Nasal Surface Research Articles

Inhalation and deposition of spherical and pollen particles after middle turbinate resection in a human nasal cavity

Middle turbinate resection significantly alters the anatomy and redistributes the inhaled air. The superior half of the main nasal cavity is opened up, increasing accessibility to the region. This is expected to increase inhalation dosimetry to the region during exposure to airborne particles. This study investigated the influence of middle turbinate resection on the deposition of inhaled pollutants that cover spherical and non-spherical particles (e.g. pollen). A computational model of the nasal cavity from CT scans, and its corresponding post-operative model with virtual surgery performed was created. Two constant flow rates of 5 L/min, and 15 L/min were simulated under a laminar flow field. Inhaled particles including pollen (non-spherical), and a spherical particle with reference density of 1000 kg/m3 were introduced in the surrounding atmosphere. The effect of surgery was most prominent in the less patent cavity side, since the change in anatomy was proportionally greater relative to the original airway space. The left cavity produced an increase in particle deposition at a flow rate of 15 L/min. The main particle deposition mechanisms were inertial impaction, and to a lesser degree gravitational sedimentation. The results are expected to provide insight into inhalation efficiency of different aerosol types, and the likelihood of deposition in different nasal cavity surfaces.

Detection of Foot-and-Mouth Disease Virus in the Absence of Clinical Disease in Cattle and Buffalo in South East Asia.

Foot-and-mouth disease virus (FMDV) is widespread throughout much of the world, including parts of South East Asia. Surveillance is often limited in endemic areas, relying predominantly on passive outbreak reporting. As part of the World Organisation for Animal Health (OIE)'s South East Asia and China Foot-and-Mouth Disease Project (SEACFMD), field sampling was performed to help understand evidence of widespread virus exposure observed in previous studies. Serum and dry mucosal swabs were collected to evaluate the presence of FMDV RNA on the nasal, oral, and dorsal nasopharyngeal mucosal surfaces of 262 healthy cattle (n = 84 in Laos; n = 125 in Myanmar) and buffalo (n = 48 in Laos; n = 5 in Myanmar) immediately following slaughter in three slaughterhouses. Swabs and serum were tested by the OIE/FAO World Reference Laboratory for foot-and-mouth disease (WRLFMD) using pan-serotypic real-time reverse transcription-PCR (rRT-PCR) and serum was evaluated using the FMD PrioCHECK non-structural protein (NSP) ELISA. In total, 7.3% of animals had detectable FMDV RNA in one or more of the three sites including 5.3% of nasopharyngeal swabs, 2.3% of oral swabs, and 1.5% of nasal swabs. No FMDV RNA was detected in serum. Overall, 37.8% of animals were positive for NSP antibodies, indicating likely past natural exposure to FMDV. Results were comparable for Laos and Myanmar, and for both cattle and buffalo, and were not significantly different between age groups. Detectable FMDV RNA present on the oral and nasal mucosa of clinically-healthy large ruminants in Laos and Myanmar demonstrates the importance of sampling asymptomatic animals as part of surveillance, and may indicate that subclinical infection plays a role in the epidemiology of FMD in these countries.

Aerodynamically Driven Translocation of Non-newtonian Fluids: the Relevance for Intranasal Drug Delivery

Intranasal drug delivery depends on the effective and possibly homogenous application of medical solution on the whole surface of nasal cavity (NC). As known from previous studies, droplets of sprayed medicine administered from an atomizer can penetrate only to the very anterior parts of the NC. This study demonstrates the possibility of translocation of liquid droplets due to interactions with air flowing through a shallow channel used as a model of nasal airspaces. The liquids used in the study are non-Newtonian to simulate the properties of real pharmaceutical formulation used in modern nasal drugs. The experimental data confirmed that aerodynamic shear forces induced by the airflow facilitate translocation of droplets of non-Newtonian fluids along the horizontal channel and this displacement is characterized by dynamic motion of droplets, in contrast to a steady spreading observed in the case of a viscous Newtonian fluid. The displacement pattern depends on the rheological characteristics of liquid, airflow rate, and also on the wettability of the wall. The results obtained in this study indirectly confirm that the inhalation airflows in the nasal channels should allow to spread the deposited liquid drugs to the distal parts of NC, providing the mechanism of more homogeneous drug distribution on the nasal surface.

An Instant, Safe, Antihistamine, Anti-Inflammatory and Decongestant Polymeric Nasal Barrier to Prevent and To Treat Allergic Rhinitis in Children

Introduction: Allergic rhinitis (AR) in children is a common chronic pathology with a strong impact on patient quality of life. The main physiopathology affects the nasal cavity as a multi-factorial disease involving nasal mucosa damage, nasal inflammation with high concentrations of histamine, pro-inflammatory cytokines such as histamine, TNF-α, IL-4, IL-5, IL-6, IL-10, IL-13, and IgE antibodies on the nasal mucosa. Systemic entry of these proteins through damaged nasal mucosa maintains continued inflammatory and allergen cascades. Therefore, an ideal treatment should be multitarget in order to stop allergen exposure, inflammation, and nasal mucosa barrier degradation, but such treatments are nearly impossible to conceive. We envisaged an osmotic and protective nasal barrier film, not only capable of protecting the nasal mucosa from allergen exposure but also of trapping and neutralizing selected cytokines and cleaning the nasal surface continuously without using any harmful substance for children. Materials and Methods: We associated highly osmotic glycerol solution with specific plant polymers to conceive an osmotic but stable film. As plant polymers (tannins) can bind with selective proteins, a range of glycerol binding non-cytotoxic polymers were screened using the sandwich ELISA method to select those having binding affinity for allergen induced nasal proinflammatory cytokines. After verifying cytotoxicity and irritant potential, a 15-day observational clinical study was performed with approval from the ethics committee on 30 children aged between 4-13, suffering from allergic rhinitis. The test product (TP) was supplied in 15-ml nasal sprays and applied 2-3 times per day for a period of 15 days. Saline solution served as control (CP). The scores of nasal and ocular symptoms, effect on quality of life, eosinophil count in nasal smears, and need for antihistamine treatment was evaluated at the start, at 30 minutes and on days 2, 3 and 15 of treatment. Results: A few specific polymers were able to bind with selected cytokines and histamine at adequate filmogen concentrations. The osmotic film was stable, non-irritant and was able to clean the nasal mucosa continuously for 4-6h after each application. Clinical observations of Total Nasal Symptom Score (TNSS) grouping the scores of nasal congestion, runny nose, sneezing, and itching, revealed a strong decrease right after the 1st treatment in both groups but the reduction was much stronger and faster with the TP. The mean TNSS score reduction was 44.74% in CP vs 83.53% in the TP group after 7 days of treatment (p<0.001). Total Ocular Symptom Score (TOSS) was decreased by 21.13% and 51.41% in CP v/s 35.12 and 99.59% in TP group on days 2 and 7, respectively. Nasal smear eosinophil count was equally strongly reduced in the TP v/s CP group. No treatment-related side effects were recorded in any of the groups. Conclusion: Protecting the nasal mucosa against allergens, neutralizing inflammatory cytokines, and keeping the nasal surface clean with an osmotic polymeric film, constitute a major breakthrough for the treatment of allergic rhinitis in children. This simple but scientific and logical approach should avoid exposing children to chemicals and to their long-term side effects.

Clinical Efficacy of an Osmotic, Antiviral and Anti-Inflammatory Polymeric Nasal Film to Treat Covid-19 Early-Phase Respiratory Symptoms

Background: Covid-19 infection is a multifactorial disease where the virus mainly enters through the nasal cavity, grows, triggers inflammation, and destroys nasal mucosa cells, allowing systemic virus entry and infection of other organs. When symptoms appear, the disease physiopathology is already established. The immune system tries to control the infection but if the infection persists, it gets tired, fatigued, stressed, and finally, there is burnout. Therefore, an effective treatment should be multi-targeted and should not focus only on one parameter. Minimizing virus concentration, reducing nasal mucosa inflammation, and keeping the nasal surface clean should lessen systemic infection and the probability of developing severe respiratory distress. We evaluated clinical efficacy and safety of an osmotic nasal surface cleaning, virus and cytokine trapping polymeric film, in early-stage Covid-19 positive symptomatic patients. Methods: A randomized, multicentric, observational study was performed to evaluate the efficacy and safety of the osmotic film in 213 patients, randomized in 2 equal arms, and confined for 14-days just after the RT-PCR+ test. Due to ethical reasons, all patients received symptomatic treatments (ST). In addition, the patients in Arm-1 received the test product (ST+TP, 2-3 sprays, 4-5 times/ day) for 14-days. Leicester Cough Questionnaire, Visual Analogue Scale, and Covid-19-associated symptoms such as fever, pain, taste, smell, and headache were evaluated daily. Home-confined patients were immediately hospitalized in case of aggravation of any life-threatening clinical sign. Results: Among 213 patients, 98 in the ST and 102 in the ST+TP group completed the study. Thirteen patients did not complete the study as 8 in the ST group and 5 in the ST+TP group were hospitalized during the study due to low blood oxygen levels or sudden health deterioration and were excluded from the study. In the remaining control standard treatment group (n=98), clinical signs sharply aggravated on day 1-2 followed by stabilisation between days 3-6 and progressive reduction thereafter. In the test product group (n=102), symptoms were stabilized just after the first application and improved progressively. Only 42/102 patients in the test product group presented nasal discharge or irritation due to the osmotic properties of the product. Conclusion: The continuous multi-target approach of detaching and neutralizing virus particles and pro-inflammatory cytokines from the nasal surface to minimize systemic virus exposure is a very logical and efficient approach to avoid Covid-19-induced systemic pathology.

Influence of surface anesthesia of the nasal cavity on oral tissues in the anterior region - a pilot study.

Nasal surface anesthesia is a simple, non-invasive method with a not yet fully understood effect on oral tissues. Should it prove to be successful in dental medicine, it could replace or at least complement the more invasive injection anesthesia, especially in children after dental trauma. The local anesthetic Tenaphin (tetracaine hydrochloride and naphazoline nitrate) was applied to 105 patients prior to ear, nose and throat medical diagnosis or therapy. After different exposure times, the influence on the oral tissues in the anterior region was examined by a dentist in the context of a pilot study. The effect of the mucosal anesthesia increased in the canine and anterior region the further mesial the tooth was located and the longer the application time was. In the buccal and palatinal area the effect increased from apical to incisal. The pulps of the central incisors and the canines were better anesthetized than those of the lateral incisors. Nasal surface anesthesia has the potential to replace the more invasive injection anesthesia in the anterior region of the upper jaw or to complement it. Dosage and exposure time will have to be investigated in more detail.

Profile shape variation and sexual dimorphism amongst middle-aged Northern Europeans.

To explore profile shape variation in a large population of middle-aged individuals and investigate features of sexual dimorphism. Facial profile photographs of 1776 individuals (964 females and 812 males; 46 years old), members of the Northern Finland Birth Cohort 1966 (NFBC1966), were uploaded and digitized with Viewbox software. Profile shape was defined with 47 landmarks (4 fixed and 43 sliding semi-landmarks). Digitized images were reoriented and scaled with Procrustes Superimposition, and shape variation was determined with a Principal Component Analysis. More than 90 per cent of profile shape variation was explained by Principal Components (PC) 1-9. PC1, explaining the largest amount of variation (33.1 per cent) described changes in facial convexity, slope of the forehead, lip, and chin protuberance. PC2 (23.1 per cent variation) was more related to vertical changes of the lower facial third and PC3 (11 per cent variation) primarily described changes in lip protrusion and nasal projection. Shape analysis showed a significant difference between the average female and the average male profile shape (P < 0.001); however, this was not evident upon visual observation. The shape variable most associated with sex was PC3 (η 2 = 0.245; P < 0.001), which described changes in lip prominence and in projection of the dorsal nasal surface. An additional discriminant analysis showed that profile shape predicted sex in 76 per cent of males and 79.6 per cent of females. There is significant sexual dimorphism in facial profile among middle-aged adults. Profile shape variation was associated to changes in lip protrusion, nasal protuberance, and chin projection.

Anti-Inflammatory and Antiviral Osmotic Polymeric Film to Treat Covid-19 Early-Stage Infection.

BackgroundCovid-19 infection starts in the nasal cavity when viral S1 and RBD proteins bind to the host cell ACE2 receptors, the virus multiplies, causes cell lysis, and enters the circulation. This triggers a strong cytokine release and inflammation of the nasal mucosa. A multitarget approach of cleaning the nasal mucosa and suppressing chances of nasal and systemic inflammation should minimize severe respiratory consequences. Unfortunately, no such treatments are yet available.MethodsWe describe the conception of an osmotic polymeric film using an in vitro nasal mucosa mimicking model, containing polymers to neutralize Covid-19 specific viral S1, RBD proteins and selected proinflammatory cytokines.ResultsThe filmogen barrier forms a stable and osmotic film on the nasal mucosa. Hypotonic liquid exudation from the nasal surface detaches and drains the inflammatory cytokines and other contaminants towards the film where selected polymers bind and neutralize SARS-CoV-2 spike S1 and RBD protein as well as Covid-19 disease-specific key pro-inflammatory IL-6, TNF-α, IL-10, IL-13, and GM-CSF cytokines.ConclusionMinimizing the nasal surface concentration of pro-inflammatory cytokines and viruses should help nasal mucosa repair and avoid immune stress. This nearly instant, simple, scientific, safe, and logical approach should help attenuate Covid-19 induced systemic inflammation at an early stage without being affected by viral S1 spike protein mutations.

Bridle operation for incomplete oculomotor nerve paralysis (superior rectus and lateral rectus nasal inferior transposition)

ZielDemonstration der Technik und Wirksamkeit der Zügeloperation bei Okulomotoriusparalyse mit erhaltener Hebungsfähigkeit.MethodeTransposition der Mm. recti lateralis (hinter Mm. obliquus und rectus inferior) und superior (hinter Obliquus-superior-Sehne und M. rectus medialis) in den nasal unteren Quadranten.ErgebnisseIm exemplarisch dargestellten Fall korrigierte der Eingriff ohne wesentlichen Verrollungseffekt eine paralytische Exo-Hypertropie von 30–40°/20–30°.SchlussfolgerungDie Zügeloperation erweitert das chirurgische Repertoire zur Korrektur paralytischen Schielens.

ANALYSIS OF CONJUNCTIVAL VASCULAR DENSITY IN SCLERAL CONTACT LENS WEARERS USING OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY

PurposeTo investigate conjunctival vascular density (VD) using Anterior Segment Optical Coherence Tomography Angiography (OCTA) in Scleral Contact Lens (ScCL) wearers. MethodsIn this cross-sectional study, the conjunctival blood VD was assessed using OCTA with an anterior segment lens adapter. The nasal surface of each eye (6 ×6 mm) was scanned to a depth of 800 μm with ScCL and fifteen minutes after removing the lens. Conjunctival VD was defined as the percentage of the scanned volume occupied by vessels in which blood flow was measured. Measures of limbal indentation were subjectively determined by two independent observers using Anterior Segment Optical Coherence Tomography (AS-OCT). Comparisons between VD measurements before and after ScCL removal and correlations between conjunctival VD, time of use, vault and indentation values were also investigated. ResultsA total of 23 patients (3 females, 20 males) with keratoconus, with a mean age (years±SD) of 38.74±10.38 were included in the study. VD was significantly higher without ScCL (71.75%±2.97) than VD measured with ScCL (69.81%±2.63), p=0.02. A moderately negative correlation was found between indentation and vault (r=-0.44, p<0.05) and a positive tendency regarding the time of wearing ScCL and indentation (r=0.11 and r=0.068, respectively). ConclusionsUsing OCTA with an anterior segment lens adapter, the ocular surface blood VD was imaged and assessed with good repeatability and reliability. This study presents a new possible application of OCTA to investigate and monitor conjunctival vasculature in ScCL wearers. This results cautiously suggest that the repeated use of ScCL can cause vascular alterations in conjunctiva of the eyes of ScCL wearers, possibly due to a hidden hypoxia caused by prolonged limbal indentation.

Influence of surface anesthesia of the nasal cavity on oral tissues in the anterior region - a pilot study.

Nasal surface anesthesia is a simple, non-invasive method with a not yet fully understood effect on oral tissues. Should it prove to be successful in dental medicine, it could replace or at least complement the more invasive injection anesthesia, especially in children after dental trauma. The local anesthetic Tenaphin (tetracaine hydrochloride and naphazoline nitrate) was applied to 105 patients prior to ear, nose and throat medical diagnosis or therapy. After different exposure times, the influence on the oral tissues in the anterior region was examined by a dentist in the context of a pilot study. The effect of the mucosal anesthesia increased in the canine and anterior region the further mesial the tooth was located and the longer the application time was. In the buccal and palatinal area the effect increased from apical to incisal. The pulps of the central incisors and the canines were better anesthetized than those of the lateral incisors. Nasal surface anesthesia has the potential to replace the more invasive injection anesthesia in the anterior region of the upper jaw or to complement it. Dosage and exposure time will have to be investigated in more detail.

Anterior scleral thickness and shape changes with different levels of simulated convergence

PurposeConvergence plays a fundamental role in the performance of near visual tasks. We measured the effect of two levels of convergence on anterior scleral thickness and shape in emmetropes, low to moderate myopes and high myopes. MethodsForty-five healthy young adults aged between 18 and 35 years including 15 emmetropes, 15 low/moderate myopes, and 15 high myopes were recruited. Anterior segment optical coherence tomography and eye surface profilometry were used to evaluate the anterior scleral thickness (nasal only, n = 42) and shape (n = 40), before and during two visual tasks involving 9° and 18° convergence, in those participants with complete and reliable data. ResultsConvergence led to a thickening of the total anterior eye wall (5.9 ± 1.4 μm) and forward movement (10 ± 2 μm) of the nasal anterior scleral surface (both p < 0.001). Larger changes were found at 18° than at 9° convergence and in more peripheral nasal scleral regions. There was a significant association between total wall thickening and forward movement of the scleral surface. Refractive group was not a significant main effect, but there were significant interactions between refractive group and the thickness changes with convergence in different scleral regions. ConclusionDuring convergence, the biomechanical forces acting on the eye lead to nasal anterior scleral thickening and forward movement of the nasal scleral surface.

CD44v3-Positive Intermediate Progenitor Cells Contribute to Airway Goblet Cell Hyperplasia.

In allergic airway diseases, intermediate progenitor cells (IPCs) increase in number in the surface epithelium. IPCs arise from basal cells, the origin of hallmark pathological changes, including goblet cell hyperplasia and mucus hypersecretion. Thus, targeting IPCs will benefit future treatment of allergic airway diseases. However, the lack of adequate cell surface markers for IPCs limits their identification and characterization. We now show that CD44 containing exon v3 (CD44v3) is a surface marker for IPCs that are capable of both proliferating and generating differentiated goblet cells in allergic human nasal epithelium. In primary human nasal epithelial cells that had differentiated at an air-liquid interface, IL-4 upregulated mRNA expression of three CD44v variants that include exon v3 (CD44v3-v6, CD44v3,v8-v10, and CD44v3-v10), and it induced expression of CD44v3 protein in the basal and suprabasal layers of the culture. FACS analysis revealed two subpopulations differing in CD44v3 concentrations, as follows: CD44v3low cells expressed high amounts of proliferative and basal cell markers (Ki-67 and TP63), whereas CD44v3high cells strongly expressed progenitor and immature and mature goblet cell markers (SOX2, CA2, and SPDEF). Importantly, a blocking anti-CD44 antibody suppressed IL-4-induced mucin production by human nasal epithelial cells. Furthermore, CD44v3 was coexpressed with TP63, KRT5, or SOX2 and was upregulated in the basal and suprabasal layers of the nasal surface epithelium of subjects with allergic rhinitis. Taken together, these data demonstrate that high CD44v3 expression contributes to goblet cell hyperplasia in inflammation of the allergic airway.

Observation of the Epithelial Cell Behavior in the Nasal Septum During Primary Palate Closure in Mice.

Epithelial fusion is critical in palatogenesis, and incomplete fusion results in various type of facial cleft, depending on the region that fails to fuse. In mammalian palatogenesis, the bilateral secondary palatal processes fuse in the middle of the face to form the secondary palate. Later, the dorsal side of the secondary palatal shelves fuses with the nasal septum to complete palatogenesis. Importantly, the anterior border of the secondary palatal shelf fuses with the primary palate, which is located at the anterior and ventral border of the nasal septum. While numerous studies have investigated the mechanism of fusion between secondary palatal shelves, very little is known about how the primary palate touches and fuses with the secondary palatal shelves. In this study, we investigate the possible epithelial cell behaviors on the surface of the primary palate using palatal explant cultures of K14-GFP mice. A time-lapse observation of the GFP-labeled epithelium and an SEM analysis revealed that the extrusion epithelium appeared at the region corresponding to the fusing area and expanded rostrally on the nasal septum surface in the absence of the secondary palatal processes. Unlike on the secondary palate surface, cellular migration and subsequent autonomous mesenchymal exposure were not evident on the nasal septum or the primary palate. TUNEL staining revealed that these extrusion epithelia were undergoing apoptosis. These findings indicated that extrusion with apoptosis was autonomously initiated at the presumptive region of the fusion without contact with the opposing secondary palate.

Efficacy of Povidone-Iodine Nasal and Oral Antiseptic Preparations Against Severe Acute Respiratory Syndrome-Coronavirus 2 (SARS-CoV-2).

Severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) is the pathogen responsible for the global pandemic of coronavirus disease 2019 (COVID-19). From the first reported cases in December 2019, the virus has spread to over 4 million people worldwide. Human-to-human transmission occurs mainly through the aerosolization of respiratory droplets. Transmission also occurs through contact with contaminated surfaces and other fomites. Improved antisepsis of human and nonhuman surfaces has been identified as a key feature of transmission reduction. There are no previous studies of povidone iodine (PVP-I) against SARS-CoV-2. This study evaluated nasal and oral antiseptic formulations of PVP-I for virucidal activity against SARS-CoV-2. This is the first report on the efficacy of PVP-I against the virus that causes COVID-19. Povidone iodine nasal antiseptic formulations and PVP-I oral rinse antiseptic formulations from 1% to 5% concentrations as well as controls were studied for virucidal efficacy against the SARS-CoV-2. Test compounds were evaluated for ability to inactivate SARS-CoV-2 as measured in a virucidal assay. SARS-CoV-2 was exposed directly to the test compound for 60 seconds, compounds were then neutralized, and surviving virus was quantified. All concentrations of nasal antiseptics and oral rinse antiseptics evaluated completely inactivated the SARS-CoV-2. Nasal and oral PVP-I antiseptic solutions are effective at inactivating the SARS-CoV-2 at a variety of concentrations after 60-second exposure times. The formulations tested may help to reduce the transmission of SARS-CoV-2 if used for nasal decontamination, oral decontamination, or surface decontamination in known or suspected cases of COVID-19.

Prospects for mucosal vaccine: shutting the door on SARS-CoV-2

ABSTRACT The sudden emergence of a highly transmissible and pathogenic coronavirus SARS-CoV-2 in December 2019 from China and its rapid global spread has posed an international health emergency. The rapid development of an effective vaccine is imperative to control the spread of SARS-CoV-2. A number of concurrent efforts to find an effective therapeutic agent or vaccine for COVID-19 (coronavirus disease 2019) are being undertaken globally. Oral and nasal mucosal surfaces serve as the primary portal of entry for pathogens like coronaviruses in the human body. As evidenced by studies on similar coronaviruses (SARS-CoV and MERS-CoV), mucosal vaccination can provide a safe and effective means for the induction of long-lasting systemic and mucosal immunity to confer protection against SARS-CoV-2. This article summarizes the approaches to an effective mucosal vaccine formulation which can be a rewarding approach to combat the unprecedented threat posed by this emerging global pandemic.

Inferior Meatus Mucosal Flap for Septal Reconstruction and Resurfacing After Nasoseptal Flap Harvest.

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Nasal Reconstruction in Darker Skin: Is the Subunit Principle Valid?!

The Subunit principle of Aesthetic Nasal Reconstruction is well known among Reconstructive surgeons and it is considered to be the excellence of care. It advocates to reconstruct a nasal defect as per the specific subunit, placing the suture line at a border of one subunit and its adjacent within the nasal surface. Individuals with skin types III to V are prone to hyperpigmentation, hypertrophic scars, keloids and obvious suture marks. Applying the Subunit principle in these darker complexion patients would not be sufficient. In fact, it would result in a scarred nose with a patch. With our frequent experience in such cases, it was very important to revisit the mentioned principle. In darker complexion individuals requiring significant part of their nose to be reconstructed, a consideration should be given to entire nasal unit reconstruction. This would allow placing the seams at junction with adjacent regions (cheek, lip) rather than within the nose and much acceptable aesthetic outcome.

The Effects of Trabecular Bypass Surgery on Conventional Aqueous Outflow, Visualized by Hemoglobin Video Imaging.

Hemoglobin Video Imaging (HVI) provides a noninvasive method to quantify aqueous outflow (AO) perioperatively. Trabecular bypass surgery (TBS) is able to improve, and in some cases re-establish, conventional AO. The purpose of this study was to use HVI to illustrate and quantify effects of TBS on AO through the episcleral venous system. This is a prospective observational cohort study. Patients were recruited from Sydney Eye Hospital, Australia. The study included 29 eyes from 25 patients, 15 with glaucoma and 14 normal controls. TBS (iStent Inject) was performed on 14 glaucomatous eyes (9 combined phacoemulsification/TBS and 5 standalone TBS). Cataract surgery alone was performed on the remaining eye from the glaucoma group and 2 eyes from the control group. We used HVI, a novel clinic-based tool, to visualize and quantify AO perioperatively during routine follow-up to 6 months. Angiographic blood flow patterns were observed within prominent aqueous veins on the nasal and temporal ocular surface. Aqueous column cross-section area (AqCA) was compared before and after surgery. AqCA, number of aqueous veins, intraocular pressure (IOP) before and after surgery, and number of IOP-lowering medications. Patients with glaucoma had reduced AqCA compared with normal controls (P=0.00001). TBS increased AqCA in 13 eyes at 1 month (n=14; P<0.002), suggesting improved AO. This effect was maintained at 6 months in 7 eyes (n=9, P≤0.05). All patients with unrecordable AO before surgery (n=3; 2 standalone TBS, 1 combined cataract/TBS) established measurable flow after TBS. IOP and/or medication burden became reduced in every patient undergoing TBS. Cataract surgery alone (n=3) increased AqCA in nasal and temporal vessels at 4 weeks after surgery. HVI provides a safe method for detecting and monitoring AO perioperatively in an outpatient setting. Improvement of AO into the episcleral venous system is expected after TBS and can be visualized with HVI. TBS is able to improve, and in some cases re-establish, conventional AO. Cataract surgery may augment this. Some aqueous veins were first seen after TBS and these patients had unstable postoperative IOP control, which possibly suggests reorganization of aqueous homeostatic mechanisms. HVI may confirm adequacy of surgery during short-term follow-up, but further work is required to assess the potential of HVI to predict surgical outcomes and assist with personalized treatment decisions.

Nasal reconstruction in darker skin: is the subunit principle valid?

&lt;p&gt;The subunit principle of aesthetic nasal reconstruction is well known among reconstructive surgeons and it is considered to be the excellence of care. It advocates to reconstruct a nasal defect as per the specific subunit, placing the suture line at a border of one subunit and its adjacent within the nasal surface. Individuals with skin types III to V are prone to hyperpigmentation, hypertrophic scars, keloids and obvious suture marks. Applying the subunit principle in these darker complexion patients would not be sufficient. In fact, it would result in a scarred nose with a patch. With our frequent experience in such cases, it was very important to revisit the mentioned principle. In darker complexion individuals requiring significant part of their nose to be reconstructed, a consideration should be given to entire nasal unit reconstruction. This would allow placing the seams at junction with adjacent regions (cheek and lip) rather than within the nose and much acceptable aesthetic outcome.&lt;/p&gt;