Jolanta Gronkowska-Serafin

Clinical outcomes after cataract surgery with implantation of the Tecnis ZMB00 multifocal intraocular lens

Background The aim of this study was to evaluate visual performance, contrast sensitivity, and patient satisfaction in patients undergoing cataract surgery with bilateral implantation of the Tecnis ZMB00 diffractive multifocal IOL (intraocular lens). Material/Methods This was a prospective study of 40 eyes of 20 patients with an age range from 48 to 67 years and undergoing cataract surgery with implantation of the diffractive 1-piece IOL Tecnis ZMB00 (Abbott Medical Optics) in 1 eye and 3 weeks later in the other eye. The following parameters were evaluated at 3 and 6 months after the operation: binocular uncorrected distance, intermediate and near visual acuity (UDVA, UIVA, UNVA), uncorrected binocular photopic and mesopic distance and photopic near contrast sensitivity (CSV-1000), subjective symptoms, and patient satisfaction (VF-14). Results No significant change was observed in logMAR UDVA between 3 and 6 months postoperatively (−0.11±0.14 vs. −0.10±0.13, p>0.05). In contrast, UNVA (0.06±0.12 vs. −0.02±0.12, p=0.004) and UIVA (0.12±0.15 vs. 0.07±0.11, p=0.005) in this period improved significantly. At 3 and 6 months after surgery, 85% of patients no longer needed to wear corrective lenses. Contrast sensitivity under different conditions was within normal age-matched limits, with significant improvements for some spatial frequencies at 3 and 6 months after surgery (p<0.04). Mean overall patient satisfaction was 9.39±1.06 and 9.19±1.20 (scale from 1 to 10, with 10 being the best score) at 3 and 6 months, respectively. Low level of halo perception was reported in 75% of patients. Conclusions The Tecnis ZMB00 IOL provides an effective restoration of the distance, intermediate, and near visual function, allowing patients to be totally free of need to wear corrective lenses and providing high levels of patient satisfaction.

Cell Detection in Corneal Endothelial Images Using Directional Filters

The article presents an algorithm for the detection of corneal endothelium cells in images obtained with confocal microscopy (KH algorithm). Firstly, preprocessing issues are presented. The proposed methodology is based on image processing algorithms, especially filters. The method outputs images that are prepared for further analysis, e.g. stereological measurements. Each step of the algorithm is discussed in detail and other methods of digital images processing are compared to the research results.

Towards Precise Segmentation of Corneal Endothelial Cells

This article describes an algorithm for defining the precise, objective, repeatable and unambiguous segmentation of cells in images of the corneal endothelium. This issue is important for clinical purposes, because the quality of the grid cells is assessed on the basis of segmentation. Other solutions, including commercial software, do not always mark cell boundaries along lines of lowest brightness.

Problems of corneal endothelial image binarization

In this paper we present two methods of binarization of corneal endothelial images. The binarization is a first step of advanced image analysis. Images of corneal endothelial obtained by the specular microscopy have a poor dynamic range and they are usually non-uniformly illuminated. The binarization endothelial images is not trivial. Two binarization algorithms are proposed. The output images are presented. The quality of algorithms is discussed.

Corneal Endothelial Grid Structure Factor Based on Coefficient of Variation of the Cell Sides Lengths

Description of the corneal endothelial cell grid is a valuable diagnostic pointer, used in Ophthalmology. Until now, two quality factors were used: hexagonality (H) and the relative standard deviation of the cell surface (CV). Both the factors do not take into account the length measure of the grid cells, which has been presented in an article on the sample images. The authors propose an additional factor, the average relative standard deviation of the cell sides lengths (CVSL), which takes the cells non-uniformity into account.

Influence of applied corneal endothelium image segmentation techniques on the clinical parameters

The corneal endothelium state is verified on the basis of an in vivo specular microscope image from which the shape and density of cells are exploited for data description. Due to the relatively low image quality resulting from a high magnification of the living, non-stained tissue, both manual and automatic analysis of the data is a challenging task. Although, many automatic or semi-automatic solutions have already been introduced, all of them are prone to inaccuracy. This work presents a comparison of four methods (fully-automated or semi-automated) for endothelial cell segmentation, all of which represent a different approach to cell segmentation; fast robust stochastic watershed (FRSW), KH method, active contours solution (SNAKE), and TOPCON ImageNET. Moreover, an improvement framework is introduced which aims to unify precise cell border location in images pre-processed with differing techniques. Finally, the influence of the selected methods on clinical parameters is examined, both with and without the improvement framework application. The experiments revealed that although the image segmentation approaches differ, the measures calculated for clinical parameters are in high accordance when CV (coefficient of variation), and CVSL (coefficient of variation of cell sides length) are considered. Higher variation was noticed for the H (hexagonality) metric. Utilisation of the improvement framework assured better repeatability of precise endothelial cell border location between the methods while diminishing the dispersion of clinical parameter values calculated for such images. Finally, it was proven statistically that the image processing method applied for endothelial cell analysis does not influence the ability to differentiate between the images using medical parameters.

Comparison of Assessment Regularity Methods Dedicated to Isotropic Cells Structures Analysis

Assessment of regularity based on quantitativemeasurements is important for biological structures analysis. The most important is the analysis of the cells’ structures. In this paper a few assessment methods are compared: hexagonality, coefficient of variation of sizes, and average coefficient of variation of cells’ sides lengths (the new proposed by the authors). This evaluation is based on synthetically generated image datasets for unbiased Monte Carlo analysis. The cell structures are time– evolved using optimization approach starting from irregular to regular.

Towards Automated Cell Segmentation in Corneal Endothelium Images

This article addresses the problem of corneal endothelium image segmentation. The aim is an objective determination of boundaries between cells. This problem has not been solved yet as a fully automatic process, the majority of commercial software requires additional correction by an ophthalmologist.

Clinical Outcomes after Uncomplicated Cataract Surgery with Implantation of the Tecnis Toric Intraocular Lens

Purpose. To evaluate the clinical outcomes after uncomplicated cataract surgery with implantation of an aspheric toric intraocular lens (IOL) during a 6-month follow-up. Methods. Prospective study including 27 consecutive eyes of 18 patients (mean age: 66.1 ± 11.4 years) with a visually significant cataract and corneal astigmatism ≥ 0.75 D and undergoing uncomplicated cataract surgery with implantation of the Tecnis ZCT toric IOL (Abbott Medical Optics). Visual, refractive, and keratometric outcomes as well as IOL rotation were evaluated during a 6-month follow-up. At the end of the follow-up, patient satisfaction and perception of optical/visual disturbances were also evaluated using a subjective questionnaire. Results. At 6 months after surgery, mean LogMAR uncorrected (UDVA) and corrected distance visual acuity (CDVA) were 0.19 ± 0.12 and 0.14 ± 0.10, respectively. Postoperative UDVA of 20/40 or better was achieved in 92.6% of eyes. Mean refractive cylinder decreased significantly from −3.73 ± 1.96 to −1.42 ± 0.88 D (p < 0.001), while keratometric cylinder did not change significantly (p = 0.44). Mean absolute IOL rotation was 1.1 ± 2.4°, with values of more than 5° in only 2 eyes (6.9%). Mean patient satisfaction score was 9.70 ± 0.46, using a scale from 0 (not at all satisfied) to 10 (very satisfied). No postoperative optical/visual disturbances were reported. Conclusion. Cataract surgery with implantation of the Tecnis toric IOL is an effective method of refractive correction in eyes with corneal astigmatism due to the good IOL positional stability, providing high levels of patients satisfaction.