Bilateral acute depigmentation of the iris (BADI) and bilateral acute iris transillumination (BAIT): A case series from a center in Brazil.

Bilateral acute depigmentation of the iris and bilateral acute iris transillumination (BAIT) are similar clinical entities. The former causes acute-onset depigmentation of the iris stroma without transillumination, whereas the latter causes depigmentation of the iris pigment epithelium with transillumination. The etiopathogenesis of these conditions is not yet fully understood, but the proposed causes include the use of systemic antibiotics (especially moxifloxacin) and viral triggers. We present a case series of five female patients with a mean age of 41 (32-45) years, all of whom suffered acute onset of bilateral pain and redness of the eyes after moxifloxacin use (oral or topical). It is important for ophthalmologists to be aware of the two forms of iris depigmentation since this case series suggests that SARS-CoV-2 or its empirical treatment with moxifloxacin may trigger iris depigmentation. If this is the case, clinicians will likely see increased incidences of bilateral acute depigmentation of the iris and bilateral acute iris transillumination during and after the COVID-19 pandemic.

Epibulbar simple cartilaginous choristoma associated with unique pigmented multicystic component.

PURPOSE: To report an atypical presentation of an epibulbar simple cartilaginous choristoma with a unique pigmented multicystic component. CASE DESCRIPTION: A 69-year-old African American female presented for evaluation of a right nasal epibulbar lesion that had progressed over the prior year. Slit-lamp evaluation revealed an immobile, mildly pigmented multicystic lesion measuring 6.0 × 4.5 mm that involved the nasal bulbar conjunctiva and the plica semilunaris. The lesion appeared benign, without feeder vessels or features of epithelial dysplasia. Given its recent growth and the patient's cosmetic concerns, the lesion was excised with ocular surface reconstruction. Histopathological evaluation disclosed a well-circumscribed nodule of well-differentiated cartilage in the substantia propria, consistent with a simple cartilaginous choristoma. The overlying conjunctival stroma contained multiple cysts lined by focally pigment epithelium. The patient recovered well from surgery, with satisfactory cosmetic results. CONCLUSIONS: Our case of epibulbar simple cartilaginous choristoma includes a prominent superficial component of pigmented epithelial cysts, which has not been previously reported in the literature. This augments our knowledge on the spectrum of presentations of cartilaginous choristomas and underscores the importance of histopathological evaluation for definitive diagnosis.

Acute Posterior Multifocal Placoid Pigment Epitheliopathy: A Rare Presentation of Anklylosing Spondylitis or a Paradoxical Reaction to Secukinumab?

PURPOSE: To describe an atypical presentation of acute posterior multifocal placoid pigment epitheliopathy (APMPPE) in a patient with ankylosing spondylitis (AS) receiving secukinumab. METHODS: Retrospective chart review. RESULTS: A 48-year-old female patient with AS receiving secukinumab complained of impaired vision in her left eye. Left eye examination revealed multiple yellow-white lesions at the posterior pole and central subfoveal fluid.The lesions regressed without scarring. The case was diagnosed with clinically APMPPE. CONCLUSION: In AS patients, posterior uveitis can manifest as APMPPE. It should be recorded as an entity to be considered in the differential diagnosis.

Pigment deposits in the retrolental space of Berger: a rare feature of pigment dispersion syndrome? / Depósitos de pigmento no espaço de Berger: uma característica rara de síndrome de dispersão pigmentar?

ABSTRACT Pigment dispersion syndrome is associated with clinical features such as Krukenberg's spindles, trabecular pigmentation, Scheie's stripe and Zentmayer's ring. Another less common feature of this syndrome is retrolental pigment deposits due to anterior hyaloid detachment or a defect in the Wieger's ligament. We present two cases of pigment deposits on the posterior lens capsule. In both cases, there is bilateral dispersion of pigment throughout the anterior segment. The retrolental deposits are unilateral in the first case and bilateral in the second. Both patients report a history of ocular trauma. This is a possible important clinical sign of pigment dispersion syndrome, rarely described.

RESUMO A síndrome de dispersão pigmentar associa-se a sinais clínicos característicos como fuso de Krukenberg, hiperpigmentação da malha trabecular, linha de Scheie e anel de Zentmeyer. Um sinal menos comum dessa síndrome é o depósito de pigmento posterior ao cristalino, que ocorre por um descolamento da hialoide anterior ou um defeito no ligamento de Wieger. Apresentamos dois casos de depósitos de pigmento posterior à cápsula posterior do cristalino. Em ambos os casos, existia dispersão bilateral de pigmento por todo o segmento anterior. No primeiro caso, os depósitos eram unilaterais e, no segundo, estavam presentes em ambos os olhos. Este pode corresponder a um sinal potencialmente importante da síndrome de dispersão pigmentar, raramente descrito.

[Adenocarcinoma of nonpigmented ciliary body epithelium (clinical cases)]. / Adenokartsinoma iz bespigmentnogo epiteliya tsiliarnogo tela (klinicheskie nablyudeniya).

The article presents two clinical cases of adenocarcinoma of nonpigmented epithelium of the ciliary body, which is a very rare malignant tumor of the organ of vision with distinctive features. Surgical treatment is necessary to verify this tumor and assess the degree of its aggressiveness in terms of the prognosis of the disease, with subsequent pathomorphological and immunohistochemical studies. The article also discusses the epidemiological aspects, morphological features, clinical manifestations of this pathological condition, as well as possible treatment options and features of follow-up monitoring of this group of patients.

Engineering a Biomimetic In Vitro Model of Bruch's Membrane Using Hagfish Slime Intermediate Filament Proteins.

Bruch's membrane resides in the subretinal tissue and regulates the flow of nutrients and waste between the retinal pigment epithelial (RPE) and vascular layers of the eye. With age, Bruch's membrane becomes thicker, stiffer, and less permeable, which impedes its function as a boundary layer in the subretina. These changes contribute to pathologies such as age-related macular degeneration (AMD). To better understand how aging in Bruch's membrane affects surrounding tissues and to determine the relationship between aging and disease, an in vitro model of Bruch's membrane is needed. An accurate model of Bruch's membrane must be a proteinaceous, semipermeable, and nonporous biomaterial with similar mechanical properties to in vivo conditions. Additionally, this model must support RPE cell growth. While models of subretinal tissue exist, they typically differ from in vivo Bruch's membrane in one or more of these properties. This study evaluates the capability of membranes created from recombinant hagfish intermediate filament (rHIF) proteins to accurately replicate Bruch's membrane in an in vitro model of the subretinal tissue. The physical characteristics of these rHIF membranes were evaluated using mechanical testing, permeability assays, brightfield microscopy, and scanning electron microscopy. The capacity of the membranes to support RPE cell culture was determined using brightfield and fluorescent microscopy, as well as immunocytochemical staining. This study demonstrates that rHIF protein membranes are an appropriate biomaterial to accurately mimic both healthy and aged Bruch's membrane for in vitro modeling of the subretinal tissue.

[Acute posterior multifocal placoid pigment epitheliopathy, serpiginous choroiditis and related diseases]. / Épithéliopathie en plaque, choroïdite serpigineuse et leurs formes frontières.

Acute Posterior Multifocal Placoid Pigment Epitheliopathy (APMPPE) and serpiginous choroiditis are two diseases classified as "white spot syndromes." Both are inflammatory/autoimmune diseases with suspected primary involvement of the choriocapillaris. The former usually has an excellent prognosis, while the latter can rapidly induce legal blindness. Whereas these diseases are well defined and well known, other entities (such as persistent placoid maculopathy or ampiginous choroiditis) with features of both APMPPE and serpiginous choroiditis have been described more recently. This review aims to describe demographic characteristics and multimodal imaging features to help differentiate between these four diseases.

Regulation of Aqueous Humor Secretion by Melatonin in Porcine Ciliary Epithelium.

Secretion of melatonin, a natural hormone whose receptors are present in the ciliary epithelium, displays diurnal variation in the aqueous humor (AH), potentially contributing to the regulation of intraocular pressure. This study aimed to determine the effects of melatonin on AH secretion in porcine ciliary epithelium. The addition of 100 µM melatonin to both sides of the epithelium significantly increased the short-circuit current (Isc) by ~40%. Stromal administration alone had no effect on the Isc, but aqueous application triggered a 40% increase in Isc, similar to that of bilateral application without additive effect. Pre-treatment with niflumic acid abolished melatonin-induced Isc stimulation. More importantly, melatonin stimulated the fluid secretion across the intact ciliary epithelium by ~80% and elicited a sustained increase (~50-60%) in gap junctional permeability between pigmented ciliary epithelial (PE) cells and non-pigmented ciliary epithelial (NPE) cells. The expression of MT3 receptor was found to be >10-fold higher than that of MT1 and MT2 in porcine ciliary epithelium. Aqueous pre-treatment with MT1/MT2 antagonist luzindole failed to inhibit the melatonin-induced Isc response, while MT3 antagonist prazosin pre-treatment abolished the Isc stimulation. We conclude that melatonin facilitates Cl- and fluid movement from PE to NPE cells, thereby stimulating AH secretion via NPE-cell MT3 receptors.

Mechanobiological implications of age-related remodelling in the outer retina.

The outer retina consists of the light-sensitive photoreceptors, the pigmented epithelium, and the choroid, which interact in a complex manner to sustain homeostasis. The organisation and function of these cellular layers are mediated by the extracellular matrix compartment named Bruch's membrane, situated between the retinal epithelium and the choroid. Like many tissues, the retina experiences age-related structural and metabolic changes, which are relevant for understanding major blinding diseases of the elderly, such as age-related macular degeneration. Compared with other tissues, the retina mainly comprises postmitotic cells, making it less able to maintain its mechanical homeostasis over the years functionally. Aspects of retinal ageing, like the structural and morphometric changes of the pigment epithelium and the heterogenous remodelling of the Bruch's membrane, imply changes in tissue mechanics and may affect functional integrity. In recent years, findings in the field of mechanobiology and bioengineering highlighted the importance of mechanical changes in tissues for understanding physiological and pathological processes. Here, we review the current knowledge of age-related changes in the outer retina from a mechanobiological perspective, aiming to generate food for thought for future mechanobiology studies in the outer retina.

Placental growth factor stabilizes VEGF receptor-2 protein in retinal pigment epithelial cells by downregulating glycogen synthase kinase 3 activity.

Placental growth factor (PlGF) belongs to the vascular endothelial growth factor (VEGF) family of proteins that participate in angiogenesis and vasculogenesis. Anti-VEGF therapy has become the standard treatment for ocular angiogenic disorders in ophthalmological practice. However, there is emerging evidence that anti-VEGF treatment may increase the risk of atrophy of the retinal pigment epithelium (RPE), which is important for the homeostasis of retinal tissue. Whereas the cytoprotective role of VEGF family molecules, particularly that of VEGF A (VEGFA) through its receptor VEGF receptor-2 (VEGFR-2), has been recognized, the physiological role of PlGF in the retina is still unknown. In this study, we explored the role of PlGF in the RPE using PlGF-knockdown RPE cells generated by retrovirus-based PlGF-shRNA transduction. We show that VEGFA reduced apoptosis induced by serum starvation in RPE cells, whereas the antiapoptotic effect of VEGFA was abrogated by VEGFR-2 knockdown. Furthermore, PlGF knockdown increased serum starvation-induced cell apoptosis and unexpectedly reduced the protein level of VEGFR-2 in the RPE. The antiapoptotic effect of VEGFA was also diminished in PlGF-knockdown RPE cells. In addition, we found that glycogen synthase kinase 3 activity was involved in proteasomal degradation of VEGFR-2 in RPE cells and inactivated by PlGF via AKT phosphorylation. Overall, the present data demonstrate that PlGF is crucial for RPE cell viability and that PlGF supports VEGFA/VEGFR-2 signaling by stabilizing the VEGFR-2 protein levels through glycogen synthase kinase 3 inactivation.

Melanosome Motility in Fish Retinal Pigment Epithelial (RPE) Cells.

Several model systems have been developed to investigate mechanisms and regulation of intracellular organelle motility. The fish retinal pigment epithelial (RPE) cell represents an unusual but simple system for the study of actin-dependent organelle motility. Primary cultures of RPE dissociated from the eye are amenable to motility studies using a simple perfusion chamber and conventional phase contrast microscopy. In vivo, melanin-containing pigment granules (melanosomes) within fish RPE migrate distances up to 100 µm in response to light flux. When sheets of RPE are removed from the eye and dissociated, they attach to the substrate with apical projections extending radially from the central cell body. Melanosomes can be chemically triggered to aggregate or disperse throughout the projections. Melanosome migration in RPE apical projections is dependent on actin filaments and thus renders this model system useful for investigations of actin-dependent organelle motility.

Bacillary Layer Detachment in Hyper-acute Stage of Acute Posterior Multifocal Placoid Pigment Epitheliopathy: A Case Series.

BACKGROUND: The term bacillary layer detachment (BLD) represents a possible separation between the myoid and ellipsoid component of the inner segment, following insult or injury to the outer retina. It has been described previously in cases of toxoplasma retinochoroiditis, central serous chorioretinopathy, Vogt Koyanagi Harada disease and trauma. PURPOSE: To describe the presence of BLD in Acute Posterior Multifocal Placoid Pigment Epitheliopathy (APMPPE). METHOD: Clinical and OCT-based description of three consecutive cases of APMPPE with BLD. RESULT: All the three cases (a 25-year-old female, a 36-year-old male, and a 32-year-old male) presented with unilateral, diminution of vision of acute onset. They were diagnosed as APMPPE and OCT revealed a splitting of the ellipsoid zone, resembling a BLD. All the three cases showed complete resolution by 1 week. CONCLUSION: BLD appears in the acute stage of APMPPE and resolves rapidly within a week.

Single-cell RNA-sequencing analysis of the ciliary epithelium and contiguous tissues in the mouse eye.

The ciliary epithelium plays a central role in ocular homeostasis but cells of the pigmented and non-pigmented layers are difficult to isolate physically and study. Here we used single-cell RNA-sequencing (scRNA-seq) to analyze the transcriptional signatures of cells harvested from the ciliary body and contiguous tissues. Microdissected tissue was dissociated by collagenase digestion and the transcriptomes of individual cells were obtained using a droplet-based scRNA-seq approach. In situ hybridization was used to verify the expression patterns of selected differentially-expressed genes. High quality transcriptomes were obtained from 10,024 cells and unsupervised clustering distinguished 22 cell types. Although efforts were made to specifically isolate the ciliary body, approximately half of the sequenced cells were derived from the adjacent retina. Cluster identities were assigned using expression of canonical markers or cluster-specific genes. The transcriptional signature of cells in the PCE and NPCE were distinct from each other and from cells in contiguous tissues. PCE cell transcriptomes were characterized by genes involved in melanin synthesis and transport proteins such as Slc4a4. Among the most differentially expressed genes in NPCE cells were those encoding members of the Zic family of transcription factors (Zic1, 2, 4), collagen XVIII (Col18a1), and corticotrophin-releasing hormone-binding protein (Crhbp). The ocular melanocyte population was distinguished by expression of the gap junction genes Gjb2 and Gjb6. Two fibroblast signatures were detected in the ciliary body preparation and shown by in situ hybridization to correspond to uveal and scleral populations. This cell atlas for the ciliary body and contiguous layers represents a useful resource that may facilitate studies into the development of the ciliary epithelium, the production of the aqueous and vitreous humors, and the synthesis of the ciliary zonule.

Long-term outcomes of "open iridectomy" for secondary anterior chamber epithelial iris cysts.

Epithelial cysts run a high risk of recurrence and conversion to sheet-like ingrowth after surgical intervention. In this retrospective study, we introduced a modified iridectomy for treatment of secondary epithelial iris cysts (EICs) in the anterior chamber. Twenty-nine patients (29 eyes) aged 2-61 years received "open iridectomy" for EICs between April 1995 and July 2019. After viscodissection, most of the cyst wall was cut using a 20-gauge aspiration cutter via a 2.5-mm clear corneal incision. The residue closely adhering to the iris stroma was remained to avoid photophobia and diplopia. At 3 months, best corrected visual acuity was ≥ 20/100 in 55.5% (15/27, except two pediatric patients with poor cooperation) of patients. Among the eight patients suffering partial corneal edema preoperatively, six patients received surgery treatment at 3-6.5 months, and the cornea in the other two patients became transparent after medication. In a mean follow-up of 47.4 months, recurrence occurred in 3 patients at 7, 37, and 118 months, respectively. The percentage of treatment success was 96%, 87%, and 65% at 1, 5, and 10 years, respectively. "Open iridectomy" was effective for EICs, with a minimal invasion, less damage to the corneal endothelium, and a low recurrence rate.