- Email: [email protected]
Autumn National Aro Meeting
1218
AMERICAN JOURNAL OF OPHTHALMOLOGY
man with a genius for administration. His hallmark was surrounding himself with highly talented people, which he did, not only during his career at General Motors, but also during his second career, the estab lishing of the Alfred P. Sloan Foundation. Frank W. Newell
AUTUMN NATIONAL ARO MEETING The fall meeting of the Association for Research in Ophthalmology was held in Chicago on October 13 to 15, 1966. The meeting featured 22 papers covering a wide variety of subjects and symposia on extraocular muscles and glaucoma. The two sympo sia were supported in part by the National Society for the Prevention of Blindness. Kayes reported that the rabbit trabecular meshwork, studied with the electron mi croscope, contains narrow bands of smooth muscle fibers from the ciliary body which course to within one cell layer of the outflow channels. Staflova noted that adrenergic nerves in the iris and ciliary body supply blood vessels and form numerous subepithelial plexuses. However, the function of the latter fibers is uncertain since none ap pear to cross the epithelial basement mem brane. Kuwabara and Poulimenos found a de struction of the horizontal cells and their connections to the receptor cells as the ini tial changes produced by iodoacetic-acid poi soning. It was emphasized that these early morphologic changes, seen by electron mi croscopy, are unlike those of early retinitis pigmentosa which are found in the pigment epithelium. Bernstein noted irregular secre tory granules in the pigment epithelium of light-adapted rats, cats and rabbits, which disappeared largely with prolonged dark adaptation. No definite relationship of these granules to visual pigments was demon strated. Cohen showed that glutaraldehydeosmium fixed human optic nerves possess
DECEMBER, 1966
myelinated axons, fibrous astrocytes and presumptive oligodendroglia. Jampel and Mindel localized the nucleus of accommodation in the macaque in the anteromedian subnuclei of the oculomotor complex. The nucleus consists of paired masses of motor cells near the midline which are closely related to the more poste riorly and ventrally located Eddinger-Westphal nucleus affecting pupillary constriction. Concomitant accommodation and pupillary constriction occurred with electrode stimula tion in areas between the two nuclei. Ac commodative changes did not affect intraoc ular pressure. Goldstein and Botelho recorded the effects of intravenous pilocarpine and norepinephrine upon lacrimal-gland flow in rabbits. Pilocarpine (0.1 mg/kg) caused a tenfold maximal increase and norepinephrine (10 |xg /kg) a threefold maximal increase in tear volume. However, norepinephrine preceded by pilocarpine caused an initial inhibition of tear flow which was followed by the three fold maximal increase. Bracher studied rates of synthesis in the corneal stroma adjacent to a previous inju ry. Using specific radioactive precursors and then measuring their uptake he found that protein synthesis occurred most rapidly and sul fated mucopolysaccharide synthesis least rapidly. Feldman and Feldman found that sphingolipids constituted 36% of the total lipids in the lens and 4 3 % of those in the cornea. Mishima, Kudo and Rabino found complete K E I medium to be the best for maintenance of normal thickness of in cubated isolated cornea. Goldor and Gay studied the long-term effects of selective occlusions of the choroidal and retinal vasculature in the dog eye produced by using Latex microspheres of known size. A unique finding in their study was the deterioration in three to six months of all retinal layers with pigment migration and giant cyst formation after occlusion of the larger choroidal vessels. Oppelt de scribed a method for the continuous estima-
VOL. 62, NO. 6
EDITORIALS
tion of aqueous humor production over sev eral hours. The degree of dilution and perfusion rate of inulin allowed calculation of the flow rate. With this technique, intrave nous acetazolamide in a dose of 10 mg/kg produced a maximum reduction in aqueous flow of 50%. Using fundus reflectometry, Carr, Ripps, Siegel and Weale found rhodopsin kinetics to be normal in two congenitally night-blind patients and implicated transmission defects in each. Riggs, the Friedenwald Lecturer, reviewed evidence supporting the trichroma tic theory at the receptor level including data from a recent flicker electroretinography experiment of his own. After injecting intramuscular epinephrine in oil, Laibson and Kibrick were able to show virus reactivation, about 10% to 30% of the time, in rabbits which had recovered from primary corneal herpetic keratitis. Hyndiuk and Kaufman compared three an tiviral drugs in the treatment of rabbit her petic corneal lesions and found trifluorothymidine to be the most effective in eliminating corneal lesions and assayable virus from the infected rabbit cornea. No corneal toxicity was found in rabbits or normal humans using the drug for three weeks. Schwartz, Reinstein and Lieberman at tempted to establish normal optic-nerve pa rameters with data obtained from photo graphs of optic nerves from 140 normal subjects. Atterman and Henkind found that radial peripapillary capillaries are particu larly vulnerable to acute pressure elevations. Hamasaki and Fujino produced intraocular pressure elevations in the primate of 30 to 90 mm Hg and noted a decrease in retinal, choroidal and optic-nerve circulation at all pressure levels. A cavernous degeneration ensued with the earliest changes at and pos terior to the lamina cribrosa. Michon and Kinoshita found that high doses of humersol or Phospholine Iodide produced cataracts in isolated rabbit lenses in tissue culture. Humersol produced ante rior subcapsular vacuoles and Phospholine
1219
Iodide produced equatorial vesicles initially and posterior subcapsular vacuoles eventual ly. Lee, Donovan and Schepens produced an aqueous venous shunt in monkeys by cannulating the anterior ciliary vein of the superi or rectus muscle with a small diameter poly ethylene tube extending into the anterior chamber. This shunt resulted in a marked lowering of intraocular pressure. The symposium on extraocular muscles stressed recent studies and new concepts. Evidence from several disciplines favored the existence of at least two types of muscle fibers in extraocular muscles-—fast fibers which play a role in saccadic eye movements and slow fibers which probably relate to tonic or sustained eye movements. Nastuk discussed current concepts of neuromuscular transmission. Eakins described how the autonomic nervous system affects extraocu lar muscle function. He noted that intrave nous epinephrine or postganglionic superior cervical nerve stimulation caused a gradual increase in the action potential recorded from the superior rectus or the nictitating membrane of the cat. Alpha-receptor block ing agents or atropine antagonized and co caine enhanced these effects. Katz presented findings that contradict the classically held concept that extraocular muscles are more sensitive than skeletal muscles to most drugs. When comparing fast firing fibers from the tibialis anterior and extraocular muscles, he noted about equal sensitivity to succinylcholine, decamethonium, d-tubocurarine, nonpolarizing agents and neostigmine. Osterman who first described the Tensilon test for myasthenia gravis, pre sented recent concepts of this disease and summarized data from a large series of cases. An interesting diagnostic ocular sign emphasized by the speaker was alternating ptosis. The glaucoma symposium featured a number of diverse topics of recent inter est. Henkind described the radial peripapil lary capillary circulation in the monkey, cat and pig. Cotton-wool spots and radial hem-
1220
AMERICAN JOURNAL OF OPHTHALMOLOGY
orrhages, which are more common near the disc, may originate from these capillaries but, most important, is the possibility of their role in glaucoma in the development of Bjerrum scotomas. Zimmerman discussed recent concepts of Schnabel's cavernous atrophy. H e found that the initial changes in cavernous atrophy from glaucoma differ from those resulting from ischemic infarction (for example, with temporal arteritis). After the latter process, there are large numbers of glial cells, rather than a disappearance, and empty spaces seen behind the lamina cribrosa are not filled with pale staining mucoidlike material as in glaucoma. Ballin studied 100 normal subjects who were 60 years of age or more and found more borderline values of pressure, outflow and glaucoma indices than in younger nor mal groups studied. Fifty-five members of this group were given topical dexamethonium to one eye for four weeks and 3 5 % of them then had ocular tensions greater than 20 mm H g . However, none had ten sions greater than 31 mm H g after steroid. It was postulated that most of the patients with borderline values or positive responses to steroid were probably carriers of one glaucoma gene who tended to show more minimal abnormalities with age. Draeger discussed a portable applanation tonometer of his own design which uses the same applaned area as the Goldmann applanation tonometer. Supine tensions with this instru ment were about 1.0 mm H g higher on the average than those obtained in the upright position. Gills discussed the mechanism of action of cyclodialysis implants on the basis of tonography and intraocular manometric determinations in two blind eyes. Glaser discussed Tensilon tonography in the diagnosis of myasthenia gravis. H e found that Tensilon produced a pressure rise easily seen on a tonography recording in the 12 myasthenics studied but had no effect on intraocular pressure in 10 normals. Ophthalmologists, as well as glaucoma pa
DECEMBER, 1966
tients, will be happy to hear the results of the last lecture at the symposium. Houle used alcohol in the form of whiskey and beer by intravenous injection and produced a fall in intraocular pressure. Vasopressin alone had no effect but when used prior to alcohol prevented any change in intraocular pressure. T h e awards banquet, as usual a festive occasion, was highlighted by several honors. Lorrin Riggs received the Friedenwald Medal and Kenneth Ogle recalled the pioneer contributions of the medalist in the field of electroretinography. Everett Kinsey and Irving Leopold received plaques noting their contributions as past chairmen of the Board of Trustees of the Association for Research. Marie Jakus, of the National In stitutes of Health, a friend of ophthalmol ogy and an outstanding contributor to studies concerning the fine structure of the eye, was named an honorary member. T h e next national meeting will be held in Clearwater, Florida, on May 1 and 2, 1967. Alex E . Krill
CORRESPONDENCE M Y TWO CRYOPEXIES: A PERSONAL ACCOUNT
Editor, American Journal of Ophthalmology: Cryopexy under topical anesthesia is a remarkable technologic advance in the treat ment of retinal holes and tears. Since it has appeared only recently on the ophthalmic scene, it is important for ophthalmologists to know what the patient experiences during the procedure. I recently underwent cryopexy under top ical anesthesia for a small peripheral tear and adjacent hole in one retina and for a small peripheral retinal hole in an area of lattice degeneration in the second eye. There was an interval of five weeks between the two procedures.
AMERICAN JOURNAL OF OPHTHALMOLOGY
man with a genius for administration. His hallmark was surrounding himself with highly talented people, which he did, not only during his career at General Motors, but also during his second career, the estab lishing of the Alfred P. Sloan Foundation. Frank W. Newell
AUTUMN NATIONAL ARO MEETING The fall meeting of the Association for Research in Ophthalmology was held in Chicago on October 13 to 15, 1966. The meeting featured 22 papers covering a wide variety of subjects and symposia on extraocular muscles and glaucoma. The two sympo sia were supported in part by the National Society for the Prevention of Blindness. Kayes reported that the rabbit trabecular meshwork, studied with the electron mi croscope, contains narrow bands of smooth muscle fibers from the ciliary body which course to within one cell layer of the outflow channels. Staflova noted that adrenergic nerves in the iris and ciliary body supply blood vessels and form numerous subepithelial plexuses. However, the function of the latter fibers is uncertain since none ap pear to cross the epithelial basement mem brane. Kuwabara and Poulimenos found a de struction of the horizontal cells and their connections to the receptor cells as the ini tial changes produced by iodoacetic-acid poi soning. It was emphasized that these early morphologic changes, seen by electron mi croscopy, are unlike those of early retinitis pigmentosa which are found in the pigment epithelium. Bernstein noted irregular secre tory granules in the pigment epithelium of light-adapted rats, cats and rabbits, which disappeared largely with prolonged dark adaptation. No definite relationship of these granules to visual pigments was demon strated. Cohen showed that glutaraldehydeosmium fixed human optic nerves possess
DECEMBER, 1966
myelinated axons, fibrous astrocytes and presumptive oligodendroglia. Jampel and Mindel localized the nucleus of accommodation in the macaque in the anteromedian subnuclei of the oculomotor complex. The nucleus consists of paired masses of motor cells near the midline which are closely related to the more poste riorly and ventrally located Eddinger-Westphal nucleus affecting pupillary constriction. Concomitant accommodation and pupillary constriction occurred with electrode stimula tion in areas between the two nuclei. Ac commodative changes did not affect intraoc ular pressure. Goldstein and Botelho recorded the effects of intravenous pilocarpine and norepinephrine upon lacrimal-gland flow in rabbits. Pilocarpine (0.1 mg/kg) caused a tenfold maximal increase and norepinephrine (10 |xg /kg) a threefold maximal increase in tear volume. However, norepinephrine preceded by pilocarpine caused an initial inhibition of tear flow which was followed by the three fold maximal increase. Bracher studied rates of synthesis in the corneal stroma adjacent to a previous inju ry. Using specific radioactive precursors and then measuring their uptake he found that protein synthesis occurred most rapidly and sul fated mucopolysaccharide synthesis least rapidly. Feldman and Feldman found that sphingolipids constituted 36% of the total lipids in the lens and 4 3 % of those in the cornea. Mishima, Kudo and Rabino found complete K E I medium to be the best for maintenance of normal thickness of in cubated isolated cornea. Goldor and Gay studied the long-term effects of selective occlusions of the choroidal and retinal vasculature in the dog eye produced by using Latex microspheres of known size. A unique finding in their study was the deterioration in three to six months of all retinal layers with pigment migration and giant cyst formation after occlusion of the larger choroidal vessels. Oppelt de scribed a method for the continuous estima-
VOL. 62, NO. 6
EDITORIALS
tion of aqueous humor production over sev eral hours. The degree of dilution and perfusion rate of inulin allowed calculation of the flow rate. With this technique, intrave nous acetazolamide in a dose of 10 mg/kg produced a maximum reduction in aqueous flow of 50%. Using fundus reflectometry, Carr, Ripps, Siegel and Weale found rhodopsin kinetics to be normal in two congenitally night-blind patients and implicated transmission defects in each. Riggs, the Friedenwald Lecturer, reviewed evidence supporting the trichroma tic theory at the receptor level including data from a recent flicker electroretinography experiment of his own. After injecting intramuscular epinephrine in oil, Laibson and Kibrick were able to show virus reactivation, about 10% to 30% of the time, in rabbits which had recovered from primary corneal herpetic keratitis. Hyndiuk and Kaufman compared three an tiviral drugs in the treatment of rabbit her petic corneal lesions and found trifluorothymidine to be the most effective in eliminating corneal lesions and assayable virus from the infected rabbit cornea. No corneal toxicity was found in rabbits or normal humans using the drug for three weeks. Schwartz, Reinstein and Lieberman at tempted to establish normal optic-nerve pa rameters with data obtained from photo graphs of optic nerves from 140 normal subjects. Atterman and Henkind found that radial peripapillary capillaries are particu larly vulnerable to acute pressure elevations. Hamasaki and Fujino produced intraocular pressure elevations in the primate of 30 to 90 mm Hg and noted a decrease in retinal, choroidal and optic-nerve circulation at all pressure levels. A cavernous degeneration ensued with the earliest changes at and pos terior to the lamina cribrosa. Michon and Kinoshita found that high doses of humersol or Phospholine Iodide produced cataracts in isolated rabbit lenses in tissue culture. Humersol produced ante rior subcapsular vacuoles and Phospholine
1219
Iodide produced equatorial vesicles initially and posterior subcapsular vacuoles eventual ly. Lee, Donovan and Schepens produced an aqueous venous shunt in monkeys by cannulating the anterior ciliary vein of the superi or rectus muscle with a small diameter poly ethylene tube extending into the anterior chamber. This shunt resulted in a marked lowering of intraocular pressure. The symposium on extraocular muscles stressed recent studies and new concepts. Evidence from several disciplines favored the existence of at least two types of muscle fibers in extraocular muscles-—fast fibers which play a role in saccadic eye movements and slow fibers which probably relate to tonic or sustained eye movements. Nastuk discussed current concepts of neuromuscular transmission. Eakins described how the autonomic nervous system affects extraocu lar muscle function. He noted that intrave nous epinephrine or postganglionic superior cervical nerve stimulation caused a gradual increase in the action potential recorded from the superior rectus or the nictitating membrane of the cat. Alpha-receptor block ing agents or atropine antagonized and co caine enhanced these effects. Katz presented findings that contradict the classically held concept that extraocular muscles are more sensitive than skeletal muscles to most drugs. When comparing fast firing fibers from the tibialis anterior and extraocular muscles, he noted about equal sensitivity to succinylcholine, decamethonium, d-tubocurarine, nonpolarizing agents and neostigmine. Osterman who first described the Tensilon test for myasthenia gravis, pre sented recent concepts of this disease and summarized data from a large series of cases. An interesting diagnostic ocular sign emphasized by the speaker was alternating ptosis. The glaucoma symposium featured a number of diverse topics of recent inter est. Henkind described the radial peripapil lary capillary circulation in the monkey, cat and pig. Cotton-wool spots and radial hem-
1220
AMERICAN JOURNAL OF OPHTHALMOLOGY
orrhages, which are more common near the disc, may originate from these capillaries but, most important, is the possibility of their role in glaucoma in the development of Bjerrum scotomas. Zimmerman discussed recent concepts of Schnabel's cavernous atrophy. H e found that the initial changes in cavernous atrophy from glaucoma differ from those resulting from ischemic infarction (for example, with temporal arteritis). After the latter process, there are large numbers of glial cells, rather than a disappearance, and empty spaces seen behind the lamina cribrosa are not filled with pale staining mucoidlike material as in glaucoma. Ballin studied 100 normal subjects who were 60 years of age or more and found more borderline values of pressure, outflow and glaucoma indices than in younger nor mal groups studied. Fifty-five members of this group were given topical dexamethonium to one eye for four weeks and 3 5 % of them then had ocular tensions greater than 20 mm H g . However, none had ten sions greater than 31 mm H g after steroid. It was postulated that most of the patients with borderline values or positive responses to steroid were probably carriers of one glaucoma gene who tended to show more minimal abnormalities with age. Draeger discussed a portable applanation tonometer of his own design which uses the same applaned area as the Goldmann applanation tonometer. Supine tensions with this instru ment were about 1.0 mm H g higher on the average than those obtained in the upright position. Gills discussed the mechanism of action of cyclodialysis implants on the basis of tonography and intraocular manometric determinations in two blind eyes. Glaser discussed Tensilon tonography in the diagnosis of myasthenia gravis. H e found that Tensilon produced a pressure rise easily seen on a tonography recording in the 12 myasthenics studied but had no effect on intraocular pressure in 10 normals. Ophthalmologists, as well as glaucoma pa
DECEMBER, 1966
tients, will be happy to hear the results of the last lecture at the symposium. Houle used alcohol in the form of whiskey and beer by intravenous injection and produced a fall in intraocular pressure. Vasopressin alone had no effect but when used prior to alcohol prevented any change in intraocular pressure. T h e awards banquet, as usual a festive occasion, was highlighted by several honors. Lorrin Riggs received the Friedenwald Medal and Kenneth Ogle recalled the pioneer contributions of the medalist in the field of electroretinography. Everett Kinsey and Irving Leopold received plaques noting their contributions as past chairmen of the Board of Trustees of the Association for Research. Marie Jakus, of the National In stitutes of Health, a friend of ophthalmol ogy and an outstanding contributor to studies concerning the fine structure of the eye, was named an honorary member. T h e next national meeting will be held in Clearwater, Florida, on May 1 and 2, 1967. Alex E . Krill
CORRESPONDENCE M Y TWO CRYOPEXIES: A PERSONAL ACCOUNT
Editor, American Journal of Ophthalmology: Cryopexy under topical anesthesia is a remarkable technologic advance in the treat ment of retinal holes and tears. Since it has appeared only recently on the ophthalmic scene, it is important for ophthalmologists to know what the patient experiences during the procedure. I recently underwent cryopexy under top ical anesthesia for a small peripheral tear and adjacent hole in one retina and for a small peripheral retinal hole in an area of lattice degeneration in the second eye. There was an interval of five weeks between the two procedures.