Publications

2013

Patel M, Vavvas D. Fundus autofluorescence in ampiginous choroiditis. Ophthalmic Surg Lasers Imaging Retina. 2013;44(4):393–7.
Fundus autofluorescence (FAF) is being increasingly employed in the evaluation of retinal diseases. We report the first description of FAF findings during the natural history of ampiginous choroiditis and correlate these findings to fundus photography, infrared imaging, and cross-sectional optical coherence tomography. In a patient with a 12-month recurring, relapsing course of ampiginous choroiditis, there was a predictable pattern of FAF findings. At the time of presentation with a whitish-yellow, creamy clinical lesion, FAF reveals a diffuse, subtle hyperautofluorescence at the site of activity. As the clinical lesion fades, the FAF takes on a more intense, discrete, coalesced hyperautofluorescence, which decreases and becomes stippled over time, eventually giving way to a patch of hypoautofluorescence at the site of inactivity. Examination over the patient's long course suggests that FAF evolves predictably during exacerbations and remissions, and the FAF findings reveal activity well after the clinical lesion resolves. FAF is a simple, noninvasive, and effective modality for following the evolution of ampiginous choroiditis.
Patel M, Jakobiec F, Zakka F, Du R, Annino D, Borboli-Gerogiannis S, Daniels A. Intraorbital metastasis from solitary fibrous tumor. Ophthalmic Plast Reconstr Surg. 2013;29(3):e76–9.
Solitary fibrous tumor (SFT) is a rare spindle cell tumor of mesenchymal origin that usually arises from pleura or pericardium but can also arise from many extraserosal sites. Although more than 50 cases of primary SFT of the orbit have been reported, there are no reports to date of a malignant nonophthalmic SFT metastasizing in the orbital soft tissues (although sphenoid wing bony involvement has been reported). The authors report here the first case of a patient with intraorbital metastasis of a CD34-positive malignant SFT. The patient was a 57-year-old man with a history of malignant pleural SFT and a prior kidney metastasis. He presented with the rapid appearance of proptosis and massive conjunctival chemosis preventing eyelid closure, and he was found to have a well-circumscribed metastasis to his lateral rectus muscle. Surgical excision cured his ocular symptoms, although he died 3 months later from brain and widespread metastases.
Patel M, Lefebvre D, Lee G, Brachtel E, Rizzo J, Freitag S. Gaze-evoked amaurosis from orbital breast carcinoma metastasis. Ophthalmic Plast Reconstr Surg. 2013;29(4):e98-e101.
Gaze-evoked amaurosis (GEA) is a transient monocular vision loss provoked by eccentric gaze. Gaze-evoked amaurosis has been associated with a variety of orbital lesions, most commonly optic nerve sheath meningiomas and cavernous hemangiomas. The authors describe the first report in the literature of GEA as the presenting symptom of an orbital metastasis. The patient was a 47-year-old woman with a history of breast cancer with no known history of metastasis or active disease who presented with several weeks of vision loss in the OD upon rightward gaze. She was found to have enophthalmos and optic disc edema of the OD. Imaging revealed an intraorbital lesion, and a biopsy was consistent with a scirrhous metastasis of her breast carcinoma. This case highlights the importance of considering orbital metastases among the differential for gaze-evoked amaurosis.
Approximately one third of all cases of dermatomyositis may be associated with malignancy. We describe a patient with unexplained rash, joint pain, and muscle weakness, who subsequently developed a cavernous sinus syndrome due to a central nervous system chondrosarcoma. Discovery of this tumor and further dermatologic evaluation, including skin biopsy, resulted in diagnosis of paraneoplastic dermatomyositis due to cavernous sinus chondrosarcoma.
Pennock S, Kim D, Mukai S, Kuhnle M, Chun D, Matsubara J, Cui J, Ma P, Maberley D, Samad A, Van Geest R, Oberstein S, Schlingemann R, Kazlauskas A. Ranibizumab is a potential prophylaxis for proliferative vitreoretinopathy, a nonangiogenic blinding disease. Am J Pathol. 2013;182(5):1659–70.
Proliferative vitreoretinopathy (PVR) exemplifies a disease that is difficult to predict, lacks effective treatment options, and substantially reduces the quality of life of an individual. Surgery to correct a rhegmatogenous retinal detachment fails primarily because of PVR. Likely mediators of PVR are growth factors in vitreous, which stimulate cells within and behind the retina as an inevitable consequence of a breached retina. Three classes of growth factors [vascular endothelial growth factor A (VEGF-A), platelet-derived growth factors (PDGFs), and non-PDGFs (growth factors outside of the PDGF family)] are relevant to PVR pathogenesis because they act on PDGF receptor α, which is required for experimental PVR and is associated with this disease in humans. We discovered that ranibizumab (a clinically approved agent that neutralizes VEGF-A) reduced the bioactivity of vitreous from patients and experimental animals with PVR, and protected rabbits from developing disease. The apparent mechanism of ranibizumab action involved derepressing PDGFs, which, at the concentrations present in PVR vitreous, inhibited non-PDGF-mediated activation of PDGF receptor α. These preclinical findings suggest that available approaches to neutralize VEGF-A are prophylactic for PVR, and that anti-VEGF-based therapies may be effective for managing more than angiogenesis- and edema-driven pathological conditions.
Poole Perry L, Jakobiec F, Zakka F, Reichel E, Herwig M, Perry A, Brat D, Grossniklaus H. Reactive retinal astrocytic tumors (so-called vasoproliferative tumors): histopathologic, immunohistochemical, and genetic studies of four cases. Am J Ophthalmol. 2013;155(3):593–608.e1.
PURPOSE: To evaluate the cellular nature of and diagnostic terminology used in connection with acquired retinal "vasoproliferative tumors." DESIGN: Retrospective clinicopathologic study. METHODS: Clinical records and microscopic slides of 4 enucleated globes were reviewed. Special stains and immunohistochemical probes for CD31, CD34, p53, glial fibrillary acidic protein (GFAP), CD163, and Ki67 (cell replication) were employed; ultrastructural and fluorescence in situ hybridization (FISH) analyses were performed. RESULTS: Tumors were located inferotemporally in middle-aged patients. They were uniformly composed of compacted elongated, GFAP-positive spindle cells (due to intermediate filaments identified ultrastructurally) with a Ki67 index of less than 1%. Rosenthal fibers and eosinophilic granular bodies were observed. Hyalinized periodic acid-Schiff-positive vessels were widely separated. CD31 and CD34 revealed a sparse microvasculature. Tumor-associated exudate spread predominantly subretinally. The retinal pigment epithelium had undergone extensive placoid fibrous metaplasia with focal ossification. P53 upregulation, BRAF-KIAA gene rearrangement, and IDH1R132H mutation typically associated with low-grade astrocytic neoplasms were absent. CONCLUSIONS: Retinal "vasoproliferative" tumors have been mischaracterized, because they actually display a paucity of microvessels. Proliferating fibrous astrocytes with a very low proliferation index predominate, without immunohistochemical or genetic evidence favoring a neoplasm. Subretinal exudate appeared capable of provoking widespread fibrous metaplasia of the pigment epithelium that was mainly responsible for secondary retinal damage. The term "reactive retinal astrocytic tumor" is proposed as more appropriate for this entity. In carefully selected progressive lesions, consideration should be given to earlier surgical intervention before extensive subretinal exudate accumulates and pigment epithelial proliferation with fibrous metaplasia ensues.
Qazi Y, Hamrah P. Gene therapy in corneal transplantation. Semin Ophthalmol. 2013;28(5-6):287–300.
Corneal transplantation is the most commonly performed organ transplantation. Immune privilege of the cornea is widely recognized, partly because of the relatively favorable outcome of corneal grafts. The first-time recipient of corneal allografts in an avascular, low-risk setting can expect a 90% success rate without systemic immunosuppressive agents and histocompatibility matching. However, immunologic rejection remains the major cause of graft failure, particularly in patients with a high risk for rejection. Corticosteroids remain the first-line therapy for the prevention and treatment of immune rejection. However, current pharmacological measures are limited in their side-effect profiles, repeated application, lack of targeted response, and short duration of action. Experimental ocular gene therapy may thus present new horizons in immunomodulation. From efficient viral vectors to sustainable alternative splicing, we discuss the progress of gene therapy in promoting graft survival and postulate further avenues for gene-mediated prevention of allogeneic graft rejection.
Qazi Y, Hamrah P. Corneal Allograft Rejection: Immunopathogenesis to Therapeutics. J Clin Cell Immunol. 2013;2013(Suppl 9).
Corneal transplantation is among the most successful solid organ transplants. However, despite low rejection rates of grafts in the 'low-risk' setting, rejection can be as high as 70% when grafted into 'high-risk' recipient beds. Under normal homeostatic conditions, the avascular cornea provides a unique environment that facilitates immune and angiogenic privilege. An imbalance in pro-inflammatory, angiogenic and lymphangiogenic mediators leads to a breakdown in corneal immune privilege with a consequent host response against the donor graft. Recent developments in lamellar and endothelial keratoplasties have reduced the rates of graft rejection even more, while providing improved visual outcomes. The corneal layer against which an immune response is initiated, largely determines reversibility of the acute episode. While epithelial and stromal graft rejection may be treated with topical corticosteroids with higher success, acute endothelial rejection mandates a more aggressive approach to therapy due to the lack of regenerative capacity of this layer. However, current immunosuppressive regimens come with the caveat of ocular and systemic side effects, making prolonged aggressive treatment undesirable. With the advent of biologics, efficacious therapies with a superior side effect profile are on the horizon. In our review we discuss the mediators of ocular immune privilege, the roles of cellular and molecular immune players in graft rejection, with a focus on human leukocyte antigen and antigen presenting cells. Furthermore, we discuss the clinical risk factors for graft rejection and compare rates of rejection in lamellar and endothelial keratoplasties to traditional penetrating keratoplasty. Lastly, we present the current and upcoming measures of therapeutic strategies to manage and treat graft rejection, including an overview of biologics and small molecule therapy.
Reactive gliosis is a complex process that involves changes in gene expression and morphological remodeling. The mouse optic nerve, where astrocytes, microglia and oligodendrocytes interact with retinal ganglion cell axons and each other, is a particularly suitable model for studying the molecular mechanisms of reactive gliosis. We triggered gliosis at the mouse optic nerve head by retro orbital nerve crush. We followed the expression profiles of 14,000 genes from 1 day to 3 months, as the optic nerve formed a glial scar. The transcriptome showed profound changes. These were greatest shortly after injury; the numbers of differentially regulated genes then dropped, returning nearly to resting levels by 3 months. Different genes were modulated with very different time courses, and functionally distinct groups of genes responded in partially overlapping waves. These correspond roughly to two quick waves of inflammation and cell proliferation, a slow wave of tissue remodeling and debris removal, and a final stationary phase that primarily reflects permanent structural changes in the axons. Responses from astrocytes, microglia and oligodendrocytes were distinctively different, both molecularly and morphologically. Comparisons to other models of brain injury and to glaucoma indicated that the glial responses depended on both the tissue and the injury. Attempts to modulate glial function after axonal injuries should consider different mechanistic targets at different times following the insult.
Raghuram A, Hansen R, Moskowitz A, Fulton A. Photoreceptor and postreceptor responses in congenital stationary night blindness. Invest Ophthalmol Vis Sci. 2013;54(7):4648–58.
PURPOSE: To investigate photoreceptor and postreceptor retinal function in patients with congenital stationary night blindness (CSNB). METHODS: Forty-one patients with CSNB (ages 0.19-32 years) were studied. ERG responses to a series of full-field stimuli were obtained under scotopic and photopic conditions and were used to categorize the CSNB patients as complete (cCSNB) or incomplete (iCSNB). Rod and cone photoreceptor (R(ROD), S(ROD), R(CONE), S(CONE)) and rod-driven postreceptor (V(MAX), log σ) response parameters were calculated from the a- and b-waves. Cone-driven responses to 30 Hz flicker and ON and OFF responses to a long duration (150 ms) flash were also obtained. Dark-adapted thresholds were measured. Analysis of variance was used to compare data from patients with cCSNB, patients with iCSNB, and controls. RESULTS: We found significant reduction in saturated photoreceptor amplitude (R(ROD), R(CONE)) but normal photoreceptor sensitivity (S(ROD), S(CONE)) in both CSNB groups. Rod-driven postreceptor response amplitude (V(MAX)) and sensitivity (log σ) were significantly reduced in CSNB. Log σ was significantly worse in cCSNB than in iCSNB; this was the only scotopic parameter that differed between the two CSNB groups. Photopic b-wave amplitude increased monotonically with stimulus strength in CSNB patients rather than showing a normal photopic hill. The amplitude of the 30-Hz flicker response was reduced compared with controls, more so in iCSNB than in cCSNB. The mean dark-adapted threshold was significantly elevated in CSNB, more so in cCSNB than in iCSNB. CONCLUSIONS: These results are evidence of normal photoreceptor function (despite the low saturated photoresponse amplitude) and anomalous postreceptor retinal circuitry.