Clinical trials

Cataract surgery is one of the most common performed surgeries in the world. While in the early beginnings of cataract surgery, visual rehabilitation was the main goal of the procedure, refractive outcome and subsequent relative spectacles independency is gaining increasing importance in patients' demands. Due to the improvements in measurement techniques and prediction formulas, the prediction of postoperative refraction is possible with high accuracy. However, there are still some sources of error that lead to deviations of predicted postoperative refraction. For instance, it was shown that tear film osmolarity, an established biomarker for dry eye disease (DED), plays an important role in preoperative precision of keratometry measurements. Keratometry, the measurement of corneal curvature, is an important part of preoperative biometry. Errors in preoperative keratometry measurements lead to nearly one-to-one deviations from the predicted refraction. Therefore, proper keratometry measurements are a key element in intraocular lens (IOL) power calculations. To counteract the issue of DED in preoperative biometry, the principle of using lubricating eye drops before ocular biometry has been investigated and it was shown that the use of ocular lubricants may lead to increased variability of keratometry measurements. From our clinical observations, another possible mechanism to improve keratometry is eyelid closure for some minutes. In contrast to the long-term use of ocular lubricants to stabilize the tear film, eyelid closure is an easy and fast intervention to possibly improve the precision of keratometry measurements. Additionally, a clinical trial investigating the usage of lubricating eye drops for two weeks found no improvement of variability of keratometry in DED patients. Therefore, this study aims to investigate the effect of eyelid closure on the quality index of keratometric measurements in patients with a warning for the quality of keratometric measurements. For this purpose, a single study day including 4 repeated measurements (2 without and 2 with lid closure for 3 minutes) using an ocular biometer (IOLMaster700) will be performed.

Comparison of the visual function of two enhanced monofocal intraocular lenses after cataract surgery

This study aims to explore the mechanical properties of the cornea using a non-invasive imaging technique called Brillouin microscopy. This innovative method measures corneal elasticity by detecting small shifts in light frequency, which occur due to interactions with acoustic waves in the tissue. These measurements can provide insights into how corneal stiffness is altered in various eye diseases or after surgery. The study includes 100 participants, divided into different groups: patients with Fuchs' Endothelial Dystrophy (FED), Map Dot Fingerprint Dystrophy (MDFD), and those who have undergone corneal surgeries such as Penetrating Keratoplasty (PKP), Descemet's Stripping Automated Endothelial Keratoplasty (DSAEK), and Descemet Membrane Endothelial Keratoplasty (DMEK). Healthy individuals will also be studied as a control group. Participants will first receive a standard eye exam, including a slit-lamp examination. Then, Brillouin microscopy will be used to measure the cornea's mechanical stiffness. Additional tests include optical coherence tomography (OCT), corneal topography and tomography, pachymetry (measuring corneal thickness), endothelial cell count, and intraocular pressure (IOP) measurement. The purpose of this study is to better understand how diseases and surgeries affect corneal biomechanics. The researchers will also examine how well the Brillouin measurements match with findings from other clinical imaging tests. The results may help improve diagnosis and treatment options for corneal disorders.

Intra-individual comparison of the PureSee EDOF IOL with the Acunex Vario EDOF IOL set for emmetropia.