Uveitis is a potentially visually threatening disease accounting for 10% of vision loss in the developed world. The most common cause of vision loss in patients with uveitis has been shown to be macular edema (ME). The early detection and management of ME is critical to preserve vision in these patients. Optical coherence tomography (OCT) is a valuable tool in the management of many ocular diseases. The use of OCT has revolutionized the diagnosis and management of macular edema from a wide variety of ophthalmological diseases, including uveitis. In this review, we evaluate the role of OCT in the diagnosis and management of uveitic macular edema.
PURPOSE: The purpose of this study is to report the use of intravitreal triamcinolone for treatment of cancer-associated retinopathy (CAR) refractory to systemic therapy. METHODS: This was a retrospective chart review study. RESULTS: A 67-year-old man presented with cancer-associated retinopathy with antibodies against a 46-kDa retinal protein, alpha enolase. There was disease progression despite therapy with mycophenolate and intravenous immunoglobulin. Serial intravitreal injections of triamcinolone resulted in restoration of photoreceptor anatomy on optical coherence tomography and visual improvement. The patient's vision was preserved at 20/40 OD and 20/32 OS until his death from lung cancer 31 months after CAR diagnosis. CONCLUSIONS: Intravitreal triamcinolone may be beneficial for maintenance of vision in patients with CAR.
Pituicytomas are rare neoplasms of the sellar region. We report a case of vision loss and a junctional scotoma in a 43-year-old woman caused by compression of the optic chiasm by a pituitary tumor. The morphological and immunohistochemical characteristics of the tumor were consistent with the diagnosis of pituicytoma. The tumor was debulked surgically, and the patient's vision improved.
PURPOSE: The aim of this study was to describe a novel primary orbital vascular tumor combining elements of a vascular leiomyoma (angioleiomyoma) and a cavernous hemangioma. METHODS: A critical review of clinical records, diagnostic tests, and radiographic studies combined with histopathologic evaluation with standard and special histochemical staining and immunohistochemical investigations was conducted. RESULTS: A 44-year-old man slowly developed 5 mm of well-tolerated relative right proptosis with minimal motility disturbance and no visual decline. Computed tomography and magnetic resonance imaging demonstrated a medial and intraconal rounded mass that perfused slowly and whose anterior surface was well circumscribed. At surgery, the tumor was solid and pink with intersecting white bands and densely attached to surrounding normal tissues. The most adherent apical portion of the mass was left behind after subtotal excision. Histopathologically, only a partial pseudocapsule was discovered. The tumor was composed of cavernous channels, capillary zones, compressed lumens with linear strands of endothelium, and collections of muscular veins devoid of an elastica. Striking smooth muscle actin positivity was identified in disorganized masses of smooth muscle cells in the intervascular spaces and around the cavernous vascular units; these myocytes were intermixed with bundles of interstitial keloidal collagen. The endothelium was CD31 and CD34 positive for vascular endothelium and D2-40 negative for lymphatic endothelium. CONCLUSIONS: The authors have classified this hybrid tumor an angiomyofibroma with low neoplastic potential and features of a malformation. It is a composite variant of cavernous hemangioma associated with a conspicuous proliferation of anomalous disorganized smooth muscle cells (leiomyoma). Most of the lesion lacked a pseudocapsule, which impeded surgical delivery. Incomplete excision is recommended in such cases as preferable to the complications that could ensue from overly aggressive efforts at complete removal, particularly at the orbital apex. Supporting this position is the observation that incompletely excised cavernous hemangioma generally does not recur.
The corneal endothelial monolayer helps maintain corneal transparency through its barrier and ionic "pump" functions. This transparency function can become compromised, resulting in a critical loss in endothelial cell density (ECD), corneal edema, bullous keratopathy, and loss of visual acuity. Although penetrating keratoplasty and various forms of endothelial keratoplasty are capable of restoring corneal clarity, they can also have complications requiring re-grafting or other treatments. With the increasing worldwide shortage of donor corneas to be used for keratoplasty, there is a greater need to find new therapies to restore corneal clarity that is lost due to endothelial dysfunction. As a result, researchers have been exploring alternative approaches that could result in the in vivo induction of transient corneal endothelial cell division or the in vitro expansion of healthy endothelial cells for corneal bioengineering as treatments to increase ECD and restore visual acuity. This review presents current information regarding the ability of human corneal endothelial cells (HCEC) to divide as a basis for the development of new therapies. Information will be presented on the positive and negative regulation of the cell cycle as background for the studies to be discussed. Results of studies exploring the proliferative capacity of HCEC will be presented and specific conditions that affect the ability of HCEC to divide will be discussed. Methods that have been tested to induce transient proliferation of HCEC will also be presented. This review will discuss the effect of donor age and endothelial topography on relative proliferative capacity of HCEC, as well as explore the role of nuclear oxidative DNA damage in decreasing the relative proliferative capacity of HCEC. Finally, potential new research directions will be discussed that could take advantage of and/or improve the proliferative capacity of these physiologically important cells in order to develop new treatments to restore corneal clarity.
Karamichos D, Zareian R, Guo X, Hutcheon A, Ruberti J, Zieske J. NovelModel for Keratoconus Disease. J Funct Biomater. 2012;3(4):760–775.
Keratoconus is a disease where the cornea becomes cone-like due to structural thinning and ultimately leads to compromised corneal integrity and loss of vision. Currently, the therapeutic options are corrective lenses for early stages and surgery for advanced cases with no model available. In this study, we used human corneal fibroblasts (HCFs) and compared them to human Keratoconus fibroblasts (HKCs) cultured in a 3-dimensional (3D) model, in order to compare the expression and secretion of specific extracellular matrix (ECM) components. For four weeks, the cells were stimulated with a stable Vitamin C (VitC) derivative ± TGF-β1 or TGF-β3 (T1 and T3, respectively). After four weeks, HKCs stimulated with T1 and T3 were significantly thicker compared with Control (VitC only); however, HCF constructs were significantly thicker than HKCs under all conditions. Both cell types secreted copious amounts of type I and V collagens in their assembled, aligned collagen fibrils, which increased in the degree of alignment upon T3 stimulation. In contrast, only HKCs expressed high levels of corneal scarring markers, such as type III collagen, which was dramatically reduced with T3. HKCs expressed α-smooth muscle actin (SMA) under all conditions in contrast to HCFs, where T3 minimized SMA expression. Fast Fourier transform (FFT) data indicated that HKCs were more aligned when compared to HCFs, independent of treatments; however, HKC's ECM showed the least degree of rotation. HKCs also secreted the most aligned type I collagen under T3 treatment, when compared to any condition and cell type. Overall, our model for Keratoconus disease studies is the first 3D tissue engineered model that can mimic the Keratoconus disease and may be a breakthrough in efforts to understand the progression of this disease.
Retinal laser injuries are often associated with aberrant migration of the retinal pigment epithelium (RPE), which can cause expansion of the scar beyond the confines of the original laser burn. In this study, we devised a novel method of laser-induced injury to the RPE layer in mouse models and began to dissect the mechanisms associated with pathogenesis and progression of laser-induced RPE injury. We have hypothesized that the proto-oncogene receptor, c-Met, is intimately involved with migration of RPE cells, and may be an early responder to injury. Using transgenic mouse models, we show that constitutive activation of c-Met induces more robust RPE migration into the outer retina of laser-injured eyes, while abrogation of the receptor using a cre-lox method reduces these responses. We also demonstrate that retinal laser injury increases expression of both HGF and c-Met, and activation of c-Met after injury is correlated with RPE cell migration. RPE migration may be responsible for clinically significant anatomic changes observed after laser injury. Abrogation of c-Met activity may be a therapeutic target to minimize retinal damage from aberrant RPE cell migration.
PURPOSE: The aim of the study was to report a case of Trichosporon asahii in a patient with a type I Boston keratoprosthesis and contact lens with review of the literature. METHODS: A case report and literature review are provided. RESULTS: A 70-year-old monocular South Asian man with light perception vision and dense corneal scarring from previously failed amniotic membrane grafting and one failed corneal transplant was evaluated for a keratoprosthesis for visual rehabilitation. Three months after undergoing uneventful implantation of a type I Boston keratoprosthesis and placement of a therapeutic contact lens, he was found on routine follow-up to have a corneal infiltrate that was culture positive for T. asahii. The fungal keratitis was successfully treated with topical amphotericin B and oral ketoconazole. CONCLUSIONS: Contact lens wear is a known risk factor for fungal keratitis. Trichosporon is an uncommon agent of fungal keratitis. We report the first known case of fungal keratitis caused by T.asahii in a patient with a keratoprosthesis and contact lens.
PURPOSE: Androgens exert a significant influence on the structure, function and/or pathophysiology of the meibomian gland and conjunctiva. We sought to determine whether this hormone action involves the regulation of epithelial cell gene expression in these tissues. METHODS: Immortalized human meibomian gland and conjunctival epithelial cells were treated with placebo or dihydrotestosterone (DHT) and processed for molecular biologic procedures. Gene expression was evaluated with BeadChips and data were analyzed with bioinformatic and statistical software. RESULTS: Androgen treatment significantly influenced the expression of approximately 3,000 genes in immortalized human meibomian gland and conjunctival epithelial cells. The nature of DHT action on gene activity was predominantly cell-specific. Similarly, DHT exerted a significant, but primarily cell-specific, influence on many gene ontologies and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. These included groups of genes related, for example, to lipid dynamics, innate immunity, cell cycle, Janus kinase (JAK)-signal transducer and activator of transcription (stat) cascades, oxidative phosphorylation, the proteasome, and mammalian target of rapamycin (mTOR), Wnt, and peroxisome proliferator-activated receptor (PPAR) signaling. CONCLUSIONS: Our findings support our hypothesis that androgens regulate gene expression in human meibomian gland and conjunctival epithelial cells. Our ongoing studies are designed to determine whether many of these genes are translated and play a role in the health and well being of the eye.