth order. A meridian analysis instantaneous...

To evaluate whether significant change occurs in the topography of anterior or posterior cornea corneal thickness with accommodation.Contact Lens and Visual Optics Laboratory, School Optometry, Queensland University Technology, Brisbane, Queensland, Australia.Corneal data were acquired for 12 young, healthy emmetropic subjects under 2 accommodation levels (relaxed approximately 5.0 diopters) using a rotating Scheimpflug camera. Anterior elevation sagittal curvature as well pachymetry...

To investigate the accuracy of a new ray-tracing-based intraocular lens (IOL) power calculation method and to compare outcomes with different IOL formulas.Hanusch Hospital, Vienna, Austria.Theoretical prospective monocentric study.Monofocal aspheric plate haptic (CT Asphina 409M/MP) implantation was performed in 40 cataractous eyes. At 1 month postoperatively, manifest refraction optical coherence tomography-based biometry (IOLMaster 700) conducted. The refractive spherical equivalent...

Purpose. To investigate the effects of eyelid pressure on corneal topography in different angles gaze and under eye movement conditions. Methods. Ten young subjects with healthy eyes were recruited for study. Corneal right was measured a videokeratoscope before after four 15-minute visual tasks (downward 25° or 45°, both no movements 1 Hz movements). The conducted separate mornings. Results. All showed significant regions topographic change each tasks. In general, found to cause greater...

We aimed to minimize the effect of ocular microfluctuations during videokeratoscopy improve qualitative and quantitative analysis corneal topography.A technique was developed measure tilt, displacement, cyclotorsion in multiple videokeratographs from same cornea. This information used reposition each videokeratograph according average position a sample measurements. The topography 10 subjects measured 20 times each, using videokeratoscopy.The root mean square error calculated difference...

Purpose. The purpose of this article is to investigate the magnitude lid-induced corneal topography changes as a function time spent reading and subsequent course regression these changes. Methods. Six young subjects, five myopes one emmetrope with normal ocular health, participated in study. Corneal eye was measured videokeratoscopy before four sessions 10, 30, 60, 120 min duration performed on separate mornings. again at fixed intervals up 180 after each session. A control trial without...

To investigate analytically whether higher-order wavefront errors comprising combinations of trefoil along 30 degrees (trefoil30), vertical coma, and spherical aberration could provide cues to sphero-cylindrical refractive error development.A total 25 test wavefronts, subdivided into five different types levels root mean square (HO-RMS), were created for the study. One type contained only, producing HO-RMS between 0.1 0.5 microm. Four trefoil, various sign also From power maps 2025 added...

To establish repeatability and validity of a partial coherence interferometry (PCI) device in patients with astigmatism.Industry university.Observational studies.A prospective study determined the agreement between IOLMaster 500 PCI Marco 1-position manual keratometer for measurement mean corneal power, astigmatic axis. Interinstrument interoperator reproducibility was also assessed. A retrospective Javal 2-position keratometer. Repeatability The 95% limits (LoA) were all...

Purpose To assess the scan quality of foveal pit morphology (FPM) and to quantify central retinal thickness (CRT) during routine optical biometry measurements with a full-eye-length swept-source coherence tomography (SS-OCT) biometer prototype (IOLMaster700) compare these results standard examinations using spectral-domain (SD-OCT) technique (Cirrus4000 SD-OCT). Methods As part SS-OCT protocol measure biometric parameters for intraocular lens power calculation, horizontal 1 mm B scans were...

Following our previous work on optimal modeling of corneal surfaces with Zernike polynomials, we have developed a refined bootstrap-based procedure which improves the accuracy method. We show that for normal corneas, number terms usually corresponds to fourth or fifth radial order expansion polynomials. On other hand, distorted corneas such as those encountered in keratoconus surgically altered cases, estimated model was found be up three orders higher than corneas.