Toshiaki Goseki

Effect and Mechanism of Betaxolol and Timolol on Vascular Relaxation in Isolated Rabbit Ciliary Artery

PurposeIn order to clarify the vasodilatory mechanism of betaxolol and timolol, we studied the effects of these drugs in isolated rabbit ciliary arteries.MethodsRabbit ciliary artery specimens were mounted in a double myograph system, and betaxolol, timolol, or another agent was introduced into the organ chamber. The mechanical response of the arteries was studied using an isometric tension recording method. The intracellular free calcium concentration [Ca2+]i was also measured using fluorescence photometry.ResultsBetaxolol and timolol induced dose-dependent relaxation in the rabbit ciliary arteries precontracted by high-K+ Krebs solution. The minimum concentrations required to cause relaxation were 10 µM of betaxolol, and 30 µM of timolol. At the maximum concentration of 1 mM, betaxolol induced almost complete relaxation of the ciliary arteries, whereas timolol induced approximately 70% relaxation. These actions were not inhibited by pretreatment with 100 µM NG-nitro-l-arginine methylester (L-NAME), a nitric oxide synthase inhibitor, or by denudation of the vascular endothelium. However, 300 µM of betaxolol or timolol decreased the [Ca2+]i of the vascular smooth muscle, an action similar to that of diltiazem, a typical L-type voltage calcium-channel blocker.ConclusionsBetaxolol, a selective β1-adrenoceptor antagonist, and timolol, a nonselective β-adrenoceptor antagonist, both frequently used in the medical management of glaucoma, decrease [Ca2+]i by acting as Ca2+ channel blockers, thus causing relaxation of isolated rabbit ciliary artery.

Possible mechanism of intraoperative floppy iris syndrome: a clinicopathological study

Recently “intraoperative floppy iris syndrome (IFIS)” was observed during cataract surgery. The fluttering of the iris during phacoemulsification occurs,1 but its mechanism is unknown. The present study examines three eyes of two patients with conditions similar to IFIS after chronic topical use of bunazosin (Detantol, Santen, Osaka, Japan) an α1-adrenoceptor blocker. The medication is used in Japan for the treatment of glaucoma. A histological study was conducted to provide the explanation for the syndrome. Both patients, a 77-year-old woman and a 79-year-old man, who had used bunazosin eye-drops for 3 years, had unremarkable medical histories, with no trauma. Slit-lamp biomicroscopy revealed no abnormalities other than glaucoma and cataract. Both patients underwent cataract surgery, during which IFIS was observed, but no other complications were seen in either. In each eye, we performed peripheral iridectomy (about 1 mm) and, after immediately …

Effects of Age and Sex on Values Obtained by RAPDx(®) Pupillometer, and Determined the Standard Values for Detecting Relative Afferent Pupillary Defect.

Purpose To determine the effects of age and sex on the amplitude and latency scores obtained by the RAPDx® pupillometer, and to determine the standard values for detecting relative afferent pupillary defect (RAPD) in healthy subjects. Methods The study was conducted on 84 healthy subjects (52 males, 32 females), who had no ophthalmic diseases other than refractive errors with a mean age of 32 years. The amplitude and latency scores of the males were compared to that of females and also among the different age groups. The correlations between the amplitude and latency scores and age were determined. The standard values with the 90%, 95%, and 99% prediction intervals of the measured values were also calculated. Results The differences in the amplitude and latency scores between the sexes were not significant. In addition, both scores were not significantly related with age. The mean amplitude score for all subjects with prediction intervals of 90%, 95%, and 99% was 0.02 (−0.26 to 0.30, −0.32 to 0.35, and −0.42 to 0.46, respectively); the latency score was −0.02 (−0.24 to 0.20, −0.28 to 0.25, and −0.37 to 0.33, respectively). Conclusions RAPD is not present when the absolute values of the amplitude score and latency scores, measured by the RAPDx® pupillometer, are ≤ 0.2 log units. RAPD is present when either of the values are ≥ 0.5 log units. Translational Relevance Results of this study can be used for detection of RAPD in the clinic and it will be the basic data of RAPDx® pupillometer for future research.

Effect of motion stimulation without changing binocular disparity on stereopsis in strabismus patients.

Purpose To evaluate the effect of motion stimulation without changing binocular disparity on stereopsis in strabismic patients. Methods Static and moving stereopsis were measured in 120 normal children and 30 strabismic patients (9 esotropia, 14 exotropia, 7 intermittent exotropia). Using a portable game device (PSP®; SONY, Japan), we created stereoscopic targets and produced stereopsis using a closed tube binocular viewing device. Stereoscopic disparity of targets was adjusted in 20 steps of 100 s each over a range from 2000 s to 100 s. In stereo testing using our apparatus, static test targets were used for static stereograms (SS), and test targets with clockwise planar rotation were used for moving stereograms (MS) without changing binocular disparity. Results All normal children were able to perceive stereopsis with stereoscopic disparity from 2000 s to 100 s, and were interested in our apparatus, more than the Titmus stereo tests. All esotropic patients failed both SS and MS. In the exotropic patients (14 exotropia and 17 intermittent exotropia patients), 19 (90.4%) passed the MS, and 13 (61.9%) passed the SS. Conclusion The exotropic patient might be able to perceive the binocular stereopsis by moving stereogram that was created by adding clockwise planner rotation without changing the binocular disparity to the static stereopsis target.

Evaluation of Relative Afferent Pupillary Defect Using RAPDx Device in Patients with Optic Nerve Disease

ABSTRACT We previously reported the standard values of the amplitude and latency scores in the RAPDx device for evaluating relative afferent pupillary defect (RAPD). Here, we evaluated RAPD in patients with optic nerve disease by using these standard values. Twenty-eight patients with current or previous optic nerve disease were enrolled in this study. Additionally, the data of 84 healthy subjects from our previous report were used as control data. We measured the amplitude and latency scores using RAPDx. We then compared their mean values and the percentages of individuals with standard values within a certain range between the optic nerve disease group and healthy group. Additionally, we evaluated their correlation with visual acuity and the critical flicker fusion frequency in the optic nerve disease group. Both parameters were significantly higher in the optic nerve disease group than in the control group (p < 0.0001). The detection rate of RAPD when using the standard value of amplitude score was 75%. Additionally, both parameters showed a significant correlation with laterality-based differences in visual acuity and critical flicker fusion frequency values in the optic nerve disease group (r = 0.59–0.75, p < 0.001). The amplitude and latency scores determined using RAPDx are useful in evaluating RAPD, particularly the standard value of the amplitude score.

Daytime variations in pupil size under photopic conditions.

Purpose. To assess the daytime variations in pupil size when far and near targets are viewed under photopic conditions. Methods. We prospectively examined 20 eyes of 20 healthy subjects [27.3 years ± 4.1 (SD)]. Using an open view-type infrared video pupillometer, pupil sizes were measured in subjects looking at targets 5 m or 1/3 m away under photopic conditions (400 lux). The first measurement was performed at 8.00 h, with following measurements at 3-h intervals until 20.00 h. The average pupil size for 5 s consecutive measurements was used for analysis. Results. The respective pupil sizes during far and near viewing were 3.80 ± 0.72 and 3.15 ± 0.62 (mean ± SD); 3.73 ± 0.78 and 3.08 ± 0.70; 3.74 ± 0.82 and 3.06 ± 0.68; 3.79 ± 0.67 and 3.17 ± 0.71; and 3.91 ± 0.76 and 3.13 ± 0.70 mm, at 8.00, 11.00, 14.00, 17.00, and 20.00 h. The pupil sizes did not differ significantly with time over the course of the day [far (p = 0.94) and near (p = 0.98) (one-way analysis of variance)]. The daytime variations of pupil size were 0.64 ± 0.33, and 0.41 ± 0.29 mm, respectively. Two eyes (10%) and one eye (5%) showed differences of more than 1.0 mm during daytime hours in pupil sizes while viewing far and near target, respectively. Conclusions. In this study, young adults show no significant variations in photopic pupil size throughout daytime hours. However, a single pupil size measurement appears to be insufficient for clinical use in some eyes.

Pupillary Size and Light Reflex in Premature Infants

ABSTRACT The authors examined pupillary light reflexes to both red and blue stimuli using infrared video-pupillography in premature infants. Pupillary light reflexes were obtained in response to 470 nm blue and 635 nm red stimuli with varying intensities of 10 cd/m2 and 100 cd/m2. Red stimuli did not evoke a pupillary response in premature infants. However, blue stimuli produced a pupillary reflex, and the extent of the reaction was dependent on the intensity of the stimulus. These results suggest that in premature infants, the origin of light reflex may be mediated predominately by melanopsin-containing retinal ganglion cells.

Evaluation of a Relative Afferent Pupillary Defect using the RAPDx® Device Before and After Treatment in Patients with Optic Nerve Disease

ABSTRACT We evaluated the amplitude and latency scores in the RAPDx® device together with other ophthalmic examinations, before and after treatment in four patients with optic nerve disease. In all patients, the visual acuity (VA) and visual field (VF) after treatment was resolved. Both scores after treatment were lower, with reduced laterality-based differences in VA and critical flicker fusion frequency (CFF). Even after treatment, 3 patients had laterality-based differences in circumpapillary retinal nerve fiber layer thickness (cpRFNLT). Both scores for evaluation of RAPD by RAPDx® correlated with subjective examinations and were useful for evaluation of the efficacy of treatment.

Causes, background, and characteristics of binocular diplopia in the elderly

PurposeWe evaluated the background and characteristics of elderly patients with binocular diplopia including diseases caused by abnormalities in orbital pulleys.Study designRetrospective.MethodsThe participants were 236 patients aged 60 years or older who visited Kitasato University Hospital complaining of binocular diplopia. We classified strabismus by types and investigated the causes for each group. We diagnosed orbital pulley disorders using magnetic resonance imaging (MRI). Patients with orbital pulley disorders exhibited esotropia and/or vertical strabismus and did not present with cranial nerve palsy, systemic illness, or ocular injury.ResultsClassification of strabismus types was: exotropia (24.2%); esotropia (25.0%); vertical strabismus (30.1%), combined strabismus (20.8%). There were 50.9% cases of strabismus associated with vertical deviation. The causes of disease in each group were as follows: in the exotropia group, 50.9% convergence insufficiency exotropia, 21.1% basic exotropia; in the esotropia group: 35.6% orbital pulley disorder 33.9% sixth cranial nerve palsy; in the vertical strabismus group: 32.4% forth cranial nerve palsy, 31.0% orbital pulley disorder; in the combined strabismus group: 28.6% orbital pulley disorder, 28.6% forth cranial nerve palsy.ConclusionsAbout half of the elderly patients with binocular diplopia exhibited vertical deviation. In addition, binocular diplopia was often caused by orbital pulley disorders. It is the first epidemiological study focusing on orbital pulley disorders diagnosed on the basis of MRI.

Evaluation of the Effects of the Occlu-Pad for the Management of Anisometropic Amblyopia in Children

ABSTRACT Purpose: In recent years, amblyopia treatment device that can be used with both eyes open have been reported. The Occlu-pad is a device that can present images of tablet terminals to one eye only under binocular open conditions. Till date, no study has reported the effectiveness of Occlu-pad training for anisometropic amblyopia in a series of cases. In the present study, we evaluated the effectiveness of the Occlu-pad for the management of anisometropic amblyopia without the use of occlusion therapy (eyepatch). Materials and Methods: We implemented Occlu-pad training for 22 children (mean age ± standard deviation: 4.7 ± 1.2 years) with anisometropic amblyopia. The visual acuity before treatment initiation was 0.25 ± 0.08. The difference in refraction between the healthy and amblyopic eyes was 3.10 ± 0.58 D. Results: The visual acuity at 3 months and 6 months after training initiation was 0.06 ± 0.09 and −0.04 ± 0.07, respectively; this indicates a significant improvement in vision. The compliance rates for Occlu-pad use during 0 − 3 months and 4 − 6 months after training initiation were 88.6% ± 18.9% and 73.2% ± 18.9%; these rates decreased significantly with time. Conclusions: Our findings suggest that the Occlu-pad is an effective tool for the management of anisometropic amblyopia in children.