statplus regression wont pick up dependent variable

The first AS CI OCT screenshot was taken at the beginning of surgery (“phakic,” Fig. Surgery was performed under topical anesthesia in all cases by one experienced surgeon (OF).

However, these methods cannot predict with certainty either the IOL position immediately after surgery, or the ACD shift within the first months after surgery. 11 and Norrby 12 developed ray tracing programs for IOL power calculation purposes.

Olsen 10 developed a thick lens formula using AL, ACD, crystalline lens thickness (LT), corneal radius (CR), and preoperative refraction in a prediction algorithm for ELP. Haigis 9 used AL and preoperative ACD for estimation of ELP. 8 used axial eye length (AL) and corneal power (K) for estimation of ELP and subsequent IOL power calculation. Retzlaff et al., 6 Hoffer, 7 and Holladay et al. However, it does not directly correlate with the anatomical IOL position. 5 Different IOL power formulae were developed to overcome this problem using the so-called effective lens position (ELP), which can be interpreted as a “fudge” factor used to attempt to optimize the formulae for empirical data. Approximately 50% of this postoperative refractive error is the imprecise prediction of the postoperative IOL position, or postoperative anterior chamber depth (ACD). However, after cataract surgery, approximately 9% 2, 3 to 20% 4 of all patients need a refractive correction of more than 1 diopter (D). Postoperative emmetropia is the major determining factor for patient satisfaction after cataract surgery 1-and especially critical for functioning of modern intraocular lens (IOL) designs, such as aspherical, multifocal, and toric IOLs. The main problem of IOL power calculation, the prediction of the IOL position after surgery, could possibly be reduced by using intraoperative lens capsule measurements instead of preoperative ACD measurements.

PLSR showed that the anterior lens capsule measured after removing the crystalline lens and after implanting a CTR was a significantly better predictor for the postoperative ACD compared with preoperative ACD measurements. Mean axial eye length was 23.6 mm (range, 20.6 mm–30.8 mm), mean used IOL power was 22.2 diopters (D range, 6.0 D–31.5 D). In total, 70 eyes of 70 patients were included. Partial least squares regression (PLSR) was used to assess the influence of different pre- and intraoperatively measured parameters. Partial coherence interferometry was used to measure anterior chamber depth (ACD) immediately before, and 1 hour and 3 months postoperatively. In all cases, a capsular tension ring (CTR) was used to tauten the lens capsule. A prototype operating microscope with an integrated continuous OCT device was used to measure the anterior and posterior lens capsule position at different time points during cataract surgery. This prospective study included patients who were scheduled for cataract surgery. The aim of this study was to assess, if measuring the position of the lens capsule intraoperatively with a continuous intraoperative optical coherence tomography (OCT) device could be useful to improve the prediction of the intraocular lens (IOL) position.

Statplus regression wont pick up dependent variable