Chang Rae Rho

Effects of steep meridian incision on corneal astigmatism in phacoemulsification cataract surgery.

PURPOSE: To evaluate surgically induced astigmatism (SIA) when the clear corneal incision is located on the preoperative steep meridian of the corneal astigmatism in phacoemulsification cataract surgery. SETTING: Seoul St. Marys Hospital, Seoul, South Korea. DESIGN: Comparative case series. METHODS: Patients with preoperative corneal astigmatism greater than 0.50 diopter (D) were evaluated. The corneal incision meridian was chosen by rounding the steep corneal meridian to the closest 10 degrees. All incisions were enlarged to 3.0 mm before intraocular lens implantation. Patients were grouped according to incision location (temporal, superotemporal, superior). Preoperative keratometric data were compared with data collected 2 months postoperatively. Polar value analysis was used to analyze the SIA. The Hotelling trace test was used for comparison of intraindividual changes. RESULTS: The study evaluated 95 patients (30 eyes temporal incision, 32 eyes superotemporal incision, 33 eyes superior incision). Two months postoperatively, the combined mean polar values for SIA changed significantly in the temporal group (Hotelling T2 = 0.418; P=.008), superotemporal group (Hotelling T2 = 1.078; P<.001), and superior incision group (Hotelling T2 = 1.175; P<.001). The SIA was 0.28 @ 79, 0.40 @ 85, and 0.46 @ 92, respectively. CONCLUSIONS: Choosing the corneal incision based on the preoperative steep meridian significantly decreased keratometric astigmatism at the temporal, superotemporal, and superior locations. Thus, it is desirable to place the corneal incision on the steep meridian in eyes with corneal astigmatism higher than 0.50 D. Financial Disclosure: Neither author has a financial or proprietary interest in any material or method mentioned.

Clock-hour laminar displacement and age in primary open-angle glaucoma and normal tension glaucoma.

Background:  To find out the relationship between laminar displacement and age between patients with primary open‐angle glaucoma and normal tension glaucoma.

Inhibition of Lymphangiogenesis and Hemangiogenesis in Corneal Inflammation by Subconjunctival Prox1 siRNA Injection in Rats

PURPOSE Prospero homeobox 1 (Prox1) siRNA is a small interfering RNA that is designed to specifically bind Prox1 mRNA. We determined whether Prox1 siRNA inhibits lymphangiogenesis and hemangiogenesis after acute corneal inflammation. METHODS Three Prox1 siRNAs were synthesized and investigated for their effects on Prox1 mRNA expression and tube formation in human dermal lymphatic endothelial cells (HDLECs) in vitro. The in vivo effects of Prox1 siRNA were assessed in alkali burn-induced inflammatory corneal neovascularization in rats. Prox1 siRNA was administered via subconjunctival injection. Corneal flat mounts were stained for lymphatic vessel endothelial hyaluronan receptor (LYVE)-1 to show lymphatic vessels. Lymphangiogenesis and hemangiogenesis were analyzed morphometrically using Image J software. Corneal inflammatory cell infiltration was evaluated by immunostaining for F4/80 and CD45. Protein levels of LYVE-1, podoplanin, VEGF receptor 2 (VEGFR2), and VEGFR3 were analyzed by Western blotting. RESULTS Prox1 siRNA treatment decreased Prox1 mRNA expression and tube formation in cultured HDLECs. Subconjunctival injection of Prox1 siRNA significantly inhibited alkali burn-induced lymphangiogenesis and hemangiogenesis in the cornea compared with those of scrambled siRNA (negative control). This inhibition was comparable to that induced by bevacizumab (positive control). Prospero homeobox 1 knockdown by Prox1 siRNA also inhibited macrophage and leukocyte infiltration into the cornea. Prox1 siRNA downregulated the expression of all four proteins. CONCLUSIONS Prox1 siRNA is a strong inhibitor of inflammatory corneal lymphangiogenesis and hemangiogenesis in vivo. Prox1 siRNA may be useful in preventing immune rejection after penetrating keratoplasty by suppressing lymphangiogenesis.

Topically administered gold nanoparticles inhibit experimental corneal neovascularization in mice.

Purpose: The aim of this study was to evaluate the in vivo effects and mechanism of topically administered gold nanoparticles (AuNP) in a mouse model of corneal neovascularization. Methods: Inflammatory corneal neovascularization was induced by alkali burns, and the corneas were treated with topical AuNPs. After 1 week, the area of corneal neovascularization was measured using image analysis. The levels of vascular endothelial growth factor receptor 2 and extracellular signal-regulated kinase (ERK1/2) were evaluated by Western blotting. Results: The area of corneal neovascularization was significantly reduced by 39.8% in the AuNP group compared with the control group (P = 0.002). Corneal vascular endothelial growth factor receptor 2 level was higher in the control group than in the AuNP-treated group (P = 0.029). AuNP treatment similarly inhibited burn-induced phosphorylation of ERK (P = 0.029). Conclusions: Topical administration of AuNPs significantly reduced development of inflammatory corneal neovascularization by inhibiting the ERK pathway.

The Antiangiogenic Effects of Gold Nanoparticles on Experimental Choroidal Neovascularization in Mice

Purpose The purpose of this study was to evaluate the antiangiogenic effect of gold nanoparticles (AuNPs) on experimental choroidal neovascularization (CNV) in mice. Methods Choroidal neovascularization was induced by rupturing the Bruchs membrane using laser photocoagulation in C57BL/6 mice. The following day, intravitreal injections of AuNPs were administered. The control group received PBS injection of the same volume. Two weeks after laser injury, CNV lesions were evaluated by examination of choroidal flat-mounts using fluorescein-labeled dextran and immunofluorescence staining with isolectin B4. The effects of AuNPs on endothelial cell tube formation, proliferation, and cytotoxicity were evaluated using human umbilical vein endothelial cells (HUVECs) or human RPE cells. The activity of extracellular signal-regulated kinase (ERK)1/2, protein kinase B (Akt), and focal adhesion kinase (FAK) signaling pathways was also analyzed. Results The AuNPs reduced the extent of CNV. Mice treated with intravitreal AuNPs injections exhibited a 67.9% reduction in the extent of CNV lesions compared with the control group (P < 0.001). The size of the isolectin B4-labeled area was also significantly smaller in AuNP-treated groups compared with the control group (P < 0.001). Gold nanoparticles decreased vascular endothelial growth factor-induced HUVEC tube formation and proliferation but showed no RPE cell toxicity with the treatment doses administered. The phosphorylation of ERK1/2, Akt, and FAK in HUVECs was suppressed by AuNPs. Conclusions Gold nanoparticles can inhibit laser-induced CNV in mice and may have an indication for the treatment of CNV.

Corneal swelling caused by conventional and new-design low-Dk soft contact lenses following a 10-day daily wear trial regime

PURPOSE To investigate the efficacy and safety of a fenestrated and channelled soft contact lens (F-SCL) compared to a standard and non-fenestrated soft contact lens (S-SCL) in experienced soft contact lens (SCL) wearers. METHODS This was a randomised, crossover, single-blinded (subject), and multicentre clinical trial. Sixteen experienced SCL wearers were randomly divided into two groups (FS and SF). The FS group first wore F-SCLs followed by S-SCLs, each for 10 days, separated by a 1-week washout period, whereas the SF group wore the S-SCLs first and crossed over to F-SCLs in the same manner. The F-SCLs were designed with three equally spaced, symmetrical fenestrations and a partial-thickness, connecting, circumferential channel on the back surface of the mid-periphery of the lens. Measurement of central corneal thickness using ultrasonic pachymetry was performed on the day of screening, after the 1-week washout period, and after 10 days of wearing each kind of lens, based on which central corneal swelling was calculated and compared. One eye in each subject was chosen at random for analysis. RESULTS Central corneal swelling was 1.92±1.73% vs. 5.26±2.14% in F-SCLs vs. S-SCLs wearers, which was statistically significant (P<0.001). There was no significant difference between the groups in terms of SCL-corrected visual acuity or SCL-related adverse events. CONCLUSION The use of F-SCLs led to reduced corneal swelling compared to S-SCLs. The newly incorporated features appear to improve tear mixing and thereby the oxygen supply to the cornea, which results in reduced corneal oedema.

Effects of Granulocyte-Macrophage Colony-Stimulating (GM-CSF) Factor on Corneal Epithelial Cells in Corneal Wound Healing Model.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a pleiotropic cytokine that activates granulocyte and macrophage cell lineages. It is also known to have an important function in wound healing. This study investigated the effect of GM-CSF in wound healing of human corneal epithelial cells (HCECs). We used human GM-CSF derived from rice cells (rice cell-derived recombinant human GM-CSF; rhGM-CSF). An in vitro migration assay was performed to investigate the migration rate of HCECs treated with various concentrations of rhGM-CSF (0.1, 1.0, and 10.0 μg/ml). MTT assay and flow cytometric analysis were used to evaluate the proliferative effect of rhGM-CSF. The protein level of p38MAPK was analyzed by western blotting. For in vivo analysis, 100 golden Syrian hamsters were divided into four groups, and their corneas were de-epithelialized with alcohol and a blade. The experimental groups were treated with 10, 20, or 50 μg/ml rhGM-CSF four times daily, and the control group was treated with phosphate-buffered saline. The corneal wound-healing rate was evaluated by fluorescein staining at the initial wounding and 12, 24, 36, and 48 hours after epithelial debridement. rhGM-CSF accelerated corneal epithelial wound healing both in vitro and in vivo. MTT assay and flow cytometric analysis revealed that rhGM-CSF treatment had no effects on HCEC proliferation. Western blot analysis demonstrated that the expression level of phosphorylated p38MAPK increased with rhGM-CSF treatment. These findings indicate that rhGM-CSF enhances corneal wound healing by accelerating cell migration.

Antiangiogenic Effects of Topically Administered Multiple Kinase Inhibitor, Motesanib (AMG 706), on Experimental Choroidal Neovascularization in Mice

PURPOSE To investigate the effect of topical motesanib, an inhibitor of receptor tyrosine kinase, on experimental choroidal neovascularization (CNV). METHODS CNV was induced in 46 nine-week-old male C57BL/6 mice using fundus laser photocoagulation. The right eye of each mouse was treated with motesanib eye drop (4 times daily) and the left eye with vehicle eye drop (4 times daily) for 14 days. To evaluate changes in the CNV lesions, fluorescein angiography, immunofluorescence staining with CD34, and histological examinations were performed 14 days after CNV induction. The expression of phosphorylated extracellular signal-regulated kinase (ERK1/2) in choroidal tissues was determined using western blot analysis to demonstrate the inhibitory effect of topically administered motesanib on intracellular signaling pathways involved in CNV development. RESULTS Fluorescein angiography showed that fluorescence leakage in eyes treated with topical motesanib was significantly less than in mice treated with vehicle (P=0.01). On immunofluorescence staining, the CD34-labeled area was smaller in topical motesanib-treated eyes (P<0.001). The expression level of phosphorylated ERK1/2 relative to that of total ERK1/2 decreased in eyes treated with topical motesanib compared with eyes treated with vehicle. CONCLUSION Topical motesanib significantly reduced laser-induced CNV in the experimental mouse model.

A case of concomitant keratoconus and granular corneal dystrophy type II

PURPOSE We report a Korean case of concomitant keratoconus and granular corneal dystrophy type II. METHODS Case report. RESULTS A 29-year-old man visited our clinic for a routine ocular check-up. Slit-lamp examination revealed a few well-circumscribed, greyish-white, discrete granular opacities in the central corneal stromae of both eyes. Direct sequencing of exon 4 of the BIGH3 gene revealed a heterozygous transversion from G to A in the second-nucleotide position of codon 124. In addition, a Fleischer ring and Vogts striae were evident in the cornea. The corneal topography was suggestive of keratoconus. CONCLUSION Granular corneal dystrophy type II can co-exist with keratoconus and should be included in the differential diagnosis.