[Hyperbaric oxygen therapy and eye disease: Review of the literature]

Hyperbaric oxygen therapy consists of breathing 100% oxygen continuously or intermittently in a chamber at a pressure equal to or greater than 1.4 absolute atmospheres. Indicated for the emergency treatment of carbon monoxide poisoning and other medical-surgical pathologies such as gas embolism or necrotizing soft-tissue infections, various studies have shown a beneficial effect of hyperbaric oxygen therapy in certain ocular pathologies, notably of microcirculatory origin, such as central retinal artery occlusion or macular edema linked to retinal vein occlusions. In addition, hyperbaric oxygen might represent an alternative treatment for ocular quinine toxicity and might also be useful as an adjuvant to surgery and antibiotics in cases of periorbital necrotizing fasciitis. On the other hand, oxygen in high concentrations has toxic ocular effects due to the production of reactive oxygen derivatives.

[Review by the French Glaucoma Society on the roles of new surgical techniques in glaucoma]

The surgical management of glaucoma has been enriched in recent years by the arrival of new surgical techniques as a group known as MIGS (minimally invasive glaucoma surgery). The objective of these new techniques is to reduce intraocular pressure (IOP) while limiting the risk of complications of conventional filtering surgery and allowing faster visual recovery. MIGS can be classified into three main categories depending on the route used to promote the outflow of aqueous humor: the trabecular route, the suprachoroidal route and the subconjunctival route. MIGS using the subconjunctival route are also called minimally invasive bleb surgery (MIBS). These new techniques do not replace conventional filtering surgery, which remains the gold standard technique, but now offer new alternatives for the surgical management of glaucoma patients in combination with cataract surgery or as stand-alone procedures.

[Biomechanics of the lamina cribrosa: A determining factor in glaucomatous neuropathy. A review of the literature]

Glaucoma is a chronic optic neuropathy characterized by progressive sclero-laminar remodeling. The main factor at the origin of these deformations is the intraocular pressure (IOP), the effect of which varies according to the biomechanical properties of the individual lamina cribrosa (LC). In this environment, the LC represents a malleable zone of weakness within a rigid corneoscleral shell. It is a dynamic structure whose movements play a key role in the pathogenesis of glaucoma: displacing it posteriorly, in addition to contributing to the characteristic appearance of glaucomatous cupping, would increase constriction on the nerve fibers and the laminar capillaries. Often incorrectly considered permanent in adults, these deformations have a certain degree of reversibility, which is currently better characterized thanks to progress in imaging techniques. The occurrence of anterior displacement and laminar thickening following a reduction in IOP could thus constitute a good prognostic factor by reducing mechanical stress on this region. These changes would tend to reduce laminar pore tortuosity and shear forces, which are probably key mechanisms of axonal loss in glaucoma.

[Corneal epithelial biomechanics: Resistance to stress and role in healing and remodeling]

The corneal epithelium is one of the first tissue barriers of the eye against the environment. In recent years, many studies provided better knowledge of its healing, its behavior and its essential role in the optical system of the eye. At the crossroads of basic science and clinical medicine, the study of the mechanical stresses applied to the cornea makes it possible to learn the behavior of epithelial cells and better understand ocular surface disease. We describe herein the current knowledge about the adhesion systems of the corneal epithelium and their resistance to mechanical stress. We will also describe the involvement of these mechanisms in corneal healing and their role in epithelial dynamics. Adhesion molecules of the epithelial cells, especially hemidesmosomes, allow the tissue cohesion required to maintain the integrity of the corneal epithelium against the shearing forces of the eyelids as well as external forces. Their regeneration after a corneal injury is mandatory for the restoration of a healthy epithelium. Mechanotransduction plays a significant role in regulating epithelial cell behavior, and the study of the epithelium's response to mechanical forces helps to better understand the evolution of epithelial profiles after refractive surgery. A better understanding of corneal epithelial biomechanics could also help improve future therapies, particularly in the field of tissue engineering.

[From ocular itching to eye rubbing: a review of the literature]

Ocular itching and eye rubbing are frequent complaints in an ophthalmology practice. Numerous studies address the consequences of eye rubbing, such as keratoconus. However, there are few studies concerning the pathophysiology of itching, its transmission pathways, or its interactions with eye rubbing. Through this literature review, we will address the various clinical, physiological and therapeutic aspects of this pair of symptoms with a variety of ocular consequences. We will then describe the state of the art in itching and scratching in dermatology, in order to draw a parallel between these two vicious cycles. A better understanding of the pathophysiology of ocular itching and eye rubbing, as well as new studies based on dermatological data, might allow more appropriate clinical management of our patients and their symptoms.

Safety and efficacy of iStent Inject trabecular micro-bypass stents in combination with phacoemulsification for chronic open angle glaucoma associated with cataract

BACKGROUND

The goal of this study was to assess the efficacy and safety of phacoemulsification combined with iStent Inject® implantation for the treatment of chronic open-angle glaucoma controlled on topical anti-glaucoma medications and associated with cataract.

METHODS

This study was a retrospective analysis of patients who underwent phacoemulsification and implantation of an iStent Inject® for chronic open-angle glaucoma associated with cataract. For all patients, pre- and postoperative characteristics, including number of glaucoma medications and intraocular pressure (IOP), were compared using Paired-sample t-tests and Wilcoxon signed-rank tests, respectively. Postoperative visits were scheduled at 7 days and 1, 3, 6, and 12 months after surgery.

RESULTS

Forty-nine eyes of 39 patients were included in the study. Mean preoperative IOP at baseline was 16.3±4.3mmHg (range, 10-29mmHg) with a mean of 2.2±1.0mmHg antiglaucoma medications. At 1 month, the mean IOP reduction was 16% (P<0.05) along with an 18.7% reduction in the mean number of medications. At 6 months, the mean IOP was 12.8±2.6, with a mean of 1.1±0.9 antiglaucoma medications. The mean IOP reduction at 6 months was 22% (P<0.05) along with a 49% reduction in the mean number of medications. At 12 months, the mean IOP was 13.8±2.5 with a mean of 1.1±1.2 medications. The mean IOP reduction at 12 months was 15% (P<0.05) along with a 47% reduction in the mean number of medications. No severe device-related side effects were observed.

CONCLUSIONS

iStent Inject® implantation combined with phacoemulsification resulted in effective IOP reduction and medication burden in patients with mild to advanced chronic open-angle glaucoma and preoperative IOP well controlled with topical hypotensive medications.

Hit Expansion of a Noncovalent SARS-CoV-2 Main Protease Inhibitor

Inhibition of the SARS-CoV-2 main protease (M^pro) is a major focus of drug discovery efforts against COVID-19. Here we report a hit expansion of non-covalent inhibitors of M^pro. Starting from a recently discovered scaffold (The COVID Moonshot Consortium. Open Science Discovery of Oral Non-Covalent SARS-CoV-2 Main Protease Inhibitor Therapeutics. bioRxiv 2020.10.29.339317) represented by an isoquinoline series, we searched a database of over a billion compounds using a cheminformatics molecular fingerprinting approach. We identified and tested 48 compounds in enzyme inhibition assays, of which 21 exhibited inhibitory activity above 50% at 20 μM. Among these, four compounds with IC₅₀ values around 1 μM were found. Interestingly, despite the large search space, the isoquinolone motif was conserved in each of these four strongest binders. Room-temperature X-ray structures of co-crystallized protein–inhibitor complexes were determined up to 1.9 Å resolution for two of these compounds as well as one of the stronger inhibitors in the original isoquinoline series, revealing essential interactions with the binding site and water molecules. Molecular dynamics simulations and quantum chemical calculations further elucidate the binding interactions as well as electrostatic effects on ligand binding. The results help explain the strength of this new non-covalent scaffold for M^pro inhibition and inform lead optimization efforts for this series, while demonstrating the effectiveness of a high-throughput computational approach to expanding a pharmacophore library.

Structural, Electronic, and Electrostatic Determinants for Inhibitor Binding to Subsites S1 and S2 in SARS-CoV-2 Main Protease

Creating small-molecule antivirals specific for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) proteins is crucial to battle coronavirus disease 2019 (COVID-19). SARS-CoV-2 main protease (Mpro) is an established drug target for the design of protease inhibitors. We performed a structure-activity relationship (SAR) study of noncovalent compounds that bind in the enzyme's substrate-binding subsites S1 and S2, revealing structural, electronic, and electrostatic determinants of these sites. The study was guided by the X-ray/neutron structure of Mpro complexed with Mcule-5948770040 (compound 1), in which protonation states were directly visualized. Virtual reality-assisted structure analysis and small-molecule building were employed to generate analogues of 1. In vitro enzyme inhibition assays and room-temperature X-ray structures demonstrated the effect of chemical modifications on Mpro inhibition, showing that (1) maintaining correct geometry of an inhibitor's P1 group is essential to preserve the hydrogen bond with the protonated His163; (2) a positively charged linker is preferred; and (3) subsite S2 prefers nonbulky modestly electronegative groups.

The trabecular meshwork in glaucoma: An inflammatory trabeculopathy?

Glaucoma is an optic neuropathy in which the primary risk factor is increased intraocular pressure (IOP), attributed to increased resistance to trabecular outflow of aqueous humor (AH). This resistance is believed to result from trabecular degeneration secondary to chronic oxidative stress and cellular senescence but may also involve inflammatory mechanisms whose roles are little known. In fact, inflammatory processes play a major role in the pathophysiology of glaucoma to varying degrees, affecting all structures of the eye, including the ocular surface, the anterior and posterior segments, and even the visual pathways of the brain. These processes are thought to result from dysfunction of a regulatory, protective para-inflammation, becoming chronic and harmful in glaucoma. While the mechanisms of the retinal inflammation which accelerates the degeneration of retinal ganglion cells (RGCs) as well as the inflammation of the ocular surface aggravated by long-term use of preserved glaucoma eye drops have been described for several years, very little is known about the pathophysiology of trabecular inflammation in glaucoma. The objective of this literature review is to provide a synthesis of knowledge on the roles and mechanisms of inflammation in both the healthy and glaucomatous trabecular meshwork, as well as its role in the pathophysiology of glaucoma. Therefore, after a review of the mechanisms of cellular senescence and oxidative stress - sources of trabecular inflammation, we will approach the study of the expression and roles of the main inflammatory mediators within the trabecular meshwork. Finally, we will discuss current knowledge on the toxicity of glaucoma eye drops and their preservatives on the ocular surface and trabecular meshwork as well as their role in trabecular inflammation.

Evaluation of pterygium severity with en face anterior segment optical coherence tomography and correlations with in vivo confocal microscopy

PURPOSE

To describe en face anterior segment optical coherence tomography (EF-OCT) characteristics of pterygia and their correlation with in vivo confocal microscopy (IVCM).

PATIENTS AND METHODS

In this observational case series, we prospectively included 21 eyes of 17 subjects with pterygium. All subjects underwent detailed ophthalmic examination, anterior segment photography, an ocular surface disease index (OSDI) questionnaire, IVCM, and EF-OCT. Eyes were divided into two groups according to pterygium severity (Modified Pterygium Classification System) and OSDI score. EF-OCT images for both groups were analyzed for surface area of Fuchs Patches (FP). The IVCM activity score was based on the number of inflammatory cells, blood vessels, activated keratocytes and the appearance of the cornea/pterygium at the head of the pterygium. The correlations between EF-OCT and IVCM images were then analyzed and compared in both groups.

RESULTS

EF-OCT permits clear visualization and evaluation of FPs and the border between the pterygium and the adjacent cornea. The severe pterygium group was characterized by irregular borders and larger FPs (0.13±0.06 mm² versus 0.06±0.02 mm² respectively) (P=0.003). The mean IVCM activity score was 2.36±0.81 in the severe pterygium group and 1.2±0.42 in the mild pterygium group (P=0.0013). There was a positive correlation between FP surface area and IVCM activity score. A larger FP surface area was associated with a higher activity score on IVCM.

CONCLUSION

EF-OCT allows good evaluation of pterygium extension, borders and FP surface area. EF-OCT analysis of pterygium could represent a simple, non-invasive and reproducible method to evaluate pterygium severity and activity.

[Prevalence of visual impairment in school-age children: Data analysis from PlanVue® pilot project]

PURPOSE

To assess the prevalence of visual disturbances among school-aged children in prioritized education zones in France.

METHODS

The PlanVue® pilot project was designed to detect and manage visual disturbances in school-aged children in the prioritized education areas of the city of Nanterre, France. During this pilot study, a cohort of 515 children aged 4 to 13 years underwent a school vision screening between January and March 2019, consisting of an overall evaluation of the child's visual behavior, measurement of uncorrected visual acuity in each eye, objective refraction with a photoscreener and strabismus screening. If the examination was abnormal as determined by impaired vision or an algorithm based on the abnormalities found, the children were referred to an ophthalmologist.

RESULTS

Decreased visual acuity was found in 20% of school-aged children. Out of the 515 children screened, 22% were referred to an ophthalmologist. Among these children, 13% were diagnosed with amblyopia, 73% with spherical ametropia, 57% with astigmatism and 2% with strabismus. Of the entire population screened, 12% of the children needed optical correction but had not received glasses.

CONCLUSION

This study confirms the high prevalence of uncorrected refractive errors among school-age children. A screening program carried out in a school environment by paramedical professionals might make it possible to considerably reduce the rate of uncorrected visual disorders and their consequences.

Excimer laser programming of refractive astigmatism vs. anterior corneal astigmatism in the case of ocular residual astigmatism (ORA)

PURPOSE

To determine whether manifest refractive astigmatism (RA) or anterior corneal astigmatism (CA) is the best value for excimer laser programming in cases of ocular residual astigmatism (ORA).

PATIENTS AND METHODS

Patients who had undergone LASIK surgery with a disagreement between manifest refractive and corneal cylinder (ocular residual astigmatism ORA)>0.75 D were included retrospectively in this study. We calculated target induced astigmatism vector (TIA), surgically induced astigmatism vector (SIA), difference vector between the astigmatism correction programmed in the excimer laser and refractive astigmatism (DVRA), difference vector between the astigmatism correction programmed in the excimer laser and corneal astigmatism (DVCA) and difference vector between TIA and SIA (DV), by the Alpins method. Vectorial differences between DV and DVRA, and between DV and DVCA, were then calculated to determine whether RA or CA was closest to the ideal cylinder for laser programming.

RESULTS

Of a total of 104 eyes undergoing LASIK, 22 eyes of 12 patients (21.1%) had an ORA>0.75 D and were included. Mean ORA was 0.9±0.2 D and mean postoperative subjective cylinder was 0.45 D. The DV-DVRA difference vector was 0.57±0.2 D, and the DV-DVCA difference vector was 0.86±0.4 D (P=0.02). RA was closer than CA to the ideal astigmatism correction.

CONCLUSION

In cases of discrepancy between manifest astigmatism and corneal astigmatism, correction of manifest refractive astigmatism seems to give a better refractive result.

[Radius-Maumenee syndrome: A rare cause of glaucoma]

Radius-Maumenee syndrome is a rare cause of severe secondary open-angle glaucoma. The ocular hypertension is due to episcleral venous hypertension. This syndrome consists of open angle glaucoma and episcleral venous dilatation without orbital or systemic abnormalities. It is diagnosis of exclusion after ruling out carotid-cavernous fistula, thyroid orbitopathy and an invasive orbital process that might explain the elevated episcleral venous pressure. Treatment begins with glaucoma eyedrops and, in case of failure, filtering surgery. Uveal effusion syndrome and postoperative choroidal detachment are frequent complications of filtering surgery in patients with this syndrome. We present the case report of a 59-year-old woman with Radius-Maumenee syndrome.

[Allergic immunotherapy in children and adolescents]

L’immunothérapie spécifique allergénique nécessite l’administration répétée d’allergènes dans le but de provoquer une tolérance clinique et immunologique. C’est la seule thérapeutique à visée étiologique qui permet de modifier l’évolution de la maladie en assurant une rémission après l’interruption de la procédure. La prévention de nouvelles sensibilisations par l’immunothérapie reste discutée. Nous envisagerons dans cette revue les principaux mécanismes immunologiques et les indications de l’immunothérapie chez l’enfant et l’adolescent.

[The trabecular meshwork: Structure, function and clinical implications. A review of the littérature (French translation of the article)]

Glaucoma is a blinding optic neuropathy, the main risk factor for which is increased intraocular pressure (IOP). The trabecular meshwork, located within the iridocorneal angle, is the main pathway for drainage of aqueous humor (AH) out of the eye, and its dysfunction is responsible for the IOP elevation. The trabecular meshwork is a complex, fenestrated, three-dimensional structure composed of trabecular meshwork cells (TMC) interdigitated into a multilayered organization within the extracellular matrix (ECM). The purpose of this literature review is to provide an overview of current understanding of the trabecular meshwork and its pathophysiology in glaucoma. Thus, we will present the main anatomical and cellular bases for the regulation of aqueous humor outflow resistance, the pathophysiological mechanisms involved in trabecular dysfunction in the various types of glaucoma, as well as current and future therapeutic strategies targeting the trabecular meshwork.

Acute ischemic optic nerve disease: Pathophysiology, clinical features and management

Ischemic optic neuropathies are among the leading causes of severe visual acuity loss in people over 50 years of age. They constitute a set of various entities that are clinically, etiologically and therapeutically different. Anatomically, it is necessary to distinguish anterior and posterior forms. From an etiological point of view, the diagnosis of the arteritic form due to giant cell arteritis requires emergent management to prevent blindness and even death in the absence of prompt corticosteroid treatment. When this diagnosis has been ruled out with certainty, non-arteritic ischemic optic neuropathies represent a vast etiological context that in the majority of cases involves a local predisposing factor (small optic nerves, disc drusen) with a precipitating factor (severe hypotension, general anesthesia or dialysis) in a context of vascular disease (sleep apnea syndrome, hypertension, diabetes, etc.). In the absence of specific available treatment, it is the responsibility of the clinician to identify the risk factors involved, in order to reduce the risk of contralateral recurrence that may occur even several years later. Due to their complexity, these pathologies are the subject of debates regarding both the pathophysiological and therapeutic perspectives; this review aims to provide a synthesis of validated knowledge while discussing controversial data.

In vivo Meibomian gland imaging techniques: A review of the literature

Meibomian gland dysfunction (MGD) includes a group of complex disorders of the ocular surface. It represents one of the main etiologies of dry eye as well as one of the main reasons for patient visits to the ophthalmologist. Classic clinical tests (dry eye symptoms, tear film break-up time, evaluation of gland expressibility or Schirmer's testing) only provide an indirect assessment of the function of the Meibomian glands and the meibum. Various in vivo testing methods have therefore been developed to image the Meibomian glands, such as Meibography, optical coherence tomography, ultrasound, or even in vivo confocal microscopy. Some are accessible in clinical practice, while others are limited to the realm of clinical research. All of these techniques aim to develop a direct structural analysis of the Meibomian glands so as to assist in the diagnosis of MGD as well as to better understand the pathophysiology of the Meibomian glands. This review of the literature hopes to provide an overview of the current imaging modalities and their role in the evaluation of the Meibomian glands and MGD.

[Tear film analysis and evaluation of optical quality: A review of the literature (French translation of the article)]

Dry eye is a complex multifactorial disease of the ocular surface and tears. It is associated with ocular surface symptoms and is one of the most common causes for ophthalmologic consultation. Despite their frequent use in clinical practice, the usual tests to evaluate dry eye and ocular surface disease-history of symptoms, tear break-up time (TBUT), Meibomian gland evaluation, corneal fluorescein staining, Schirmer test-have shown low reproducibility and reliability. In addition, subjective symptoms are often weakly or poorly correlated with objective signs. Since the tear film is the first system through which light must pass, the optical quality of the eye is highly dependent on the homogeneity of the tear film. Various investigative methods have been developed to evaluate both the structural and functional quality of the tear film, such as corneal topography, interferometry, tear meniscus measurement, evaporation rate, tear osmolarity and even aberrometry. Some are easily accessible to clinicians, while others remain in the field of clinical research. All of these tests provide a better understanding of the pathophysiology of the tear film. This review hopes to provide an overview of the existing tests and their role in evaluating the significance of the tear film in visual function.

XEN® Gel Stent for management of chronic open angle glaucoma: A review of the literature

PURPOSE

The purpose of this study was to analyze the change in intraocular pressure (IOP) and glaucoma medications using the XEN^® Gel Stent as a solo procedure or in association with phacoemulsification in patients with chronic open angle glaucoma (OAG).

METHODS

We included cohort studies with at least one year of follow-up in patients with primary open angle glaucoma (POAG), pseudo-exfoliative glaucoma (PXG) or pigmentary glaucoma (PG) who received a XEN^® gel stent. The main outcome measure was IOP reduction at 12 months follow-up. Secondary outcomes were the decrease in glaucoma medications 12 months after surgery, frequency and type of postoperative interventions and complication rate.

RESULTS

A total of 8 case series published between 2016 and 2018 were included; six were prospective studies, and two were retrospective. There was no randomized controlled trial. The data concerned a total of 958 eyes of 777 patients. The various studies showed a mean IOP at 12 months between 13 and 16mmHg, which represented an IOP reduction between 25 and 56% (mean: 42%). This decrease was associated with a reduction in glaucoma medications in all studies. The decrease in IOP was significantly greater in XEN^® implantation as a stand-alone procedure (44%) than in combined surgery (32%) (P<0.05). Transient hypotony (< 1 month) (3%), choroidal detachment or choroidal folds (1.5%), hyphema (1.9%), bleb leak (1.1%) and shallow anterior chamber (1.1%) were the most frequent complications. As for severe complications, four cases of malignant glaucoma (0.4%) and one case of retinal detachment have been reported. In the follow-up period, needling has been required in 32% of cases, and a total of 55 eyes (5.7%) required repeat filtering surgery or cyclodestructive procedure.

CONCLUSION

XEN^® Gel Stent appears effective for reducing IOP and the number of medications in OAG patients within 1 year postoperatively with an acceptable safety profile. However, vigilant postoperative follow-up and frequent postoperative maneuvers are required.

Tear film analysis and evaluation of optical quality: A review of the literature

Dry eye is a complex multifactorial disease of the ocular surface and tears. It is associated with ocular surface symptoms and is one of the most common causes for ophthalmologic consultation. Despite their frequent use in clinical practice, the usual tests to evaluate dry eye and ocular surface disease-history of symptoms, tear break-up time (TBUT), Meibomian gland evaluation, corneal fluorescein staining, Schirmer test-have shown low reproducibility and reliability. In addition, subjective symptoms are often weakly or poorly correlated with objective signs. Since the tear film is the first system through which light must pass, the optical quality of the eye is highly dependent on the homogeneity of the tear film. Various investigative methods have been developed to evaluate both the structural and functional quality of the tear film, such as corneal topography, interferometry, tear meniscus measurement, evaporation rate, tear osmolarity and even aberrometry. Some are easily accessible to clinicians, while others remain in the field of clinical research. All of these tests provide a better understanding of the pathophysiology of the tear film. This review hopes to provide an overview of the existing tests and their role in evaluating the significance of the tear film in visual function.

[Primary open-angle glaucoma]

Primary open-angle glaucoma is a progressive chronic optic neuropathy, typically bilateral, that occurs after the age of 40 years. It is the second leading cause of irreversible blindness in the world. Primary open-angle glaucoma corresponds to a progressive loss of retinal ganglion cell characterized by an excavation of the optic disc associated with typical visual field defects. Elevated intraocular pressure is the main risk factor of primary open-angle glaucoma. Diagnosis and monitoring of primary open-angle glaucoma arebased on both analysis of structural alteration, by clinical examination of optic disc completed by imaging tests (Ocular Coherence Tomography), and functional alterations, by visual field tests. The only effective treatment to slow primary open-angle glaucoma progression is the reduction of the intraocular pressure with anti-glaucomatous eye drops, laser or surgical treatments.

[Topical cyclosporine A and risk of ocular surface neoplasia]

INTRODUCTION

Cyclosporine A (CsA) has well-known cutaneous carcinogenic effects when administered systemically. In ophthalmology, it is increasingly used in the form of eye drops since its indication for moderate to severe eye dry eye. The goal of this review of the literature is to evaluate a possible link between topical ocular CsA use and the occurrence of ocular surface neoplasia.

MATERIALS AND METHODS

A literature review was performed. Publications evaluating the safety and efficacy of topical CsA as well as studies on the epidemiology and risk factors for conjunctival neoplasia and cases of conjunctival neoplasia were analyzed. Finally, post-market surveillance data from commercially available CsA eye drops were also evaluated.

RESULTS

Five cases of conjunctival neoplasia in patients treated with systemic and/or topical CsA have been described in the literature, three with systemic administration alone, another with combined systemic and local administration, and one case of local administration alone. In these cases, no direct link with the administration of ocular topical CsA could be determined. Among the numerous prospective studies evaluating the safety and efficacy of topical CsA as well as the case-control studies evaluating the risk factors for developing conjunctival neoplasia, no relationship between the occurrence of conjunctival neoplasia and the use of topical ocular CsA was observed.

CONCLUSION

Despite plausible pathophysiologic mechanisms, to date there is no evidence of an increased risk of ocular surface neoplasia with the use of topical ocular CsA. Further studies specifically addressing this question and with a longer duration are needed in order to precisely evaluate this theoretical risk.

[Role of laser peripheral iridotomy in pigmentary glaucoma and pigment dispersion syndrome: A review of the literature [French version]]

PURPOSE

Pigment dispersion syndrome (PSD) is characterized by a structural abnormality of the posterior surface of the iris causing contact with the zonular fibers. It can lead to an open-angle glaucoma secondary to pigment dispersion into the trabecular meshwork. Laser peripheral iridotomy (PI) has been proposed as a treatment for pigmentary glaucoma (PG) and pigment dispersion syndrome (PDS) by reducing the dispersion of pigment. The goal of this review was to assess the effects of PI for PSD and PG.

METHODS

We included six randomized controlled trials and two cohort studies (286 eyes of 218 participants). Four trials included participants with PG, and 4 trials enrolled participants with PSD with or without elevated intraocular pressure (IOP).

RESULTS

Among patients with PG, at an average of 9 months of follow-up, the mean difference in IOP between groups was 2.69mmHg less in the PI group (95 % CI: -6.05 to 0.67; 14 eyes). In patients with PDS, the average IOP was statistically lower after PI as compared to baseline (Student test, t=11.49, P<0.01). With regard to visual field progression in participants with GP, after an average follow-up of 28 months, the risk of progression was not influenced by PI (RR 1.00 95 %: CI 0.16 to 6.25; 32 eyes). No trials that enrolled patients with PSD showed a diminution of the risk of glaucoma conversion at mid- and long-term.

CONCLUSION

PI decreases the biomechanical factor causing contact between the iris and zonular fibers and may lower IOP over the long-term. Nevertheless, the effects of PI on visual field changes or progression have not been established in PG and PDS. There is no scientific evidence as of yet to advocate PI as a treatment for PDS or PG.

Elimination of blinding trachoma in China

OBJECTIVE

To present the change in the prevalence of blindness caused by trachoma between 1987 and 2006 by secondary data analysis based on two China National Sample Surveys on Disability (CNSSD).

METHODS

Secondary data analysis was performed on two China National Sample Surveys on Disability (CNSSD), which were national representative household surveys conducted in 1987 and 2006. The prevalence of blindness caused by trachoma was estimated by 10-year age group. In addition, the proportion of various causes of blindness was evaluated. The geographical distribution of blindness caused by trachoma both in 1987 and 2006 was analyzed in order to visualize the hot spots of blinding trachoma in China.

RESULTS

The prevalence of blindness caused by trachoma in China decreased from 51.5/100,000 in 1987 to 17.6/100,000 in 2006. In addition, the proportion of blindness attributed to trachoma also decreased from 10.1% (1987) to 0.9% (2006). Moreover, the prevalence of blindness caused by trachoma was over 200/100,000 in 2.2% of sampled counties in 2006 as compared to 8.6% in 1987. The hot spots of blinding trachoma were shown to be limited to underdeveloped mountain areas in Hubei and Guizhou provinces.

CONCLUSION

Although blinding trachoma is no longer the leading cause of blindness in China since the 2000's, the prevalence of trachoma should still be monitored in some underdeveloped mountain areas. Therefore, health organization must continue to fight against blinding trachoma in underdeveloped areas.

[A new classification for meibomian gland diseases with in vivo confocal microscopy]

INTRODUCTION

Meibomian gland dysfunction (MGD) is a frequent disorder often associated with dry eye disease. Slit-lamp examination with digital expression of the tarsal Meibomian glands allows examination of the contents of the distal Meibomian gland and the meatus. However, the Meibomian epithelium, interglandular space and proximal secretions cannot be clinically assessed. In vivo confocal microscopy (IVCM) is a rapid and non-invasive imaging technique that provides high-resolution images of the ocular surface and eyelids. The primary objective of the present study was to establish a classification of MGD with IVCM. Secondary objectives were to evaluate this scoring system by analyzing the correlation with OSDI, infrared (IR) meibography and Demodex infestation.

MATERIAL AND METHODS

Forty-six dry eye patients (Ocular Surface Disease Index [OSDI] >13) associated with MGD were enrolled. Ten healthy subjects without dry eye disease or blepharitis were also included as controls. An OSDI questionnaire, clinical examination, IVCM and infrared meibography of the lower lid were performed in all subjects by the same examiner.

RESULTS

A new MGD score was established based on IVCM findings: the first stage was Meibomian obstruction with a clear epithelium, the second stage was an inflammatory state with Meibomian gland obstruction, epithelial and interglandular inflammation, and the last stage was glandular fibrosis. This score was significantly correlated with the meiboscore obtained with infrared meibography (correlation coefficient 0.47, CI95% [0.22-0.66]).

CONCLUSION

IVCM of the Meibomian gland complex complements the clinical examination by determining the stage of dysfunction and may help clinicians evaluate and treat MGD.

[Imaging of corneal dystrophies: Correlations between en face anterior segment OCT and in vivo confocal microscopy]

PURPOSE

To evaluate the usefulness of en face Optical Coherence Tomography (OCT) for evaluation of corneal dystrophies and to describe correlations with in vivo confocal microscopy (IVCM).

PATIENTS AND METHODS

Thirty-two eyes of 16 patients with 4 types of corneal dystrophies (epithelial basement membrane dystrophy, Fuchs dystrophy, Reis-Bücklers corneal dystrophy and Crocodile Shagreen dystrophy) were enrolled in this study. Axial and reconstructed en face scans were acquired using OCT. Images were then correlated to IVCM findings.

RESULTS

En face OCT provided new insights into the structure, size and depth of corneal tissue alterations in various corneal dystrophies. OCT en face images were well correlated with IVCM features. Despite lower resolution than IVCM, en face OCT offers the advantages of being non-invasive and allowing the analysis of larger corneal areas.

CONCLUSION

En face OCT provides useful new information in corneal dystrophies. This imaging technique will probably increase in popularity in the near future for the assessment of various anterior segment diseases.

Acute flaccid paralysis following enterovirus D68 associated pneumonia, France, 2014

Human enterovirus D68 (EV-D68) is known to be associated with mild to severe respiratory infections. Recent reports in the United States and Canada of acute flaccid paralysis (AFP) in children with detection of EV-D68 in respiratory samples have raised concerns about the aetiological role of this EV type in severe neurological disease. This case study is the first report of AFP following EV-D68 infection in Europe.

[Acanthamoeba keratitis]

Early diagnosis and appropriate therapy are key elements for a good prognosis in Acanthamoeba keratitis (AK). AK should be considered in any case of corneal trauma complicated by exposure to soil or contaminated water, and in all contact lens (CL) wearers. A presumptive diagnosis of AK can be made clinically and with in vivo confocal microscopy, although a definitive diagnosis requires identification of Acanthamoeba on direct scraping, histology, or identification of Acanthamoeba DNA by polymerase chain reaction (PCR). We use cysticidal drugs for treating AK because encysted forms are more resistant than trophozoites to treatment. The treatment protocol used a biguanide (PHMB 0.02% or chlorhexidine 0.02%) and a diamidine (propamidine 0.1% or hexamidine 0.1%). New diagnostic modalities and more specific topical anti-amoebic treatments would substantially benefit patients with AK.

[Lactic acidosis in a child with acute severe asthma]

La survenue d’une acidose lactique dans l’asthme aigu grave (AAG) est classique chez l’adulte mais peu décrite chez l’enfant. Sa reconnaissance peut avoir des conséquences sur la prise en charge thérapeutique de la crise d’asthme. Une petite fille de 2 ans a été hospitalisée en réanimation pédiatrique pour un AAG, traité par oxygénothérapie à haut débit, méthylprednisolone et salbutamol par voie intraveineuse. Elle a présenté une acidose métabolique (pH = 7,29) avec hypocapnie (26 mmHg), chute des bicarbonates (12 mmol/L), trou anionique (20 mmol/L) et augmentation des lactates (8 mmol/L). La recherche d’une maladie métabolique sous-jacente a été négative. L’évolution a été favorable avec amélioration spontanée de l’acidose lactique permettant la sortie de l’unité de réanimation après 72 heures. L’origine d’une acidose lactique au cours de l’AAG est multifactorielle. Bien que sa résolution soit spontanée, il est essentiel de la reconnaître car elle peut modifier la symptomatologie respiratoire et conduire à une escalade thérapeutique inappropriée.

[Characteristics of admissions to pediatric emergency departments for exacerbations of asthma. Assessment and prospects for improving prehospital care]

INTRODUCTION

The frequency of emergency department visits for asthma is a major public health problem in pediatrics. The aim of this study is to establish the characteristics of children visiting pediatric emergency departments for acute asthma and to assess their therapeutic management prior to admission.

METHODS

A prospective clinical study performed during 3 months at the pediatric emergency department of the university teaching hospital of Clermont-Ferrand, of children aged 1 to 16 years admitted to the department with a clinical diagnosis of asthma exacerbation.

RESULTS

One hundred and forty-three patients were included in the study. Asthma crises were moderate to severe in 69.2% of cases (n=99). Initial therapeutic management prior to the admission to the emergency department was appropriate in 17.5% of cases (n=25). Most of the known asthmatic patients had not been followed up by a pediatric pulmonologist (n=56). A crisis protocol had been set up in 16.5% of cases (n=20). Exacerbations were more severe among younger patients (P=0.002) and economically disadvantaged children (P=0.025).

CONCLUSIONS

This study uncovers poor knowledge of the disease among asthmatic children and their families, and an insufficient awareness among health practitioners of current recommendations for the treatment of asthmatic children. Admissions to the emergency department for asthma could be partly avoided by improving diagnosis and therapeutic education.