Big data simulations for capacity improvement in a general ophthalmology clinic

PURPOSE Long total waiting times (TWT) experienced by patients during a clinic visit have a significant adverse effect on patient's satisfaction. Our aim was to use big data simulations of a patient scheduling calendar and its effect on TWT in a general ophthalmology clinic. Based on the simulation, we implemented changes to the calendar and verified their effect on TWT in clinical practice. DESIGN AND METHODS For this retrospective simulation study, we generated a discrete event simulation (DES) model based on clinical timepoints of 4.401 visits to our clinic. All data points were exported from our clinical warehouse for further processing. If not available from the electronic health record, manual time measurements of the process were used. Various patient scheduling models were simulated and evaluated based on their reduction of TWT. The most promising model was implemented into clinical practice in 2017. RESULTS During validation of our simulation model, we achieved a high agreement of mean TWT between the real data (229 ± 100 min) and the corresponding simulated data (225 ± 112 min). This indicates a high quality of the simulation model. Following the simulations, a patient scheduling calendar was introduced, which, compared with the old calendar, provided block intervals and extended time windows for patients. The simulated TWT of this model was 153 min. After implementation in clinical practice, TWT per patient in our general ophthalmology clinic has been reduced from 229 ± 100 to 183 ± 89 min. CONCLUSION By implementing a big data simulation model, we have achieved a cost-neutral reduction of the mean TWT by 21%. Big data simulation enables users to evaluate variations to an existing system before implementation into clinical practice. Various models for improving patient flow or reducing capacity loads can be evaluated cost-effectively

Response of neovascular central serous chorioretinopathy to an extended upload of anti-VEGF agents

Purpose To determine the anatomical and functional outcomes of an extended 6-month intravitreal anti-vascular endothelial growth factor (anti-VEGF) upload in choroidal neovascularization (CNV) secondary to chronic central serous chorioretinopathy (CSCR). Methods A retrospective database analysis was performed applying the following inclusion criteria: (1) diagnosis of CSCR, (2) diagnosis of secondary CNV, and (3) treatment of at least six consecutive injections of anti-VEGF. Outcome measures included the change of central retinal subfield thickness, remodeling of the pigment epithelium detachments, and change in visual function. Results Twenty-one eyes of 21 patients were included. Mean patient age was 65 ± 8.3 years, and 35% of the patients (n = 8) were female. Mean disease duration before diagnosis of CNV was 48 ± 25.3 months. Mean central retinal thickness decreased from 346 ± 61 to 257 ± 57 μm (p < 0.01) after the sixth injection while mean visual acuity improved from 0.65 ± 0.35 to 0.49 ± 0.29 (logMAR; p < 0.01). Of note, an extended upload of six as opposed to three injections yielded an additional mean central retinal thickness reduction (280 ± 46 μm vs. 257 ± 57 μm, p = 0.038). Significant CNV remodeling was observed as a decrease in pigment epithelium detachment (PED) vertical (p = 0.021) and horizontal diameter (p = 0.024) as well as PED height (p < 0.01). Conclusion An extended anti-VEGF upload of six consecutive injections seems to be effective in inducing CNV remodeling and fluid resorption in CNV complicating chronic CSCR

Evaluation of Functional Outcomes and OCT-Biomarkers after Intravitreal Dexamethasone Implant for Postoperative Cystoid Macular Edema in Vitrectomized Eyes

Purpose. To evaluate the efficacy of dexamethasone implant (DEX) for the treatment of postoperative cystoid macular edema (PCME) in vitrectomized eyes and to investigate visual and morphological OCT predictive factors. Methods. In this retrospective study, eyes with PCME after vitrectomy were treated with at least one DEX injection and were observed over 12 months. Indications for surgery were epiretinal membrane (ERM) or rhegmatogenous retinal detachment (RRD) without macular involvement. Prior treatments, if any, were noted. Best corrected visual acuity (BCVA), central foveal thickness (CFT), and OCT morphology including the presence of intraretinal cysts/fluid or subretinal fluid (IRF/SRF) and ellipsoid zone (EZ) continuity were evaluated. Correlations between OCT measures and visual outcomes were analyzed by the generalized estimating equations procedure. Results. Forty-six eyes with ERM and 15 eyes with RRD were enrolled. The ERM group was more likely to gain BCVA than RRD (odds ratio (OR), 1.168;95% confidence interval (CI), 1.003-1.360;p=0.046). The absence of SRF (OR, 0.860;95% CI, 0.743-0.995;p=0.043) was predictive of worse BCVA, whereas the integrity of EZ (OR, 1.094;95% CI, 0.951-1.257;p=0.209) or naive status (OR, 0.946;95% CI, 0.871-1.137, p=0.853) was not. Eyes with a worse baseline BCVA were more likely to gain >1 line after 12 months (OR, 1.485;95% CI, 1.171-1.884;p=0.001). Conclusion. The efficacy of the treatment of PCME in vitrectomized eyes seems to be affected by baseline BCVA, the absence of SRF, and the indication for surgery. Naive status appears not to play any significant role in the prediction of BCVA. This trial is registered with DRKS00018955

Impact of Sub-Retinal Fluid on the Long-Term Incidence of Macular Atrophy in Neovascular Age-related Macular Degeneration under Treat & Extend Anti-Vascular Endothelial Growth Factor Inhibitors

Sub-retinal fluid (SRF) has been discussed as a protective factor against macular atrophy in eyes with neovascular age-related macular degeneration (nAMD).To gauge the impact of SRF on macular atrophy, a database of 310 nAMD eyes was screened for eyes manifesting an SRF-only phenotype under treat & extend anti-VEGF treatment, defined as nAMD expressing CNV exudation beyond the three monthly anti-VEGF loading doses by SRF only without any signs of exudative intra-retinal fluid (IRF) for >= 3 years. Incidence of macular atrophy and treatment responses were evaluated on multimodal imaging, including optical coherence tomography (OCT), blue autofluorescence (BAF) and near-infrared (NIR) confocal scanning laser ophthalmoscopy and fluorescence and indocyanine green angiography (FAG/ICGA). In total, 27 eyes (8.7%) of 26 patients with a mean follow-up of 4.2 +/- 0.9 (3-5) years met the inclusion criteria. Mean age was 72 +/- 6 (range: 61-86) years. The SRF only phenotype was seen from baseline in 14 eyes (52%), and in 13 eyes (48%) after a mean 1.0 +/- 1.3 (1-3) injections. In years 1 to 5, mean 7.5, 5.9, 6.1, 6.1 and 7.0 anti-VEGF injections were given (p=0.33). Cumulative macular atrophy incidence was 11.5% at year 1, 15.4% throughout years 2 to 4, and 22.4% at year 5. In conclusion, eyes manifesting activity by SRF only in treat & extend anti-VEGF regimen for nAMD seem to exhibit rather low rates of macular atrophy during long-term follow-up. SRF might be an indicator of a more benign form of nAMD

Differences in corneal clinical findings after standard and accelerated cross-linking in patients with progressive keratoconus

Background: The purpose of this study was to identify differences in clinical corneal findings after standard and accelerated epithelial off cross-linking (CXL) during a long-term follow-up. Methods: Two hundred forty-one patients (184 male) were included in this monocentric, retrospective, non-randomized and unmasked study. One hundred forty-eight eyes were treated with the accelerated protocol and 138 with the standard protocol with epithelial off CXL, if diagnosed with keratoconus and a progression in Kmax of more than one dioptre during the preceding 6 months, plus a minimal pachymetry measurement of 400 mu m in keratometry (Pentacam, Oculus GmbH, Wetzlar, Germany). Exclusion criteria were previous surgery, other corneal conditions or age above 50 years. Follow-up time was 36 months with clinical examination and keratometry at every visit. Outcome measures were the observed rate of corneal changes, differences between treatment groups and correlation with keratometry measurements. Results: In patients with accelerated CXL, significantly more clear corneas were seen at three (p = 0.015) and six (p = 0.002) months after surgery than following the standard protocol. The rate of clear corneas dropped from 52.2% pre-operation (OP) to a minimum of 19.3% after 6 months in the standard protocol group compared with 50.7% clear corneas pre-OP and a minimum of 40.8% in the accelerated group. In the standard protocol group, more striae were found 3 months after intervention than in the accelerated group (p = 0.05). Conclusions: In patients with accelerated CXL, fewer morphological corneal changes were observed than after conventional CXL. However, rarely, corneal changes persisted for a long time

Venous thromboembolism in critically ill COVID-19 patients receiving prophylactic or therapeutic anticoagulation: a systematic review and meta-analysis

Many aspects of care such as management of hypercoagulable state in COVID-19 patients, especially those admitted to intensive care units is challenging in the rapidly evolving pandemic of novel coronavirus disease 2019 (COVID-19). We seek to systematically review the available evidence regarding the anticoagulation approach to prevent venous thromboembolism (VTE) among COVID-19 patients admitted to intensive care units. Electronic databases were searched for studies reporting venous thromboembolic events in patients admitted to the intensive care unit receiving any type of anticoagulation (prophylactic or therapeutic). The pooled prevalence (and 95% confidence interval [CI]) of VTE among patients receiving anticoagulant were calculated using the random-effects model. Subgroup pooled analyses were performed with studies reported prophylactic anticoagulation alone and with studies reported mixed prophylactic and therapeutic anticoagulation. We included twelve studies (8 Europe; 2 UK; 1 each from the US and China) in our systematic review and meta-analysis. All studies utilized LMWH or unfractionated heparin as their pharmacologic thromboprophylaxis, either prophylactic doses or therapeutic doses. Seven studies reported on the proportion of patients with the previous history of VTE (range 0–10%). The pooled prevalence of VTE among ICU patients receiving prophylactic or therapeutic anticoagulation across all studies was 31% (95% CI 20–43%). Subgroup pooled analysis limited to studies reported prophylactic anticoagulation alone and mixed (therapeutic and prophylactic anticoagulation) reported pooled prevalences of VTE of 38% (95% CI 10–70%) and 27% (95% CI 17–40%) respectively. With a high prevalence of thromboprophylaxis failure among COVID-19 patients admitted to intensive care units, individualised rather than protocolised VTE thromboprophylaxis would appear prudent at interim

Development and Valuation of a Preference-Weighted Measure in Age-Related Macular Degeneration From the Vision Impairment in Low Luminance Questionnaire—A MACUSTAR Report

Objectives: This study generates VILL-UI (Vision Impairment in Low Luminance - Utility Index), a preference-weighted measure (PWM) derived from the VILL-33 measure for use in patients with age-related macular degeneration (AMD) and valued to generate United Kingdom and German preference weights. Methods: A PWM consists of a classification system to describe health and utility values for every state described by the classification. The classification was derived using existing data collected as part of the MACUSTAR study, a low-interventional study on AMD, conducted at 20 clinical sites across Europe. Items were selected using psychometric and Rasch analyses, published criteria around PWM suitability, alongside instrument developer views and concept elicitation work that informed VILL-33 development. An online discrete choice experiment (DCE) with duration of the health state was conducted with the United Kingdom and German public. Responses were modeled to generate utility values for all possible health states. Results: The classification system has 5 items across the 3 domains of VILL-33: reading and accessing information, mobility and safety, and emotional well-being. The DCE samples (United Kingdom: n = 1004, Germany: n = 1008) are broadly representative and demonstrate good understanding of the tasks. The final DCE analyses produce logically consistent and significant coefficients. Conclusions: This study enables responses to VILL-33 to be directly used to inform economic evaluation in AMD. The elicitation of preferences from both United Kingdom and Germany enables greater application of VILL-UI for economic evaluation throughout Europe. VILL-UI fills a gap in AMD in which generic preference-weighted measures typically lack sensitivity