Norihiro Mita

Effect of rebamipide ophthalmic suspension on signs and symptoms of keratoconjunctivitis sicca in Sjögren syndrome patients with or without punctal occlusions.

Purpose: The aim of this study was to investigate the efficacy of 2% rebamipide suspension in treatment of keratoconjunctivitis sicca (KCS) in patients with Sjögren syndrome (SS) with or without punctal occlusions. Methods: Thirty patients with SS, diagnosed based on the presence of autoantibodies and/or focus score >1 on lip biopsies, with corneal fluorescein staining scores (FSS) >3, and conjunctival lissamine green–staining scores (LSS) >3, were treated 4 times daily for 4 weeks with 2% rebamipide ocular suspension. Ocular examinations were performed before treatment and 2 and 4 weeks after treatment to evaluate FSS (0–9), LSS (0–6), and tear film break-up time (BUT). Hyaluronate and/or artificial tears were not discontinued. The patients were interviewed regarding the 5 major KCS symptoms, foreign body sensation, dry eye sensation, photophobia, ocular pain, and blurred vision, with each graded from none (0) to very severe (4). Results: Of the 30 patients, 3 failed to attend all sessions, leaving 27 (25 females, 2 males, mean age 62.5 ± 10.8 years) to be studied. FSS and LSS showed improvement at week 2, but BUT showed improvement later, at week 4. All 5 symptoms improved significantly. When the patients were divided into 3 groups according to the presence of punctal occlusions, FSS and LSS were found to improve in all groups, but BUT improved only in patients with both puncta occluded at week 4. Conclusions: Rebamipide ophthalmic suspension was effective in treating KCS of patients with SS, probably by increasing mucins and suppressing inflammatory cytokines. Punctal occlusions resulted in sufficient retention of tear fluid to enhance the activities of rebamipide and improve BUT.

Optical simulation for subsurface nanoglistening

Purpose To determine whether subsurface nanoglistening in hydrophobic acrylic intraocular lenses (IOL) diminishes visual performance. Setting Department of Ophthalmology, Kanazawa Medical University, Uchinada, Ishikawa, Japan. Design Experimental study. Methods The effect of subsurface nanoglistenings was simulated using optical design software Lighttools and Code V with the Liou‐Brenann model eye and an acrylic IOL. Peak irradiance of the retina, forward light scattering, and modulation transfer function (MTF) were evaluated. During optical simulation, particle diameters were set at 100 nm, 150 nm, and 200 nm and volume ratios at 0%, 0.05%, 0.1%, 0.2%, 0.5%, and 1.0%. Results Peak irradiance decreased as subsurface nanoglistening volume ratio and particle size increased. At a volume ratio of 0.05%, the peak irradiance of subsurface nanoglistening particles 100 nm, 150 nm, and 200 nm in diameter decreased 0.7%, 1.8%, and 2.9%, respectively, compared with those at volume ratio 0% (no subsurface nanoglistenings). At a volume ratio of 0.1%, the peak irradiance of subsurface nanoglistening particles 100 nm, 150 nm, and 200 nm decreased 1.5%, 3.6%, and 5.7%, respectively. Forward light scattering increased with increased size of subsurface nanoglistening particle and volume ratio. The MTF was not altered by changes in subsurface nanoglistening particle size or volume ratio. Conclusions Subsurface nanoglistenings increased forward scattering slightly and reduced irradiance but significantly diminished retinal image. The effect of subsurface nanoglistenings on visual function in the absence of severe retinal disease was minimal. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Multiple Comparisons for a Psychophysical Test in Bootstrap Logistic Regression

We propose an algorithm of multiple comparisons with a control for a psychophysical test. Our algorithm is based on the step-down procedure and is applicable to the bootstrap test in logistic regression. We use logistic regression combined with guessing rate and log-likelihood ratio test statistics of multiple samples in order to test hypotheses by using non-parametric bootstrap resampling. We apply our algorithm to visual acuity measurement, and show that bootstrap resampling can be used to resolve problems with multiple comparisons especially when the numbers of observations among samples are not identical.

Multiple comparisons in two-factor testing of psychophysical thresholds by the delta test method

Abstract We propose an algorithm of multiple comparisons in two-factor testing of psychophysical thresholds. We use logistic regression combined with guessing rate and adopt the step-down procedure with Ryan–Einot–Gabriel–Welsch (REGW) significance levels for multiple test. We test hypotheses of main effects and interaction in two-factor problem by using the delta test statistics.

Repeatability of visual acuity testing using a psychometric function

AbstractPurpose To evaluate the repeatability of a new method of measurement of visual acuity by use of a psychometric function.MethodsThe visual acuity of 15 healthy adults was measured by use of a psychometric function (PFVA) and by use of a conventional method using a decimal visual acuity chart (DeVA). We performed two tests. To evaluate intra-rater reliability, a tester measured the visual acuity three times for each subject, and the intraclass correlation coefficients, ICC (1,1), were calculated for PFVA and DeVA. Next, to evaluate inter-rater reliability, three testers measured the visual acuity for one subject, and the ICC (2,1) were calculated for PFVA and DeVA. The PFVA and DeVA of five subjects with ocular diseases were also measured.ResultsIn the evaluation of intra-rater reliability, the ICC (1,1) of the DeVA was 0.83 and the ICC (1,1) of the PFVA was 0.95. In the evaluation of inter-rater reliability, the ICC (2,1) of the DeVA was 0.88 and the ICC (2,1) of the PFVA was 0.93. In both tests the standard deviations of the PFVA were significantly lower than those of the DeVA. For four of the five subjects with ocular diseases, the PFVA was significantly improved by treatment.ConclusionThe repeatability of our method is better than that of the conventional method using a decimal visual acuity chart.

Relation between Visual Acuity and Slope of Psychometric Function in Young Adults

Mita et al. (2010) devised a technique of comparing a visual acuity (VA) change in an individual with more accurate VA than conventional VA tests by significant difference examined logarithmic (Log) VA ± standard deviation (SD). Using this technique, in this study, we examined a relation between VA and the slope of the psychometric function in normal young subjects. Six occlusion foil conditions were employed (1.0, 0.8, 0.6, 0.4, 0.1 and without the foil) under a full refractive correction. Ten normal young adults (22.8 years old on average) who have no ophthalmologic disease except ametropia participated in the measurement. The experiment was carried out with the constant method, a series of ten Landolt rings were used and each ring was presented 20 times randomly in a measurement. A 5.6-inch type of liquid crystal display driven by a computer, which has 1,280×800 pixels spatial resolution, was used to present the stimulus. In the normal young adults, the slope of the psychometric function did not change as the VA change systematically, and there was almost no correlation between them (r = −0.103).