Image-guided system versus manual marking for toric intraocular lens alignment in cataract surgery

Purpose To compare the accuracy of toric intraocular lens (IOL) alignment using the Verion Image-Guided System versus a conventional manual ink-marking procedure. Setting University Eye Clinic Maastricht, Maastricht, the Netherlands. Design Prospective randomized clinical trial. Methods Eyes with regular corneal astigmatism of at least 1.25 diopters (D) that required cataract surgery and toric IOL implantation (Acrysof SN6AT3-T9) were randomly assigned to the image-guided group or the manual-marking group. The primary outcome was the alignment of the toric IOL based on preoperative images and images taken immediately after surgery. Secondary outcome measures were residual astigmatism, uncorrected distance visual acuity (UDVA), and complications. Results The study enrolled 36 eyes (24 patients). The mean toric IOL misalignment was significantly less in the image-guided group than in the manual group 1 hour (1.3 degrees ± 1.6 [SD] versus 2.8 ± 1.8 degrees; P =.02) and 3 months (1.7 ± 1.5 degrees versus 3.1 ± 2.1 degrees; P &lt;.05) postoperatively. The mean residual refractive cylinder was −0.36 ± 0.32 D and −0.47 ± 0.28 D in the image-guided group and manual group, respectively (P &gt;.05). The mean UDVA was 0.03 ± 0.10 logarithm of minimum angle of resolution (logMAR) and 0.04 ± 0.09 logMAR, respectively (both P &gt;.05). No intraoperative complications occurred during any surgery. Conclusion The IOL misalignment was significantly less with digital marking than with manual marking; this did not result in a better UDVA or lower residual refractive astigmatism.</p

Handling duplicated tasks in process discovery by refining event labels

Processes may require to execute the same activity in different stages of the process. A human modeler can express this by creating two different task nodes labeled with the same activity name (thus duplicating the task). However, as events in an event log often are labeled with the activity name, discovery algorithms that derive tasks based on labels only cannot discover models with duplicate labels rendering the results imprecise. For example, for a log where “payment” events occur at the beginning and the end of a process, a modeler would create two different “payment” tasks, whereas a discovery algorithm introduces a loop around a single “payment” task. In this paper, we present a general approach for refining labels of events based on their context in the event log as a preprocessing step. The refined log can be input for any discovery algorithm. The approach is implemented in ProM and was evaluated in a controlled setting. We were able to improve the quality of up to 42%of the models compared to using a log with imprecise labeling using default parameters and up to 87% using adaptive parameters. Moreover, using our refinement approach significantly increased the similarity of the discovered model to the original process with duplicate labels allowing for better rediscoverability. We also report on a case study conducted for a Dutch hospital

Trial-based cost-effectiveness analysis of Descemet membrane endothelial keratoplasty (DMEK) versus ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK)

Purpose To evaluate the cost-effectiveness of Descemet Membrane Endothelial Keratoplasy (DMEK) versus Ultrathin Descemet Stripping Automated Endothelial Keratoplasty (UT-DSAEK). Methods A cost-effectiveness analysis using data from a multicenter randomized clinical trial was performed. The time horizon was 12 months postoperatively. Patients with Fuchs' endothelial dystrophy were randomized to DMEK (n = 29) or UT-DSAEK (n = 24). Relevant resources from healthcare and societal perspectives were included in the cost analysis. Quality-Adjusted Life Years (QALYs) were determined using the Health Utilities Index Mark 3 (HUI3) and the EuroQol EQ-5D-5L questionnaires. The main outcome was the incremental cost-effectiveness ratio (ICER; incremental societal costs per QALY). Results Societal costs averaged euro8851 (US$11 406) for DMEK and euro8320 (US$10 722) for UT-DSAEK. Higher costs in the DMEK group were mainly caused by higher rebubbling and regraft rates (21% and 7%, vs. 4% and 0% in the UT-DSAEK group). HUI3 QALYs were 0.70 (DMEK) and 0.79 (UT-DSAEK). EQ-5D-5L QALYs were 0.83 (DMEK) and 0.86 (UT-DSAEK). The ICER indicated DMEK was dominated by UT-DSAEK in both analyses. The cost-effectiveness probability for DMEK ranged from 21% to 5% (HUI3 QALYs) and 27%-14% (EQ-5D-5L QALYs), assuming the maximum acceptable ICER ranged from euro2500 to euro80.000 (US$3222-US$103 093) per QALY. Conclusion The base case cost-effectiveness analysis favoured UT-DSAEK over DMEK, as costs of DMEK were higher while QALYs were lower. Further studies are required to assess long-term rebubbling and regraft rates and graft survival

Safety and Comfort of an Innovative Drug Delivery Device in Healthy Subjects

Purpose: The aim of this study was to investigate safety and comfort of two versions of a placebo-microsphere filled ocular coil (straight and curved) in healthy subjects.Methods: The study was a single-center intervention study. One ocular coil was placed in the inferior conjunctival fornix for the intended duration of 28 days. Forty-two healthy adult subjects were included. At baseline, 30 minutes, 8 hours, 24 hours, 48 hours, 7 days, 14 days, 21 days, and 28 days after insertion, examinations were performed, including slit lamp evaluation to score ocular redness, intraocular pressure measurement, visual acuity, tear secretion test, and questionnaires.Results: The straight and curved ocular coils had a median retention time of 5 days and 12 days, respectively. After 48 hours, 57% and 81% subjects retained the straight and curved ocular coil, respectively. Four (19%) subjects with the straight coil and six (29%) with the curved coil completed the entire study period. Minor changes in ocular hyperemia were observed in both groups. On day 7, the straight coil was more comfortable than the curved coil with a visual analogue scale (VAS) score of 77 +/- 21 compared to 94 +/- 11 (P = 0.028), respectively. No other ocular adverse events were observed.Conclusions: Comfort and safety of the straight and curved ocular coil are high. Because the retention time is too short for long-term sustained drug release, the use in the perioperative or immediate postoperative period could prove to be more valuable. Translational Relevance: The ocular coil is a noninvasive, comfortable and safe short-term drug delivery device

Detecting deviating behaviors without models

Deviation detection is a set of techniques that identify deviations from normative processes in real process executions. These diagnostics are used to derive recommendations for improving business processes. Existing detection techniques identify deviations either only on the process instance level or rely on a normative process model to locate deviating behavior on the event level. However, when normative models are not available, these techniques detect deviations against a less accurate model discovered from the actual behavior, resulting in incorrect diagnostics. In this paper, we propose a novel approach to detect deviation on the event level by identifying frequent common behavior and uncommon behavior among executed process instances, without discovering any normative model. The approach is implemented in ProM and was evaluated in a controlled setting with artificial logs and real-life logs. We compare our approach to existing approaches to investigate its possibilities and limitations. We show that in some cases, it is possible to detect deviating events without a model as accurately as against a given precise normative model

Pharmacokinetics and efficacy of a ketorolac-loaded ocular coil in New Zealand white rabbits

Eye drops are considered standard practice for the delivery of ocular drugs. However, low patient compliance and low drug levels compromise its effectiveness. Our group developed a ketorolac-loaded ocular coil for sustained drug delivery up to 28 days. The aim of this study was to gain insight into the pharmacokinetics and efficacy of the ocular coil. The pharmacokinetics of the ketorolac-loaded ocular coil versus eye drops were tested in New Zealand White rabbits by repetitive sampling for 28 days. Efficacy of the ocular coil was also tested in New Zealand White rabbits. Ocular inflammation was induced where after the ocular coil was inserted, or eye drops, or no treatment was provided. The total protein concentration and cytokine levels were measured in tears, aqueous humor, and plasma at 4 h, 8 h, 24 h, 4 d, 7 d, 14 d, 21 d, and 28 d. Four h after inserting the ocular coil in the eye, ketorolac levels in aqueous humor and plasma were higher in the ocular coil group than in the eye drop group. Ketorolac released from the ocular coil could be detected up to 28 d in tears, up to 4 d in aqueous humor and up to 24 h in plasma. After inducing inflammation, both the ocular coil and eye drops were able to suppress prostaglandin E-2, TNF alpha and IL-6 levels in aqueous humor and plasma as compared to the group that received no treatment. To conclude, the ocular coil facilitated a sustained release of the drug and showed similar therapeutic benefit in suppressing post-operative inflammation as eye drops

Surface metrology and 3-dimensional confocal profiling of femtosecond laser and mechanically dissected ultrathin endothelial lamellae

PURPOSE: To determine the feasibility of confocal profiling in measuring surface roughness and obtaining 3-dimensional reconstructions of mechanically dissected and femtosecond (fs)-laser photodisrupted endothelial lamellae. To determine the predictability of single-pass dissection of ultrathin endothelial lamellae using a novel motor-driven linear microkeratome. METHODS: Thirty (n = 30) human corneas were harvested using a motor-driven linear microkeratome (n = 20); a hand-driven rotatory microkeratome (n = 6); and a 60-kHz fs laser (n = 4). Surface roughness was measured using an optical profiler operated in confocal microscopy mode followed by environmental scanning-electron-microscopy. RESULTS: Mean surface roughness for the fs laser, motor-driven linear microkeratome, and hand-driven rotatory microkeratome measured 1.90 ± 0.48 µm, 1.06 ± 0.42 µm, and 0.93 ± 0.25 µm, respectively. Femtosecond photodisrupted lamellae were significantly rougher than mechanically dissected lamellae (P <0.001). Mean (±SD) cutting depth with the motor-driven linear microkeratome measured: 552 ± 11 µm (550-µm head); 505 ± 19 µm (550-µm head); 459 ± 19 µm (450-µm head); and 392 ± 20 µm (400-µm head). CONCLUSIONS: Confocal microscopy allows quantitative surface roughness analysis and 3-dimensional reconstruction of human corneal lamellae. Femtosecond-laser photodisruption at 60 kHz results in rougher surfaces compared with mechanical dissection. The motor-driven linear microkeratome allows single-pass dissection of ultrathin endothelial lamellae with a standard deviation =20 µm

Prevention of Cystoid Macular Edema after Cataract Surgery in Nondiabetic and Diabetic Patients: A Systematic Review and Meta-Analysis

PURPOSE: To evaluate the optimum medical strategy to prevent cystoid macular edema (CME) after cataract surgery. DESIGN: Systematic review and meta-analysis. METHODS: SETTING: Cochrane, MEDLINE, and EMBASE databases were searched to identify eligible randomized controlled trials (RCTs). STUDY POPULATION: RCTs comparing medical strategies to prevent CME after uncomplicated cataract surgery in nondiabetic and diabetic patients. OBSERVATION PROCEDURES: Data were extracted by 2 authors independently. Quality of individual RCTs was assessed using the Cochrane Collaboration's tool for assessing risk of bias and Delphi criteria. MAIN OUTCOME MEASURES: Odds of developing CME within 3 months postoperatively and foveal thickness, macular volume and corrected distance visual acuity change within 3 months postoperatively, as compared to baseline. RESULTS: Seventeen trials reported incidence rates. Topical nonsteroidal anti-inflammatory drugs (NSAIDs) significantly reduced the odds of developing CME as compared to topical corticosteroids in nondiabetic (odds ratio [OR] 0.11; 95% confidence interval [95% CI] 0.03-0.37) and mixed populations (OR 0.05; 95% CI 0.02-0.11). A combination of topical corticosteroids and NSAIDs significantly reduced the odds of developing CME as compared to topical corticosteroids in nondiabetic (OR 0.21; 95% CI 0.10-0.44) and diabetic patients (OR 0.17; 95% CI 0.05-0.50). Intravitreal corticosteroid or anti vascular endothelial growth factor injections did not show any additional benefit in diabetic subjects. CONCLUSIONS: Topical NSAIDs significantly reduced the odds of developing CME, as compared to topical corticosteroids, in nondiabetic and mixed populations. A combination of topical NSAIDs and corticosteroids reduced the odds of developing CME in nondiabetic and diabetic patients, as compared to topical corticosteroids