De Castro DK, Hadlock T, Fay A. Dynamic imaging of paralytic eyelid disorders. Semin Ophthalmol 2012;27(5-6):167-74.Abstract
PURPOSE: Eyelid dysmotility may result from trauma, tumors, inflammation, infection, and a variety of other conditions. In these cases, a mechanical effect is disrupting a normal neuromuscular apparatus. Dysmotility can also be caused by paralytic eyelid disorders; included in this broad category are neurologic and myogenic disorders of eyelid opening and/or closure. Secondary effects include spastic eyelid closure and synkinesis syndromes. These conditions, by definition, are disorders of movement, and can only be studied adequately using dynamic imaging techniques. METHODS: A comprehensive literature search was performed on PubMed. Ninety abstracts were reviewed. RESULTS: Dynamic eyelid imaging has evolved dramatically over the past two decades, at least partially due to the rise of inexpensive digital technology. Magnetic search coil imaging, high- and low-speed videography, electromyography, and high-resolution microscopy coil magnetic resonance imaging each has its advantages and disadvantages, an understanding of which will guide appropriate selection of technology in any given clinical situation. CONCLUSIONS: Dynamic eyelid imaging is useful to study dysmotility. The optimal technique depends upon the clinical setting and the physiologic or pathologic topic of interest. To our knowledge, a report of this type has not been previously summarized.
Dela Paz NG, Walshe TE, Leach LL, Saint-Geniez M, D'Amore PA. Role of shear-stress-induced VEGF expression in endothelial cell survival. J Cell Sci 2012;125(Pt 4):831-43.Abstract
Vascular endothelial growth factor (VEGF) plays a crucial role in developmental and pathological angiogenesis. Expression of VEGF in quiescent adult tissue suggests a potential role in the maintenance of mature blood vessels. We demonstrate, using a Vegf-lacZ reporter mouse model, that VEGF is expressed by arterial but not by venous or capillary endothelial cells (ECs) in vivo. Using an in vitro model, we show that arterial shear stress of human umbilical vein ECs (HUVECs) decreases apoptosis and increases VEGF expression, which is mediated by the induction of Krüppel-like factor 2 (KLF2). Additionally, shear stress stimulates the expression of VEGF receptor 2 (VEGFR2) and is associated with its activation. Knockdown of VEGF in shear stressed HUVECs blocks the protective effect of shear stress, resulting in EC apoptosis equivalent to that in control ECs cultured under static conditions. Similarly, treatment of ECs subjected to arterial shear stress with the VEGF receptor tyrosine kinase inhibitor SU1498, or VEGFR2 neutralizing antiserum, led to increased apoptosis, demonstrating that the mechanoprotection from increased shear is mediated by VEGFR2. Taken together, these studies suggest that arterial flow induces VEGF-VEGFR2 autocrine-juxtacrine signaling, which is a previously unidentified mechanism for vascular EC survival in adult arterial blood vessels.
Ding J, Sullivan DA. Aging and dry eye disease. Exp Gerontol 2012;47(7):483-90.Abstract
Dry eye disease is a prevalent eye disorder that in particular affects the elderly population. One of the major causes of dry eye, meibomian gland dysfunction (MGD), shows increased prevalence with aging. MGD is caused by hyperkeratinization of the ductal epithelium of meibomian gland and reduced quantity and/or quality of meibum, the holocrine product that stabilizes and prevents the evaporation of the tear film. Of note, retinoids which are used in current anti-aging cosmetics may promote the development of MGD and dry eye disease. In this review, we will discuss the possible mechanisms of age-related MGD.
Dryja TP. Interview with Thaddeus P. Dryja, MD. Interviewed by George B. Bartley. Arch Ophthalmol 2012;130(1):111-2.
Durrani K, Foster SC. Fundus autofluorescence imaging in posterior uveitis. Semin Ophthalmol 2012;27(5-6):228-35.Abstract
Although the phenomenon of fundus autofluorescence has been known for decades, it has only recently been recognized as a measure of retinal pigment epithelial function and health. Characteristic fundus autofluorescence patterns have been described in eyes affected by inflammation of the posterior segment, and these patterns have provided insights into the pathogenesis of posterior uveitis entities. In addition, preliminary data indicate that fundus autofluorescence characteristics may serve as markers of disease activity, allow prediction of visual prognosis, and may help determine the adequacy of therapy. We provide an overview of the current state of fundus autofluorescence imaging technology and review our current knowledge of fundus autoflourescence findings and their clinical use in the posterior uveitis entities.
Farkas MH, Grant GR, Pierce EA. Transcriptome analyses to investigate the pathogenesis of RNA splicing factor retinitis pigmentosa. Adv Exp Med Biol 2012;723:519-25.
Fay A, Santiago YMB. A modified levine palpebral spring for the treatment of myogenic ptosis. Ophthalmic Plast Reconstr Surg 2012;28(5):372-5.Abstract
PURPOSE: Surgical treatment of myogenic ptosis usually requires a form of frontalis suspension. Complications can include entropion, headache, contour abnormalities, and poor eyelid excursion. The Levine palpebral spring has been used successfully to augment eyelid closure in more than 2,000 patients. The authors present a modified Levine spring to correct ptosis in a patient with poor levator function. METHODS: Interventional case report. A 55-year-old man with profound myogenic ptosis was treated with bilateral modified Levine palpebral springs. Eyelid position, contour and excursion, blink reflex, lagophthalmos, and ocular surface were evaluated. RESULTS: The Levine palpebral spring functioned well to open both eyelids. Margin reflex distance improved from -3 mm to 3 m postoperatively. Excellent contour and excursion were observed. Orbicularis action, including blink reflex, was preserved, and ocular surface was not compromised. CONCLUSION: The modified Levine palpebral spring is an alternative to frontalis suspension in treating select patients with eyelid ptosis with poor levator function.
Fostad IG, Eidet JR, Shatos MA, Utheim TP, Utheim OA, Raeder S, Dartt DA. Biopsy harvesting site and distance from the explant affect conjunctival epithelial phenotype ex vivo. Exp Eye Res 2012;104:15-25.Abstract
The purpose of the study was to investigate if the number of goblet cells expanded ex vivo from a conjunctival explant is affected by the biopsy harvesting site on the conjunctiva and the distance from the explant. Conjunctival explants from six regions: superior and inferior bulbus, fornix, and tarsus of male Sprague-Dawley rats were grown in RPMI 1640 with 10% fetal bovine serum on coverslips for eight days. Histochemical and immunofluorescent staining of goblet (CK-7/UEA-1/MUC5AC), stratified squamous, non-goblet (CK-4), proliferating (PCNA) and progenitor (ABCG2) cells were analyzed by epifluorescence and laser confocal microscopy. Outgrowth was measured with NIH ImageJ. For statistical analysis the Mann-Whitney test and Spearman's rank-order correlation test were used. Cultures from superior and inferior fornix contained the most goblet cells as indicated by the presence of CK-7+, UEA-1+ and MUC5AC+ cells. Superior and inferior forniceal cultures displayed 60.8% ± 9.2% and 64.7% ± 6.7% CK-7+ cells, respectively, compared to the superior tarsal (26.6% ± 8.4%; P < 0.05), superior bulbar (31.0% ± 4.0%; P < 0.05), inferior bulbar (38.5% ± 9.3%; P < 0.05) and inferior tarsal cultures (27.7% ± 8.3%; P < 0.05). While 28.4% ± 6.3% of CK-7+ goblet cells co-labeled with PCNA, only 7.4% ± 1.6% of UEA-1+ goblet cells did (P < 0.01). CK-7+ goblet cells were located at a lower concentration close to the explant (39.8% ± 3.1%) compared to near the leading edge (58.2% ± 4.5%; P < 0.05). Both markers for goblet cell secretory product (UEA-1 and MUC5AC), however, displayed the opposite pattern with a higher percentage of positive cells close to the explant than near the leading edge (P < 0.05). The percentage of CK-4+ cells was higher near the explant compared to near the leading edge (P < 0.01). The percentage of CK-7+ goblet cells in the cultures did not correlate with the outgrowth size (r(s) = -0.086; P = 0.435). The percentage of UEA-1+ goblet cells correlated negatively with outgrowth size (r(s) = -0.347; P < 0.01), whereas the percentage of CK-4+ cells correlated positively with the outgrowth size (r(s) = 0.473; P < 0.05). We conclude that forniceal explants yield the highest number of goblet cells ex vivo and thereby seem to be optimal for goblet cell transplantation. We also suggest that CK-7+/UEA-1- cells represent highly proliferative immature goblet cells. These cells could be important during conjunctival migration as they are mostly located close to the leading edge and their density does not decrease with increasing outgrowth size.
Gologorsky D, Thanos A, Vavvas D. Therapeutic interventions against inflammatory and angiogenic mediators in proliferative diabetic retinopathy. Mediators Inflamm 2012;2012:629452.Abstract
The global prevalence of diabetes is estimated to be 336 million people, with diabetic complications contributing to significant worldwide morbidity and mortality. Diabetic retinopathy results from cumulative microvascular damage to the retina and inflammation is recognized as a critical driver of this disease process. This paper outlines the pathophysiology leading to proliferative diabetic retinopathy and highlights many of the inflammatory, angiogenic, and cytokine mediators implicated in the development and progression of this disease. We focus a detailed discussion on the current targeted therapeutic interventions used to treat diabetic retinopathy.
Greiner JV. A single LipiFlow® Thermal Pulsation System treatment improves meibomian gland function and reduces dry eye symptoms for 9 months. Curr Eye Res 2012;37(4):272-8.Abstract
PURPOSE: To evaluate the effect of a single treatment with the LipiFlow(®) Thermal Pulsation System on signs of meibomian gland dysfunction (MGD) and dry eye symptoms over a 9-month period. METHODS: Patients (n = 42 eyes, 21 subjects) diagnosed with MGD and dry eye symptoms were recruited for a non-significant risk, prospective, open-label, 1-month clinical trial. Patients received a single 12-minute treatment using the LipiFlow(®) Thermal Pulsation System on each eye. The LipiFlow(®) device applies heat to the conjunctival surfaces of the upper and lower inner eyelids while simultaneously applying pulsatile pressure to the outer eyelid surfaces to express the meibomian glands. Patient symptoms were evaluated using the Ocular Surface Disease Index (OSDI) and Standard Patient Evaluation for Eye Dryness (SPEED) dry eye questionnaires; tear break-up time was measured with the dry eye test (DET™); and meibomian gland function was evaluated using a standardized diagnostic expression technique. Data are presented for patient's pre-treatment (baseline) and at 1-month and 9-month post-treatment. RESULTS: Meibomian gland secretion scores improved significantly from baseline (4.4 ± 4.0) to 1-month post-treatment (11.3 ± 6.2; p < 0.0001) and this improvement was maintained with no significant regression at 9 months (11.7 ± 5.9). Similarly, baseline tear break-up time (4.8 ± 3.2) was significantly increased at 1 month (9.6 ± 7.6; p < 0.001) and this increase was maintained with no significant regression at 9 months (7.1 ± 5.6). Symptom scores on both OSDI and SPEED questionnaires improved significantly at 1 month (p < 0.0001) and this improvement was maintained at 9 months. CONCLUSION: With such prolonged improvement in signs and symptoms of dry eye disease, the LipiFlow(®) Thermal Pulsation System offers a technological advancement for the treatment of dry eye disease secondary to meibomian gland dysfunction. A single 12-minute LipiFlow(®) treatment results in up to 9 months of sustained improvement of meibomian gland function, tear break-up time and dry eye symptoms that are unparalleled with current dry eye treatments.
Haddadin RI, Oh D-J, Kang MH, Villarreal G, Kang J-heon, Jin R, Gong H, Rhee DJ. Thrombospondin-1 (TSP1)-null and TSP2-null mice exhibit lower intraocular pressures. Invest Ophthalmol Vis Sci 2012;53(10):6708-17.Abstract
PURPOSE: Thrombospondin-1 (TSP1) and TSP2 are matricellular proteins that have been shown to regulate cytoskeleton, cell adhesion, and extracellular matrix remodeling. Both TSP1 and TSP2 are found in the trabecular meshwork (TM). In cadaver eyes with primary open-angle glaucoma (POAG), TSP1 is increased in one third of patients. We hypothesized that TSP1 and TSP2 participate in the regulation of intraocular pressure (IOP). Methods. IOPs of TSP1-null, TSP2-null mice, and their corresponding wild-type (WT) mice were measured using a commercial rebound tonometer. Fluorophotometric measurements assessed aqueous turnover. Central corneal thickness (CCT) was measured by optical coherence tomography. Iridocorneal angles were examined using light microscopy (LM), immunofluorescence (IF), and transmission electron microscopy (TEM). RESULTS: Average IOPs of TSP1-null and TSP2-null mice were 10% and 7% less than that of the corresponding WT mice, respectively. CCTs were 6.5% less in TSP1-null mice (P < 0.05) and 1.1% less in TSP2-null mice (P > 0.05). Fluorophotometric measurements suggest that aqueous turnover rates in TSP1-null and TSP2-null mice are greater than those of WT mice. LM of the TSP1-null and TSP2-null iridocorneal angles reveals morphology, which is indistinguishable from that of their corresponding WTs. IF revealed possible concurrent underexpression of TSP2 in TSP1-null mice and of TSP1 in TSP2-null mice. TEM revealed larger collagen fibril diameters in TSP1-null and TSP2-null mice compared with WTs. CONCLUSIONS: TSP1-null and TSP2-null mice have lower IOPs than their WT counterparts. The rate of aqueous turnover suggests that the mechanism is enhanced outflow facility. An alteration in the extracellular matrix may contribute to this finding.
Hamrah P, Sahin A, Dastjerdi MH, Shahatit BM, Bayhan HA, Dana R, Pavan-Langston D. Cellular changes of the corneal epithelium and stroma in herpes simplex keratitis: an in vivo confocal microscopy study. Ophthalmology 2012;119(9):1791-7.Abstract
PURPOSE: To analyze the morphologic features of corneal epithelial cells and keratocytes by in vivo confocal microscopy in patients with herpes simplex keratitis (HSK) as associated with corneal innervation. DESIGN: Prospective, cross-sectional, controlled, single-center study. PARTICIPANTS: Thirty-one eyes with the diagnosis HSK and their contralateral clinically unaffected eyes were studied and compared with normal controls (n = 15). METHODS: In vivo confocal microscopy (Confoscan 4; Nidek Technologies, Gamagori, Japan) and corneal esthesiometry (Cochet-Bonnet; Luneau Ophthalmologie, Chartres, France) of the central cornea were performed bilaterally in all patients and controls. Patients were grouped into normal (>5.5 cm), mild (>2.5-5.5 cm), and severe (<2.5 cm) loss of sensation. MAIN OUTCOME MEASURES: Changes in morphologic features and density of the superficial and basal epithelial cells, as well as stromal keratocytes, were assessed by 2 masked observers. Changes were correlated to corneal sensation, number of nerves, and total length of nerves. RESULTS: There was a significant and gradual decrease in the density of superficial epithelial cells in HSK eyes, with 852.50 ± 24.4 cells/mm(2) in eyes with severe sensation loss and 2435.23 ± 224.3 cells/mm(2) in control eyes (P = 0.008). Superficial epithelial cell size was 2.5-fold larger in HSK eyes (835.3 μm(2)) compared with contralateral or normal eyes (407.4 μm(2); P = 0.003). A significant number of hyperreflective desquamating superficial epithelial cells were present in HSK eyes with normal (6.4%), mild (29.1%), and severe (52.2%) loss of sensation, but were absent in controls. The density of basal epithelial cells, anterior keratocytes, and posterior keratocytes did not show statistical significance between patients and controls. Changes in superficial epithelial cell density and morphologic features correlated strongly with total nerve length, number, and corneal sensation. Scans of contralateral eyes did not show any significant epithelial or stromal changes compared with controls. CONCLUSIONS: In vivo confocal microscopy reveals profound HSK-induced changes in the superficial epithelium, as demonstrated by increase in cell size, decrease in cell density, and squamous metaplasia. This study demonstrated that these changes correlate strongly with changes in corneal innervation.
Hemberg M, Gray JM, Cloonan N, Kuersten S, Grimmond S, Greenberg ME, Kreiman G. Integrated genome analysis suggests that most conserved non-coding sequences are regulatory factor binding sites. Nucleic Acids Res 2012;40(16):7858-69.Abstract
More than 98% of a typical vertebrate genome does not code for proteins. Although non-coding regions are sprinkled with short (<200 bp) islands of evolutionarily conserved sequences, the function of most of these unannotated conserved islands remains unknown. One possibility is that unannotated conserved islands could encode non-coding RNAs (ncRNAs); alternatively, unannotated conserved islands could serve as promoter-distal regulatory factor binding sites (RFBSs) like enhancers. Here we assess these possibilities by comparing unannotated conserved islands in the human and mouse genomes to transcribed regions and to RFBSs, relying on a detailed case study of one human and one mouse cell type. We define transcribed regions by applying a novel transcript-calling algorithm to RNA-Seq data obtained from total cellular RNA, and we define RFBSs using ChIP-Seq and DNAse-hypersensitivity assays. We find that unannotated conserved islands are four times more likely to coincide with RFBSs than with unannotated ncRNAs. Thousands of conserved RFBSs can be categorized as insulators based on the presence of CTCF or as enhancers based on the presence of p300/CBP and H3K4me1. While many unannotated conserved RFBSs are transcriptionally active to some extent, the transcripts produced tend to be unspliced, non-polyadenylated and expressed at levels 10 to 100-fold lower than annotated coding or ncRNAs. Extending these findings across multiple cell types and tissues, we propose that most conserved non-coding genomic DNA in vertebrate genomes corresponds to promoter-distal regulatory elements.
Hemmati HD, Gologorsky D, Pineda R. Intraoperative wavefront aberrometry in cataract surgery. Semin Ophthalmol 2012;27(5-6):100-6.Abstract
Intraoperative wavefront aberrometry is a relatively new technology that aims to improve refractive outcomes following cataract surgery by optimizing the spherical power of the intraocular lens implant or calculating the appropriate axis and power of toric lenses during cataract surgery in an aphakic state. This article reviews the literature on intraoperative wavefront aberrometry and provides a critical assessment of the benefits and shortcomings of that technology.
Hisatomi T, Nakao S, Murakami Y, Noda K, Nakazawa T, Notomi S, Connolly E, She H, Almulki L, Ito Y, Vavvas DG, Ishibashi T, Miller JW. The regulatory roles of apoptosis-inducing factor in the formation and regression processes of ocular neovascularization. Am J Pathol 2012;181(1):53-61.Abstract
The role of apoptosis in the formation and regression of neovascularization is largely hypothesized, although the detailed mechanism remains unclear. Inflammatory cells and endothelial cells both participate and interact during neovascularization. During the early stage, these cells may migrate into an angiogenic site and form a pro-angiogenic microenvironment. Some angiogenic vessels appear to regress, whereas some vessels mature and remain. The control mechanisms of these processes, however, remain unknown. Previously, we reported that the prevention of mitochondrial apoptosis contributed to cellular survival via the prevention of the release of proapoptotic factors, such as apoptosis-inducing factor (AIF) and cytochrome c. In this study, we investigated the regulatory role of cellular apoptosis in angiogenesis using two models of ocular neovascularization: laser injury choroidal neovascularization and VEGF-induced corneal neovascularization in AIF-deficient mice. Averting apoptosis in AIF-deficient mice decreased apoptosis of leukocytes and endothelial cells compared to wild-type mice and resulted in the persistence of these cells at angiogenic sites in vitro and in vivo. Consequently, AIF deficiency expanded neovascularization and diminished vessel regression in these two models. We also observed that peritoneal macrophages from AIF-deficient mice showed anti-apoptotic survival compared to wild-type mice under conditions of starvation. Our data suggest that AIF-related apoptosis plays an important role in neovascularization and that mitochondria-regulated apoptosis could offer a new target for the treatment of pathological angiogenesis.
Hodges RR, Bair JA, Carozza RB, Li D, Shatos MA, Dartt DA. Signaling pathways used by EGF to stimulate conjunctival goblet cell secretion. Exp Eye Res 2012;103:99-113.Abstract
The purpose of this study was to identify the signaling pathways that epidermal growth factor (EGF) uses to stimulate mucin secretion from cultured rat conjunctival goblet cells and to compare the pathways used by EGF with those used by the known secretagogue muscarinic, cholinergic agonists. To this end, goblet cells from rat conjunctiva were grown in culture using RPMI media. For immunofluorescence experiments, antibodies against EGF receptor (EGFR) and ERK 2 as well as muscarinic receptors (M(1)AchR, M(2)AchR, and M(3)AchR) were used, and the cells viewed by fluorescence microscopy. Intracellular [Ca(2+)] ([Ca(2+)](i)) was measured using fura 2/AM. Glycoconjugate secretion was determined after cultured goblet cells were preincubated with inhibitors, and then stimulated with EGF or the cholinergic agonist carbachol (Cch). Goblet cell secretion was measured using an enzyme-linked lectin assay with UEA-I or ELISA for MUC5AC. In cultured goblet cells EGF stimulated an increase in [Ca(2+)](i) in a concentration-dependent manner. EGF-stimulated increase in [Ca(2+)](i) was blocked by inhibitors of the EGF receptor and removal of extracellular Ca(2+). Inhibitors against the EGFR and ERK 1/2 blocked EGF-stimulated mucin secretion. In addition, cultured goblet cells expressed M(1)AchR, M(2)AchR, and M(3)AchRs. Cch-stimulated increase in [Ca(2+)](i) was blocked by inhibitors for the M(1)AchRs, matrix metalloproteinases, and EGF receptors. Inhibitors against the EGF receptor and ERK 1/2 also blocked Cch-stimulated mucin secretion. We conclude that in conjunctival goblet cells, EGF itself increases [Ca(2+)](i) and activates ERK 1/2 to stimulate mucin secretion. EGF-stimulated secretion is dependent on extracellular Ca(2+). This mechanism of action is similar to cholinergic agonists that use muscarinic receptors to transactivate the EGF receptor, increase [Ca(2+)](i), and activate ERK 1/2 leading to an increase in mucin secretion.
Hunter RS, Skondra D, Papaliodis G, Sobrin L. Role of OCT in the diagnosis and management of macular edema from uveitis. Semin Ophthalmol 2012;27(5-6):236-41.Abstract
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.
Huynh N, Shildkrot Y, Lobo A-M, Sobrin L. Intravitreal triamcinolone for cancer-associated retinopathy refractory to systemic therapy. J Ophthalmic Inflamm Infect 2012;2(3):169-71.Abstract
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.
Huynh N, Stemmer-Rachamimov AO, Swearingen B, Cestari DM. Decreased vision and junctional scotoma from pituicytoma. Case Rep Ophthalmol 2012;3(2):190-6.Abstract
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.
Jacobo SMP, Kazlauskas A. Focus on molecules: HtrA1 and neovascular AMD. Exp Eye Res 2012;94(1):4-5.