Perifoveal microcirculation in eyes with epiretinal membranes

BACKGROUND/AIMS: Eyes with epiretinal membranes (ERMs) often have alterations of retinal vessels. The authors studied perifoveal microcirculation in eyes with epiretinal membranes (ERMs) using scanning laser ophthalmoscope (SLO) fluorescein angiography. METHODS: Mean capillary blood flow velocity (CFV) was measured as an index of perifoveal microcirculation by SLO fluorescein angiography in 26 eyes with ERMs (19 eyes with idiopathic epiretinal membranes, seven eyes with epiretinal membranes after retinal detachment surgery) before and 6 months after vitreous surgery, and in 23 healthy control subjects. RESULTS: The mean CFV was significantly reduced in eyes with ERMs compared with healthy controls (p=0.012), and the postoperative mean CFV was significantly increased compared with the preoperative mean CFV (p=0.041). CONCLUSION: Significant changes of capillary blood flow velocity in the perifoveal areas were observed between normal subjects and eyes with epiretinal membranes. This indicates that eyes with ERMs show abnormal haemodynamics in the perifoveal capillaries.     

Wavefront analysis of acrylic spherical and aspherical intraocular lenses

PURPOSE: To compare higher order wavefront aberrations in eyes implanted with acrylic aspherical intraocular lenses (IOLs) with a modified prolate anterior surface with conventional acrylic spherical IOLs by using the optical path difference method. METHODS: In a nonrandomized parallel cohort investigation, 36 eyes of 31 patients implanted with aspherical IOLs (Tecnis ZA9003) and 37 eyes of 23 age-matched patients implanted with spherical IOLs (SENSOR AR40e) were evaluated with a wavefront analyzer (OPD-Scan II) preoperatively and 1 month after surgery. The higher order aberrations for a 4.0-mm pupil diameter were expanded into Zernike's polynomial expression. Coma aberration, spherical aberration, and total higher order aberrations were evaluated as root mean square values. RESULTS: Postoperatively, coma and total higher order aberrations of spherical and aspherical IOLs significantly improved in both eyes. Spherical aberration improved in eyes with aspherical IOLs only (P < 0.01). CONCLUSION: After implantation of acrylic aspherical IOLs, postoperative higher order aberrations were not necessarily lower than after implantation of acrylic spherical IOLs, but compared with levels following implantation of acrylic spherical IOLs, a significant reduction in spherical aberration was achieved.     

Evaluation of the safety of xenon/bandpass light in vitrectomy using the A2E-laden RPE model

Background The purpose of the study was to investigate the brightness of the xenon/bandpass light in vitrectomy and assess its phototoxic effects using A2E-laden retinal pigment epithelial (RPE) cells. Methods The total luminous flux and spectral irradiance of 20- and 25-gauge endoilluminators connected to xenon lamps were measured and compared to those of 20- and 25-gauge endoilluminators connected to a halogen lamp. In vitro, A2E-laden cells were evenly exposed to xenon/bandpass light for 5 to 30 min positioned at 1 cm and 2 cm for a standard light probe and an implantable “chandelier” light probe, respectively, above the cells, and the cell viability was assessed using WST-1 assay. The cell viability was compared with cells exposed to 30 min of halogen light projected through a 20-gauge endoilluminator. Results The maximal total luminous flux of xenon/bandpass light emitted through the 20-gauge endoilluminator was 2.8 times higher than that of the halogen light. The total luminous flux of the 25-gauge endoilluminators was 0.6-1.1 times greater than the 20-gauge endoilluminators connected to the halogen light. The viability of the A2E-laden cells after exposure to the xenon/bandpass light was no different than that of the cells exposed to the halogen light when the total luminous flux of these lights was at the same level. Xenon/bandpass light from an implantable “chandelier” light probe induced A2E-mediated RPE damage to a similar extent as that of the halogen light through a 20-gauge endoilluminator. Conclusions A2E-mediated phototoxicity of xenon/bandpass light is comparable to that of halogen light.     

Strategic design to create HER2-targeting proteins with target-binding peptides immobilized on a fibronectin type III domain scaffold

Tumor-binding peptides such as human epidermal growth factor receptor 2 (HER2)-binding peptides are attractive therapeutic and diagnostic options for cancer. However, the HER2-binding peptides (HBPs) developed thus far are susceptible to proteolysis and lose their affinity to HER2 in vivo. In this report, a method to create a HER2-binding fluctuation-regulated affinity protein (HBP-FLAP) consisting of a fibronectin type III domain (FN3) scaffold with a structurally immobilized HBP is presented. HBPs were selected by phage-library screening and grafted onto FN3 to create FN3-HBPs, and the HBP-FLAP with the highest affinity (HBP sequence: YCAHNM) was identified after affinity maturation of the grafted HBP. HBP-FLAP containing the YCAHNM peptide showed increased proteolysis-resistance, binding to HER2 with a dissociation constant (K_D) of 58 nM in ELISA and 287 nM in biolayer interferometry and specifically detects HER2-expressing cancer cells. In addition, HBP-FLAP clearly delineated HER2-expressing tumors with a half-life of 6 h after intravenous injection into tumor-bearing mice. FN3-based FLAP is an excellent platform for developing target-binding small proteins for clinical applications.

A HER2-binding protein, HBP-FLAP, developed by peptide immobilization specifically binds to HER2 and has improved resistance to proteases.     

One-year outcome of combination therapy with intravitreal anti-vascular endothelial growth factor and photodynamic therapy in patients with pachychoroid neovasculopathy

Graefe's Archive for Clinical and Experimental Ophthalmology - To identify the functional outcome and evaluate the morphologic changes of patients with pachychoroid neovasculopathy (PNV)...     

Simulation of airbag impact on eyes after photorefractive keratectomy by finite element analysis method

BACKGROUND: A simulation model of the human eye which we have developed was applied to simulated airbag ocular injury, to determine the physical and mechanical conditions of the impacting airbag that would cause globe rupture in a post-photorefractive keratectomy (PRK) eye. METHODS: Simulations were performed with a computer using the finite element analysis program PAM-CRASH()(Nihon ESI, Tokyo, Japan). The airbag was set to impact on the surface of post-PRK eyes-D3, D6, D10, and D15-and an intact eye at various impact velocities. Strain on the cornea and sclera exceeding 18.0% and 6.8%, respectively, was assumed to indicate the possibility of rupture of each tissue. RESULTS: In contrast to the intact eye, in post-PRK eyes, at the lowest velocity of 20 m/s, some of the element reached the strain threshold in D15. At the medium velocity of 30 m/s, limited corneal rupture was observed in all situations. At the high velocity, 40 m/s, scleral laceration was found in eyes with all diopters, and apparent corneal rupture was observed in D10 and D15, indicating that globe rupture was very likely to occur. CONCLUSION: These results suggest that severe ocular trauma can be caused in post-PRK eyes by airbags at high impact velocities. Preoperative discussion with candidates for laser refractive surgery regarding the potential for severe ocular injury if the normal integrity of the eye is compromised by surgery may be appropriate. Research on modification of airbag design and deployment to minimize the risk of ocular injury is important.     

Tear osteopontin levels in patients with allergic conjunctival diseases

BACKGROUND: Recent reports have revealed the importance of several cytokines in chronic conjunctival allergic diseases (ACD) such as vernal keratoconjunctivitis (VKC) and atopic keratoconjunctivitis (AKC). Osteopontin (OPN) is a noncollagenous adhesive matrix protein that is expressed by activated macrophages. There has been considerable interest in the potential role of OPN in monocyte infiltration at sites of inflammation. We measured OPN level in tears using ELISA, to determine whether the level of this cytokine is elevated in ACD. METHODS: The level of OPN in tears was measured by ELISA using samples from patients with VKC, AKC or allergic conjunctivitis (AC) and from normal subjects. The level of OPN in tears was compared with the clinical severity of ACD and serum level of total IgE. RESULTS: The level of OPN in tears in AKC patients was significantly higher than that in AC and normal controls. Tear level of OPN in patients with VKC was also significantly elevated compared to those with AC and to normal controls. The clinical severity of ACD correlated significantly with the level of OPN. However, no correlation was observed between tear OPN level and serum level of total IgE. CONCLUSIONS: These results indicate that OPN plays an important pathophysiological role in severe ocular allergic conditions and that an elevated level of OPN in tear fluid reflects the local clinical status of ocular allergy, which may be an example of tissue remodeling.     

Treatment of retinal detachment resulting from myopic macular hole with internal limiting membrane removal

PURPOSE: To examine the efficacy of vitrectomy with internal limiting membrane removal for retinal detachment resulting from a macular hole in highly myopic eyes. METHODS: Eleven consecutive highly myopic eyes (11 patients) with retinal detachment resulting from a macular hole were treated by vitrectomy with removal of the internal limiting membrane, which was stained with indocyanine green and sulfur hexafluoride gas injection. Postoperatively, the patients were instructed to remain prone for 2 weeks. The excised specimens were evaluated with transmission electron microscopy. RESULTS: The mean postoperative follow-up was 9.2 +/- 2.3 months (range, 7 to 13 months). In 10 of the 11 eyes (91%) the retina was reattached during the initial surgery. Redetachment occurred in one eye, which was successfully treated during the second surgery. Best-corrected visual acuity improved in all eyes and ranged from 20/400 to 20/50. Pathologic examination showed that the internal limiting membrane and epiretinal tissues were present in all specimens. CONCLUSIONS: The use of indocyanine green staining can facilitate removal of a macular internal limiting membrane and overlying epiretinal membrane, resulting in complete relief of the macular traction. Primary removal of the internal limiting membrane may contribute to a high initial success rate for retinal reattachment and be an important adjuvant to the treatment of retinal detachment resulting from a macular hole in highly myopic eyes.