Advances In Optical Axial Length Acquisition In Eyes With Dense Cataracts: Comparison Of The Argos- And The Iol-Master 700-Biometer

To compare acquisition rates of the axial length measurement of two swept source (SS)-biometers, the IOL-Master 700 (Carl Zeiss Meditec AG) and the ARGOS-Biometer with the Enhanced Retinal Visualization (ERV)-mode (Alcon Inc.), in the subgroup of eyes with dense cataracts. The ERV-mode is designed to augment the detection of the retina by shifting the focus of the SS-OCT signal towards the posterior segment of the eye.

Department of Ophthalmology, GLG-Klinikum Barnim, Werner Forßmann Krankenhaus, Eberswalde, Germany. Prospective, single-center, interventional study in a German teaching hospital. The study was revised by the institutional ethic committee of the Brandenburg Chamber of Physicians.

40 otherwise healthy eyes with very dense cataracts according to the LOC-scale III grading (≥N0/NC5, ≥C5, or ≥P5) were included in the study. Density was also quantified with the Pentacam nucleus staging (PNS) module (OCULUS, Wetzlar). The two devices were applied in a randomized order. If both biometers failed, ultrasound was deployed (eye cubed, Ellex). Furthermore K-values, central corneal thickness (CCT), anterior chamber depth (ACD) and lens thickness (LT) were compared. The extraction of the very mature cataracts was performed with phacoemulsification or lens expression. 6 weeks after surgery, the refractive results were assessed to calculate the predictive error (PE) and mean absolute error (MAE).

19 eyes had a preoperative visual acuity of finger counting or worse. 16 surgeries were performed as lens expression. The axial length acquisition rate of the Argos biometer (90%) in eyes with dense cataracts was significantly higher than the acquisition rate of the IOL-Master 700 (62,5%). The ARGOS-Biometer was successful in all eyes, in which the IOL-Master was successful. The ERV-mode was used in 17%. The ARGOS biometer was superior in nuclear and cortical opacifications and higher PNS. The performance of both biometers was equal in subcapsular cataracts. The measured axial lengths of the two devices was not significantly different. There were minor differences in K-values, ACD and CCT. The MedAE was 0,562 D and 0,375 D, respectively

Even though SS-OCT biometers has significantly improved optical axial length acquisition. The ARGOS biometer with ERV- technology seem to add further amendment with a success rate of 90% in eye with very dense cataracts.