| OCR Text |
Show Jourrud of Clinical Neuro- ophthalmology 10( 3): 223-- 225, 1990. The 1989 Japanese Neuro- ophthalmology Society Meeting . Masato Wakakura, M. D., D. Se. © 1990 Raven Press, Ltd., New York The 27th meeting of the Japanese Neuroophthalmology Society was held in Tokyo ( organizer was Professor Hiroshi Matsuzaki) on October 2~ 22, 1989. Ninety- five papers, including 11 posters were presented. A mini- symposium on neurotransmitters in the visual system was organized by Professor Tamai ( Sendai), and seven speakers were selected to participate. Dr. Takeshi Tabira also presented a lecture on Experimental Autoimmune Optic Neuritis. This article introduces several original papers of particular interest. OPTIC PATHWAY In an investigation using human embryonal tissues, Tetsumoto ( Kobe) obtained evidence that programmed cell death occurred in the retina abruptly from the 20th to 26th gestational week. Subsequent to that, the density of retinal cells decreased gradually becoming stable at 2 years of age. Disc swelling is often seen in idiopathic optic neuritis in children, but is rather uncommon in adults. Okano ( Kitasato) examined 49 consecutive adult cases with idiopathic optic neuritis and found ophthalmoscopically unequivocal disc swelling in 21 of them ( 43%) during the clinical course. This percentage is higher than the cases presented in English literature, indicating possibly different causative or anatomical factor( s) in Japanese cases. Most Japanese ophthalmologists consider high- dose corticosteroids to be absolutely necessary for treating optic neuritis. In a retrospective study, Wakakura ( Kitasato) could find no sta- From the Department of Ophthalmology, School of Medicine, Kitasato University, Kitasato Sagamihara Kanagawa, Japan. Address correspondence and reprint requests to Dr. M. Wakakura at the Department of Ophthalmology, School of Medicine, Kitasato University, 1- 15- 1 Kitasato Sagamlhara Kanagawa 228, Japan. 223 tistical difference between pulse therapy with methylprednisolone and noncorticosteroid therapy for idiopathic optic neuritis. The number of patients used in his study was small, and a more extensive study should be conducted. Tsubakihara ( Sapporo) reported three cases of bilateral optic neuropathy due to dysthyroid ophthalmopathy. Satisfactory results were not achieved by high- dose therapy of corticosteroids, and consequently, irradiation therapy ( 20- 24 Gy) was carried out on all patients. There was significant visual recovery in two cases. An uncommon case with bilateral optic neuropathy complicated with ulcerative colitis was reported by Suzuki ( Saitama). A 38- year- old man with a lO- year history of ulcerative colitis was in a remissive state following aggravation for 3 months when sudden bilateral visual loss was noted. There was no evidence of uveitis, and the diagnosis was consequently bilateral optic neuropathy. Systemic corticosteroid brought about full visual recovery. OCULAR MOTOR SYSTEM In regard to the anatomical localization of the superior levator muscle subnucleus, previous studies are in disagreement. Sekiya ( Kitasato) attempted to clarify this point using the horseradish peroxidase technique. Special attention was directed to the complete separation of the superior levator muscle from the superior rectus muscle. These muscles were well- separated, and each was enveloped in a super glue. The results obtained support Warwick's study for the most part: that the ipsilateral levator muscle projects from bilateral caudal central nuclei. Evidence was also obtained that contralateral projection is slightly predominant. The cytogenetic approach to chronic progressive external ophthalmoplegia ( CPEO) was presented 224 M. WAKAKURA by two independent authors. Using a polymerase chain reaction or southern blot technique, mitochondrial DNA ( mtDNA) was analyzed in CPEO. In four out of seven cases with CPEO without chorioretinal degeneration ( Ibi, Aichi) and in four cases with Kearn- Sayre syndrome ( Ohta, Nagoya), a mtDNA was found to be definitely defective. Biopsied muscle is usually examined in such study, but Ohta successfully analyzed DNA from platelets obtained easily from the patients. Since defective mtDNA was not found in the controls or in the normal parents of the patients, the results appear significant. Several new or uncommon syndromes were reported at the meeting. Nishimaki ( Kitasato) presented two girls with occipital dysmyelination showing very similar symptoms such as bilateral visual loss with optic atrophy possibly due to transsynaptic degeneration, defective smooth pursuit movement, esotropia, and manifest latent nystagmus. Both cases were low- birth- weight babies and had asymmetric high- intensity lesions at the occipital white matter on magnetic resonance imaging ( MRI). Smooth pursuit movement to the dominantly affected side was apparently more impaired, indicating possibly that the capacity for normal smooth pursuit movement was not acquired during development. Kumagai and Yuda ( Yokohama) reported pendular convergence nystagmus at the eyes- closure to have been evident in a patient with germinoma on the pineal body. The patient, a 28- year- old man, had retraction nystagmus but no convergence nystagmus on opening the eyes. Convergence insufficiency, down gaze palsy, and bilateral mild ptosis were also noted. The pendular convergence nystagmus was not seen at eye- opening in either light or darkness. This nystagmus appeared to have a phase and frequency different from those of retraction nystagmus. This is the first such report, and the mechanism remains unknown. External ophthalmoplegia is often observed in acute infectious pOlyneuropathy such as Fisher's syndrome, but is quite rare in chronic inflammatory demyelinating polyradiculoneuritis ( ClOP). Watabiki ( Akita) reported a 21- year- old woman with external ophthalmoplegia in this disease. Facial palsy, hearing loss, and impaired taste on the right side were noted for 3 months following the appearance of common cold- like symptoms. Diplopia, numbness, and weakness were noted in all the extremities. Right ptosis and paresis in the right superior rectus and oblique muscles as well as areflexia were evident, but the pupillary system was intact. Cerebrospinal fluid showed increased JClin Neuro- ophthalmol. Vol. 10. No. 3. 1990 protein content, but without cellular _.> ponse. Conduction tests on peripheral nerves indicated local block due possibly to demyelination. These findings were identical to ClOP. Isolated opsodonus in a patient with lung small cell carcinoma was reported by Nagai ( Shimane). No abnormality of the cerebellum and brain stem were noted either by roentgenographic diagnosis or autopsy. Paraneoplastic effects may, thus, possibly be involved in the mechanism. PUPILLARY SYSTEM Computer- assisted videopupillography certainly facilitates evaluation of the pupillary response system. However, the parameters to be evaluated should be accurately determined and used. The independence of the parameters to be calculated is a problem, though. Sugiyama ( Osaka) calculated each parameter of normal controls, such as initial pupillary size, latency for initial response, and amplitude of constriction, and determined the correlations among them. The amplitude of constriction was proportional to initial pupillary size, and maximum constriction velocity and maximum dilation velocity were each essentially linearly related to the amplitude of constriction. For diagnostic purposes, use of the ratio of two parameters correlated to each other is advised. By pupillographic analysis using this ratio, essential anisocoria was shown to be more frequent than ordinarily thought. Several interesting observations of the pupillary system were presented. Tanaka ( Aichi) examined pupillary pharmacological response in patients with the pseudoexfoliation syndrome. The results showed variation, but in some cases, there was indication of an impaired dilator musde, postsynaptic sympathetic neuropathy, or both. MISCELLANEOUS Sawa ( Sapporo) confirmed by electrophysiological experiment that the lateral suprasylvian area ( LSA) is a primary central site responsible for lens accommodation in cats. Infrared optometry was carried out during electrical stimulation with microelectrode at LSA. Apparent accommodation was induced by stimulation from the Al to A4 areas of LSA. Ocular findings in three cases ( 45- year- old female, 41- year- old male, and 13- year- old male) with galactosialidosis, a very rare hereditary disease, were reported by Usui ( Niigata). This disease is characterized by reduction in both B- galactosidase and neuraminidase in the leukocytes. Ocular JAPANESE NEURO- OPHTHALMOLOGY SOCIETY MEETING 225 complications are bilateral visual loss, central scotoma, corneal diffuse opacity, and optic atrophy. A cherry red spot at the macula was either ambiguously evident or cannot be seen in these cases. A case of a 13- year- old boy was autopsied, and a scattered lipid deposit was confirmed present in the peripheral and central nervous systems. A number of retinal ganglion cells, however, disappeared, and some lipid- containing phagocytes could be seen. Since the lipid- laden retinal ganglion cells may be responsible for perifoveal greyness forming the cherry red spot, the disappearance of retinal ganglion cells would explain the absence of this feature in this patient. The next meeting of the Japanese Neuroophthalmology Society is scheduled to be held in Shiga City, near Lake Biwa ( organizer will be Dr. Kazutaka Kani), September 6-- 8, 1990. 1Clin Neuro- ophthnlmol, Vol. 10, No. 3, 1990 |
