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.
AbstractPURPOSE: 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.
AbstractPURPOSE: 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.
AbstractMore 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.
AbstractIntraoperative 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.
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.
AbstractUveitis 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.
AbstractPURPOSE: 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.