Hiruma Hasebe

Changes in oculomotor functions before and after loading of a 3-D visually-guided task by using a head-mounted display.

Changes in visual and oculomotor functions were tested in eight young volunteer subjects after performing a 3-D visually-guided task for 25 min. The visual stimuli were given by using a head-mounted display. No significant change was detected in the AC/A ratio and the stereo acuity. Changes were found in refraction and ocular convergence. Slight but significant hyperopic changes were detected in refraction after the task. The mean amplitude of convergence eye movement elicited by test stimuli after the task was significantly changed in the pooled data. They were significantly reduced when the subjects were tested by the disparity step of 0.7 degrees, but significantly increased when tested by the step of 6 degrees. The mean amplitudes were not significantly changed after the task when the subjects were tested by the intermediate disparity steps of 1.5 and 3 degrees. In data obtained for each subject, the amplitude of ocular convergence evoked by test stimuli after the task was reduced significantly in most subjects. In the majority of subjects, however, the results were not consistently significant when they were tested by step stimuli with different disparities. In only a few subjects, the changes were consistently significant except when the largest disparity was tested. On the other hand, the mean peak velocities of ocular convergence after the task were not significantly changed in the pooled data. In individual subjects, the changes of velocities of ocular convergence evoked by test stimuli after the task were more variable: they increased in some subjects but decreased in other subjects. Consequently, in only one subject, both amplitudes and peak velocities of ocular convergence tested by the disparity steps of 0.7, 1.5 and 3 degrees were consistently reduced after the task. The changes in refraction or ocular convergence found in this study were relatively small, and were not in the pathological range. The significance of these data are discussed. The results of the present study provide the basis for the more detailed analyses of the human factor in the head-mounted display.

Foveal translocation with scleral imbrication in patients with myopic neovascular maculopathy

PURPOSE To report our surgical results of foveal translocation with scleral imbrication in patients with myopic neovascular maculopathy. DESIGN Noncomparative, interventional, consecutive case series. METHODS Ten eyes of 10 myopic patients with subfoveal neovascular membranes that had undergone foveal translocation with scleral imbrication were recruited for this retrospective study. Inclusion criteria were myopia 6.0 diopters or greater in refractive error (or axial length 26.5 mm or longer), subfoveal choroidal neovascularization, and preoperative best-corrected visual acuity of 20/100 or worse. None of these eyes had undergone prior laser photocoagulation or submacular surgery. The main outcome measures were surgical complications and postoperative visual function. RESULTS Postoperatively, visual acuity had improved more than 3 lines in the logarithm of minimum angle of resolution (logMAR) measurement in all eyes. The mean preoperative, postoperative best, and final visual acuity were 0.12, 0.59, and 0.51, respectively. Of the 10 eyes, six achieved a postoperative final visual acuity of 20/40 or better. The mean postoperative foveal displacement was 0.78 disk diameter (range, 0.3--1.3 disk diameter). Two patients underwent a reoperation because of insufficient foveal displacement. Furthermore, one of these two patients required a third operation to reduce an excessive retinal fold involving the fovea induced by the second surgery. Of the 10 patients, two noted transient diplopia. This complaint, however, resolved over time as suppression developed. Although unintentional iatrogenic retinal tears formed intraoperatively in two eyes, these were successfully treated without serious complications. Postoperatively, mild retinal pigment epithelial changes were observed in all cases, but none led to significant deterioration of visual acuity during the follow-up period. All patients but one were followed for a minimum of 6 months. CONCLUSIONS In eyes with myopic neovascular maculopathy, foveal translocation with scleral imbrication may be useful in improving visual acuity. Further refinements in surgical technique and assessment of the long-term complications will be needed to make this procedure safer and more useful.

Effects of localized lesions in the lateral suprasylvian cortex on convergence eye movement in cats

We evaluated the effects of electrolytic lesions in the extrastriate cortical area on the amplitudes and velocities of vergence eye movements in six alert cats that were trained to track a target moving in depth. Bilateral or unilateral lesions in the lateral suprasylvian (LS) cortex reduced the amplitudes and velocities of vergence eye movements, but the positive correlation between them was maintained. Furthermore, unilateral lesions changed the symmetry of eye movements. Movements of the left eye were decreased by lesions in the right LS cortex, resulting in asymmetric vergence eye movement with right eye predominance, and vice versa. These results support the hypothesis that the LS cortex plays an essential role in controlling vergence eye movement.

Functional magnetic resonance imaging of visual cortex in a patient with cerebrovascular insufficiency

We compare the findings of functional magnetic resonance imaging (MRI) of the visual cortex in a patient with moyamoya disease with other neuro-imaging techniques. Automated static perimetry demonstrated a slight depression of the left visual field in both eyes. MRI of the brain showed diffuse atrophy of the right cerebral hemisphere, sparing the occipital lobe. Single-photon emission computed tomography showed relatively preserved perfusion to the right occipital lobe. Functional MRI during visual stimulation, however, demonstrated an apparent lack of activation of the right primary visual cortex, which did not correlate with the known retinotopic map of the visual cortex. The patient seems to have had a lack of reserved ability to respond to visual stimuli with maximal autoregulatory vasodilatation in the visual cortex, even though apparent morphologic change and dense visual field defects had not been observed.

Sub-Tenon Injections of Triamcinolone Acetonide Had Limited Effect on Cystoid Macular Edema Secondary to Nanoparticle Albumin-Bound-Paclitaxel (Abraxane)

Purpose. To report the first case of cystoid macular edema (CME) induced by nanoparticle albumin-bound- (nab-) paclitaxel treated with sub-Tenon injections of triamcinolone acetonide (STTA) with detailed long-term follow-up. Case. A 39-year-old Japanese woman with breast cancer presents with decreased vision in both eyes while receiving nab-paclitaxel. Two STTA treatments were administered for persistent CME in her right eye. Central retinal thickness (CRT) of the treated eye decreased after the first STTA, but there was no change after the second STTA. CRT of the other eye and bilateral visual acuity (VA) showed no change after each treatment. However, this patient experienced gradual recovery of visual function after nab-paclitaxel treatment was completed, 3 months after the second STTA. Improvements in VA and CRT did not overlap in time. Moreover, there was a big improvement time lag in VA between the eyes. Conclusion. Cessation of nab-paclitaxel could lead to resolution of CME more than STTA, although STTA had some effect. Since nab-paclitaxel has been recently approved for treating more types of malignancies, the number of the patients with this CME is expected to increase in the near future. Patients and physicians should understand this side effect and prepare for other treatment options.

Secondary glaucoma associated with bilateral complete ring cysts of the ciliary body.

Purpose:To report a case of acute glaucoma due to complete ring cyst of the ciliary body. Patients and Methods:A 33-year-old woman experienced blurred vision in her left eye. Intraocular pressure of the left eye was elevated accompanied with a very shallow anterior chamber. Anterior segment-optical coherence tomography and ultrasound biomicroscopy detected ring-shaped ciliary masses in the both eyes. Myopic change and contact between the ciliary mass and lens in the left eye suggested the presence of aqueous misdirection resulting in forward displacement of the lens-iris diaphragm. Because elevated intraocular pressure was refractory to conservative management, the left eye underwent clear lens aspiration and implantation of intraocular lens. Results:Although the anterior chamber became deep in the left eye initially after lens extraction in conjunction with core vitrectomy, possible aqueous misdirection recurred. Second vitrectomy in the left eye together with posterior and anterior capsulotomies, to establish humoral communication between the anterior and posterior chambers, deepened the anterior chamber and lowered the intraocular pressure. The anterior chamber in the fellow right eye remained deep a year after the episode. Conclusions:This is the first reported case of bilateral ring cysts of the ciliary body. The manifestation caused secondary glaucoma, which was resolved by lensectomy and vitrectomy.

Functional magnetic resonance imaging of visual function in postpapilledema optic atrophy

We studied a girl with intraventricular brain tumor who developed postpapilledema optic atrophy and severe concentric visual field constriction in both eyes. The patient had mild symptoms despite severe visual field loss. We performed functional magnetic resonance imaging using two kinds of visual stimulation to assess her residual visual function. The functional magnetic resonance imaging demonstrated that the activity in her association visual cortex was largely intact bilaterally, although the activation of the calcarine cortex was decreased in the left calcarine cortex. Her activity in the visual cortex seemed to correspond well to her visual symptom. Functional magnetic resonance imaging may be useful in objectively documenting residual visual function in patients with severe visual loss.

1643 Regional differences in the lateral suprasylvian area and the evoked potentiation of ocular convergence in cats

Ocular convergence during 3-D task was continuously monitored by using the magnetic search coil method or an infrared eye tracker. Eleven young subjects worn eye-coils in both eyes were asked to perform 120 trials of a stereoscopic task in 20 minutes, using both disparity and size cues of a target (a light bar with a minimum width) given through a head mounted display (HMD) with two LCDs (430x237). The images for each eye were produced by a laboratory computer, and given alternately at 30 Hz. Their abilities to converge at a target in three different positions in depth, and the changes in the performance based on the memorized positional informations in depth were estimated. The several factors which may cause changes in the traces of ocular convergence, including adaptation and fatigue, are discussed.

Restoration of the Ellipsoid Zone and Visual Prognosis at 1 Year after Surgical Macular Hole Closure

Purpose. To evaluate the restoration of the ellipsoid zone (EZ) and its influence on visual prognosis 1 year after surgical macular hole (MH) closure. Method. Subjects were patients with stage 2, 3, or 4 idiopathic MH who underwent primary vitrectomy that resulted in successful hole closure. Nineteen eyes with both EZ disruption with foveal detachment and a continuous external limiting membrane on optical coherence tomography during the early postoperative period were included in this study. Result. EZ disruption was restored in 10 eyes (53%, Group A) and remained in 9 eyes (47%, Group B) at 1 year after surgery. In Group B, the diameter of the residual EZ disruption was 54.7 ± 33.1 μm. LogMAR visual acuity (VA) 1 year after surgery was significantly better than preoperative VA in each group (Group A: −0.007 ± 0.102; P < 0.001; Group B: 0.051 ± 0.148; P < 0.001), but there was no significant difference between the 2 groups (P = 0.332). There was no significant correlation between logMAR VA and EZ disruption diameter at 1 year after surgery. Conclusion. EZ was restored in 53% of eyes at 1 year after surgical closure of idiopathic MH. Mean residual EZ disruption diameter was 54.7 ± 33.1 μm. Neither resolved nor residual EZ disruption influenced postoperative VA.

Vergence eye movement and lens accommodation: cortical processing and neuronal pathway

The contribution of the extrastriate visual cortex to ocular convergence and lens accommodation were studied by means of lesion, microstimulation, and recording of neuronal activities in the cat. The results support the hypothesis that the lateral suprasylvian cortex plays an essential role in these ocular movements.