| OCR Text |
Show Journal of Cli ..ical Neuro-ol'hthalmology 13(2): 144--146, 1993. The 1991 Japanese Neufo-ophthalmology Society Meeting Masato Wakakura, M.D., D.Sc. © 1993 Raven Press, Ltd., New York At the 29th meeting of the Japanese Neuroophthalmology Society, held in Kagoshima (organizer, Professor Norio Ohba) on November 7-8, 1991, 125 papers were presented. This article discusses several papers of particular interest. OPTIC PATHWAY Professor Mitsuhiro Osame (Kagoshima) presented an overview on HTLV-I-associated myelopathy (HAM), According to a nationwide survey of HAM in Japan, there were 710 patients with HAM (1), and approximately 1,150 patients throughout the world. Ocular complications include anterior uveitis, retinal vasculitis, cotton-wool spots, pigmentary retinal degeneration, and keratoconjunctivitis sicca. Sekine and colleagues (Sapporo) reported unilateral macular degeneration and disc edema associated with HAM. Arimura and colleagues (Kagoshima) observed abnormal smooth pursuit movements in 12 of 26 HAM patients, which appeared to be related to the severity of myelopathy, possibly due to the involvement of the optic pathway by leukoariosis usually present in brain white matter of these patients on magnetic resonance imaging (MRl) , A retinal cause is usually suggested for visual disturbance in the multiple evanescent white-dot syndrome (MEWDS), Ozaki and colleagues (Miyazaki) reported two cases with MEWDS, both shoWing unilateral enlargement of the blind spot, reduced ratio of the light peak/dark trough of EOG, and subnormal ERG, However, in one of the cases, From the Department of Ophthalmology, School of Medicine Kitasato University, Sagamihara, Japan. Address correspondence and reprint requests to Dr. M. Wakakura at the Department of Ophthalmology, School of Medicine, Kitasato University, 1-15-1 Kitasato Sagamihara Kanagawa 228, Japan. 144 there were unilateral visual loss, relative afferent pupillary defects, and reduced critical fusion flicker frequency. Optic neuropathy was thus suspected. These findings support those of Dodwell and colleagues (2). An 83-year-old man, who has lived alone for the past 30 years, noted bilateral visual loss. Corrected visual acuity of 0.2 OD and 0.5 OS could not be explained by his condition of mild cataracts. Low blood level of the vitamin B group was found. Visual recovery was followed relatively quickly by regular intake of food and vitamin B treatment. Such patients with mild deficiency optic neuropathy have recently been found to be rather prevalent in Japan. (Taguchi and colleagues, Hiroshima). Studies for evaluating visual function in optic neuritis were reported. P-lOO latency in pattemvisual evoked potentials show slower recovery than visual acuity or latency of light response (Chin and colleagues, Sapporo). Temporal modulation transfer function is recovered more slowly than visual acuity or Humphrey perimetry (Abe and colleagues, Niigata). Woung and colleagues (Sagamihara) found central critical flicker frequency to be a sensitive means for detecting subtle abnormality at the recovery stage or in the fellow eye for cases of unilateral visual loss. Prostatic cancer metastasizes approximately 2% to 4% to the brain, and prognosis is quite poor. A 62-year-old man, who had compression optic neuropathy due to metastasized prostatic cancer at the suprachiasmal region, was treated with progesterone and then Estracite (estrogen + nitrogen mastard). Dramatic recovery from the original cancer, metastasized cancer, and optic neuropathy was achieved (Morikawa and colleagues, Osaka). Acquired cerebral dyschromatopsia was discussed by three speakers (Yoshizawa and colleagues, Niigata; Takano and colleagues, Tokyo; Yokoyama and colleagues, Akita). Their clinical findings JAPANESE NEURO-OPHTHALMOLOGY SOCIETY MEETING 145 showed some variation, this depending partly on the particular tests used. There still appears to be no adequate examination for detecting cerebral dyschromatopsia. OCULAR MOTOR SYSTEM Miniature eye movement was studied, using a fundus haploscope with a half-mirror (Sato, Shiga). The half-mirror is positioned such a way as to visualize the subject's fundus image on a television monitor. When the fundus image was completely synchronized with eye movement, the stabilized retinal image could not be seen by the subject. Under this condition, there was only slight drift movement. The hypothesis that the physiological role of the miniature movement is to maintain fixation was confirmed. Takano and colleagues (Sagamihara) presented four cases with carotid-cavernous fistula (CCF) who had ocular motor abnormality but neither chemosis nor proptosis. By superselective angiography, atypical CCF was shown to drain into cortical veins rather than into opthalmic veins. Such cases may be difficult to diagnose initially as CCF, and there is great risk of brain hemorrhage. Oku and colleagues (Osaka) reviewed 19 cases of diabetic ophthalmoplegia and found 14 cases of abducens palsy to have better control on HbAIC than 3 cases with oculomotor palsy. Spontaneous recovery was seen in all cases at 95 days on average. It was considered that surgery should not be conducted until at least 3 months had passed from the onset. Four cases with alternating skew deviation (ASD) or bilateral adducting hypotropia were presented by Kiyosawa and colleagues (Sendai). Three cases were pinealoma and another was postviral encephalitis. In all cases, ASD was followed by unilateral skew deviation. The authors suggest ASD to be a transient phenomenon appearing when midline lesion at the midbrain is symmetrically stimulated. Thyrotropin-releasing hormone (TRH) is widely distributed in the central nervous system and may be a neuromodulator. Intravenous TRH-tartate (500 I-Lg) was administered to 11 cases with various abnormal eye movement due to brainstem lesions. Significant recovery of the amplitude ratio of saccade and depression of nystagmus were observed for 20 to 60 minutes following the administration (Saito and colleagues, Nagoya). Matsumura and colleagues (Kumamoto) observed downbeat nystagmus in three monkeys (common marmoset) chronically intoxicated with methylmercury, as an experimental model of Minamata disease. Histopathological examination showed significant neuronal cells disappearance and proliferation of astroglia in the superior vestibular nucleus. Esotropia appears as often complicated with periventricular leukomalacia, according to a review of 9 cases by Hiramoto and colleagues (Sagamihara). The lesion in the white matter about the parieto-occipital lobe may promote the inducer most of esotropia. Ogasawara and colleagues (Sapporo) found it difficult to initiate the slow phase of optokinetic nystagmus and reduced the gain in smooth pursuit movement in a case with infantile esotropia. They considered the area responsible for this abnormality to possibly be the middle temporal area and/or middle superior temporal area. MISCELLANEOUS Development of the human ciliary muscle was studied immunohistochemically by Tanino and colleagues (Tokyo). Ciliary muscle cells were identified in specimens at the 12th gestational week and actin-positive cells were observed initially in the posterior half of the ciliary body at 17th gestational week. Development of the anterior half of the ciliary muscle is apparently delayed. Image analysis of pupillary movement by computer was reported by Fujita and colleagues (Sagamihara). Six cases with tonic pupil were analyzed and all showed segmental palsy of the pupil. Nasal side was more dilated in five cases than the temporal side and light response was significantly reduced on the nasal side in three cases. The oculomotor nerve to the iris may be differently innervated for the temporal and nasal sides, and damage to the nasal side may occur earlier. LEBER'S HEREOITARY OPTIC NEUROPATHY Eight papers were presented in a minisymposium entitled "Mitochondrial Mutations and Neuro-ophthalmology." The main topic was genetic analysis in Leber's hereditary optic neuropathy. Dr. J. Imachi who has studied very large series of this disease (3) organized this symposium. The extraordinary development in this field has demonstrated the need to clarify several problems, such as why there are more female cases in Japan than in Europe and the United States, possible factors that initiate optic neuropathy in cases with J Clm Neuro-ophtlullmol, Vol. 13, No.2, 1993 146 M. WAKAKURA mitochondrial mutation, the research for spontaneous recovery, and the availability of drugs effective for recovery. The significance of heteroplasmy is also of interest in regard to this disease, but in reported cases in Japan, heteroplasmy apparently is not related to severity or onset. It is expected that this disease will be studied further throughout the world because of the limited number of cases and the racial differences. I Clill Neuro·ophlhalmol. Vol. 13. No.2. 1993 REFERENCES 1. Dodwell DC, Jampol LM, Rosenberg M, Berman A, Zaret CR. Optic nerve involvement associated with the multiple evanescent white dot syndrome. Ophthalmology 1990;97: 862-8. 2. Osame M, Janssen R, Kubota H, et al. Nationwide survey of HTLV-l-associated myelopathy in Japan: association with blood transfusion. Ann Neurol 1990;28:50-6. 3. Imachi J: Leber's disease. Nippon Ganka Gakkaishi 1973;77: 1658--735. |
