Optical Coherence Tomography Angiography Changes in Patients Diagnosed With Acute Coronary Syndrome: A Systematic Review and Meta-Analysis.

We conducted a systematic review and meta-analysis to assess the association between optical coherence tomography angiography (OCTA) parameters and acute coronary syndrome (ACS). Two independent reviewers searched the electronic databases (MEDLINE (Medical Literature Analysis and Retrieval System Online), Scopus, Embase (Excerpta Medica Database), Cochrane Library, ClinicalTrials.gov, and World Health Organization International Clinical Trials Registry Platform) from inception until April 2023. According to the inclusion criteria of this review, eligible were observational studies, randomized control trials, and registry/database studies that included the eyes of adult ACS patients and assessed OCTA parameters within the macula. The pooled standardized mean differences (SMD) between patients diagnosed with ACS and healthy controls with a confidence interval (CI) of 95% were calculated using the Hartung-Knapp-Sidik-Jonkman random-effects method. The heterogeneity was assessed by I2 and the Cochran Q and a random effects model was applied. Seven studies were eligible and included in our systematic review (n = 898), of which three were included in the meta-analysis (n = 341). The pooled SMD in the superficial vascular plexus (SVP), deep vascular plexus (DVP), and foveal avascular zone (FAZ) were -0.46 (95% CI: -0.94 to 0.01, p = 0.05, I2 = 0%, three studies), -0.10 (95% CI: -3.20 to 3.00, p = 0.75, I2 = 67%, two studies), and 0.43 (95% CI: -1.22 to 2.09, p = 0.38, I2 = 92%, three studies), respectively. Our findings suggest that there are no differences in OCTA metrics between ACS patients and healthy individuals.

Correlation Between Coronary and Retinal Microangiopathy in Patients With STEMI.

Purpose: To investigate the morphological and functional correlation between microvascular retinal changes in optical coherence tomography angiography (OCTA) and the microvascular coronary circulation in patients with ST elevation myocardial infarction (STEMI) coronary heart disease (CHD). Methods: A total of 330 eyes from 165 participants (88 cases and 77 controls) were enrolled and imaged. Superficial capillary plexus (SCP) and deep capillary plexus (DCP) vascular density was measured in the central (1 mm) and perifoveal (1-3 mm) areas and in the superficial foveal avascular zone (FAZ) and choriocapillaris (3 mm). These parameters were then correlated to the left ventricular ejection fraction (LVEF), and the number of affected coronary arteries. Results: Decreased vessel densities in the SCP and DCP and choriocapillaris were positively correlated to the LVEF values (P = 0.006, P = 0.026, and P = 0.002, respectively). No statistically significant correlation between the SCP and DCP central area or FAZ area was found. Regarding the number of affected vessels, significant negative correlations were revealed for the SCP and DCP central vessel densities (P < 0.001 and P < 0.001, respectively) and the SCP perifoveal vascular density (P = 0.009). Conclusions: OCTA vascular indices are significantly correlated with morphological and functional parameters in patients with STEMI CHD. SCP vascular density especially seems to be a promising biomarker for the extent of both macrovascular damage (number of affected coronary arteries) and microvascular damage, as mirrored in the decreased LVEF at admission. Translational Relevance: OCTA vascular indices offer a valuable insight into the microvascular status of coronary circulation.

Impact of Cataract Surgery on IOP and Ocular Structures in Normotensive Patients and Primary and Exfoliation Open-Angle Glaucoma Patients.

Purpose: The aim of this study was to evaluate and compare the changes in Intraocular Pressure (IOP) and other ocular parameters: the Anterior Chamber Angle (ACA), Anterior Chamber Volume (ACV), and Anterior Chamber Depth (ACD) during phacoemulsification surgery in Greek patients with normotensive eyes and those with well-controlled Open-Angle Glaucoma (OAG). Additionally, parameters such as the Corneal Thickness (CCT), Axial Length (AL), Central Macular Thickness (CMT), and Retinal Nerve Fibre Layer (RNFL) were also examined. Patients and Methods: This was a prospective observational case-control study that included 50 phakic eyes, 25 normotensive (Group 1), and 25 with OAG: 15 Primary Open-Angle Glaucoma (POAG) and 10 Exfoliation Glaucoma (EXG) (Group 2). Ophthalmic assessment included IOP measurements, ocular biometry, and anterior and posterior segment optical coherence tomography evaluation of the aforementioned ocular parameters, prior and 6 months after phacoemulsification surgery. Results: At the 6 months post-operative review, a greater IOP reduction was recorded in eyes with OAG, in comparison to normotensive ones (5.3mmHg and 1.6 mmHg respectively). In addition, a significant but similar increase was recorded in the values of the ACA, ACV, and ACD of both groups between the pre- and the post-op period. Furthermore, the CCT and AL values remained unaltered. Finally, there was a non-statistically significant change in the mean CMT and the mean average RNFL of both groups. Conclusion: Eyes with OAG tend to undergo a greater reduction in IOP post-phacoemulsification surgery, in comparison to normotensive eyes. This reduction may not be solely attributed to ocular anatomical changes after phacoemulsification surgery but may also be due to the remodeling of the trabecular meshwork and the ciliary body. This may be especially true in the case of OAG eyes, which already start off with a compromised trabecular endothelium prior to surgery.

UGH Syndrome Resolution after IOL Explantation and Concomitant Carlevale IOL Implantation.

OBJECTIVE: To examine the use of Carlevale IOL placement in patients with UGH, and to evaluate surgical outcomes. DESIGN: In this retrospective study, 28 patients with UGH syndrome that were subjected to IOL explantation and concomitant Carlevale IOL implantation were included in the study. METHODS: Information about VA, IOP, number of glaucoma medication, need for glaucoma surgery, presence of hemorrhage and inflammation were recorded up to 6 months after the procedure. RESULTS: We found a statistically significant increase in mean visual acuity and complete resolution of uveitis in all patients. Mean IOP and the mean number of glaucoma medications were significantly decreased postoperatively, while 14% of patients required additional glaucoma surgery. CONCLUSIONS: IOL explantation and concomitant Carlevale IOL implantation may provide a viable solution for UGH syndrome resolution, increases visual acuity, and decreases the need for glaucoma medication.

Late PAMM-Like Lesions in a Patient with HIV Retinopathy.

This report describes a case of a newly diagnosed 49-year-old HIV patient, who presented with decreased visual acuity and retinal lesions characterized by ischemia at the level of the deep retinal capillary plexus, documented with optical coherence tomography (OCT), OCT angiography, fluorescein angiography, and visual fields testing. These lesions closely resembled the morphologic and clinical characteristics of late paracentral acute middle maculopathy. The presence of these lesions suggests that HIV microangiopathy can potentially affect both superficial and deep retinal capillary plexuses.

Impact of flight and equivalent short-term high-altitude exposure on ocular structures and function.

Background: Exposure to high-altitude conditions during flight or similar activities affects many aspects of visual function, which is critical not only for flight safety but for any altitude-related activity. We aimed to summarize the available literature pertaining to ocular changes during flight or equivalent short-term high-altitude exposure (e.g., hypobaric chamber, effortless ascent lasting ≤ 24 h) and to highlight future research priorities. Methods: Using the PubMed/MEDLINE and Web of Science/ISI Web of Knowledge databases with structured search syntax, we conducted a systematic review of the literature spanning a 40-year period (January 1, 1983, to October 10, 2023). Articles pertaining to ocular changes during flight or flight-equivalent exposure to altitude were retrieved. The reference lists of retrieved studies were also searched, and citations of these references were included in the results. Results: Of 875 relevant PubMed and ISI publications, 122 qualified for inclusion and 20 more were retrieved from the reference lists of initially selected records, for a total of 142 articles. Reported anterior segment changes included deterioration in tear film stability and increased dry eye incidence, increased corneal thickness, discomfort and bubble formation in contact lens users, refraction changes in individuals with prior refractive surgery, decreased intraocular pressure, and alterations in pupillary reaction, contrast sensitivity, and visual fields. Photoreceptor-visual pathway changes included alterations in both photoreceptors and neuro-transduction, as evidenced in dark adaptation, macular recovery time, reduction in visual field sensitivity, and optic neuritis (likely an element of decompression sickness). Retinochoroidal changes included increases in retinal vessel caliber, retinal blood flow, and choroidal thickness; central serous chorioretinopathy; and retinal vascular events (non-arteritic ischemic optic neuropathy, high-altitude retinopathy, and retinal vein occlusion). Conclusions: The effect of short-term high-altitude exposure on the eye is, in itself, a difficult area to study. Although serious impairment of visual acuity appears to be rare, ocular changes, including tear film stability, contact lens wear, central corneal thickness, intraocular pressure, contrast sensitivity, stability of refractive surgeries, retinal vessels, visual fields, and macula recovery time, should be considered in civilian aviators. Our report provides guidance to climbers and lowlanders traveling to altitude if they have pre-existing ocular conditions or if they experience visual symptoms while at altitude. However, key outcomes have been contradictory and comprehensive studies are scarce, especially those pertaining to the choroid and retina. Such studies could not only deepen our understanding of high-altitude ocular pathophysiology, but could also offer valuable information and treatment possibilities for a constellation of other vision-threatening diseases.

Choroidal thickness in patients with systemic arterial hypertension: a systematic review and meta-analysis.

Background: The global burden of hypertension is constantly increasing with adverse cardiovascular and ocular sequelae. The association between elevated blood pressure and choroidal thickness (CT), as assessed via optical coherence tomography (OCT), is poorly understood. Objectives and Design: Studies including hypertensive adults and normotensive controls undergoing OCT were evaluated for inclusion in this meta-analysis. The primary endpoint was CT difference between hypertensive and normotensive adults. Data Sources and Methods: We conducted a systematic review and after searching 1011 results from MEDLINE, ClinicalTrials.gov, medRxiv and Cochrane Library, six studies were deemed eligible and were pooled according to a random-effect model. Results: A statistically significant reduction in choroidal thickness was found in hypertensive adults (n = 454) as compared with normotensive controls (n = 365) [mean difference: -0.77; 95% confidence intervals: (-1.20, -0.34); p = 0.0004]. The main limitations of this meta-analysis are the relatively small population included and the high statistical heterogeneity (I 2 = 87%) among the various studies. Of note, after excluding one study the heterogeneity was markedly reduced. Conclusion: Choroidal thickness is reduced among hypertensive subjects compared with normotensive controls. This finding mandates further examination in the context of long-term clinical outcomes.

Periostin as a biomarker in chronic rhinosinusitis: A contemporary systematic review.

BACKGROUND: The role of periostin, a matricellular protein encoded by the POSTN gene, in chronic rhinosinusitis with nasal polyposis (CRSwNP) is reviewed. Periostin is considered a potential biomarker of endotype and may be useful for evaluating response to treatment. METHODS: Search terms in PubMed and Web of Science (1990-March 2022) included: ((periostin) OR (POSTN)) AND ((sinusitis) OR (nasal polyp) OR (CRSwNP) OR (CRS). The primary outcomes were differences in tissue, serum, and nasal lavage between CRSwNP and CRS without NP (CRSsNP) or controls. Associated factors reported to affect periostin expression, data regarding participants' clinical characteristics, disease endotypes, laboratory methods, and samples' origin were also pooled. Studies on <10 patients were excluded. RESULTS: Out of 101 records harvested through database searching, 29 prospective cross-sectional or case-control studies were eligible for review and qualitative analysis. Tissue sample origin, concurrent infection, current and past medication, primary or recurrent disease, allergic rhinitis, and smoking status should be considered as confounding factors for periostin levels. Periostin and POSTN messenger RNA (mRNA) levels were consistently and significantly higher in CRSwNP than CRSsNP and controls. Despite the distinctly different inflammation patterns among CRSwNP endotypes, periostin-related remodeling patterns seemed to be similar. CONCLUSION: Tissue and serum periostin levels, and POSTN expression appear elevated in CRSwNP, especially in eosinophilic inflammation, compared to CRSsNP and controls. Disease severity and comorbidities are also reflected in periostin and POSTN values. Carefully designed prospective studies may establish the role of periostin as a biomarker in CRSwNP and allow its incorporation in clinical practice.

Erdheim-Chester disease: a comprehensive review from the ophthalmologic perspective.

Erdheim-Chester disease (ECD) is a rare clonal histiocytic neoplasm with less than 1200 documented cases to date. The disease is life-threatening and difficult to recognize, although increasing awareness as well as the integration of clinical, imaging, pathology information, and genetic studies have led to a recent exponential increase in new reported cases. ECD affects multiple organs and systems, including skeletal, neurologic, and cardiovascular. Pulmonary, retroperitoneal, and cutaneous lesions have also been reported in various combinations. Until the discovery that more than half of ECD patients harbor the BRAF-V600E mutation or other mutations in the mitogen-activated protein kinase (MAPK) and RAS pathways, Interferon-a was the first-line treatment. Nowadays BRAF and MEK-inhibitors targeted therapies are the mainstay of treatment. Ophthalmologic involvement occurs in 25% -30% of ECD cases, usually in the form of orbital involvement presenting with exophthalmos and ophthalmoplegia. Other ophthalmologic manifestations include palpebral xanthelasmas, anterior uveitis and vitritis, optic disk edema, choroidal infiltration, recurrent serous retinal detachment, retinal drusen-like deposits and retinal pigment epithelial changes. ECD patients can also present with ocular symptoms as a result of adverse effects of the treatment regimens. In some cases with smoldering or protean symptoms, the emergence of eye manifestations triggered the diagnosis. Ophthalmologists have to be aware of the disease, recognize the constellation of ECD symptoms, and contribute to the diagnosis, treatment, and follow-up of ECD patients.

Scleral fixation of Carlevale intraocular lens: A new tool in correcting aphakia with no capsular support.

PURPOSE: To report the clinical outcomes of the use of a novel specially designed scleral fixated intraocular lens, the Carlevale intraocular lens (carlevale IOL, Soleko, Italy) for the correction of aphakia in the absence of capsular support of variable etiology. METHODS: This retrospective, non-comparative study included 169 eyes of 169 consecutive patients who underwent 3-port pars plana vitrectomy and scleral fixation on Carlevale IOL. Inclusion criteria were at least 6 months' follow-up period, patients > 18 years old who underwent vitrectomy and Carlevale IOL placement for aphakia and inadequate capsular support. RESULTS: The median follow up period of 9 months (range 6-18 months). Mean post-operative BCVA at the last follow-up visit was 20/25 (0.09 ± 0.1 LogMAR), improving from a mean baseline BCVA of 20/80 (0.58 ± 0.49 LogMAR), a statistically significant change (p = 0.0001). Regarding the post-operative complications, a transient rise in the IOP was observed in 28 patients (16.5%) and mild vitreous hemorrhage was observed in the immediate post-operative period in eight eyes (4.7%) and it spontaneously resolved within 3 weeks. All patients demonstrated good IOL position at the end of the follow-up without IOL capture. None of the patients required re-operation. CONLCUSION: The present study represents the largest to date in evaluating the use of carlevale IOL in patients with aphakia and inadequate capsular support. The technique is safe and provides excellent post-operative IOL fixation without IOL capture in any of the patients studied.

A fingerprint hidden inside the eye. A unique pattern of outer retina splitting as seen on en-face OCT and OCT-angiography.

A splitting of the outer plexiform retinal layer in a saw-like hyporeflective pattern in addition to partially formed concentric circles centred at the foveola were observed using en-face OCT and OCT-angiography in a 27-year-old female patient with rhegmatogenous retinal detachment and a 50-year-old female patient with Vogt-Koyanagi-Harada chorioretinopathy.

Ophthalmologic manifestations of adult patients with cystic fibrosis.

INTRODUCTION: Cystic fibrosis (CF) is the most common life-shortening recessive genetic disease in Caucasians, affecting primarily the lungs. The objective of our study was to investigate potential ophthalmologic involvement in adult patients with CF. METHODS: Fifty adult patients with cystic fibrosis and 60 age- and sex-matched controls underwent complete ophthalmologic examination including tear-film Break-Up Time (BUT), Macular Thickness, and peripapillary Retinal Nerve Fiber Layer (pRNFL) thickness measurements using Spectral Domain-OCT. RESULTS: CF patients had significantly lower nasal-inferior pRNFL thickness (median 82 IQR 67-102 vs 92.5 IQR 82-107, p = 0.005) and lower percentage of normal tear Break-Up Time (56.0% vs 96.7%, p = 0.001) than healthy controls. All CF patients with BUT <10 s were diagnosed with blepharitis at the time of our assessement. The subgroup of patients homozygous for the most common CF mutation, F508del, had lower nasal-inferior pRNFL thickness (p = 0.014) and lower percentage of normal tear Break-Up Time (p = 0.001) compared to the control group. Additional findings, present in the CF group only, were punctuate retinal hemorrhages (four patients), vessel tortuosity (four patients), snail-track degeneration, and retinal tufts (two patients without refractive error). There were no significant differences in visual acuity, refractive errors, gonioscopic findings, or intraocular pressure between the groups. CONCLUSIONS: Our study is, to the best of our knowledge, the largest ophthalmologic study of patients with cystic fibrosis. We found that CF patients had significantly decreased inferior-quadrant peripapillary retinal nerve fiber layer thickness and decreased tear-film break-up time compared to controls. We highlight the importance of careful regular ophthalmologic assessment and follow-up of these patients.

Reduction of Foveal Avascular Zone After Vitrectomy Demonstrated by Optical Coherence Tomography Angiography.

PURPOSE: To investigate the effect of pars plana vitrectomy on foveal circulation, and in particular the foveal avascular zone (FAZ), using optical coherence tomography angiography (OCTA). METHODS: This was a prospective, non-randomized, comparative case series of patients that underwent vitrectomy. Twenty-six eyes of 26 patients that underwent vitrectomy were studied postoperatively by OCTA. Our patients underwent 23 or 25G pars plana vitrectomy (PPV) for any posterior segment pathology. Three-dimensional OCTAs (DRI Triton Swept Source OCT; Topcon) of the capillary plexus were obtained three months post-operatively. The FAZ measurements of the fellow eyes were used as controls. MAIN OUTCOME MEASURES: Change in FAZ area between vitrectomized eyes and controls. RESULTS: From a total of 26 patients, 17 underwent vitrectomy due to retinal detachment (RD). Almost all patients demonstrated a statistically significant reduction in FAZ size based on the OCTA measurements. Τhe mean difference in FAZ size for the superficial capillary plexus (SCP) was -93.77 ± 71.73 µm and for the deep capillary plexus (DCP) -88.87 ± 75.41 µm, both statistically significant (p=0.000), while the amount of reduction in µm was the same for both SCP and DCP. CONCLUSION: The foveal avascular zone seems to be reduced following vitrectomy as shown by optical coherence tomography angiography. It is postulated that this may be the result of changes in the physiology of the vitrectomized eye, and that this change should be attributed to the removal of the vitreous itself rather than other structures such as the internal limiting membrane.

Cardiac Output Estimation: Online Implementation for Left Ventricular Assist Device Support.

OBJECTIVE: We present a novel pipeline that consists of various algorithms for the estimation of the cardiac output (CO) during ventricular assist devices (VADs) support using a single pump inlet pressure (PIP) sensor as well as pump intrinsic signals. METHODS: A machine learning (ML) model was constructed for the prediction of the aortic valve opening status. When a closed aortic valve is detected, the estimated CO equals the estimated pump flow. Otherwise, the estimated CO equals the sum of the estimated pump flow and the aortic valve flow, estimated via a Kalman-filter approach. Both the pathophysiological conditions and the pump speed of an in-vitro test bench were adjusted in various combinations to evaluate the performance of the pipeline, as well as the individual estimators. RESULTS: The ML model yielded a Matthews correlation coefficient of 0.771, a sensitivity of 0.913 and a specificity of 0.871. An overall CO root mean square error (RMSE) of 0.69 L/min was achieved. Replacing the pump flow and aortic pressure estimators with sensors would decrease the RMSE below 0.5 L/min. CONCLUSION: The performance of the proposed pipeline is considered the state of the art for VADs with an integrated PIP sensor. The effect of the individual estimators on the overall performance of the pipeline was thoroughly investigated and their limitations were identified for future research. SIGNIFICANCE: The clinical application of the proposed solution could provide the clinicians with essential information about the interaction between the patient's heart and the VAD to further improve the VAD therapy.

Factors Associated with the Clinical Course of Vitreomacular Traction.

BACKGROUND: To analyze the optical coherence tomography (OCT) characteristics as well as the clinical and demographic features to investigate their possible role to the course of vitreomacular traction syndrome. METHODS: The inclusion criteria were vitreomacular adhesion with traction causing distortion of the retinal architecture, with or without the presence of an epiretinal membrane, regardless of the size of the adhesion; age >18 years; follow-up of at least three months; and adequate quality OCT scan. Measurements of foveal thickness, average macular thickness, macular volume, maximum vertical and horizontal vitreomacular adhesion, nasal and temporal angles of traction, hyaloid hyperreflectivity, the presence of an epiretinal membrane (ERM), and cone outer segment tips detachment were obtained. RESULTS: 150 eyes were included in the analysis. 36 eyes (24%) developed complete resolution at the last visit, 19 eyes (12.7%) formed a full-thickness macular hole, and 95 eyes (63.3%) showed no resolution of the traction. Better BCVA at the first visit was associated with an increased likelihood of resolution of the VMT, but increasing age, CMT, and BCVA in the end of the follow-up was associated with a reduction in the likelihood of resolving. Of the other variables that were studied, no statistical significant predictors were identified. CONCLUSIONS: Better BCVA in the first visit was associated with an increased likelihood of resolution of the VMT that occurred in 24% of our cases. Other factors such as the vertical area of adhesion and the angle of adhesion were not identified as prognostic factors affecting the clinical course of the disease.

A Pilot Optical Coherence Tomography Angiography Study on Superficial and Deep Capillary Plexus Foveal Avascular Zone in Patients With Beta-Thalassemia Major.

Purpose: To investigate foveal avascular zone (FAZ) changes in the superficial (SCP) and deep (DCP) capillary plexuses in beta-thalassemia major (BTM) patients, as shown in optical coherence tomography angiography. Methods: Nonrandomized, comparative case series of 54 eyes of 27 BTM patients and 46 eyes of 23 healthy controls, utilizing an automated FAZ detection algorithm. Measurements included FAZ area and FAZ shape descriptors (convexity, circularity, and contour temperature). Results were compared between the two groups, and correlated to iron load and chelation therapy parameters. Results: SCP and DCP FAZ area were not significantly different between the control and BTM groups (P = 0.778 and P = 0.408, respectively). The same was true regarding SCP FAZ convexity (P = 0.946), circularity (P = 0.838), and contour temperature (P = 0.907). In contrast, a statistically significant difference was detected between controls and BTM group regarding DCP FAZ convexity (P = 0.013), circularity (P = 0.010), and contour temperature (P = 0.014). Desferrioxamine dosage was strongly correlated to the DCP area (r = 0.650, P = 0.05) and liver magnetic resonance imaging/T2-star to DCP circularity (r = -0.492, P = 0.038). Correlations were also revealed between urine Fe excretion and DCP convexity (r = 0.531, P = 0.019), circularity (r = 0.661, P = 0.002), and contour temperature (r = -0.591, P = 0.008). Conclusions: Retinal capillary plexuses and especially DCP seem to present unique morphologic changes in BTM patients, not in the FAZ area, but in specific shape descriptors, indicating minor but detectable FAZ changes. These changes correlate well with iron load and chelation therapy parameters. Their clinical importance and pathophysiologic implications remain to be elucidated through further studies.

Efficacy and safety of dexamethasone intravitreal implant in patients with retinal vein occlusion resistant to anti-VEGF therapy: a 12-month prospective study.

Purpose: To evaluate the safety and efficacy of repeated intravitreal dexamethasone implant (Ozurdex) injections administrated on an "as-needed" protocol for retinal vein occlusion patients with macular oedema, previously subjected to at least five anti-vascular endothelial growth factor (VEGF) injections with poor or no response. Methods: Prospective interventional case series of 13 branch retinal vein occlusion (BRVO) and 10 central retinal vein occlusion (CRVO) patients with persistent macular oedema (>250 µm) after at least five anti-VEGF injections. Exclusion criteria included: baseline visual acuity worse than 1.5 logMAR, previous intravitreal implant, history of vitreoretinal surgery, manifest glaucoma or ocular hypertension, epiretinal membrane, retinal neovascularization, massive retinal or macular ischaemia, vitreous haemorrhage or severe lens opacity, previous laser photocoagulation treatment. Each patient received an initial intraocular dexamethasone implant and the procedure was repeated at 6 months "as needed." Patients were followed up at months 2, 4, 6, 8, 10 and 12 with spectral domain optical coherence tomography and best corrected visual acuity measurements. Exclusion criteria included: baseline visual acuity worse than 1.5 logMAR, previous intravitreal implant, history of vitreoretinal surgery, manifest glaucoma or ocular hypertension, epiretinal membrane, retinal neovascularization, retinal or macular ischaemia, vitreous haemorrhage or severe lens opacity, previous laser photocoagulation treatment. Patients on topical or systemic corticosteroid therapy (during the last 3 months), and known steroid responders as well as diabetic patients were also excluded. Results: In the BRVO group, the mean central retinal thickness (CRT) and best corrected visual acuity (BCVA) significantly improved from 482.92 ± 139.99 µm (0.55 ± 0.12 logMAR) at baseline, to 369.31 ± 119.72 µm (0.43 ± 0.18 logMAR) at 6 months (p = 0.011/p = 0.019). At 12 months CRT was 295.82 ± 135.48 µm (p = 0.026) and BCVA 0.29 ± 0.17 logMAR (p = 0.002). Minimum CRT values were achieved at 3.45 months after the first injection, and 2.46 months after the second injection (197.00 ± 84.27 and 180.00 ± 76.89 µm, respectively). Best BCVA values were achieved at a mean of 4 ± 0.853 months after the first injection, and 4 months after the second injection (0.219 ± 0.129 and 0.222 ± 0.078 logMAR, respectively). In the CRVO group, neither the mean CRT nor BCVA improved significantly at 6 months: from 669.70 ± 203.20 µm (0.80 ± 0.231 logMAR) at baseline, to 586.20 ± 237.63 µm (0.740 ± 0.268 logMAR) at 6 months (p = 0.131/p = 0.333). At 12 months CRT was significantly improved: 549.90 ± 191.26 µm (p = 0.047), but BCVA lacked significant improvement: 0.690 ± 0.285 logMAR (p = 0.072). Minimum CRT values were achieved at a mean of 2 months after the first injection, and also 2 months after the second injection (261.60 ± 121.31 and 280.00 ± 177.43 µm, respectively). Best BCVA values were achieved at a mean of 2 months after the first injection, and 2 months after the second injection and were 0.390 ± 0.173 and 0.385 ± 0.233 logMAR, respectively. Cataract progression was a rare event (2/23 eyes), while transient steroid-induced ocular hypertension (5/23 eyes) was managed successfully with IOP-lowering medication Conclusion: Dexamethasone implant should be considered as an effective and safe alternative in patients with BRVO and CRVO who have failed anti-VEGF therapy. Shortening the re-injection interval especially for CRVO cases should be considered.

Viscosity Prediction in a Physiologically Controlled Ventricular Assist Device.

OBJECTIVE: We present a novel machine learning model to accurately predict the blood-analog viscosity during support of a pathological circulation with a rotary ventricular assist device (VAD). The aim is the continuous monitoring of the hematocrit (HCT) of VAD patients with the benefit of a more reliable pump flow estimation and a possible early detection of adverse events, such as bleeding or pump thrombosis. METHODS: A large dataset was generated with a blood pump connected to a hybrid mock circulation by varying the pump speed, the physiological requirements of the modeled circulation, and the viscosity of the blood-analog. The inlet pressure and the intrinsic signals of the pump were considered as inputs for the model. Gaussian process yielded models with the best performance, which were then combined using a variant of stacked generalization to derive the final model. The final model was evaluated with unseen testing data from the dataset created. RESULTS: For these data, the model yielded a mean absolute deviation of 1.81% from the true HCT, while it proved to correctly predict the direction of the HCT change. It showed to be independent of the set speed and of the condition of the simulated cardiovascular circulation. CONCLUSION: The accuracy of the prediction model allows an improvement of the quality of flow estimators and the detection of adverse events at an early stage. The evaluation of this approach with blood is suggested for further validation. SIGNIFICANCE: Its clinical application could provide the clinicians with reliable and important hemodynamic information of the patient and, thus, enhance patient monitoring and supervision.