Corneal Neurotization for Neurotrophic Keratopathy: Clinical Outcomes and In Vivo Confocal Microscopic and Histopathological Findings

Purpose: To describe the long-term outcomes and in vivo confocal microscopic (IVCM) and histopathological findings after corneal neurotization surgery. / Methods: We included 2 patients who underwent corneal neurotization surgery for severe unilateral neurotrophic keratopathy secondary to cerebellopontine angle meningioma. Corneal sensation was measured using the Cochet–Bonnet esthesiometer (CBE) (0–60 mm). IVCM was performed using the Heidelberg HRT3 Rostock Corneal Module. Histopathological examination was performed on the excised corneoscleral disc of patient 2. / Results: In patient 1, corneal sensation improved from 0 mm preoperatively to 60 mm in all 4 quadrants by 2 years postoperatively and was maintained at 5 years postoperatively with identifiable subbasal and stromal corneal nerves on IVCM. In patient 2, corneal sensation improved from 0 mm preoperatively to 10 mm in 3 quadrants (9 months postoperatively) but returned to 0 mm in all quadrants by 2 years postoperatively. IVCM failed to identify any subbasal and stromal corneal nerves. At 5 years postoperatively, evisceration was performed to ameliorate uncontrolled and persistent ocular pain and poor cosmesis. Histopathological examination of the excised corneoscleral disc confirmed the presence of normal-sized, central corneal stromal nerve fascicles but without direct continuity with the transplanted perilimbal nerve bundles. / Conclusions: Our study elucidates the mechanism of corneal neurotization surgery at a cellular level. Although only 1 patient achieved long-term improvement in corneal sensation postoperatively, the findings on IVCM and histopathological examination suggest that partial regeneration/maintenance of corneal nerves after corneal neurotization surgery is likely attributed to the paracrine neurotrophic support, instead of direct sprouting, from the perilimbal transplanted nerve fascicles

Multiple receptor tyrosine kinases are expressed in adult rat retinal ganglion cells as revealed by single-cell degenerate primer polymerase chain reaction

BACKGROUND: To achieve a better understanding of the repertoire of receptor tyrosine kinases (RTKs) in adult retinal ganglion cells (RGCs) we performed polymerase chain reaction (PCR), using degenerate primers directed towards conserved sequences in the tyrosine kinase domain, on cDNA from isolated single RGCs univocally identified by retrograde tracing from the superior colliculi.RESULTS: All the PCR-amplified fragments of the expected sizes were sequenced, and 25% of them contained a tyrosine kinase domain. These were: Axl, Csf-1R, Eph A4, Pdgfrbeta, Ptk7, Ret, Ros, Sky, TrkB, TrkC, Vegfr-2, and Vegfr-3. Non-RTK sequences were Jak1 and 2. Retinal expression of Axl, Csf-1R, Pdgfrbeta, Ret, Sky, TrkB, TrkC, Vegfr-2, and Vegfr-3, as well as Jak1 and 2, was confirmed by PCR on total retina cDNA. Immunodetection of Csf-1R, Pdgfralpha/beta, Ret, Sky, TrkB, and Vegfr-2 on retrogradely traced retinas demonstrated that they were expressed by RGCs. Co-localization of Vegfr-2 and Csf-1R, of Vegfr-2 and TrkB, and of Csf-1R and Ret in retrogradely labelled RGCs was shown. The effect of optic nerve transection on the mRNA level of Pdgfrbeta, Csf-1R, Vegfr-2, Sky, and Axl, and of the Axl ligands Gas6 and ProteinS, was analysed. These analyses show transection-induced changes in Axl and ProteinS mRNA levels.CONCLUSIONS: The repertoire of RTKs expressed by RGCs is more extensive than previously anticipated. Several of the receptors found in this study, including Pdgfrbeta, Csf-1R, Vegfr-2, Sky, and Axl, and their ligands, have not previously been primarily associated with retinal ganglion cells

Capturing A Screenshot in Time: Knowledge, Attitude, Practices, and Vaccine Hesitancy Among the Latinx Community in Southern California Early in the COVID-19 Pandemic (Preprint)

BACKGROUND Background: The Latinx population in the United States have experienced high rates of infection, hospitalization, and death since the beginning of the COVID-19 pandemic. There is little data on the knowledge, attitude, and practices in specifically Latinx communities in the United States. OBJECTIVE We conducted a study to assess COVID-19 KAP and vaccine hesitancy among a Latinx cohort in the early stages COVID-19 pandemic, from July 2020 to October 2020 at a unique time when a vaccine was not available. METHODS Participants 18 years and older were recruited in a primary-care clinic in Southern California and asked to self-report sociodemographic characteristics, KAP, and vaccine hesitancy. KAP items were summed to create composite scores, with higher scores reflecting increased COVID-19 knowledge, positive attitudes towards the COVID-19 pandemic, and disease prevention practices. Bivariate and multivariable regression models were fit to test associations between sociodemographic characteristics and KAP scores. For our current analysis, we only included patients who self-identified as Latinx. RESULTS Our final data set included 256 participants. Participants had a mean age of 49 years (IQR 38.5-59), 72% of which were female, 77% had at most a high school degree, 35% had an annual income &lt; $25,000, and 12% had previously tested positive for COVID-19. We found high knowledge regarding transmission and spread, moderate knowledge regarding symptoms awareness, overall negative attitudes which included high pessimism in government public health efforts and high amounts fear, anxiety, and frustration due to COVID-19 pandemic, and moderate participation in preventive practices. A college education was positively associated with a higher knowledge score compared to those without a college education (β = 0.14, 95% CI =0.01-1.60, p&lt;0.01) when adjusted for covariates. Male gender had a positive association with COVID-19 attitude scores compared to female gender (β = 1.61, 95% CI = 0.50, 2.72, p&lt;0.01) and male gender was negatively associated with the COVID-19 practices score compared to female gender (β = -0.16, 95% CI = -0.56- -0.06, p&lt;0.01), when both adjusted for covariates. Among a subset of 203 patients, 19% indicated that if the vaccine were available, they would not take a COVID-19 vaccine and 27% were unsure. CONCLUSIONS Good knowledge and preventative practices in the population may have been a reflection of effective public health messaging and implementation of public health laws during the first wave of the pandemic; however, the overall fear and anxiety and may have been a reflection of the negative impact that the pandemic had on vulnerable populations such as Latinx community. Although our data is reflection of a previous time in the pandemic, we believe it captures a critical time in that can be used to provide unique insights regarding potential avenues for better protecting Latinx communities in future vaccine-resistant COVID-19 strains. INTERNATIONAL REGISTERED REPORT RR2-10.2196/25265 </sec

Knowledge, Attitude, Practices, and Vaccine Hesitancy Among the Latinx Community in Southern California Early in the COVID-19 Pandemic: Cross-sectional Survey.

BackgroundThe Latinx population in the United States has experienced high rates of infection, hospitalization, and death since the beginning of the COVID-19 pandemic. There is little data on the knowledge, attitude, and practices (KAP) specifically in Latinx communities in the United States.ObjectiveWe aimed to assess COVID-19 KAP and vaccine hesitancy among a Latinx cohort in the early stages of the COVID-19 pandemic (from July 2020 to October 2020), at a unique time when a vaccine was not available.MethodsParticipants aged ≥18 years were recruited at a primary care clinic in Southern California and asked to self-report sociodemographic characteristics, KAP, and vaccine hesitancy. A subset of the participants answered the vaccine hesitancy assessment as it was added after the start of data collection. KAP items were summed to create composite scores, with higher scores reflecting increased COVID-19 knowledge, positive attitudes toward the COVID-19 pandemic, and disease prevention practices. Bivariate and multivariable regression models were fitted to test associations between sociodemographic characteristics and KAP scores. For our analysis, we only included patients who self-identified as Latinx.ResultsOur final data set included 265 participants. The participants had a mean age of 49 (IQR 38.5-59) years, and 72.1% (n=191) were female, 77% (n=204) had at most a high school degree, 34.7% (n=92) had an annual income ConclusionsGood knowledge and preventative practices in the population may have reflected effective public health messaging and the implementation of public health laws during the first wave of the pandemic; however, the overall fear and anxiety may have reflected the negative impact that the pandemic had on vulnerable populations such as the Latinx community. Although our data are a reflection of a previous time in the pandemic, we believe it captures a critical time that can be used to provide unique insights regarding potential avenues to better protect the Latinx communities against future vaccine-resistant COVID-19 strains.International registered report identifier (irrid)RR2-10.2196/25265