Recurrent corneal erosion syndrome (RCES) is a disorder characterised by a dysfunctional epithelial ecosystem. It often begins after trauma, or in the setting of epithelial basement membrane degeneration or dystrophy. Historically, RCES has been understood as a structural derangement of the anterior corneal architecture. More recently, studies have demonstrated the important role of neuropeptides in corneal homoeostasis. Thus, RCES may also be understood as a disorder of corneal epithelial cell biology. Management of RCES can be challenging, but newer therapies have demonstrated improved efficacy for this condition. This review examines the aetiology and pathogenesis of RCES, and provides an update on current and emerging treatment modalities for the management of this disorder.
PRéCIS:: This retrospective study found that combined phacoemulsification and endocyclophotocoagulation reduced intraocular pressure (IOP) to a greater degree in angle-closure glaucoma versus open-angle glaucoma and was effective for all stages of glaucoma. PURPOSE: Endocyclophotocoagulation (ECP) laser treatment of the ciliary processes is believed to decrease IOP by reducing aqueous production. Anecdotal experience in angle-closure glaucoma suggests that it may also lower IOP by opening the drainage angle to promote aqueous outflow. This study sought to evaluate combined phacoemulsification and ECP (phaco/ECP) in eyes with different types and stages of glaucoma. PATIENTS AND METHODS: A Retrospective chart review of eyes that underwent phaco/ECP between October 2010 and December 2016 at one institution was conducted. RESULTS: In 63 eyes of 63 patients with an average of 3.0±1.7 years of follow-up, the 22 eyes with chronic angle-closure glaucoma (CACG) had greater IOP reduction and medication reduction than the 41 eyes with primary open-angle glaucoma at both 1 year (6.4 vs. 2.1 mm Hg, P=0.01; 0.9 vs. 0.2 medications, P=0.04) and final follow-up (6.2 vs. 2.4 mm Hg, P=0.02; 0.9 vs. 0.3 medications, P=0.05). There was no difference in IOP reduction or medication reduction for eyes with mild, moderate, or advanced glaucoma at both 1 year (3.5, 3.9, 0.5 mm Hg, respectively, P=0.18; 0.3, 0.6, 0.4 medications, P=0.58) and final follow-up (3.3, 4.8, 0.7 mm Hg, P=0.11; 0.1, 0.8, 0.4 medications, P=0.14). CONCLUSIONS: Eyes with CACG were more responsive to phaco/ECP in terms of IOP and medication reduction compared with eyes with primary open-angle glaucoma. This finding could be partially or entirely due to concurrent cataract extraction and greater CACG preoperative IOP. Phaco/ECP was effective in all stages of glaucoma.
PRéCIS:: The diagnostic capability of peripapillary retinal volume is similar to peripapillary retinal nerve fiber layer thickness for diagnosing glaucoma, but with fewer artifacts. PURPOSE: To compare the diagnostic capability of 3-dimensional peripapillary retinal volume (RV) versus 2-dimensional peripapillary retinal nerve fiber layer (RNFL) thickness for open-angle glaucoma. PATIENTS AND METHODS: A retrospective cross-sectional analysis was conducted. A total of 180 subjects (113 open-angle glaucoma, 67 normal participants) had spectral domain optical coherence tomography volume scans and RNFL thickness measurements. Peripapillary RV values were calculated using a custom-designed program with 4 circumpapillary annuli (CA): CA1 had circle diameters of 2.5 and 3.5 mm; CA2, 3 and 4 mm; CA3, 3.5 and 4.5 mm; and CA4, 4 and 5 mm. Area under the receiver operating characteristic curves were calculated for global, quadrant, and octant regions for RV (CA1 to CA4) and RNFL thickness. Pair-wise comparisons were conducted. Artifacts rates were determined. RESULTS: Mean age was 62.7±15.4 years, and 47.8% (86/180) were male. Among RV measurements, best diagnostic performances were for the smallest 2 annuli for inferior RV (CA1: 0.964, CA2: 0.955). Of the 4 annuli, CA1 had the highest diagnostic performance. Of specific regions, the inferior RV quadrant had the highest performance across CA1 to CA4. Peripapillary RV had similar diagnostic capability compared with RNFL thickness (P>0.05). The artifact rate per B-scan for RV was 6.0%, which was significantly lower compared with 2-dimensional RNFL thickness in the same patient population (32.2%, P<0.0001). CONCLUSIONS: The diagnostic capability of RV is similar to RNFL thickness for perimetric open-angle glaucoma, but RV had fewer artifacts compared with RNFL thickness.
Pathological angiogenesis is a hallmark of various vascular diseases, including vascular eye disorders. Dysregulation of microRNAs (miRNAs), a group of small regulatory RNAs, has been implicated in the regulation of ocular neovascularization. This study investigated the specific role of microRNA-145 (miR-145) in regulating vascular endothelial cell (EC) function and pathological ocular angiogenesis in a mouse model of oxygen-induced retinopathy (OIR). Expression of miR-145 was significantly upregulated in OIR mouse retinas compared with room air controls. Treatment with synthetic miR-145 inhibitors drastically decreased levels of pathological neovascularization in OIR, without substantially affecting normal developmental angiogenesis. In cultured human retinal ECs, treatment with miR-145 mimics significantly increased the EC angiogenic function, including proliferation, migration, and tubular formation, whereas miR-145 inhibitors attenuated in vitro angiogenesis. Tropomodulin3 (TMOD3), an actin-capping protein, is a direct miR-145 target and is downregulated in OIR retinas. Treatment with miR-145 mimic led to TMOD3 inhibition, altered actin cytoskeletal architecture, and elongation of ECs. Moreover, inhibition of TMOD3 promoted EC angiogenic function and pathological neovascularization in OIR and abolished the vascular effects of miR-145 inhibitors in vitro and in vivo. Overall, our findings indicate that miR-145 is a novel regulator of TMOD3-dependent cytoskeletal architecture and pathological angiogenesis and a potential target for development of treatments for neovascular eye disorders.
Epithelial to mesenchymal transition (EMT) plays an important role in the pathogenesis of proliferative vitreoretinopathy (PVR). We aimed to demonstrate the role of mouse double minute 2 (MDM2) in transforming growth factor-beta 2 (TGF-β2)-induced EMT in human retinal pigment epithelial cells (RPEs). Immunofluorescence was used to assess MDM2 expression in epiretinal membranes (ERMs) from patients with PVR. A single guide (sg)RNA targeting the second promoter of MDM2 was cloned into a mutant lentiviral Clustered Regularly Interspaced Short Palindromic Repeats (lentiCRISPR) v2 (D10A and H840A) vector for expressing nuclease dead Cas9 (dCas9)/MDM2-sgRNA in RPEs. In addition, MDM2-sgRNA was also cloned into a pLV-sgRNA-dCas9-Kruppel associated box (KRAB) vector for expressing dCas9 fused with a transcriptional repressor KRAB/MDM2-sgRNA. TGF-β2-induced expression of MDM2 and EMT biomarkers were assessed by quantitative polymerase chain reaction (q-PCR), western blot, or immunofluorescence. Wound-healing and proliferation assays were used to evaluate the role of MDM2 in TGF-β2-induced responses in RPEs. As a result, we found that MDM2 was expressed obviously in ERMs, and that TGF-β2-induced expression of MDM2 and EMT biomarkers Fibronectin, N-cadherin and Vimentin in RPEs. Importantly, we discovered that the dCas9/MDM2-sgRNA blocked TGF-β2-induced expression of MDM2 and the EMT biomarkers without affecting their basal expression, whereas the dCas9-KRAB/MDM2-sgRNA suppressed basal MDM2 expression in RPEs. These cells could not be maintained continuously because their viability was greatly reduced. Next, we found that Nutlin-3, a small molecule blocking the interaction of MDM2 with p53, inhibited TGF-β2-induced expression of Fibronectin and N-cadherin but not Vimentin in RPEs, indicating that MDM2 functions in both p53-dependent and -independent pathways. Finally, our experimental data demonstrated that dCas9/MDM2-sgRNA suppressed TGF-β2-dependent cell proliferation and migration without disturbing the unstimulated basal activity. In conclusion, the CRISPR/dCas9 capability for blocking TGF-β2-induced expression of MDM2 and EMT biomarkers can be exploited for a therapeutic approach to PVR.
BACKGROUND: Teleophthalmology is an evidence-based method for diabetic eye screening. It is unclear whether the type of eye care provider performing teleophthalmology interpretation produces significant variability. INTRODUCTION: We assessed grading variability between an optometrist, general ophthalmologist, and retinal specialist using images from an urban, diabetic retinopathy teleophthalmology program. METHODS: Three readers evaluated digital retinal images in 100 cases (178 eyes from 90 patients with type 2 diabetes). Fisher's exact test, percent agreement, and the observed proportion of positive (P) or negative agreement (P) were used to assess variability. RESULTS: Among cases deemed gradable by all three readers (n = 65), there was substantial agreement on absence of any retinopathy (88% ± 4.6%, P = 0.91-0.95), presence of moderate nonproliferative or worse retinopathy (87% ± 3.9%, P = 0.67-1.00), and presence of macular edema (99% ± 0.9%, P = 0.67-1.00). There was limited agreement regarding presence of referable nondiabetic eye pathology (61% ± 11%, P = 0.21-0.59) and early, nonroutine referral for a follow-up clinical eye exam (66% ± 8.1%, P = 0.19-0.54). Among all cases (n = 100), there was acceptable agreement regarding which had gradable images (77% ± 5.0%, P = 0.50-0.90). DISCUSSION: Inclusion of multiple types of eye care providers as teleophthalmology readers is unlikely to produce significant variability in the assessment of diabetic retinopathy among high-quality images. Greater variability was found regarding image gradability, nondiabetic eye pathology, and recommended clinical referral times. CONCLUSIONS: Our results suggest that more extensive training and uniform referral standards are needed to improve consensus on image gradability, referable nondiabetic eye pathology, and recommended clinical referral times.
BACKGROUND: Preterm infants with anaemia are treated with recombinant human erythropoietin (rhEPO). It is debated whether rhEPO treatment is a risk factor for retinopathy of prematurity (ROP). We evaluated longitudinal EPO and haemoglobin levels, blood transfusions and neonatal morbidities as risk factors for severe ROP. METHOD: This prospective study included 78 Swedish infants, born <28 weeks gestational age (GA), screened for ROP. We tested serum EPO levels on postnatal days 1, 7, 14 and 28 and at postmenstrual ages 32, 36 and 40 weeks. Haemoglobin levels and blood transfusions were recorded during postnatal weeks 1-4. Anaemia was defined as haemoglobin ≤110 g/L. RESULTS: During postnatal week 1, infants with severe ROP requiring treatment (28%) more frequently developed anaemia (42.9% versus 8.0%, P = 0.003) and had higher mean EPO levels (postnatal day 7: 14.2 versus 10.8 mIU/mL, P = 0.003) compared to infants with no or less severe ROP not requiring treatment. In multivariable analyses, GA and anaemia during week 1 remained significant risk factors, but elevated EPO level postnatal day 7 was no longer significant. CONCLUSIONS: Among infants born <28 weeks GA, anaemia during week 1 was a significant risk factor for severe ROP requiring treatment but not elevated EPO levels.
OBJECTIVE: Revised diagnostic criteria for idiopathic intracranial hypertension (IIH) were proposed in part to reduce misdiagnosis of intracranial hypertension without papilledema (WOP) by using 3 or 4 MRI features of intracranial hypertension when a sixth nerve palsy is absent. This study was undertaken to evaluate the sensitivity and specificity of the MRI criteria and to validate their utility for diagnosing IIH in patients with chronic headaches and elevated opening pressure (CH + EOP), but WOP. METHODS: Brain MRIs from 80 patients with IIH with papilledema (WP), 33 patients with CH + EOP, and 70 control patients with infrequent episodic migraine were assessed in a masked fashion for MRI features of intracranial hypertension. RESULTS: Reduced pituitary gland height was moderately sensitive for IIH WP (80%) but had low specificity (64%). Increased optic nerve sheath diameter was less sensitive (51%) and only moderately specific (83%). Flattening of the posterior globe was highly specific (97%) but had low sensitivity (57%). Transverse venous sinus stenosis was moderately sensitive for IIH WP (78%) but of undetermined specificity. A combination of any 3 of 4 MRI features was nearly 100% specific, while maintaining a sensitivity of 64%. Of patients with CH + EOP, 30% had 3 or more MRI features, suggesting IIH WOP in those patients. CONCLUSION: A combination of any 3 of 4 MRI features is highly specific for intracranial hypertension and suggests IIH WOP when present in patients with chronic headache and no papilledema.
Bell's palsy is the most common neurologic condition affecting the cranial nerves. Lagophthalmos, exposure keratopathy, and corneal ulceration are potential complications. In this review, we evaluate various causes of facial paralysis as well as the level 1 evidence supporting the use of a short course of oral steroids for idiopathic Bell's palsy to improve functional outcomes. Various surgical and nonsurgical techniques are also discussed for the management of residual facial dysfunction.
Rapid and flexible learning during behavioral choices is critical to our daily endeavors and constitutes a hallmark of dynamic reasoning. An important paradigm to examine flexible behavior involves learning new arbitrary associations mapping visual inputs to motor outputs. We conjectured that visuomotor rules are instantiated by translating visual signals into actions through dynamic interactions between visual, frontal and motor cortex. We evaluated the neural representation of such visuomotor rules by performing intracranial field potential recordings in epilepsy subjects during a rule-learning delayed match-to-behavior task. Learning new visuomotor mappings led to the emergence of specific responses associating visual signals with motor outputs in 3 anatomical clusters in frontal, anteroventral temporal and posterior parietal cortex. After learning, mapping selective signals during the delay period showed interactions with visual and motor signals. These observations provide initial steps towards elucidating the dynamic circuits underlying flexible behavior and how communication between subregions of frontal, temporal, and parietal cortex leads to rapid learning of task-relevant choices.
The membrane guanylate cyclase, ROS-GC, that synthesizes cyclic GMP for use as a second messenger for visual transduction in retinal rods and cones, is stimulated by bicarbonate. Bicarbonate acts directly on ROS-GC1, because it enhanced the enzymatic activity of a purified, recombinant fragment of bovine ROS-GC1 consisting solely of the core catalytic domain. Moreover, recombinant ROS-GC1 proved to be a true sensor of bicarbonate, rather than a sensor for CO. Access to bicarbonate differed in rods and cones of larval salamander, , of unknown sex. In rods, bicarbonate entered at the synapse and diffused to the outer segment, where it was removed by Cl-dependent exchange. In contrast, cones generated bicarbonate internally from endogenous CO or from exogenous CO that was present in extracellular solutions of bicarbonate. Bicarbonate production from both sources of CO was blocked by the carbonic anhydrase inhibitor, acetazolamide. Carbonic anhydrase II expression was verified immunohistochemically in cones but not in rods. In addition, cones acquired bicarbonate at their outer segments as well as at their inner segments. The multiple pathways for access in cones may support greater uptake of bicarbonate than in rods and buffer changes in its intracellular concentration.
Industrial farms are unique, human-created ecosystems that provide the perfect setting for the development and dissemination of antibiotic resistance. Agricultural antibiotic use amplifies naturally occurring resistance mechanisms from soil ecologies, promoting their spread and sharing with other bacteria, including those poised to become endemic within hospital environments. To better understand the role of enterococci in the movement of antibiotic resistance from farm to table to clinic, we characterized over 300 isolates of cultured from raw chicken meat purchased at U.S. supermarkets by the Consumers Union in 2013. and were the predominant species found, and antimicrobial susceptibility testing uncovered striking levels of resistance to medically important antibiotic classes, particularly from classes approved by the FDA for use in animal production. While nearly all isolates were resistant to at least one drug, bacteria from meat labeled as raised without antibiotics had fewer resistances, particularly for Whole-genome sequencing of 92 isolates revealed that both commensal- and clinical-isolate-like enterococcal strains were associated with chicken meat, including isolates bearing important resistance-conferring elements and virulence factors. The ability of enterococci to persist in the food system positions them as vehicles to move resistance genes from the industrial farm ecosystem into more human-proximal ecologies. Bacteria that contaminate food can serve as a conduit for moving drug resistance genes from farm to table to clinic. Our results show that chicken meat-associated isolates of are often multidrug resistant, closely related to pathogenic lineages, and harbor worrisome virulence factors. These drug-resistant agricultural isolates could thus represent important stepping stones in the evolution of enterococci into drug-resistant human pathogens. Although significant efforts have been made over the past few years to reduce the agricultural use of antibiotics, continued assessment of agricultural practices, including the roles of processing plants, shared breeding flocks, and probiotics as sources for resistance spread, is needed in order to slow the evolution of antibiotic resistance. Because antibiotic resistance is a global problem, global policies are needed to address this threat. Additional measures must be taken to mitigate the development and spread of antibiotic resistance elements from farms to clinics throughout the world.
PURPOSE: The purpose of the study was to evaluate the tolerability and functionality of a wireless ocular telemetry sensor in African American patients with glaucoma. MATERIALS AND METHODS: In this prospective, observational cohort study, 20 African American patients with primary open angle glaucoma (POAG) were evaluated at the University of Colorado Eye Center. Before lens placement, patients recorded ocular comfort and underwent a baseline eye exam. Following the exam, patients were fitted with a SENSIMED Triggerfish contact lens sensor and data recording device. Patients were sent home and instructed to record their activities in a journal and return in 24 hours. Repeat exams were performed at various time points in clinic before and after lens removal. RESULTS: All 20 patients retained the lens for the 24-hour study period. The patient reported comfort was excellent, with a nadir of mean recorded comfort of 7.05/10. Significant clinical changes were noted in lid/conjunctival erythema, BCVA, refraction, and pachymetry over the course of lens wear. The majority of these changes were improved or resolved by 1 hour after lens removal. Voltage output was significantly greater nocturnally than diurnally (184.79 mV and 71.48 mV, respectively; P<0.0001). There was no significant change in signal variability or slope over the entire duration of the sleep/wake period based on sleep. CONCLUSIONS: The wireless ocular sensor is well tolerated over a 24-hour period in African American patients with POAG despite transient changes in visual acuity and conjunctival erythema. Clinically usable 24-hour profiles were generated for all patients, with voltage output increasing significantly during periods of sleep.
Conjunctivochalasis (CCH) is a bilateral conjunctival condition characterized by loose, redundant conjunctival folds, typically in the inferior bulbar conjunctiva. It is a common cause of ocular irritation, especially in older age. For asymptomatic CCH, no treatment is necessary. For treatment of symptomatic CCH, however, a variety of medical and surgical approaches are currently available, which will be thoroughly appraised in this review article. The first step in the management is medical therapy, which involves enhanced lubrication and use of anti-inflammatory medications. In refractory cases, a surgical approach may be undertaken for symptom relief. Several techniques have been described for this, with varying success rates. These include conjunctival cauterization, conjunctival excision, scleral fixation of the conjunctiva, conjunctival ligation, laser conjunctivoplasty, and radiowave electrosurgery. Among these, conjunctival cauterization and excision of the redundant conjunctiva, with or without tissue grafting, have gained popularity.
PURPOSE: To evaluate the therapeutic effect of subconjunctival injection of human mesenchymal stromal cells (hMSCs) in the cornea of mice with graft versus host disease (GVHD). METHODS: GVHD was induced in mice after hematopoietic stem cell transplantation (HSCT) between MHC-mismatched mouse strains. Subconjunctival injection of hMSCs was applied at day 10 post-HSCT. Infiltration of CD3 cells in the cornea and epithelial alterations were analyzed by immunofluorescence. Tear was assessed using the PRT test and TearLab Osmolarity System. qPCR was used to evaluate changes in cytokines, Pax6 and Sprr1b expression. To evaluate the effect of irradiation, we analyzed the expression of these genes in TBI mice. RESULTS: Immune cell invasion occurs in mice with GVHD, as shown by the presence of CD3 cells in the cornea. Interestingly, eyes treated with hMSC did not present CD3 cells. Tear osmolarity was increased in GVHD eyes, but not in treated eyes. TNFa expression was highly increased in all corneas except in Control and treated eyes. Pax6 in corneal epithelium showed a similar pattern in GVHD and Control mice, and its gene expression was enhanced in GVHD corneas. In contrast, Pax6 was reduced in GVHD + MSC corneas. We also found an increase in SPRR1B staining in GVHD eyes that was lower in GVHD + MSC mice, demonstrating that corneal keratinization is less frequent after treatment with hMSC. CONCLUSIONS: The treatment with hMSCs by subconjunctival injection is effective in reducing corneal inflammation and squamous metaplasia in ocular GVHD (oGVHD). Local treatment with hMSCs is a promising strategy for oGVHD.