Ocular sequelae of epidermal necrolysis: French national audit of practices, literature review and proposed management

Stevens-Johnson Syndrome (SJS) and toxic epidermal necrolysis (TEN) are serious and rare diseases, most often drug-induced, and their incidence has been estimated at 6 cases/million/year in France. SJS and TEN belong to the same spectrum of disease known as epidermal necrolysis (EN). They are characterized by more or less extensive epidermal detachment, associated with mucous membrane involvement, and may be complicated during the acute phase by fatal multiorgan failure. SJS and TEN can lead to severe ophthalmologic sequelae. There are no recommendations for ocular management during the chronic phase. We conducted a national audit of current practice in the 11 sites of the French reference center for toxic bullous dermatoses and a review of the literature to establish therapeutic consensus guidelines. Ophthalmologists and dermatologists from the French reference center for epidermal necrolysis were asked to complete a questionnaire on management practices in the chronic phase of SJS/TEN. The survey focused on the presence of a referent ophthalmologist at the center, the use of local treatments (artificial tears, corticosteroid eye drops, antibiotic-corticosteroids, antiseptics, vitamin A ointment (VA), cyclosporine, tacrolimus), the management of trichiatic eyelashes, meibomian dysfunction, symblepharons, and corneal neovascularization, as well as the contactologic solutions implemented. Eleven ophthalmologists and 9 dermatologists from 9 of the 11 centers responded to the questionnaire. Based on questionnaire results, 10/11 ophthalmologists systematically prescribed preservative-free artificial tears, and 11/11 administered VA. Antiseptic or antibiotic eye drops or antibiotic-corticosteroid eye drops were recommended as needed by 8/11 and 7/11 ophthalmologists, respectively. In case of chronic inflammation, topical cyclosporine was consistently proposed by 11/11 ophthalmologists. The removal of trichiatic eyelashes was mainly performed by 10/11 ophthalmologists. Patients were referred to a reference center for fitting of scleral lenses (10/10,100%). Based on this practice audit and literature review, we propose an evaluation form to facilitate ophthalmic data collection in the chronic phase of EN and we also propose an algorithm for the ophthalmologic management of ocular sequelae.

[Anatomic-functional correlations in birdshot chorioretinopathy: An observational single-center prospective study]

INTRODUCTION

The purpose of this study was to identify anatomic-functional correlations in patients with Birdshot chorioretinopathy in order to better understand the mechanisms of visual loss.

MATERIALS AND METHODS

We conducted a single-center observational prospective study at the Nantes University Medical Center including all patients followed for Birdshot chorioretinopathy between January 2019 and July 2019. The parameters studied were visual acuity, microperimetry, standard automated perimetry, SD-OCT, EDI-OCT, OCT-A, RNFL-OCT, wide-field fundus photographs, and fluorescein and ICG angiography.

RESULTS

Forty-four eyes were studied. A significant correlation was found between visual acuity and retinal thickness (P=0.002, r=0.44), but not choroidal thickness (P=0.16). A significant correlation was also observed between retinal sensitivity and total macular thickness (P<0.001, r=0.68) as well as inner retinal thickness (P<0.001, r=0.65), while the correlation was weaker with choroidal thickness (P=0.03, r=0.32). There was a weak correlation between retinal sensitivity and superficial capillary density (P=0.02, r=0.42) as well as deep capillary density (P=0.02, r=0.41). The peripheral hypo-autofluorescent zones correspond to the visual field defects, but these defects are larger than the hypo-autofluorescent zones. Patients with paracentral or peripheral field defects had a history of vasculitis more often than hypo-ICG spots.

DISCUSSION

We found significant correlations between functional parameters such as visual acuity and retinal sensitivity and retinal anatomic parameters, particularly the inner retina, while there was no correlation shown with choroidal anatomic parameters.

CONCLUSION

The main results of our study suggest a retinal rather than choroidal origin of the degradation of visual function in birdshot chorioretinopathy.

Efficacy and Safety of Interferon Alpha 2A and Pegylated Interferon Alpha 2A in Inflammatory Macular Edema

Purpose: The aim of this study was to further explore the efficacy and safety of interferon-α in refractory non-infectious inflammatory macular edema and to compare interferon-α2a and pegylated interferon-α2b.Methods: 34 patients with refractory non-infectious uveitic macular edemaunder interferon-α were retrospectively reviewed.Results: Mean baseline best-corrected visual acuityimproved from 0.55 logMar to 0.37 logMAR (P < 0.001) at month (M) 1 and 0.40 logMAR (P < 0.001) at M6. The mean baseline CMT decreased from 554 µm to 367 µm (P < 0.001) at M1 and 394 µm (P < 0.001) at M6. Clinical adverse effects (AEs) were observed in a third of patients, leading to treatment discontinuation because of frequent mild AEs and few severe AE. No statistically significant difference was found between both molecules.Conclusions: Anatomically and functionally, interferon-α was rapidly effective despite a low dosage regimen and no difference in efficacy and tolerance was observed between interferon-α2a and pegylated interferon-α2b.

Pancreatic acinar-cell desensitization alters InsP3 production and Ca2+ mobilization under conditions where InsP3 receptor remains intact

Desensitization of rat pancreatic acinar cells with 0.1 mM carbamoylcholine (Cch) or 0.5 nM caerulein (CAE), a cholecystokinin (CCK) agonist, altered the subsequent secretory responses to these two agonists. Changes in receptor affinities, shifts in receptor populations, receptor internalization and phosphorylation are the major modifications affecting the muscarinic and CCK receptors in response to desensitization. In this study, post-receptor alterations were examined in order to explain the altered enzyme secretion. Cch or CAE desensitization resulted in decreased Ca2+ release in response to CAE and Cch respectively. Under desensitizing conditions, the biochemical and pharmacological properties of the InsP3 receptor were not affected. Control and desensitized acini had similar Bmax. and KD values. The Ca(2+)-channel property of the InsP3 receptor was not affected, either, since Ca2+ release in response to increasing concentrations of InsP3 remained comparable in both groups of saponin-permeabilized acini. Finally, the quantities of InsP3 formed in response to Cch and CAE, measured by InsP3 radioreceptor assay, were significantly decreased in the Cch- and CAE-desensitized groups, and these decreases were not due to increased InsP3 turnover. These new data indicate that desensitization of acinar cells with Cch and CAE causes post-receptor modifications resulting in decreased InsP3 formation and decreased intracellular Ca2+ mobilization. It is suggested that the attenuated Ca2+ response is related to a decreased formation of InsP3 from PtdInsP2 hydrolysis and that phospholipase C could be the immediate target of this regulation.

Pharmacologic characterization of the inositol trisphosphate receptor in rat pancreas

Inositol 1,4,5-trisphosphate (InsP3) is an intracellular second messenger, produced upon stimulation of the phosphoinositide system, capable of mobilizing calcium from intracellular stores. The properties of InsP3 receptor sites in the rat pancreas were evaluated by binding studies with InsP3 labeled with 3H. Specific binding was very sensitive to pH variations between 7 and 9. Kinetic studies showed that specific binding of InsP3 at 0 degrees C was half-maximal in about 10 min and reached a plateau within 60 min with a K+1 = 3.37 x 10(9) mol-1min-1. Binding was reversible as addition of 10(-6) M unlabeled InsP3 was followed by dissociation of the bound ligand with a K-1 = 0.016 min-1. Scatchard analysis of the binding data was consistent with a single set of high-affinity sites with KD of 9.9 +/- 2.47 nM and a maximal binding capacity of 210 +/- 55 fmol/mg of protein (n = 7). The specificity of [3H]InsP3 binding to these sites was illustrated by the much weaker affinity for structural analogs such as inositol 1,3,4,5-tetrakisphosphate, phytic acid, fructose 1,6-bisphosphate, and heparin. To assess the functional relevance of the InsP3 binding sites, the Ca(2+)-releasing activity of InsP3 was measured in permeabilized acinar cell preparations. In the presence of oligomycin (10 micrograms/ml), Ca2+ movements were monitored with the fluorescent indicator fura-2 (free acid). Under these conditions, 4 mM ATP caused rapid uptake of Ca2+ by the vesicular component of the acinar cells. Addition of InsP3 (0.1-15 microM) caused a dose-dependent release of Ca2+ with half-maximal effect at 3.2 microM.(ABSTRACT TRUNCATED AT 250 WORDS)

The high affinity state of inositol 1,4,5-trisphosphate receptor is a functional state

Inositol 1,4,5-trisphosphate (InsP3) is a second messenger responsible for the rapid and discontinuous release of Ca2+ from intracellular stores. In this study, the effects of the sulfhydryl reagent thimerosal were investigated on Ca2+ mobilization and on InsP3 binding. Thimerosal was shown to release Ca2+, in a dose-dependent manner, with an EC50 of 135.8 +/- 5.2 microM, from bovine adrenal cortex microsomes. Thimerosal-induced Ca2+ release was not prevented by heparin (250 micrograms/ml), ruling out a participation of InsP3 receptor in that effect. The slow rate of thimerosal-induced Ca2+ release rather suggested an inhibition of microsomal Ca2+ ATPase. At submaximal concentration, thimerosal (100 microM) was also shown to potentiate the release of Ca2+ induced by InsP3. Dose-response experiments revealed that thimerosal enhanced the apparent affinity of InsP3 by a factor 2.21 +/- 0.28, without modifying the maximal amount of Ca2+ released by InsP3. Thimerosal also enhanced, in a dose-dependent manner, [3H]InsP3 binding to adrenal cortex microsomes (EC50 = 43.3 +/- 7.6 microM). A similar effect was also observed on [3H]InsP3 binding to solubilized receptors, suggesting a direct modification of the receptor protein by thimerosal. The effects of thimerosal on Ca2+ release and [3H]InsP3 binding were abolished in the presence of the reducing agent dithiothreitol (1 mM), suggesting a modification by thimerosal of specific thiol groups on these microsomal proteins. Scatchard analysis revealed that thimerosal (100 microM) increased InsP3 receptor affinity by 1.87 +/- 0.26-fold. Kinetic analysis indicated that this increased affinity was due to an enhancement of InsP3 association rate constant. The concomitant increases of binding affinity and Ca2+ releasing potency suggest that the high affinity state of InsP3 receptor is a functional state.