An in vitro assessment of the thermoreversible PLGA-PEG-PLGA copolymer: Implications for Descemet's membrane endothelial keratoplasty.

BACKGROUND: To explore the use of a thermoreversible copolymer gel coating to prevent donor tissue scrolling in Descemet's membrane endothelial keratoplasty (DMEK). METHODS: PLGA-PEG-PLGA triblock copolymer was synthesised via ring opening polymerisation. Two formulations were fabricated and gelation properties characterised using rheological analyses. Endothelial cytotoxicity of the copolymer was assessed using a Trypan Blue exclusion assay. Thickness of the copolymer gel coating on the endothelial surface was analysed using anterior segment optical coherence tomography (OCT) (RTVue-100, Optovue Inc.). Gold nanoparticles were added to the copolymer to aid visualisation using OCT. Prevention of Descemet membrane donor scrolling was represented via a novel, in vitro, immersion of copolymer coated donor graft material. RESULTS: Two different formulations of PLGA-PEG-PLGA copolymer were successfully fabricated and the desired peak gelling temperature of 24°C was achieved by polymer blending. Application of 20%, 30% and 40% (wt/vol) polymer concentrations resulted in a statistically significant increase in polymer thickness on the endothelium (p < 0.001). There was no detectable endothelial cytotoxicity. The polymer was easy to apply to the endothelium and prevented scrolling of the DMEK graft. CONCLUSION: This PLGA-PEG-PLGA thermoreversible copolymer gel could be exploited as a therapeutic aid for preventing DMEK graft scrolling.

Stability of the Interface Between Two Immiscible Liquids in a Model Eye Subject to Saccadic Motion.

The interface between silicone oil and saline layers in a three-dimensional model of the eye chamber was studied under different eye-like saccadic motions in order to determine the stability of the interface and propensity for emulsification in the bulk. The effect of level of fill, saccade amplitude, angular velocity, latency time, and orientation were investigated experimentally in spherical flasks with internal diameters 10, 28, and 40 mm, as well as a 28 mm diameter flask with an indent replicating the lens or the presence of a buckle. The deformation of the interface was quantified in terms of the change in its length in two-dimensional images. The deformation increased with Weber number, We, and was roughly proportional to We for We > 1. The presence of the lens gave rise to higher deformation near this feature. In all cases emulsification was not observed in either bulk fluid. The velocity profile in the spherical configuration was mapped using particle imaging velocimetry and is compared with an analytical solution and a short computational fluid dynamics simulation study. These confirm that the saccadic motion induces flow near the wall in the saline layer and significantly further into the chamber in the silicone oil. Surfactants soluble in the aqueous and oil phases reduced the interfacial tension, increasing deformation but did not lead to emulsification in the bulk.

Comparative Propensity Matched Outcomes in Severe COVID-19 Respiratory Failure-Extracorporeal Membrane Oxygenation or Maximum Ventilation Alone.

OBJECTIVE: Does extracorporeal membrane oxygenation (ECMO) improve outcomes in ECMO-eligible patients with COVID-19 respiratory failure compared to maximum ventilation alone (MVA)? SUMMARY BACKGROUND DATA: ECMO is beneficial in severe cases of respiratory failure when mechanical ventilation is inadequate. Outcomes for ECMO-eligible COVID-19 patients on MVA have not been reported. Consequently, a direct comparison between COVID-19 patients on ECMO and those on MVA has not been established. METHODS: A total of 3406 COVID-19 patients treated at two major medical centers in Chicago were studied. One hundred ninety-five required maximum ventilatory support, and met ECMO eligibility criteria. Eighty ECMO patients were propensity matched to an equal number of MVA patients using detailed demographic, physiological, and comorbidity data. Primary outcome was survival and disposition at discharge. RESULTS: Seventy-one percent of patients were decannulated from ECMO. Mechanical ventilation was discontinued in 75% ECMO and 16% MVA patients. Twenty-five percent of patients in the ECMO arm expired, 21% while on ECMO, compared with 74% in the MVA cohort. Mortality was significantly lower across all age and BMI groups in the ECMO arm. Sixty-eight percent ECMO and 26% MVA patients were discharged from the hospital. Fewer ECMO patients required long-term rehabilitation. Major complications such as septic shock, ventilator associated pneumonia, inotropic requirements, acute liver and kidney injuries are less frequent among ECMO patients. CONCLUSIONS: ECMO-eligible patients with severe COVID-19 respiratory failure demonstrate a 3-fold improvement in survival with ECMO. They are also in a better physical state at discharge and have lower overall complication rates. As such, strong consideration should be given for ECMO when mechanical ventilatory support alone becomes insufficient in treating COVID-19 respiratory failure.

Stickler Syndrome: Airway Complications in a Case Series of 502 Patients.

BACKGROUND: Patients with Stickler syndrome often require emergency surgery and are often anesthetized in nonspecialist units, typically for retinal detachment repair. Despite the occurrence of cleft palate and Pierre-Robin sequence, there is little published literature on airway complications. Our aim was to describe anesthetic practice and complications in a nonselected series of Stickler syndrome cases. To our knowledge, this is the largest such series in the published literature. METHODS: We retrospectively identified patients with genetically confirmed Stickler syndrome who had undergone general anesthesia in a major teaching hospital, seeking to identify factors that predicted patients who would require more than 1 attempt to correctly site an endotracheal tube (ETT) or supraglottic airway device (SAD). Patient demographics, associated factors, and anesthetic complications were collected. Descriptive statistical analysis and logistic regression modeling were performed. RESULTS: Five hundred and twoanesthetic events were analyzed. Three hundred ninety-five (92.7%) type 1 Stickler and 63 (96.9%) type 2 Stickler patients could be managed with a single attempt of passing an ETT or SAD. Advanced airway techniques were required on 4 occasions, and we report no major complications. On logistic regression, modeling receding mandible (P = .0004) and history of cleft palate (P = .0004) were significantly associated with the need for more than 1 attempt at airway manipulation. CONCLUSIONS: The majority of Stickler patients can be anesthetized safely with standard management. If patients have a receding mandible or history of cleft, an experienced anesthetist familiar with Stickler syndrome should manage the patient. We recommend that patients identified to have a difficult airway wear an alert bracelet.

Auditory dysfunction in type 2 Stickler Syndrome.

PURPOSE: To present the extent and site of lesion of auditory dysfunction in a large cohort of individuals with type 2 Stickler Syndrome. Type 2 Stickler Syndrome results from a mutation in the gene coding for α-1 type XI pro-collagen, which has been identified in the human vitreous, cartilage and the cochlea of the mouse. The condition is characterised by classic ocular abnormalities, auditory dysfunction, osteoarthropathy and oro-facial dysplasia. METHODS: This is a population study which used a combination of audiometric, tympanometric, and self-report measures on a series of 65 individuals (mean age 29.2 years, range 3-70, female 63.1%) with genetically confirmed type 2 Stickler Syndrome. RESULTS: Hearing impairment was identified in at least one ear for 69% of individuals. Analysis against age-matched normative data showed that reduced hearing sensitivity was present across all test frequencies. Sensorineural hearing loss was most common (77% of ears), with conductive (3%), mixed (7%) and no hearing loss (13%), respectively. The proportion of hypermobile tympanic membranes (24%) was less than previously documented in type 1 Stickler Syndrome. When present, this appears to arise as a direct result of collagen abnormalities in the middle ear. Self-report measures of speech and spatial hearing in sound were comparable to a non-syndromic cohort with similar audiometric thresholds. CONCLUSIONS: Auditory impairment in type 2 Stickler Syndrome is predominantly associated with cochlear hearing loss of varying severities across affected individuals. The impact on hearing thresholds can be seen across the frequency range, suggesting a contribution of defective collagen throughout the cochlea. Self-report questionnaires showed that difficulties understanding speech, and spatial information in sound (such as that used for localisation), were worse than a young, normal-hearing population but comparable to a non-syndromic cohort with similar audiometric thresholds. Therefore, it is likely that hearing loss in type 2 Stickler Syndrome arises in the auditory periphery, without significant central processing deficits.

Homozygous Type IX collagen variants (COL9A1, COL9A2, and COL9A3) causing recessive Stickler syndrome-Expanding the phenotype.

Stickler syndrome (SS) is characterized by ophthalmic, articular, orofacial, and auditory manifestations. SS is usually autosomal dominantly inherited with variants in COL2A1 or COL11A1. Recessive forms are rare but have been described with homozygous variants in COL9A1, COL9A2, and COL9A3 and compound heterozygous COL11A1 variants. This article expands phenotypic descriptions in recessive SS due to variants in genes encoding Type IX collagen. Clinical features were assessed in four families. Genomic DNA samples derived from venous blood were collected from family members. Six affected patients were identified from four pedigrees with variants in COL9A1 (one family, one patient), COL9A2 (two families, three patients), and COL9A3 (one family, two patients). Three variants were novel. All patients were highly myopic with congenital megalophthalmos and abnormal, hypoplastic vitreous gel, and all had sensorineural hearing loss. One patient had severe arthropathy. Congenital megalophthalmos and myopia are common to dominant and recessive forms of SS. Sensorineural hearing loss is more common and severe in recessive SS. We suggest that COL9A1, COL9A2, and COL9A3 be added to genetic screening panels for patients with congenital hearing loss. Although recessive SS is rare, early diagnosis would have a high impact for children with potentially dual sensory impairment, as well as identifying risk to future children.

Treatment of chronic HCV with sofosbuvir and simeprevir in patients with cirrhosis and contraindications to interferon and/or ribavirin.

OBJECTIVES: Patients with chronic hepatitis C virus (HCV) and cirrhosis are in critical need of treatment that is both effective and tolerable. The combination of simeprevir (SMV), a protease inhibitor, and sofosbuvir (SOF), a polymerase inhibitor, without peginterferon and/or ribavirin (PEGINF/RBV) has been shown to achieve sustained virologic response (SVR) exceeding 90% in patients with HCV genotype 1 with prior nonresponse and/or cirrhosis. The present report describes the efficacy of SMV and SOF in patients with cirrhosis, prior or current hepatic decompensation, and other contraindications to PEGINF/RBV. METHODS: A total of 120 consecutive patients with cirrhosis and contraindications to PEGINF/RBV were treated with SMV and SOF for 12 weeks. The primary end point was SVR at 12 weeks after the completion of treatment. RESULTS: The mean age of the cohort was 60 years; 63% were male, 48% were Caucasian, 44% were African American, 69% were of genotype 1A, 49% were treatment naïve, 96% were interleukin-28B non-CC, 33% were of Child class B or C, and 25% had prior hepatic decompensation. The SVR by intention-to-treat was 81% with a relapse rate of 14%. The SVR by per-protocol analysis was 87% with a relapse rate of 13%. The only baseline factor associated with SVR by multifactor analysis was Child class. SVR in patients with Child class A, B, and C was 87, 77, and 67%, respectively. Eleven percent of the patients developed severe adverse events, which included sepsis (two), variceal bleeding (two), hepatocellular carcinoma (two), and hyperbilirubinemia (eight). One of the patients with sepsis died. Two patients developed relapse more than 12 weeks after stopping SMV and SOF. CONCLUSIONS: The combination of SMV and SOF achieves high rates of SVR in patients with advanced cirrhosis but is lower with worsening Child class.

Moving from data collection to application: a systematic literature review of surgical capacity assessments and their applications.

BACKGROUND: Over the past decade, assessments of surgical capacity in low- and middle-income countries (LMICs) have contributed to our understanding of barriers to the delivery of surgical services in a number of countries. It is yet unclear, however, how the findings of these assessments have been applied and built upon within the published literature. METHODS: A systematic literature review of surgical capacity assessments in LMICs was performed to evaluate current levels of understanding of global surgical capacity and to identify areas for future study. A reverse snowballing method was then used to follow-up citations of the identified studies to assess how this research has been applied and built upon in the literature. RESULTS: Twenty-one papers reporting the findings of surgical capacity assessments conducted in 17 different LMICs in South Asia, East Asia and Pacific, Latin America and the Caribbean, and sub-Saharan Africa were identified. These studies documented substantial deficits in human resources, infrastructure, equipment, and supplies. Only seven additional papers were identified which applied or built upon the studies. Among these, capacity assessment findings were most commonly used to develop novel tools and intervention strategies, but they were also used as baseline measurements against which updated capacity assessments were compared. CONCLUSIONS: While the global surgery community has made tremendous progress in establishing baseline values of surgical capacity in LMICs around the world, further work is necessary to build upon and apply the foundational knowledge established through these efforts. Capacity assessment data should be coordinated and used in ongoing research efforts to monitor and evaluate progress in global surgery and to develop targeted intervention strategies. Intervention strategy development may also be further incorporated into the evaluation process itself.

Complement factor I and age-related macular degeneration.

PURPOSE: The complement system has been implicated in the pathogenesis of age-related macular degeneration (AMD). Complement factor I (CFI) is a serum protease that inhibits all complement pathways. A previous multicenter study identified a single missense CFI mutation (p.Gly119Arg) in 20/3,567 (0.56%) of AMD cases versus 1/3,937 (0.025%) of controls, thus suggesting that this mutation confers a high risk of AMD. A second CFI mutation, p.Gly188Ala, was identified in one patient with AMD. METHODS: We screened 521 unrelated AMD cases and 627 controls for the p.Gly119Arg and p.Gly188Ala variants. All participants were Caucasian and >55 years, and recruited through Southampton Eye Unit or research clinics in Guernsey. All participants underwent dilated fundal examination by an experienced retinal specialist. SNP assays were performed using KASP™ biochemistry. RESULTS: The p.Gly119Arg mutation was identified in 7/521 AMD cases compared to 1/627 age-matched controls (odds ratio [OR] = 8.47, confidence interval [CI] = 1.04-69.00, p = 0.027). There was a varied phenotype among the seven cases with the mutation, which was present in 4/254 (1.6%) cases with active or end-stage wet AMD and 3/267 dry AMD cases (1.1%). The p.Gly188Ala substitution was identified in 1/521 cases and 1/627 controls. CONCLUSIONS: Our results identified a much higher frequency of heterozygosity for p.Gly119Arg in both cases and controls than in previous studies. Of note is that our sub-cohort from Guernsey had a particularly high frequency of p.Gly119Arg heterozygosity in affected individuals (4%) compared to our sub-cohort from the mainland (0.71%). Although these data support the conclusions of van de Ven et al. that the p.Gly119Arg substitution confers a high risk of AMD, our data suggest that this missense mutation is not as rare or as highly penetrant as previously reported. There was no difference in frequency for a second CFI variant, p.Gly188Ala, between the cases and the controls.

Country Living.

Philip Alexander, MD, is a native Texan, retired physician, and accomplished musician and artist. After 41 years as an internal medicine physician, Dr. Phil retired from his practice in College Station in 2016. A lifelong musician and former music professor, he often performs as an oboe soloist for the Brazos Valley Symphony Orchestra. He began exploring visual art in 1980, evolving from pencil sketches-including an official White House portrait of President Ronald Reagan-to the computer-generated drawings featured in this journal. His images, which first appeared in this journal in the spring of 2012, are his own original creations. If you would like to see your art published in the Methodist DeBakey Cardiovascular Journal, submit your creation online at journal.houstonmethodist.org as a "Humanities" entry.

Use of vitreous phenotype as a key clinical marker to identify Ocular-only Stickler syndrome in a family with Marfan syndrome.

This clinical report describes a family with both Marfan and ocular-only Stickler syndromes. We report 2 cases of ocular-only Stickler syndrome and 2 cases of Marfan syndrome concurrent with ocular-only Stickler syndrome. Type 1 Stickler syndrome and Marfan syndrome share many clinical similarities, and it can be difficult to differentiate them solely based on clinical presentation. Vitreous phenotyping allows for the identification of vitreous anomalies pathognomonic of Stickler syndrome, which can guide future gene sequencing. Having the accurate diagnosis of Marfan or type 1 Stickler syndrome is important, as patients with type 1 Stickler syndrome have higher rates of retinal detachment and will benefit from prophylaxis.

Peripapillary Hyperreflective Ovoid Mass-Like Structures in Stickler Syndrome.

PURPOSE: To report a previously undescribed finding of peripapillary hyperreflective ovoid mass-like structures (PHOMS) in Stickler syndrome. DESIGN: Noncomparative case series. SUBJECTS: Twenty-two eyes with anomalous optic disc from 11 Stickler syndrome patients were identified and imaged. METHODS: Peripapillary hyperreflective ovoid mass-like structures were graded using enhanced-depth imaging OCT (EDI-OCT) according to the consensus recommendations of the Optic Disc Drusen Studies Consortium. All EDI-OCT scans were obtained using the Heidelberg Spectralis (Heidelberg Engineering) with a dense horizontal raster (15 × 10°, 97 sections) centered on the optic nerve head and graded by 2 independent assessors. In case of disagreement, the image was graded by a third assessor. The presence of any coexisting optic disc drusen was also assessed using EDI-OCT and autofluorescence. MAIN OUTCOME MEASURES: The presence of PHOMS, clinical characteristics and genetic mutations. RESULTS: A pilot sample of 22 eyes with phenotypic optic disc abnormalities from 11 Stickler syndrome patients were identified and imaged. Eight patients were female and 3 were male. The mean age was 31 years (13-58 years). Peripapillary hyperreflective ovoid mass-like structures were present in 91% (n = 20) of imaged eyes. Seventy percent (n = 14) were type 1 Stickler syndrome and 30% (n = 6) were type 2 Stickler syndrome. All eyes were myopic and the degree of myopia did not seem to affect whether or not PHOMS was present in this cohort. One eye with PHOMS had retinal detachment, and 77.3% (n = 17) of eyes had undergone 360o prophylactic retinopexy. Thirty-two percent (n = 7) of eyes with PHOMS were present in patients with coexisting hearing loss and 22.7% (n = 5) had orofacial manifestation of Stickler syndrome in the form of a cleft palate. Seventy-seven percent (n = 15) of eyes with PHOMS were present in patients who reported joint laxity or symptoms of arthritis. No coexisting optic disc drusen were identified and raised intracranial pressure was also excluded after neurological investigation. CONCLUSIONS: These data suggest that PHOMS are a novel finding in Stickler syndrome patients and should be considered when evaluating the optic nerves of these patients. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Vitrectomy as an Adjunct to Treat-and-Extend Anti-VEGF Injections for Diabetic Macular Edema: The Vitrectomy in Diabetic Macular Oedema (VIDEO) Randomized Clinical Trial.

Importance: There are reported benefits from vitrectomy for diabetic macular edema (DME); however, data precede anti-vascular endothelial growth therapy (VEGF) therapy, supporting a need to assess the current role of vitrectomy. Objective: To determine rates of recruitment and efficacy outcomes of vitrectomy plus internal limiting membrane (ILM) peeling adjunctive to treat-and-extend (T&E) anti-VEGF injections for diabetic macular edema (DME). Design, Setting, and Participants: This was a single-masked, multicenter randomized clinical trial at 21 sites in the United Kingdom from June 2018 to January 2021, evaluating single eyes of treatment-naive patients with symptomatic vision loss from DME for less than 1 year. Inclusion criteria were best-corrected visual acuity (BCVA) Early Treatment Diabetic Retinopathy Study letter score greater than 35 (approximate Snellen equivalent, 20/200 or better) and central subfield thickness (CST) greater than 350 µm after 3 monthly intravitreal injections of ranibizumab or aflibercept. Data analysis was performed in July 2023. Interventions: Patients were randomized 1:1 into vitrectomy plus standard care or standard care alone and further stratified into groups with vs without vitreomacular interface abnormality. Both groups received a T&E anti-VEGF injection regimen with aflibercept, 2 mg, or ranibizumab, 0.5 mg. The vitrectomy group additionally underwent pars plana vitrectomy with epiretinal membrane or ILM peel within 1 month of randomization. Main Outcomes and Measures: Rate of recruitment and distance BCVA. Secondary outcome measures were CST, change in BCVA and CST, number of injections, rate of completed follow-up, and withdrawal rate. Results: Over 32 months, 47 of a planned 100 patients were enrolled; 42 (89%; mean [SD] age, 63 [11] years; 26 [62%] male) completed 12-month follow-up visits. Baseline characteristics appeared comparable between the control (n = 23; mean [SD] age, 66 [10] years) and vitrectomy (n = 24; mean [SD] age, 62 [12] years) groups. No difference in 12-month BCVA was noted between groups, with a 12-month median (IQR) BCVA letter score of 73 (65-77) letters (Snellen equivalent, 20/40) in the control group vs 77 (67-81) letters (Snellen equivalent, 20/32) in the vitrectomy group (difference, 4 letters; 95% CI, -8 to 2; P = .24). There was no difference in BCVA change from baseline (median [IQR], -1 [-3 to 2] letters for the control group vs -2 [-8 to 2] letters for the vitrectomy group; difference, 1 letter; 95% CI, -5 to 7; P = .85). No difference was found in CST changes (median [IQR], -94 [-122 to 9] µm for the control group vs -32 [-48 to 25] µm for the vitrectomy group; difference, 62 µm; 95% CI, -110 to 11; P = .11). Conclusions and Relevance: Enrollment goals could not be attained. However, with 47 participants, evidence did not support a clinical benefit of vitrectomy plus ILM peeling as an adjunct to a T&E regimen of anti-VEGF therapy for DME. Trial Registration: isrctn.org Identifier: ISRCTN59902040.

Happy Childhood.

Philip Alexander, MD, is a native Texan, retired physician, and accomplished musician and artist. After 41 years as an internal medicine physician, Dr. Phil retired from his practice in College Station in 2016. A lifelong musician and former music professor, he often performs as an oboe soloist for the Brazos Valley Symphony Orchestra. He began exploring visual art in 1980, evolving from pencil sketches-including an official White House portrait of President Ronald Reagan-to the computer-generated drawings featured in this journal. His images, which first appeared in this journal in the spring of 2012, are his own original creations. If you would like to see your art published in the Methodist DeBakey Cardiovascular Journal, submit your creation online at journal.houstonmethodist.org as a "Humanities" entry.

Summer Dreams.

Philip Alexander, MD, is a native Texan, retired physician, and accomplished musician and artist. After 41 years as an internal medicine physician, Dr. Phil retired from his practice in College Station in 2016. A lifelong musician and former music professor, he often performs as an oboe soloist for the Brazos Valley Symphony Orchestra. He began exploring visual art in 1980, evolving from pencil sketches-including an official White House portrait of President Ronald Reagan-to the computer-generated drawings featured in this journal. His images, which first appeared in this journal in the spring of 2012, are his own original creations. If you would like to see your art published in the Methodist DeBakey Cardiovascular Journal, submit your creation online at journal.houstonmethodist.org as a "Humanities" entry.

Beachscape.

Philip Alexander, MD, is a native Texan, retired physician, and accomplished musician and artist. After 41 years as an internal medicine physician, Dr. Phil retired from his practice in College Station in 2016. A lifelong musician and former music professor, he often performs as an oboe soloist for the Brazos Valley Symphony Orchestra. He began exploring visual art in 1980, evolving from pencil sketches-including an official White House portrait of President Ronald Reagan-to the computer-generated drawings featured in this journal. His images, which first appeared in this journal in the spring of 2012, are his own original creations. If you would like to see your art published in the Methodist DeBakey Cardiovascular Journal, submit your creation online at journal.houstonmethodist.org as a "Humanities" entry.