Ichiro Hamasaki

Effect of Progressive Addition Lenses on Myopia Progression in Japanese Children: A Prospective, Randomized, Double-Masked, Crossover Trial

PURPOSE This prospective, randomized, double-masked, crossover trial was conducted to evaluate the clinical effectiveness of progressive addition lenses (PALs) compared with single-vision lenses (SVLs) on myopia progression in Japanese children. METHODS Ninety-two children fulfilling the inclusion criteria (age: 6-12 years, spherical equivalent refractive errors: -1.25 to -6.00 D) were randomly allocated to either 18 months of wearing PALs (near addition: +1.50 D) followed by 18 months of SVLs (group 1), or 18 months of wearing SVLs followed by 18 months of wearing PALs (group 2), and were followed up for 3 years (two-stage crossover design). The primary outcome measure was myopia progression, as determined by cycloplegic autorefraction. RESULTS Eighty-six (93%) children completed both treatment periods. A mixed-model, two-way analysis of variance (ANOVA) performed using 3-year data identified a significant treatment effect of PALs compared with SVLs (P = 0.0007), with a mean 18-month difference of 0.17 D (95% CI: 0.07-0.26 D). This analysis also indicated a significant period effect (P = 0.0040) and a significant treatment-by-period interaction (P = 0.0223): Group 1 showed a slower myopia progression than did group 2. CONCLUSIONS The use of PALs slowed myopia progression, although the treatment effect was small, as previously reported in ethnically diverse children in the United States. The significant treatment-by-period interaction suggests that early application of PALs would probably be more beneficial for these age and refraction ranges (isrctn.org number, 28611140).

Cycloplegic Effect of 0.5%Tropicamide and 0.5%Phenylephrine Mixed Eye Drops: Objective Assessment in Japanese Schoolchildren with Myopia

PurposeTo evaluate the cycloplegic effect of mixed eye drops containing 0.5% tropicamide and 0.5% phenylephrine in myopic children, and to determine whether their efficacy was associated with their clinical characteristics.MethodsEighty-one myopic children (age, mean ± SD, 11.0 ± 1.5 years; mean spherical equivalent refractive error, −4.27 ± 1.41 D; range, −1.57 to −8.66 D) were recruited. One drop of Mydrin-P was administered to each eye twice, with an interval of 5 min between. Twenty-five minutes after the second drop, accommodative responses were measured with an open-view autorefractometer, while the subject was encouraged to accommodate by binocularly looking at a Maltese cross located at a distance of 33 cm. The difference between the refractive reading and that obtained with a Maltese cross at 500 cm was regarded as residual accommodation (RA). The repeatability of this measurement was also evaluated.ResultsThe mean RA was 0.21 ± 0.29 D (range, −0.31 to 0.99 D). There was no association in RA between the right and left eyes, between RA and age, or between RA and sex, but RA was weakly correlated with refractive error (r = 0.274, P = 0.019). The intersubject difference found in RA can be explained mostly by the extent of repeatability (±0.71 D).ConclusionThe insignificant magnitude of RA indicated that the mixed eye drop is an acceptable and useful cycloplegic agent in Japanese schoolchildren with a wide range of myopic refractive errors. Jpn J Ophthalmol 2007;51:111–115

Downward deviation of progressive addition lenses in a myopia control trial

Purpose:  To clarify how the downward deviation of progressive addition lenses (PALs) reduces their near‐addition effect in schoolchildren participating in a myopia control trial.

Axial Length Measurement Using Partial Coherence Interferometry in Myopic Children: Repeatability of the Measurement and Comparison with Refractive Components

PurposeTo evaluate the test–retest repeatability of axial length (AL) measurements made with the IOLMaster in children with a wide range of myopic refractive errors, and to clarify the relationship between the AL and other refractive components.MethodsThe subjects were 95 children (mean age ± SD, 10.8 ± 1.3 years; range, 7–13 years; mean refractive error; −4.37 ± 1.43 D; range, −1.50 to −8.19 D) who participated in a myopia-control trial. The AL of the right eye was measured three times using an IOLMaster, and the mean value was regarded as the representative measurement. After 5 min, the measurement was performed again, and the repeatability was evaluated by analyzing the distribution of differences between the two measurements. The relationships between the AL and age, cycloplegic autorefraction (RE), and corneal radius of curvature (CR) were also examined.ResultsThe repeatability of the IOLMaster measurements was ±0.05 mm (corresponding to a refractive error of ±0.12 D) and was not affected by age or RE. AL was negatively correlated with RE (RE = −0.68 × AL + 12.74, r = −0.37) and positively correlated with CR (CR = 0.21 × AL + 2.53, r = 0.69). The highest correlation was found between the ratio of AL to CR and RE (AL/CR = −0.04 × RE + 3.08, r = −0.76). No association was observed between age and AL, nor between CR and RE.ConclusionsThe IOLMaster provides high repeatability in AL measurement in myopic children. The associations between AL and each refractive component found in this study were consistent with those in previous studies that used the ultrasound A-mode method, except for slightly higher AL/CR ratios in our study. Jpn J Ophthalmol 2007;51:105–110

Static Ocular Counterroll: Video-based Analysis After Minimizing the False-Torsion Factors

PurposeTo determine the validity and usefulness of a newly developed measurement method of static ocular counterrolling (s-OCR) that eliminates false-torsion factors and to test the Jampel hypothesis that s-OCR does not exist.MethodsA lightweight measurement device, consisting of a video camera, a coaxial light source, and a laser pointer projecting a fixation target on the wall, was fixed to a subjects head by means of a mouthpiece. In 11 healthy adults (mean age: 30 ± 15 years), digital images of the right eye were captured while the subject kept his head tilted at a randomly selected angle ranging from 0° to 50°. By a frame-by-frame analysis of movements of the corneal light reflex and the iris patterns, OCR was evaluated.ResultsTorsional eye movement in the opposite direction to head tilt was found in all subjects. The amount of torsion continuously increased until the head-tilt angle reached 40°. The average (± SD) amplitude of a fitted sine curve was 7.6 ± 3.2° (range: 4.3°–10.3°), and the individual amplitude was significantly larger than the test–retest repeatability of the measurement (±1.7°).ConclusionsThe measurement method used in this study provided good test–retest repeatability and ease of application. The characteristics of torsional eye movements that we observed after minimizing the false-torsion factors agree with previous reports supporting the existence of s-OCR. Jpn J Ophthalmol 2005;49:497–504

Relationship between static ocular counterroll and Bielschowsky head tilt phenomenon.

PURPOSE This study was conducted to assess how hyperdeviation of a paretic eye during ipsilesional head tilt-the Bielschowsky head tilt phenomenon (BHP)-can be explained by decreased compensatory ocular counterrolling (OCR) due to the depressed torque of the paretic superior oblique (SO) muscle. METHODS Thirty-three patients with clinically diagnosed SO palsy and 11 control subjects were studied. With a head-mounted video camera, static ocular counterrolling (s-OCR) was determined by measuring the inclination of a line connecting the two centroids of the characteristic iris pattern and corneal reflex. The BHP was measured with the alternate prism and cover test. RESULTS The mean (SD) amplitude of s-OCR in paretic eyes based on the fit of the regression sine curve against the ipsilesional head tilt angle was significantly decreased compared with that for contralesional head tilt, 6.3 (3.5) degrees for ipsilesional and 11.3 (3.9) degrees for contralesional (P < 0.001), and was significantly smaller than that in normal subjects: 10.9 (2.6) degrees (P < 0.001). No significant linear relation was noted between hyperdeviation on ipsilesional head tilt and the amplitude of s-OCR in paretic eyes (r(2) = 0.04; P = 0.29). However, the differences between the hyperdeviation with ipsilesional 30 degrees head tilt and with head-upright position correlated significantly with the amplitudes of s-OCR in paretic eyes (r(2) = 0.19, P = 0.01). CONCLUSIONS The absolute value of the hypertropia on ipsilesional head tilt in clinically diagnosed SO palsy does not directly assess the function of the SO muscle. The difference in hypertropia between ipsilesional head tilt and the upright position, however, may be a better indicator of SO function.

Vertical alignment in monkeys with unilateral IV section: effects of prolonged monocular patching and trigeminal deafferentation

We investigated monocular viewing and trigeminal (V) deafferentation on the vertical deviation (VD) in monkeys following intracranial IV section. Two monkeys wore a patch for four to six weeks, one over the paretic eye and the other over the normal eye following IV section. Two other monkeys had combined IV and V section with the paretic eye patched postlesion. In monkeys with IV section alone, the VD lessened within the first week postlesion but then increased gradually with the same eye still patched. Thus binocular viewing was unnecessary for the later VD increase. With combined IV and V section, the VD also transiently lessened postlesion. We have proposed that the decrease in VD after IV section is adaptive, driven by an error signal using ocular proprioception and efference copy. Since V section did not eliminate the early decrease in VD, we suggest some orbital afference is transmitted centrally via other cranial nerves. However, the later increase in VD suggests either that the proprioceptive effect cannot be sustained or that mechanical changes supervene to increase the VD.

Clinical factors underlying a single surgery or repetitive surgeries to treat superior oblique muscle palsy

Abstract The purpose of this study is to know clinical factors underlying either a single surgery or repetitive surgeries, required to treat superior oblique muscle palsy. Retrospective review was made on 246 consecutive patients with idiopathic (n = 212) or acquired (n = 34) superior oblique muscle palsy who underwent surgeries in 8 years at one institution. Idiopathic palsy included congenital and decompensated palsies while acquired palsy included traumatic and ischemic palsies. Clinical factors, compared between groups with a single surgery (n = 203) and two or more surgeries (n = 43), were surgical methods, sex, age at surgery, horizontal, vertical, and cyclotorsional deviations, and stereopsis at near fixation. Inferior oblique muscle recession on paretic side was chosen in about 60% of the single-surgery and repetitive-surgery group as an initial surgery, followed by inferior rectus muscle recession on non-paretic side. The age at surgery was significantly older, vertical and cyclotorsional deviations were significantly larger in the repetitive-surgery group, compared with the single-surgery group (P = 0.01, P < 0.001, P = 0.02, Mann–Whitney U-test, respectively). The 95% confidence interval of vertical deviations was 15–17 prism diopters in the single-surgery group and 23–28 prism diopters in the repetitive surgery group. Significant differences in vertical deviations were replicated also in subgroups of patients with either idiopathic or acquired palsy. In conclusions, the 95% confidence interval of vertical deviations, determined by alternate prism and cover test, would be used as a common benchmark for predicting either a single surgery or repetitive surgeries, required to treat idiopathic and acquired superior oblique muscle palsy, in the process of obtaining the informed consent.

Effects of vertical muscle surgery on differences in the orientation of Listing's plane in patients with superior oblique palsy

BackgroundAlthough scleral search coils are widely and accurately used for the measurement of Listing’s plane in both eyes, they require specialized equipment and are invasive. In this study, we describe a convenient and less invasive method that uses a synoptometer to analyze the differences in orientation of Listing’s plane (difLP), and the effects of vertical muscle surgery on the difLP tilt in patients with superior oblique palsy (SOP).MethodsSeventeen patients with unilateral congenital SOP (CSOP) and four patients with unilateral acquired SOP (ASOP) who had not undergone any strabismus surgeries were examined. Cyclodeviations of 13 vertical and horizontal gaze points within 30° were measured with a synoptometer, and the difLP tilts in the yaw and pitch planes were analyzed before and after vertical muscle surgery.ResultsThe difLP tilt in the CSOP patients was significantly tilted nasally (p = 0.02) and forward on the lower side (p = 0.001), whereas that in ASOP patients tended to tilt temporally (p = 0.15). Ipsilateral inferior oblique recession (IOR) performed in seven CSOP patients tended to improve the difLP tilt in both the yaw (p = 0.07) and pitch (p = 0.09) planes, whereas contralateral inferior rectus recession (IRR) performed in three CSOP patients significantly improved the difLP tilt in the pitch plane (p = 0.015). The mean excyclodeviations in the 13 gaze points were significantly improved with both procedures (p < 0.0001 for both).ConclusionsThe difLP tilt in the SOP patients could be analyzed with a convenient and less invasive method using a synoptometer, and dissimilar difLP tilts were confirmed in the ASOP and CSOP patients. The results of this study suggest that both IOR and IRR are reasonable treatments for improving the difLP tilt in CSOP patients. IOR should be selected for patients with a steep preoperative difLP tilt to the nasal side, whereas IRR should be selected for patients with a gentle preoperative difLP tilt.

Erratum: Effects of vertical muscle surgery on differences in the orientation of Listing's plane in patients with superior oblique palsy (Graefe's Archive for Clinical and Experimental Ophthalmology (2013) 251 (2437-2443) (DOI 10.1007/s00417-013-2407-3))

The original version of this article inadvertently contained mistake. Figure legends 3 wrong: The triangles indicate the mean preoperative data and the circles indicate the mean postoperative data (n =7). right: The triangles indicate the mean postoperative data and the circles indicate the mean preoperative data (n =7). Figure legends 4 wrong: The triangles indicate the mean preoperative data and the circles indicate the mean postoperative data (n =3). right: The triangles indicate the mean postoperative data and the circles indicate the mean preoperative data (n =3).