Evaluation of the point sampling method and inter-comparison of remote emission sensing systems for screening real-world car emissions.

Emissions from internal combustion vehicles are currently not properly monitored throughout their life cycle. Remote emission sensing (RES) is a technology that can measure emissions under real driving conditions without contact. Current light extinction based RES systems are capable of providing emission factors for various gases, but lack accuracy for particulate matter (PM). Point Sampling (PS) is an extraction-based RES technique that can measure gases as well as various particle metrics such as black carbon or particle number. In this work, we evaluated the performance of a recently developed PS system and the state-of-the-art light extinction based remote sensing devices EDAR (HEAT) and ORSD (OPUS RSE) during co-location measurements. Validation measurements with portable emission measurement systems and emissions screening of several thousand cars in three European cities provide detailed insights into system's performance. Meteorological evaluations showed that the PS capture rate is strongly influenced by wind, but no other weather influences were found. Both light extinction based systems are unable to measure during rain. We found that all three systems tested were capable of screening NOx emissions from pre-Euro 6 diesel cars. Measurement results show the ability of the PS system to quantify high and low PM emitters equally well. The open-path RES systems (EDAR, ORSD) are capable of estimating PM emissions from pre-Euro 5 diesel cars. However, deficiencies of open-path RES systems are evident in the quantification of PM emissions from newer engine technologies (diesel Euro 5 and beyond) and from petrol cars. The PS system has a 2 to 5 times lower capture rate than open-path RES systems, but the PS measurement results are more accurate (more than 5 times for PM and more than 1.35 times for NOx). The good accuracy of individual measurements makes PS a powerful tool for reliable high emitter identification.

TANGENTIAL RETINAL DISPLACEMENT INCREASES AFTER MACULAR PUCKER SURGERY: An Apparent Nonsense.

PURPOSE: To measure the tangential retinal displacement and vision before and after macular pucker surgery and study if pars plana vitrectomy with epiretinal membrane peeling allows the reconstitution of previous anatomy or else it results in a different configuration. METHODS: Retrospective series of patients undergoing pars plana vitrectomy for epiretinal membrane, with >6-month follow-up before and after surgery, complete with best-corrected visual acuity, optical coherence tomography, M-Charts, and infrared retinography. Tangential retinal displacement between earliest visit (T E ), time of surgery (T 0 ), and latest available visit (T L ) of the examined retina, concentric circles at 0.5, 1.5, and 4.5 mm radii, and the central horizontal and vertical meridians were measured. Tangential displacement was calculated as the optical flow of consecutive infrared photographs. RESULTS: The study comprised 32 patients: 15 men and 17 women. Average preoperative and postoperative follow-up were 23.4 ± 27.9 months and 19.2 ± 11.8 months, respectively. Best-corrected visual acuity reduced before surgery (0.69 ± 0.16 Snellen to 0.46 ± 0.17; P < 0.001) and increased after (0.866 ± 0.16 Snellen; P < 0.001). Horizontal and vertical metamorphopsia increased between before surgery but only horizontal metamorphopsia significantly reduced after. Average tangential displacement before surgery was 35.6 ± 29.9 µ m versus 56.6 ± 41.3 µ m after ( P = 0.023). Preoperative and postoperative displacement within the fovea was less than over the entire area ( P < 0.001). CONCLUSION: Retinal tangential displacement between diagnosis and surgery (T E - T 0 ) is less than the displacement occurring after surgery (T 0 - T L ). Postoperative displacement does not represent the restoration of the anatomy existing before the disease ensued but rather the resulting equilibrium of newly deployed forces.

RETINAL TECTONICS AFTER MACULAR PUCKER SURGERY: Thickness Changes and En Face Displacement Recovery.

PURPOSE: To study visual function, retinal layer thickness changes, and tangential displacement after pars plana vitrectomy for epiretinal membrane. METHODS: Retrospective series of patients undergoing pars plana vitrectomy for epiretinal membrane, with 6-month follow-up including best-corrected visual acuity, optical coherence tomography, M-charts, epiretinal membrane grading, and infrared fundus photograph at time 0 (T0, preop) at months 1 (T1), 3 (T3), and 6 (T6) postop (±1 week). Retinal layer thickness and tangential ( en face ) retinal displacement between successive times for the entire retinal surface and the central horizontal and vertical meridian were also measured. En face displacement was calculated as optical flow of consecutive images. RESULTS: Average best-corrected visual acuity improved from 0.28 ± 0.08 logarithm of Minimum Angle of Resolution at T0 to 0.16 ± 0.25 at T6 ( P = 0.05), best-corrected visual acuity improvement correlated with best corrected visual acuity (BCVA) at T0 ( P < 0.001). Vertical metamorphopsia decreased from 1.33° ± 0.70° at T0 to 0.82° ± 0.69° at T6 ( P < 0.05). Foveal thickness reduced from 453 ± 53 µ m at T0 to 359 ± 31 µ m at T6 ( P < 0.05) and reduction correlated with best-corrected visual acuity improvement ( P < 0.05). Foveal layers decreased ( P < 0.05) in all cases. The mean en face deformation was 155.82 ± 50.17 µ m and mostly occurred in the first month: T0-T1 displacement was 83.59 ± 30.28 µ m, T1-T3 was 36.28 ± 14.45 µ m, while T3-T6 was 39.11 ± 22.79 µ m ( P < 0.001) on average. Perifoveal and parafoveal deformation correlated with optical coherence tomography foveal thickness reduction at all time intervals (1, 3, and 6 months: P < 0.01). CONCLUSION: Epiretinal membrane peeling affects all retinal layer thickness and results in new force balance across the entire retina and tangential displacement. Both en face and in-depth changes correlate with visual function.

Dementia, stroke, age, use of medical devices and antipsychotic drugs may increase the risk of nosocomial infections among elderly patients hospitalized at Neurology Clinics.

Healthcare-acquired infections (HCAI) represent a major health problem worldwide. Stroke and dementia are considered risk factors for HCAI. Preliminary data suggest that use of antipsychotic drugs also increase the risk for HCAI. Here, we performed a retrospective study aimed at investigating the major risk and protective factors for HCAI in a cohort of elderly subjects hospitalized at an Italian tertiary Neurology Clinics. We included all patients with age ≥ 65 years hospitalized at Neurology Clinics of National Institute on Ageing, Ancona, Italy from 1st January 2018 to 31st December 2021. For each patient, the following data were collected: age, sex, use of medical devices, comorbidities, use of antipsychotic medications, development of HCAI. We included 1543 patients (41.4% males; median age 85 years [80-89]). According to multivariable analysis, age, stroke, duration of urinary catheter placement (for all p < 0.001) and midline placement (p = 0.035) resulted to be risk factors for HCAI, Diabetes resulted to be a protective factor for pneumonia (p = 0.041), while dementia and nasogastric tube were risks factor for this condition (p = 0.022 and p < 0.001, respectively). Urinary catheter was a risk factor for urinary tract infections (p < 0.001). Duration of placement of vascular catheters and use of antipsychotic drugs resulted to significantly increase the risk for bloodstream infections. Stroke, age and use of medical devices were confirmed to be risk factors for HCAI. Antipsychotic drugs resulted to increase risk for bloodstream infections. Further prospective studies will be needed to confirm these findings.

The Role of Subretinal Injection in Ophthalmic Surgery: Therapeutic Agent Delivery and Other Indications.

Subretinal injection is performed in vitreoretinal surgery with two main aims, namely, the subretinal delivery of therapeutic agents and subretinal injection of fluid to induce a controlled and localized macular detachment. The growing interest in this technique is mainly related to its suitability to deliver gene therapy in direct contact with target tissues. However, subretinal injection has been also used for the surgical management of submacular hemorrhage through the subretinal delivery of tissue plasminogen activator, and for the repair of full-thickness macular holes, in particular refractory ones. In the light of the increasing importance of this maneuver in vitreoretinal surgery as well as of the lack of a standardized surgical approach, we conducted a comprehensive overview on the current indications for subretinal injection, surgical technique with the available variations, and the potential complications.

Silicone Oil Tamponade Removal: Which Technique Is More Effective? An X-Ray Photoemission Spectroscopy Study.

Purpose: To compare the efficacy of two surgical techniques used to remove silicone oil (SiO) emulsion tamponade after pars plana vitrectomy: triple air-fluid exchange (AFX) and balanced salt solution lavage (BSSL). Methods: X-ray photoemission spectroscopy measured silicon content of the dry residue of fluid samples taken during AFX and BSSL. Ten patients underwent AFX and five BSSL. Three fluid samples were taken per patient, and the dry residue of 10 drops per sample were analyzed. A fluid sample from a patient who never received SiO tamponade was also analyzed to set a "blank" reference sample. Results: Patients' demographics showed no significant difference. Sample 1 of the two groups contained comparable silicon content while samples 2 and 3 of the AFX group contained significantly more silicon than that of the BSSL group (15.0 ± 0.1 and 12.0 ± 0.9 for the AFX group vs. 10.7 ± 1.4 and 5.2 ± 0.6 for the BSSL group, respectively; P < 0.05). The cumulative amount of silicon in the three successive samples was also significantly higher for the AFX group (42.3 ± 1.6 vs. 32 ± 2; P < 0.0001). The average silicon content ratio of consecutive samples was significantly higher for the AFX group compared to the BSSL group (0.90 ± 0.01 vs. 0.58 ± 0.06; P = 0.006). Conclusions: Triple AFX removed more silicon than triple lavage. The eye wall actively interacts with silicon emulsion retaining silicon content rather than behaving as a neutral container. Translational Relevance: Triple air-fluid exchange removed more silicon than BSS lavage. Neither technique behaved as a well-mixed box dilution, suggesting the eye walls actively retain emulsion and a dynamic equilibrium is established between silicon dispersion and the eye wall surface.

Phacoemulsification Tip Elongation Under Standardized Resistance: An Objective Measure of Human Crystalline Lens Hardness.

Purpose: To establish a correlation between phacoemulsification tip normalized driving voltage (NDV) and crystalline lens hardness and use it as an objective measure of lens hardness. The study used a phaco tip equipped with previously validated elongation control adjusting the driving voltage (DV) to produce invariant elongation regardless of resistance. Methods: The laboratory study measured the mean and maximum DV of the phaco tip immersed in glycerol-balanced salt solution and correlated the DV with the kinematic viscosity at 25, 50, and 75 µm tip elongation. The NDV were obtained by dividing the DV in glycerol by the DV in the balanced salt solution. The clinical arm of the study recorded DV of 20 consecutive cataract surgeries. The correlation of mean and maximum NDV to Lens Opacities Classification System (LOCS) III classification, patient's age and effective phaco time were evaluated. Results: The mean and maximum NDV correlated with the kinematic viscosity of the glycerol solution (P < 0.001 in all cases). Mean and maximum NDV during cataract surgery correlated with patients' age, effective phaco time, LOCS III nuclear color, and nuclear opalescence (P < 0.001 in all cases). Conclusions: When a feedback algorithm is running, DV variation strictly correlates with encountered resistance in glycerol solutions and real-life surgery. NDV significantly correlates with the LOCS classification. Future developments might include sensing tips that react to lens hardness in real time. Translational Relevance: The study correlates for the first time phaco tip DV and crystalline lens mechanical properties, establishing an objective and reliable measure of lens hardness. This may lead to smart phaco tips reacting to cataract hardness change in real time and sparing ultrasound dispersion.

Almost-Riemannian manifolds do not satisfy the curvature-dimension condition.

The Lott-Sturm-Villani curvature-dimension condition CD ( K , N ) provides a synthetic notion for a metric measure space to have curvature bounded from below by K and dimension bounded from above by N. It was proved by Juillet (Rev Mat Iberoam 37(1), 177-188, 2021) that a large class of sub-Riemannian manifolds do not satisfy the CD ( K , N ) condition, for any K ∈ R and N ∈ ( 1 , ∞ ) . However, his result does not cover the case of almost-Riemannian manifolds. In this paper, we address the problem of disproving the CD condition in this setting, providing a new strategy which allows us to contradict the one-dimensional version of the CD condition. In particular, we prove that 2-dimensional almost-Riemannian manifolds and strongly regular almost-Riemannian manifolds do not satisfy the CD ( K , N ) condition for any K ∈ R and N ∈ ( 1 , ∞ ) .

The Short-Term Results of Autologous Platelet-Rich Plasma as an Adjuvant to Re-Intervention in the Treatment of Refractory Full-Thickness Macular Holes.

The purpose of this study was to investigate the short-term efficacy and safety of autologous platelet-rich plasma (a-PRP) as an adjuvant to revisional vitrectomy for refractory full-thickness macular holes (rFTMHs). We conducted a prospective, non-randomized interventional study including patients with rFTMH after a pars plana vitrectomy (PPV) with internal limiting membrane peeling and gas tamponade. We included 28 eyes from 27 patients with rFTMHs: 12 rFTMHs in highly myopic eyes (axial length greater than 26.5 mm or a refractive error greater than -6D or both); 12 large rFTMHs (minimum hole width > 400 µm); and 4 rFTMHs secondary to the optic disc pit. All patients underwent 25-G PPV with a-PRP, a median time of 3.5 ± 1.8 months after the primary repair. At the six-month follow-up, the overall rFTMH closure rate was 92.9%, distributed as follows: 11 out of 12 eyes (91.7%) in the highly myopic group, 11 out of 12 eyes (91.7%) in the large rFTMH group, and 4 out of 4 eyes (100%) in the optic disc pit group. Median best-corrected visual acuity significantly improved in all groups, in particular from 1.00 (interquartile range: 0.85 to 1.30) to 0.70 (0.40 to 0.85) LogMAR in the highly myopic group (p = 0.016), from 0.90 (0.70 to 1.49) to 0.40 (0.35 to 0.70) LogMAR in the large rFTMH group (p = 0.005), and from 0.90 (0.75 to 1.00) to 0.50 (0.28 to 0.65) LogMAR in the optic disc pit group. No intraoperative or postoperative complications were reported. In conclusion, a-PRP can be an effective adjuvant to PPV in the management of rFTMHs.

DO DAILY ACTIVITIES AFFECT GAS TAMPONADE‒RETINA CONTACT AFTER PARS PLANA VITRECTOMY?: A Computational Fluid Dynamics Study.

PURPOSE: To calculate the retinal surface alternatively in contact with gas and aqueous because of fluid sloshing during daily activities such as ocular saccade, turning the head, standing up, and being a passenger of a braking car. METHODS: Fluid dynamics of aqueous and gas tamponade was reproduced using computational methods using the OpenFOAM open-source library. The double-fluid dynamics was simulated by the volume of fluid method and setting the contact angle at the aqueous-gas-retina interface. RESULTS: Sloshing increased the retinal surface in contact with aqueous by 13% to 16% regardless of fill rate and standing up determined the largest area of wet retina, followed by car braking, head rotation, and ocular saccade ( P < 0.001). All activities except the ocular saccade determined a significant increase in the surface of retina in contact with the aqueous ( P < 0.005). Car braking induced the highest shear stress (6.06 Pa); standing up determined the highest specific impulse and saccade the lowest. CONCLUSION: Daily activities instantaneously reduce the amount of retina consistently in contact with gas tamponade and increase shear stress giving aqueous a potential access to the subretinal space regardless of patients' compliance.

Silicone Oil Tamponade-Retina Contact in Highly Myopic Eyes With and Without Encircling Bands: A Computational Fluid Dynamics Study.

Purpose: To investigate the behavior of silicone oil (SiO) at a steady equilibrium and during saccades in pseudophakic highly myopic eyes with posterior staphyloma with and without an encircling band and compare it to behavior in emmetropic eyes. The SiO-retina contact area and shear stress were calculated by computational fluid dynamics. Methods: A numerical model of an emmetropic eye and a myopic eye with and without scleral band underwent a saccade of 50°/0.137 s. The vitreous chamber surface was divided into superior and inferior 180° sectors: lens, pre-equator, post-equator, and macula. SiO-retina contact was evaluated as a function of fill percentages between 80% and 90% for standing, 45° upward tilt, and supine patients. Maximum and average shear stress were calculated. Results: Overall, SiO-retina contact ranged between 40% and 83%; fill percentage varied between 80% and 95%. Neither the encircling scleral band nor the staphyloma significantly affected the SiO-retina contact area, although the presence of a scleral band proved disadvantageous when gazing 45° upward. The inferior retina-SiO contact remained below 40% despite 95% SiO fill. The SS significantly increased at the scleral band indentation and decreased elsewhere. The staphyloma greatly reduced shear stress at the macula. Conclusions: The presence of a myopic staphyloma reduces shear stress at the macula but does not alter SiO-retina contact significantly. The apposition of a 360° scleral band may reduce SiO-retina contact at least in some postures and increases the SS at the indentation. Translational Relevance: Assessing SiO-retina contact when vitreous chamber geometry changes according to pathologic or iatrogenic modifications allows accurate prediction of real-life tamponade behavior and helps explain surgical outcomes.

Human Vitreous Collagen Fragments Dimension As a Function of Vitrectomy Cut Rate.

Purpose: To study the dimensions and distribution of human vitreous collagen type II fragments collected after vitrectomy performed at varying cut rates and to evaluate if increasing the cut rate produces smaller collagen fragments, thus reducing retinal traction and/or viscosity. Methods: Fluid was collected during core vitrectomies performed for macular surgery at cut rates from 1000 to 16,000 cuts per minute (CPM) and immediately refrigerated. Protein fractions were separated by molecular weight (MW; >100 kDa, 50-100 kDa, 50-30 kDa, 30-10 kDa, and <10 kDa) through centrifugal filters. The Human Collagen II ELISA Kit colorimetric assay was then used to measure the COL2A1 in unfiltered and filtered samples. Results: Vitreous samples collected after vitrectomy performed at 16,000 CPM contained a higher concentration of protein with MW over 100 kDa than at any other cutting frequency (P < 0.01). No significant differences were found in fractions collected with a MW between 50 and 100 kDa. Collagen type II fragments over 100 kDa were significantly more represented than smaller fragments at each cut rate. The proportion of smaller (50-100 kDa) collagen fragments compared with those over 100 kDa was higher at 2000 CPM than at higher cut rates. Conclusions: Vitreous samples collected at different cut rates do not contain a significantly different proportion of collagen type II fragments of the tested MW. The extreme variability of vitreous flow through the cutter port may explain the uncertain predictability of collagen fragment MWs. Translational Relevance: Increasing the cut rate does not produce vitreous fragments of proportionally smaller dimension. It is necessary to achieve an invariant instantaneous flow through the cutter port in order to decrease retinal traction during vitrectomy.

Management of refractory and recurrent macular holes: A comprehensive review.

The primary repair of full-thickness macular holes (FTMHs) through pars plana vitrectomy with internal limiting membrane peeling and gas tamponade is the current standard of practice and offers a high closure rate of approximately 90%. On the contrary, the surgical management of refractory (or persistent) and recurrent FTMHs is still a challenging and controversial topic in vitreoretinal surgery as multiple options have been suggested, particularly over the last few years, with no consensus regarding any appropriate selection criteria or the best surgical option. Moreover, the presence of various case series / interventional studies presenting comparable outcomes, as well as the absence of studies with a direct comparison of different surgical techniques, may result in confusion. We provide a structured and comprehensive overview of the different surgical options currently available for the secondary repair of refractory and recurrent FTMHs. In addition to an update on epidemiology, diagnosis and description of the surgical steps, we highlight the evidence available to support each of the described surgical techniques, specifically focusing on the presumed mechanisms of hole closure, advantages, and known prognostic factors.

Bilateral optic neuritis as the presenting sign of post SARS-CoV-2 acute disseminated encephalomyelitis.

PURPOSE: to report a case of Acute Disseminated EncephaloMyelitis (ADEM) occurring after documented SARS-Cov2 infection and flu-like disease. OBSERVATION: A 59-years-old woman presented with progressive visual loss and right leg paresthesia started 6 days earlier when CT scan excluded abnormalities. Visual acuity was OU hand motion with bilateral slow pupillary response and unremarkable ocular extrinsic motility while visual field testing showed diffuse bilateral sensitivity reduction. The patient had also right leg paresthesia and reported a 2-weeks flu-like syndrome 15 days earlier, with nausea, diarrhea, anosmia, ageusia, cough. Brain Magnetic Resonance Imaging revealed bilateral optic nerve enhancement, multiple brain and spine lesions. SARS-CoV-2 PCR tested negative on nasal swab and positive on cerebrospinal fluid. Patient's serum tested positive for anti-SARS-CoV-2 IgG, negative for anti-aquaporin-4 and anti-myelin oligodendrocyte glycoprotein antibodies. A diagnosis of suspect ADEM post SARS-CoV-2 infection was made and treatment with high dose intravenous methylprednisolone (with subsequent prednisone tapering) and immunoglobulins started. Ten days later vision improved to 20/30 RE and 20/25 LE and 3 months later to 20/20. CONCLUSION AND IMPORTANCE: ADEM may ensue after SARS-CoV-2 virus infection. High suspicious index and prompt aggressive treatment may result in complete vision restauration.

Diesel exhaust particulate emissions and in vitro toxicity from Euro 3 and Euro 6 vehicles.

Incomplete combustion processes in diesel engines produce particulate matter (PM) that significantly contributes to air pollution. Currently, there remains a knowledge gap in relation to the physical and chemical characteristics and also the biological reactivity of the PM emitted from old- and new-generation diesel vehicles. In this study, the emissions from a Euro 3 diesel vehicle were compared to those from a Euro 6 car during the regeneration of a diesel particulate filter (DPF). Different driving cycles were used to collect two types of diesel exhaust particles (DEPs). The particle size distribution was monitored using an engine exhaust particle sizer spectrometer and an electrical low-pressure impactor. Although the Euro 6 vehicle emitted particulates only during DPF regeneration that primarily occurs for a few minutes at high speeds, such emissions are characterized by a higher number of ultrafine particles (<0.1 µm) compared to those from the Euro 3 diesel vehicle. The emitted particles possess different characteristics. For example, Euro 6 DEPs exhibit a lower PAH content than do Euro 3 samples; however, they are enriched in metals that were poorly detected or undetected in Euro 3 emissions. The biological effects of the two DEPs were investigated in human bronchial BEAS-2B cells exposed to 50 µg/mL of PM (corresponding to 5.2 µg/cm2), and the results revealed that Euro 3 DEPs activated the typical inflammatory and pro-carcinogenic pathways induced by combustion-derived particles, while Euro 6 DEPs were less effective in regard to activating such biological responses. Although further investigations are required, it is evident that the different in vitro effects elicited by Euro 3 and Euro 6 DEPs can be correlated with the variable chemical compositions (metals and PAHs) of the emitted particles that play a pivotal role in the inflammatory and carcinogenic potential of airborne PM.

Influence of anterior capsulorhexis shape, centration, size, and location on intraocular lens position: finite element model.

PURPOSE: To evaluate the influence of anterior capsulorhexis shape, dimension, and eccentricity on intraocular lens (IOL) position. SETTING: Laboratory investigation. DESIGN: Computational model. METHODS: A finite element model of the human crystalline lens capsule and zonule was created and the anterior capsule opened to simulate centered and decentered circular and elliptic rhexis. The model calculated capsular bag stress, IOL rotation, tilt, decentration, and vaulting, related to both capsular landmarks (absolute) and a reference IOL position defined as that obtained with a 5.0 mm circular and centered rhexis. RESULTS: Mean von Mises stress along the IOL major z-axis was significantly higher than that along the perpendicular x-axis in all cases (P < .001), both at the equator and at the rhexis edge. Stress at the equator was always greater than that at the rhexis edge (P < .001) regardless of the rhexis shape and position. As rhexis eccentricity increased, the stress difference between the z- and x-axes increased. Absolute IOL tilt (range 10-1 to 10-7 degrees), decentration (10-3 to 10-7 mm), rotation (10-2 to 10-3 degrees), and vaulting (10-1 mm) were negligible from an optical standpoint, but all of them were significantly greater for decentered rhexis (both round and elliptic) compared with centered (P < .05). CONCLUSIONS: Anterior capsulorhexis irregularity and/or eccentricity increase IOL tilt, decentration, rotation, and vaulting in a numerically significant but optically negligible way. Von Mises stress is much greater at the capsular bag equator compared with the rhexis edge and highly asymmetrically distributed in all cases. Stress asymmetry may influence postoperative biologic processes of capsular bag shrinking and further IOL tilting or decentration.

Mutations associated with hypokalemic periodic paralysis: from hotspot regions to complete analysis of CACNA1S and SCN4A genes.

Familial periodic paralyses (PPs) are inherited disorders of skeletal muscle characterized by recurrent episodes of flaccid muscle weakness. PPs are classified as hypokalemic (HypoPP), normokalemic (NormoPP), or hyperkalemic (HyperPP) according to the potassium level during the paralytic attacks. HypoPP is an autosomal dominant disease caused by mutations in the CACNA1S gene, encoding for Cav1.1 channel (HypoPP-1), or SCN4A gene, encoding for Nav1.4 channel (HypoPP-2). In the present study, we included 60 patients with a clinical diagnosis of HypoPP. Fifty-one (85%) patients were tested using the direct sequencing (Sanger method) of all reported HypoPP mutations in CACNA1S and SCN4A genes; the remaining 9 (15%) patients were analyzed through a next-generation sequencing (NGS) panel, including the whole CACNA1S and SCN4A genes, plus other genes rarely associated to PPs. Fifty patients resulted mutated: 38 (76%) cases showed p.R528H and p.R1239G/H CACNA1S mutations and 12 (24%) displayed p.R669H, p.R672C/H, p.R1132G/Q, and p.R1135H SCN4A mutations. Forty-one mutated cases were identified among the 51 patients managed with Sanger sequencing, while all the 9 cases directly analyzed with the NGS panel showed mutations in the hotspot regions of SCN4A and CACNA1S. Ten out of the 51 patients unresolved through the Sanger sequencing were further analyzed with the NGS panel, without the detection of any mutation. Hence, our data suggest that in HypoPP patients, the extension of genetic analysis from the hotspot regions using the Sanger method to the NGS sequencing of the entire CACNA1S and SCN4A genes does not lead to the identification of new pathological mutations.

THE PROPHYLAXIS OF FELLOW-EYE RETINAL DETACHMENT IN STICKLER SYNDROME: A RETROSPECTIVE SERIES.

PURPOSE: To evaluate retrospectively if scleral buckling combined or not to cryopexy reduces fellow-eye retinal detachment (RD) in Stickler syndrome patients who lost their first eye due to RD. METHODS: Retrospective review of 52 Stickler syndrome patients who received a 6-mm wide, 360° encircling scleral buckling. Thirty-nine (75%; Cryo + Group) also received cryo treatment, whereas the reminder 13/52 (25% Cryo - Group) did not. RESULTS: Average follow-up was 15.6 ± 2.41 years. Five patients (5/52; 9.6%) developed a retinal detachment 2.6 ± 0.55 years after prophylactic treatment, respectively, 0/39 patients in the Cryo + Group and 5/13 in the Cryo - Group (P < 0.001). All five RD eyes were successfully reattached through revised episcleral surgery and adjunctive cryo treatment. Postop refraction changed an average -1.9 ± 0.74 diopters and best corrected visual acuity at the end of follow-up was 20/25 (0.1 ± 0.07 logarithm of the minimum angle of resolution), not significantly different from the rest of sample population who did not develop RD in their fellow eye. CONCLUSION: Cryopexy significantly reduced the risk of RD in Stickler syndrome patients undergoing scleral buckling. If RD ensues, the presence of scleral buckling may ease surgical repair and improve final outcome.

Computational Fluid Dynamics of Intraocular Silicone Oil Tamponade.

Purpose: To investigate the behavior of silicone oil (SiO) at the steady equilibrium and during saccades and calculate SiO-retina contact, shear stress (SS), and shear rate (SR). Methods: A 24 mm phakic eye mesh model underwent 50°/0.137s saccade. The vitreous chamber compartment was divided into superior and inferior 180° sectors: lens, pre-equator, postequator, and macula. SiO-retina contact was evaluated as a function of fill percentages between 80% and 90% for a standing patient, 45° upward gaze, and supine. SS and SR for 1000 mPa-s (SiO1000) and 5000 mPa-s (SiO5000) silicon oil were calculated. Results: SiO fill between 80% to 90% allowed 55% to 78% retinal contact. The superior retina always kept better contact with SiO, regardless of the fill percentage (P < 0.01). SiO interface thoroughly contacted the macula only in standing position. SS followed a bimodal behavior and was always significantly higher for SiO5000 compared to SiO1000 (P < 0.01) throughout the saccade. The macula suffered the highest mean SS in standing position, while throughout the saccade the average SS was maximum at the SiO-aqueous interface. SR was significantly higher for SiO1000 compared to SiO5000 (P < 0.001). Conclusions: SS on the retinal surface may instantaneously exceed reported retinal adhesiveness values especially at the SiO-aqueous interface and possibly favor redetachment. Despite 90% SiO fill the inferior retina remains extremely difficult to tamponade. Translational Relevance: Accurate assessment of retina-tamponade interaction may explain recurrent inferior retinal redetachment, silicone oil emulsification, and help to develop better vitreous substitutes.