Toyohisa Yoshizawa

Surgical management of retinal detachment associated with myopic macular hole: anatomic and functional status of the macula☆

PURPOSE To evaluate the postoperative status of the macula after vitreous surgery with internal limiting membrane removal for macular hole related retinal detachment in patients with severe myopia. DESIGN Interventional case series. METHODS We prospectively examined 10 eyes with retinal detachment associated with a myopic macular hole from 10 consecutive patients, and performed pars plana vitrectomy with internal limiting membrane peeling. Macular buckling was performed in one eye during the initial treatment and in three eyes during subsequent operations. The main outcome measures were the anatomic reattachment rate and the postoperative status of the macular hole. We examined the macular area pre- and postoperatively with slit-lamp biomicroscopy and with a scanning laser ophthalmoscope. Cross-sectional imaging of the macular area was conducted with optical coherence tomography. RESULTS Successful retinal reattachment was achieved in seven eyes (70%) after the initial surgery and in three eyes (30%) after additional procedures. Visual acuity remained unchanged in two eyes (20%), and improved by two or more logarithmic units of minimum angle of resolution (logMAR) measurement in eight eyes (80%). The macular hole was anatomically closed in only one eye (10%). Postoperative enlargement of the macular hole was observed in seven eyes. CONCLUSIONS In highly myopic eyes with macular hole related retinal detachment, closure of the macular hole is difficult to attain despite the complete relief of tangential traction by internal limiting membrane peeling. Results indicate the presence of a possible imbalance between the retina and the choroid-sclera complex associated with axial elongation and posterior staphyloma in highly myopic eyes.

disjunctive eye movement evoked by microstimulation in an extrastriate cortical area of the cat

Slow disjunctive eye movement similar to ocular convergence was evoked by microstimulation in parts of the lateral suprasylvian area (LSA) in alert cats. A tungsten-in-glass microelectrode was used for stimulation, and eye movement was monitored using the magnetic search coil method. The velocity-versus-amplitude relationship of disjunctive eye movement evoked by microstimulation was comparable to that of ocular convergence evoked by presenting a visual target. It is suggested that the LSA plays a role in controlling convergence eye movement.

Functional roles of the lateral suprasylvian cortex in ocular near response in the cat

The lateral suprasylvian (LS) area, an extrastriate visual area in the cat, has been suggested to play an important role in processing motion in 3-dimensional visual space. In addition, the LS area is related to all three components of the ocular near response, i.e. lens accommodation, pupillary constriction, and ocular convergence: microstimulation in this area evoked these intra- and extraocular movements, and neuronal discharges associated with these movements were also found. Anatomical pathways, direct and indirect, from this area to premotor nuclei in the brainstem are known to exist. The present paper reviews studies useful for assessing the functional roles played by the LS area in triggering and modulating component movements in the ocular near response.

Ischemic optic neuropathy in a female carrier with Fabry's disease.

We report ocular findings of a patient with anterior ischemic optic neuropathy (AION) and cilioretinal artery occlusion in a female carrier of Fabrys disease. Fluorescein angiography revealed delayed filling of the upper and temporal part of peripapillary choroidal vessels and capillaries of the right optic disk and late filling of the cilioretinal artery. CT scanning was performed several times in early stages and demonstrated thickening of the intraorbital optic nerve due to ischemic edema. About 5 months later, the fellow eye showed optic disk edema, an early sign of AION, and was treated by systemic corticosteroid and urokinase whereby AION did not progress.

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.

Ocular convergence-related neuronal responses in the lateral suprasylvian area of alert cats

Neuronal spike discharges were recorded from the lateral suprasylvian (LS) area while ocular convergence was elicited in five alert cats. Ocular convergence was elicited by presenting a visual target moving in depth. Cats were rewarded for convergence eye movement. In 9 out of 426 cells sampled in the caudal postero-medial LS area, the number of spikes was positively correlated with the peak eye velocities during ocular convergence. Significant correlation was found mostly within 400 ms preceding the moment at which the maximum velocity of ocular convergence was obtained. The result favors the hypothesis that the LS area plays an important role in the integrative control of ocular convergence.

The properties of convergence eye movements evoked from the rostral and caudal lateral suprasylvian cortex in the cat.

Convergence eye movements were evoked in the lateral suprasylvian cortex (LS cortex) in the cat. Three effective regions were found: the rostral and caudal parts of the postero-medial LS cortex (the PMLS) and the rostral part of the postero-lateral LS cortex (the PLLS). These three areas represent the central and paracentral visual fields in the published retinotopic map (Palmer et al., 1978). Convergence eye movements evoked from the caudal PMLS were divided into two groups based on their latencies; the short-latency components (SLC) and long-latency components (LLC). The SLC and the LLC had differences in their symmetry of right and left eye movements during vergence eye movement. The SLC had symmetric right and left eye components and the LLC had dominant contralateral eye components. In the rostral PMLS, latencies of evoked convergence eye movement were comparable to those of the caudal PMLS, but they did not divided into two groups. Convergence eye movements evoked from the PLLS had longer latencies than those from the PMLS and asymmetric right and left eye components. It is suggested that different subregions in the LS cortex contribute to the control of convergence eye movement, playing different roles.

Temporal Modulation Transfer Function of Vision by Pattern Visual Evoked Potentials in Patients with Optic Neuritis

To reveal the impairment of the temporal modulation transfer function of vision in patients with optic neuritis, the pattern visual evoked potentials (P-VEPs) were recorded at reversal frequencies ranging from 4 to 24 per second, and the fast Fourier transform (FFT) of VEPs were investigated. In normal subjects, curves of the square root of the power of the FFTs of P-VEPs versus temporal frequency showed the maximum peak at 6 Hz (12 reversals/s). The specific distribution of the power spectrum could be found at each temporal frequency, and the amplitudes of higher harmonic components decreased while a single power spectrum peak became prominent as the temporal frequency increased. In patients with optic neuritis, an abnormality of the power spectrum of steady-state P-VEPs could by detected by estimating the 1st and 2nd harmonic components. The abnormality of the power spectrum of transient P-VEPs could be detected by estimating the higher harmonic components of the power spectrum.

Contrast Sensitivity for the Stationary and Drifting Vertical Stripe Patterns in Patients with Optic Nerve Disorders

Subjective contrast sensitivity for the stationary and horizontally drifting vertical stripe patterns was measured in normal subjects and in patients with glaucoma, optic neuritis and optic atrophy. Contrast sensitivity was also determined objectively using an eye movement reflex (optokinetic nystagmus) recorded by means of electro-oculography. The contrast sensitivity for the drifting stripe patterns in normal subjects was characterized by a depression of sensitivity at the high spatial frequency and an increased contrast sensitivity at the low spatial frequency in comparison with the results of stationary stripe patterns. The measurement of contrast sensitivity for the horizontally drifting vertical stripe patterns was found to be more sensitive for detection of minor damage to the optic nerve than that for the stationary patterns. The results of the subjective contrast sensitivity and the objective one determined using an eye movement reflex showed a good correlation.

Severe hypotony after macular translocation surgery with 360-degree retinotomy

PURPOSE To report a case of severe hypotony after macular translocation with 360-degree retinotomy. DESIGN Interventional case report. METHODS A 50-year-old woman with myopic neovascular maculopathy underwent macular translocation with 360-degree retinotomy in her left eye. RESULTS After the second procedure of silicone oil removal, severe hypotony developed. No clear sign of leakage was found. Pure perfluoropropane gas tamponade was then performed, which resulted in temporal resolution of severe hypotony, but the hypotony recurred as the gas bubble was absorbed. Ten weeks after the second surgery, the hypotonous eye was refilled with silicone oil. No apparent cyclitic membrane was observed intraoperatively. After this procedure, the choroidal and retinal folds regressed; intraocular pressure has been between 5 and 7 mm Hg for more than 4 months thereafter. CONCLUSION Severe hypotony can occur as a complication of otherwise uneventful macular translocation with 360-degree retinotomy.