Age-specific influences of refractive error and illuminance on pupil diameter.

To assess the most influential factor for pupil diameter changes among age, illuminance, and refractive state and reestablish the optimal procedures for clinical applications based on refractive state and illuminance for different age groups. The study was an observational study (repeated measure study). Participants included 219 Korean adults aged 20 to 69 years. Pupil diameters were measured using a pupilometer under scotopic, mesopic-low, and mesopic-high lighting conditions. Factor interactions among age, illuminance, and refractive state were evaluated using mixed linear model and chi-square automated interaction detection. Illuminance mainly contributed to variations in pupil diameter of participants over 50 years, whereas the refractive state was the dominant controlling factor for the pupil variation in participants below 50 years. For more generalized application, the pupil diameter decreased with older age and brighter illuminance (P < .001, inverse correlation, all comparisons). The mean pupil diameter was significantly higher in myopes and emmetropes than in hyperopes (P < .001). Pupil diameter variation modeled using the mixed model confirmed age, illuminance, and refractive error as significant factors (P < .001). Accounting for the interactions among age, illuminance, and refractive error and establishing their hierarchical dominance can be generalized using the chi-square automated interaction detection method and mixed model. Promoting age-dependent consideration for both illuminance and refractive state is necessary when pupil diameters play significant roles in clinical and manufacturing circumstances.

Gait characteristics during crossing over obstacle in patients with glaucoma using insole foot pressure.

BACKGROUND: Glaucoma, is the most common cause of irreversible visual deficits, presents as an injury to the optic nerve and it is mainly associated with elevated intraocular pressure. The main symptom of glaucoma is a reduction of the visual field, which is usually a source of complaint at the advanced stage of disease. Because of visual deficit, gait dysfunctions, including low gait speed and increased bumping into objects, postural sway, and falling are occurred. Many studies have used stopwatch or motion-sensing devices to report on gait function following glaucoma. However, there are few reports on gait dysfunction assessed by examining foot pressure. This study investigated gait ability following glaucoma according to different gait conditions by assessing foot pressure. METHODS: Thirty older adults (15 in the sex- and age-matched normal group and 15 in the glaucoma group) were recruited for this study. All participants were walked under 2 different gait conditions in an F-scan system and the subject' assessments were randomly assigned to rule out the order effect. Conditions included: gait over an obstacle in a straight 6 m path, gait in a straight path without an obstacle in the 6 m path. Gait variables included cadence, gait cycle, stance time, center of force (COF) deviation, and COF excursion. About 10 minutes were taken for gait evaluation. RESULTS: When walking without an obstacle on a 6 m path, there were significant differences between the 2 groups in gait speed, cadence, gait cycle, and stance time (P < .05). There were significant differences when walking with an obstacle on a 6 m path (P < .05). Two-way analysis of variance showed significant effects associated with "glaucoma" not gait condition on all outcomes except for COF deviation and excursion. Also, there was no the interaction effect between "glaucoma" and "gait condition." CONCLUSION: We demonstrated that glaucoma patients selected the gait strategy such as lower gait function in both gait conditions particularly, slower gait speed and cadence and longer gait cycle and stance time, as determined by examining foot pressure. We believe that our results could help to improve the quality of life of patients with glaucoma.

Accelerating repaired basement membrane after bevacizumab treatment on alkali-burned mouse cornea.

To understand the corneal regeneration induced by bevacizumab, we investigated the structure changes of stroma and basement membrane regeneration. A Stick soaked in 0.5 N NaOH onto the mouse cornea and 2.5 mg/ml of bevacizumab was delivered into an alkali-burned cornea (2 µl) by subconjunctival injections at 1 hour and 4 days after injury. At 7 days after injury, basement membrane regeneration was observed by transmission electron microscope. Uneven and thin epithelial basement membrane, light density of hemidesmosomes, and edematous collagen fibril bundles are shown in the alkali-burned cornea. Injured epithelial basement membrane and hemidesmosomes and edematous collagen fibril bundles resulting from alkali-burned mouse cornea was repaired by bevacizumab treatment. This study demonstrates that bevacizumab can play an important role in wound healing in the cornea by accelerating the reestablishment of basement membrane integrity that leads to barriers for scar formation.

Central corneal thickness and corneal endothelial cell changes caused by contact lens use in diabetic patients.

PURPOSE: To analyze the effects of soft contact lenses on central corneal thickness and morphologic characteristics of the corneal endothelium in diabetic patients. MATERIALS AND METHODS: Ultrasound pachymetry and noncontact specular microscopy were performed on 26 diabetic patients who regularly use soft contact lenses (group 1), 27 diabetic patients who do not use soft contact lenses (group 2) and 30 normal subjects (group 3). We compared the values in each group using the Mann-Whitney test. RESULTS: The central cornea was found to be thicker in diabetic patients, both those who use and do not use contact lenses, than in the normal control group. The central corneal thickness was significantly higher in group 1 (564.73 ± 35.41 µm) and group 2 (555.76 ± 45.96 µm) than in the control group (534.05 ± 27.02 µm), but there was no statistically significant difference between groups 1 and 2. Endothelial cell density was significantly different between the groups, and was smallest in the group of diabetic patients using contact lenses. The coefficient of variation of cell size was significantly higher and the percentage of hexagonal cells was significantly lower in contact lens using diabetic patients than in non-contact lens using diabetic patients and in the control group. CONCLUSION: Central corneal thickness and endothelial cell density is more affected by diabetes mellitus, and corneal endothelial cell morphology is more affected by contact lens use, when compared with normal subjects.

Valosin-containing protein is a novel autoantigen in patients with glaucoma.

PURPOSE: The purpose of this study was to identify novel autoantigens that react with specific serum autoantibodies in patients with glaucoma. METHODS: Sera from patients with glaucoma (n = 80) and healthy subjects without a known pathology (n = 20) were investigated by immunoblot performed with bovine optic nerve lysates and resolved by one- and two-dimensional electrophoresis. Proteins in the immunoreactive spots were selected and identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS) data analysis. All the sera from subjects were assayed using enzyme-linked immunosorbent assay to identify autoantibodies. RESULTS: We selected two prominent bands with molecular weights of 100 and 220 kDa by 8% sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis, and these two bands were only found in the glaucoma patients. Using one-dimensional electrophoresis and LC-MS/MS analyses, we identified these proteins to be valosin-containing protein (VCP) and fodrin, respectively, and using two-dimensional electrophoresis and LC-MS/MS analyses, VCP was identified to be a common target antigen. In patients with primary open angle glaucoma and normal tension glaucoma, the frequency of autoantibodies to recombinant human VCP was 42.0 and 23.3%, respectively (p < 0.002). In the enzyme-linked immunosorbent assay tests, autoantibody titers to recombinant human VCP were significantly higher than that in healthy controls (p < 0.025). CONCLUSIONS: VCP represents a potential candidate target for autoantibodies on the optic nerve in patients with glaucoma.