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The Optic Neuritis Treatment Trial. Putting the results in perspective
ABSTRACTS EDITED BY GEORGE B. BARTLEY, M.D.
• Bilateral cataract and high serum ferritin: a new dominant genetic disorder? Bonneau D*, WinterFuseau I, Loiseau M-N, Amati P, Berthier M, Oriot D, Beaumont C. J Med Genet 1995;32:778-9.
B
ILATERAL PULVERULENT CATARACTS WERE DIAG-
nosed in three generations of one family. The cataracts were inherited in an autosomal dominant pattern and caused visual difficulties in early child hood. An unusual orange-colored sheen to the lens opacities prompted the authors to obtain tests of iron metabolism. Serum ferritin levels were markedly in creased, although serum iron levels and transferrin iron binding capacity were normal. The authors suggested that the "cataract-hyperferritinaemia syn drome could be a new genetic disorder" in which an abnormality of ferritin metabolism leads to lens opacities, and recommended that serum ferritin levels be assayed in all cases of dominandy inherited cataract.—George B. Bartley Service de Pιdiatrie et Gιnιtique, CHU de Poitiers, BP 577, 86021 Poitiers Cedex, France.
• Epidemic optic neuropathy in Cuba—clinical characterization and risk factors. The Cuba Neu ropathy Field Investigation Team*. N Engl J Med 1995;333:1176-82.
E
PIDEMIC OPTIC AND PERIPHERAL NEUROPATHY AF-
fected more than 50,000 persons in Cuba from late 1991 through 1993, with a peak incidence in March 1993, when 3,000 to 4,000 cases per week were being reported. The number of new cases decreased after the initiation of vitamin supplementation, including parenteral vitamin B12. To characterize and identify risk factors for the optic neuropathy form of the
232
disease, the Investigation Team conducted ophthalmologic and neurologic examinations, assessed expo sure to potential toxins, administered a semiquantita tive food-frequency questionnaire, and determined serum measures of nutritional status in 123 patients with severe optic neuropathy and compared the results with randomly chosen normal subjects matched for age and sex. Prominent clinical features in patients included subacute loss of visual acuity with field defects, decreased color vision, optic disk pallor, and decreased sensitivity to vibration and tempera ture in the legs. Tobacco use, particularly cigar smoking, was associated with an increased risk of optic neuropathy; the odds ratio increased to 23 for persons who smoked four or more cigars daily. The risk of optic neuropathy was decreased in patients with greater dietary intakes of methionine, vitamin B12, riboflavin, and niacin and higher serum concen trations of antioxidant carotenoids, and among sub jects who raised chickens at home or who had relatives living overseas, factors that may be indirect measures of increased food availability. The investiga tors concluded that the epidemic appears to be linked to decreased nutrient intake caused by Cuba's deterio rating economic situation and the high prevalence of tobacco use.—George B. Bartley *Rossanne M. Philen, Centers for Disease Control and Prevention, 4770 Buford Hwy., Mailstop F-46, Atlanta, GA 30341.
• The Optic Neuritis Treatment Trial. Putting the results in perspective. Beck RW*, Trobe JD, for the Optic Neuritis Study Group. J Neuro-Ophthalmol 1995;15:131-5.
T
HE PURPOSES OF THIS ARTICLE WERE TO OFFER A
digest of how the ONTT [Optic Neuritis Treat ment Trial] was conducted, what it showed, how its
AMERICAN JOURNAL OF OPHTHALMOLOGY
FEBRUARY
1996
results may affect management of optic neuritis, and answers to some of the most frequently asked ques tions about the validity of the results, particularly with respect to the development of multiple sclerosis." Criteria for entry into the study included a diagnosis of acute unilateral optic neuritis with visual symptoms of eight days or less, age between 18 and 46 years, no previous history of optic neuritis or ophthalmoscopic signs of optic atrophy in the affected eye, no evidence of a systemic disease that might be associated with the optic neuritis, and no previous treatment with corticosteroids for optic neuritis in the fellow eye. Two primary treatment recommendations were derived from the trial: ( 1 ) oral prednisone therapy should be abandoned; and (2) patients should undergo magnet ic resonance imaging and be treated with intravenous corticosteroids if the scans demonstrate two or more signal abnormalities. Although magnetic resonance imaging is the largest additional expense evoked by the study's recommendations, it offers important prognostic information about the chances of develop ing further neurologic sequelae of multiple sclerosis. —George B. Bartley
that included determination of scotopic vision using a luxometer. The mean serum vitamin A level was lowest among children identified as night blind by both their parents and the investigators and was highest among those identified as not night blind by both parents and investigators. The authors conclud ed that parents' reports of their children's night blindness had low sensitivity compared with diagnosis using a luxometer and recommended that future studies of the prevalence of night blindness include a standard method of screening random samples of children.—George B. Bartley
"Centre for International Health, University of Bergen, Haukeland Hospital, N-5021 Bergen, Norway.
• Macular pigment density in monozygotic twins. Hammond BR Jr*, Fuld K, Curran-Celentano J. Invest Ophthalmol Vis Sci 1995;36:2531-41.
T *]aeb Center for Health Research, Inc., 3010 E. 138 Ave., Suite 9, Tampa, FL 33613.
• Diagnosis of night blindness and serum vitamin A level: a population-based study. Hussain A*, Kvβle G, Φdland M. Bull World Health Organ 1995;73:469-76.
H
YPOVITAMINOSE A IS THE MOST COMMON CAUSE
of irreversible blindness in children. Although most field assessments of childhood night blindness have relied on parents' reports, the validity of this method has been questioned. Among a crosssectional survey of 5,420 children in northern Ban gladesh, 124 were reported by their parents to have night blindness. One hundred five of these children, along with control subjects matched for age, sex, and neighborhood, underwent measurement of serum vitamin A level and an ophthalmologic examination
V0L.121, N o . 2
HE DENSITY OF MACULAR PIGMENT (XANTHOPHYLL)
varies widely among individuals, but the reasons for these differences have not been determined. Because macular pigment is thought to protect the retina and the retinal pigment epithelium from the toxic effects of short-wavelength light, decreased levels of xanthophyll may be related to diseases of the central retina, such as age-related maculopathy, and to the short-wavelength sensitivity loss of normal aging. In this study of ten pairs of monozygotic twins, the authors determined the density of macular pig ment by psychophysical means, the concentration of serum carotenoids by liquid chromatography, and dietary patterns with a questionnaire. Statistically significant differences in macular pigment optical density were found for five of the ten twin pairs; the differences were moderately related to differences in the intake of dietary fat, iron, linoleic and oleic acid, fiber, and total calories. There was no significant relationship between macular pigment density and carotenoids in the serum and diet. The authors concluded that macular pigment density is not deter mined entirely by genetic predisposition, but rather that xanthophyll deposition is influenced by several
ABSTRACTS
233
• Bilateral cataract and high serum ferritin: a new dominant genetic disorder? Bonneau D*, WinterFuseau I, Loiseau M-N, Amati P, Berthier M, Oriot D, Beaumont C. J Med Genet 1995;32:778-9.
B
ILATERAL PULVERULENT CATARACTS WERE DIAG-
nosed in three generations of one family. The cataracts were inherited in an autosomal dominant pattern and caused visual difficulties in early child hood. An unusual orange-colored sheen to the lens opacities prompted the authors to obtain tests of iron metabolism. Serum ferritin levels were markedly in creased, although serum iron levels and transferrin iron binding capacity were normal. The authors suggested that the "cataract-hyperferritinaemia syn drome could be a new genetic disorder" in which an abnormality of ferritin metabolism leads to lens opacities, and recommended that serum ferritin levels be assayed in all cases of dominandy inherited cataract.—George B. Bartley Service de Pιdiatrie et Gιnιtique, CHU de Poitiers, BP 577, 86021 Poitiers Cedex, France.
• Epidemic optic neuropathy in Cuba—clinical characterization and risk factors. The Cuba Neu ropathy Field Investigation Team*. N Engl J Med 1995;333:1176-82.
E
PIDEMIC OPTIC AND PERIPHERAL NEUROPATHY AF-
fected more than 50,000 persons in Cuba from late 1991 through 1993, with a peak incidence in March 1993, when 3,000 to 4,000 cases per week were being reported. The number of new cases decreased after the initiation of vitamin supplementation, including parenteral vitamin B12. To characterize and identify risk factors for the optic neuropathy form of the
232
disease, the Investigation Team conducted ophthalmologic and neurologic examinations, assessed expo sure to potential toxins, administered a semiquantita tive food-frequency questionnaire, and determined serum measures of nutritional status in 123 patients with severe optic neuropathy and compared the results with randomly chosen normal subjects matched for age and sex. Prominent clinical features in patients included subacute loss of visual acuity with field defects, decreased color vision, optic disk pallor, and decreased sensitivity to vibration and tempera ture in the legs. Tobacco use, particularly cigar smoking, was associated with an increased risk of optic neuropathy; the odds ratio increased to 23 for persons who smoked four or more cigars daily. The risk of optic neuropathy was decreased in patients with greater dietary intakes of methionine, vitamin B12, riboflavin, and niacin and higher serum concen trations of antioxidant carotenoids, and among sub jects who raised chickens at home or who had relatives living overseas, factors that may be indirect measures of increased food availability. The investiga tors concluded that the epidemic appears to be linked to decreased nutrient intake caused by Cuba's deterio rating economic situation and the high prevalence of tobacco use.—George B. Bartley *Rossanne M. Philen, Centers for Disease Control and Prevention, 4770 Buford Hwy., Mailstop F-46, Atlanta, GA 30341.
• The Optic Neuritis Treatment Trial. Putting the results in perspective. Beck RW*, Trobe JD, for the Optic Neuritis Study Group. J Neuro-Ophthalmol 1995;15:131-5.
T
HE PURPOSES OF THIS ARTICLE WERE TO OFFER A
digest of how the ONTT [Optic Neuritis Treat ment Trial] was conducted, what it showed, how its
AMERICAN JOURNAL OF OPHTHALMOLOGY
FEBRUARY
1996
results may affect management of optic neuritis, and answers to some of the most frequently asked ques tions about the validity of the results, particularly with respect to the development of multiple sclerosis." Criteria for entry into the study included a diagnosis of acute unilateral optic neuritis with visual symptoms of eight days or less, age between 18 and 46 years, no previous history of optic neuritis or ophthalmoscopic signs of optic atrophy in the affected eye, no evidence of a systemic disease that might be associated with the optic neuritis, and no previous treatment with corticosteroids for optic neuritis in the fellow eye. Two primary treatment recommendations were derived from the trial: ( 1 ) oral prednisone therapy should be abandoned; and (2) patients should undergo magnet ic resonance imaging and be treated with intravenous corticosteroids if the scans demonstrate two or more signal abnormalities. Although magnetic resonance imaging is the largest additional expense evoked by the study's recommendations, it offers important prognostic information about the chances of develop ing further neurologic sequelae of multiple sclerosis. —George B. Bartley
that included determination of scotopic vision using a luxometer. The mean serum vitamin A level was lowest among children identified as night blind by both their parents and the investigators and was highest among those identified as not night blind by both parents and investigators. The authors conclud ed that parents' reports of their children's night blindness had low sensitivity compared with diagnosis using a luxometer and recommended that future studies of the prevalence of night blindness include a standard method of screening random samples of children.—George B. Bartley
"Centre for International Health, University of Bergen, Haukeland Hospital, N-5021 Bergen, Norway.
• Macular pigment density in monozygotic twins. Hammond BR Jr*, Fuld K, Curran-Celentano J. Invest Ophthalmol Vis Sci 1995;36:2531-41.
T *]aeb Center for Health Research, Inc., 3010 E. 138 Ave., Suite 9, Tampa, FL 33613.
• Diagnosis of night blindness and serum vitamin A level: a population-based study. Hussain A*, Kvβle G, Φdland M. Bull World Health Organ 1995;73:469-76.
H
YPOVITAMINOSE A IS THE MOST COMMON CAUSE
of irreversible blindness in children. Although most field assessments of childhood night blindness have relied on parents' reports, the validity of this method has been questioned. Among a crosssectional survey of 5,420 children in northern Ban gladesh, 124 were reported by their parents to have night blindness. One hundred five of these children, along with control subjects matched for age, sex, and neighborhood, underwent measurement of serum vitamin A level and an ophthalmologic examination
V0L.121, N o . 2
HE DENSITY OF MACULAR PIGMENT (XANTHOPHYLL)
varies widely among individuals, but the reasons for these differences have not been determined. Because macular pigment is thought to protect the retina and the retinal pigment epithelium from the toxic effects of short-wavelength light, decreased levels of xanthophyll may be related to diseases of the central retina, such as age-related maculopathy, and to the short-wavelength sensitivity loss of normal aging. In this study of ten pairs of monozygotic twins, the authors determined the density of macular pig ment by psychophysical means, the concentration of serum carotenoids by liquid chromatography, and dietary patterns with a questionnaire. Statistically significant differences in macular pigment optical density were found for five of the ten twin pairs; the differences were moderately related to differences in the intake of dietary fat, iron, linoleic and oleic acid, fiber, and total calories. There was no significant relationship between macular pigment density and carotenoids in the serum and diet. The authors concluded that macular pigment density is not deter mined entirely by genetic predisposition, but rather that xanthophyll deposition is influenced by several
ABSTRACTS
233