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Transient Myopia and the Mechanism of Accommodation
BOOK
any candidate to examination until he has completed three years of prepara tion in ophthalmology, including formal course of study, interneship, and time spent as assistant or in independent private practice. It is obviously difficult for the Board to take the initiative in investigating the various courses of instruction in oph thalmology given at different institu tions, but it is anticipated that such in stitutions will invite this survey, at least to the extent of submitting all necessary information and a.sking for a report and classification. Much will be gained if those who wish to study ophthalmology can be furnished with collective information as to the courses of instruction which are available, and if they can be advised exactly what is regarded as adequate preparation for practice in this special field of medicine and surgery. E. C. Ellett. TRANSIENT MYOPIA A N D T H E MECHANISM OF ACCOMMO DATION Helmholtz' theory of accommodaton has been recently challenged as to its consistency with the origin of transient myopia in diabetes, in arsenobenzol in toxication, following ocular trauma, and in asthenia. In a lengthy article on this subject, A. Hudelo (Archives d'Ophtalmologie, 1930, volume 2, pages 20-95) suggests that the assumption of a ciliary spasm in transient myopia is not justifiable for the following reasons: (1) Transient myopia is not affected by the use of atropin. (2) It is not accompanied by the frontal headaches which are char acteristic of ciliary spasm. (3) Dia betes, arsenobenzol poisoning, trauma tism, and asthenia are generally causes of paralytic and not of spastic condi tions. But, according to the classical theory of accommodation, paresis of the ciliary muscle should result in an effect similar to presbyopia and not in a myopic change. Hudelo believes that in human eyes accommodation is a dual process con trolled by the antagonistic action of
NOTICES
825
the circular and anteroposterior por tions of the ciliary muscle. .According to this hypothesis, a contraction of the circular fibers of the ciliary muscle is responsible for near accommodation, while distance accommodation is ac complished through a contraction of Brücke's muscle. Hence, toxic or trau matic paralysis of the latter muscle will result in temporary "spasm of accom modation" or transient myopia. Hudelo quite fails to mention that it was the physiologist Nicati who first (Physiologie oculaire, Paris, 1909) ap plied this theory of the dual mechanism of accommodation to the pathogenesis of temporary myopia. Neither does Hudelo make any reference to the work of Sedan, who expressed similar views in 1922 (Marseille Medícale, 1922, vol ume 18, pages 871-874). Λ ί . Beigelman. BOOK NOTICES Refraction of the human eye and meth ods of estimating the refraction, in cluding a section on the fitting of spectacles and eyeglasses. By James Thorington. Second edi tion, revised, octavo, 406 pages, 322 illustrations, 28 colored. Cloth. $2.00. 1930, P. Blakiston's Son and Company, Philadelphia. In spite of some imperfections (and what book has none?) this volume must be regarded as one of the most im portant modern textbooks on refrac tion in the English language. After several large reprintings of the first edition, which was originally published many years ago, the second edition is sure of a wide circulation. It is neatly and durably bound, and of convenient size for frequent reference. The print is clear, the illustrations abundant and for the most part very well applied to their respective purpo.ses. The descrip tions of principle or technique are not always perfectly comprehensible in themselves, but will usually be grasped by one who studies carefully the ac companying illustrations. Revised forms of earlier apparatus are illus trated and described, as in the case of the ophthalmometer, the luminous
any candidate to examination until he has completed three years of prepara tion in ophthalmology, including formal course of study, interneship, and time spent as assistant or in independent private practice. It is obviously difficult for the Board to take the initiative in investigating the various courses of instruction in oph thalmology given at different institu tions, but it is anticipated that such in stitutions will invite this survey, at least to the extent of submitting all necessary information and a.sking for a report and classification. Much will be gained if those who wish to study ophthalmology can be furnished with collective information as to the courses of instruction which are available, and if they can be advised exactly what is regarded as adequate preparation for practice in this special field of medicine and surgery. E. C. Ellett. TRANSIENT MYOPIA A N D T H E MECHANISM OF ACCOMMO DATION Helmholtz' theory of accommodaton has been recently challenged as to its consistency with the origin of transient myopia in diabetes, in arsenobenzol in toxication, following ocular trauma, and in asthenia. In a lengthy article on this subject, A. Hudelo (Archives d'Ophtalmologie, 1930, volume 2, pages 20-95) suggests that the assumption of a ciliary spasm in transient myopia is not justifiable for the following reasons: (1) Transient myopia is not affected by the use of atropin. (2) It is not accompanied by the frontal headaches which are char acteristic of ciliary spasm. (3) Dia betes, arsenobenzol poisoning, trauma tism, and asthenia are generally causes of paralytic and not of spastic condi tions. But, according to the classical theory of accommodation, paresis of the ciliary muscle should result in an effect similar to presbyopia and not in a myopic change. Hudelo believes that in human eyes accommodation is a dual process con trolled by the antagonistic action of
NOTICES
825
the circular and anteroposterior por tions of the ciliary muscle. .According to this hypothesis, a contraction of the circular fibers of the ciliary muscle is responsible for near accommodation, while distance accommodation is ac complished through a contraction of Brücke's muscle. Hence, toxic or trau matic paralysis of the latter muscle will result in temporary "spasm of accom modation" or transient myopia. Hudelo quite fails to mention that it was the physiologist Nicati who first (Physiologie oculaire, Paris, 1909) ap plied this theory of the dual mechanism of accommodation to the pathogenesis of temporary myopia. Neither does Hudelo make any reference to the work of Sedan, who expressed similar views in 1922 (Marseille Medícale, 1922, vol ume 18, pages 871-874). Λ ί . Beigelman. BOOK NOTICES Refraction of the human eye and meth ods of estimating the refraction, in cluding a section on the fitting of spectacles and eyeglasses. By James Thorington. Second edi tion, revised, octavo, 406 pages, 322 illustrations, 28 colored. Cloth. $2.00. 1930, P. Blakiston's Son and Company, Philadelphia. In spite of some imperfections (and what book has none?) this volume must be regarded as one of the most im portant modern textbooks on refrac tion in the English language. After several large reprintings of the first edition, which was originally published many years ago, the second edition is sure of a wide circulation. It is neatly and durably bound, and of convenient size for frequent reference. The print is clear, the illustrations abundant and for the most part very well applied to their respective purpo.ses. The descrip tions of principle or technique are not always perfectly comprehensible in themselves, but will usually be grasped by one who studies carefully the ac companying illustrations. Revised forms of earlier apparatus are illus trated and described, as in the case of the ophthalmometer, the luminous