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Occupational conjunctivitis associated with type IV allergy to methacrylates
ABSTRACTS EDITED BY GEORGE B. BARTLEY, M.D.
• Tear film changes associated with normal aging. Mathers WD*, Lane JA, Zimmerman MB. Cornea 1996;15:229-34.
T
HE AUTHORS EVALUATED TEAR FILM FUNCTION IN
normal subjects by measuring reflex tear capacity using the Schirmer test without anesthetic, steady state tear flow using fluorophotometry, meibomian gland function based on gland dropout, expressible lipid volume and viscosity, tear loss from evaporation, and tear osmolarity. The average tear flow and tear volume measurements were 0.19 μΐ/min and 2.74 μΐ, respectively, which were less than previously reported. With the exception of the decay constant and lipid volume, increasing subject age was associated with a decline in all measured variables. The highest corre lations with aging were tear volume, Schirmer test, and tear osmolarity. The authors concluded that tear film function declines throughout life and that tear flow is considerably less than previously estimated. —George B. Bartley 'Department of Ophthalmology, University of Iowa Hospitals and Clinics, 200 Hawkins Dr., Iowa City, IA 52242.
• Decrease in corneal sensitivity and change in tear function in dry eye. Xu K-P*, Yagi Y, Tsubota K. Cornea 1996;15:235-9.
D
ECREASED CORNEAL SENSITIVITY HAS BEEN Docu mented in patients with Herpes simplex keratitis, diabetes mellitus, and leprosy; in contact lens wearers; and in patients who have undergone intraocular surgery. In this investigation, the authors examined the relationship between decreased corneal sensitivity
290
and insufficient tear secretion. The study population comprised 59 patients with dry eye (15 of whom had Sjögren syndrome) and 26 normal subjects. Corneal sensitivity was measured with esthesiometry. Addi tionally, the Schirmer test with and without anesthe sia, the tear clearance rate, the tear function index, and staining with rose bengal and fluorescein were evaluated. The average corneal sensitivity of patients with dry eye (with or without Sjögren syndrome) was significantly less than that of control subjects. Corne al sensitivity correlated significantly with the Schirmer values with anesthesia and with the tear function index. There also were significant relation ships between corneal sensitivity and the rose bengal and fluorescein scores. Because hyposecretion of tears may lead to pathologic changes in corneal epithelium and a decline in corneal sensitivity, the authors advocate prompt treatment of keratoconjunctivitis sicca to maintain a normal corneal protective mech anism.—-George B. Bartley *Department of Ophthalmology, Tokyo Dental College, 5-11-13 Sugano, Ichikawa, Chiba 272, Japan.
• Occupational conjunctivitis associated with type IV allergy to methacrylates. Estlander T*, Kanerva L, Kari O, Jolanki R, Mölsa K. Allergy 1996;51:56-9.
A
STHMA AND OTHER MUCOSAL DISEASE OCCASION-
ally may be caused by exposure to methacrylates. The authors examined three patients who developed allergic contact dermatitis after working in dental or hearing aid laboratories. Two of the patients had conjunctivitis as well. Both of these individuals were exposed to chemically curable and light-curable
AMERICAN JOURNAL OF OPHTHALMOLOGY
AUGUST
1996
methacrylates, although the authors believe that the latter compounds may be more hazardous than the former. The conjunctivitis was ascribed to a type IV allergic reaction, although type I allergy, other hypersensitivity mechanisms, and irritation could not be excluded. The patients were able to return to work after modification of the ventilation system in the laboratories and with the use of sodium chromoglycate eyedrops.—George B. Bartley 'Finnish Institute of Occupational Health, Section of Occupational Dermatology, Topeliuksenkatu 41 a A, FIN-00250 Helsinki, Finland.
• Retinal blood flow changes in type I diabetes. A long-term, follow-up study. Konno S, Feke GT*, Yoshida A, Fujio N, Goger DG, Buzney SM. Invest Ophthalmol Vis Sci 1996;37:1140-8.
T
HE AUTHORS PREVIOUSLY REPORTED IN A CROSS-
sectional study that retinal blood flow was signifi cantly slower in patients with insulin-dependent (type I) diabetes mellitus than in healthy control subjects. In this longitudinal follow-up study, blood flow in a temporal retinal artery of 24 patients with type I diabetes was measured annually using a bidirec tional laser Doppler technique and monochromatic photography. Retinopathy was scored using standard ized color fundus photography and fluorescein angiography. Follow-up ranged from two to six years. Retinal blood flow slopes were negative in 15 patients and positive in nine patients. Multiple linear regres sion analysis demonstrated that the retinal blood flow slopes were significantly related to the retinal blood flow measured at the time of enrollment in the study and to the median duration of diabetes during the follow-up interval. Additionally, the retinal blood flow slopes and the median retinopathy score correlat ed positively over time. The transition from negative to positive retinal blood flow slopes as the duration of diabetes becomes longer and the retinopathy becomes more severe and reflects the complex pathologic changes that occur in the diabetic retina. One explanation for the decrease in resistance to flow is that areas of capillary nonperfusion become short-
VOL. 122, NO. 2
circuited by dilated anastomotic channels between arterioles and venules. Autoregulatory mechanisms, such as tissue Po2, also may play a role in increasing retinal blood flow.—George B. Bartley *Schepens Eye Research Institute, 20 Stamford St., Boston, MA 02114.
• Amelioration of vascular dysfunctions in diabetic rats by an oral PKC ß inhibitor. Ishii H, Jirousek MR, Koya D, Takagi C, Xia P, Clermont A, Bursell S-E, Kern TS, Ballas LM, Heath WF, Stramm LE, Feener EP, King GL*. Science 1996;272:728-31.
O
NE AVENUE BY WHICH HYERGLYCEMIA IS THOUGHT
to cause vascular complications in diabetes mellitus is by activation of protein kinase C, an enzyme that phosphorylates serine and threonine residues of intracellular proteins and effects blood vessel permeability. The authors previously had dem onstrated that the ß2 isoenzyme of protein kinase C is preferentially activated in the retina of diabetic rats. In this investigation, the authors synthesized a selec tive, reversible, orally effective inhibitor of protein kinase C ß (LY333531) and evaluated its effect on vascular functions in diabetic rats. The drug im proved the glomerular filtration rate, albumin excre tion rate, and retinal circulation in a dose-responsive manner, parallel with its inhibition of protein kinase C activities, suggesting that abnormal activation of protein kinase C, and particularly its ß isoenzymes, may underlie some of the vascular complications of diabetes mellitus.—George B. Bartley *]oslin Diabetes Center, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 1 Joslin Place, Boston, MA 02215.
• Retinal degeneration in mice lacking the 7 subunit of the rod cGMP phosphodiesterase. Tsang SH, Gouras P, Yamashita CK, Kjeldbye H, Fisher J, Färber DB, Goff SP*. Science 1996;272:1026-9.
T
HE RETINAL CYCLIC GUANOSINE 3',5'-MONOPHOS-
phate (cGMP) phosphodiesterase (PDE) is a key regulator of phototransduction in the vertebrate visu-
ABSTRACTS
291
• Tear film changes associated with normal aging. Mathers WD*, Lane JA, Zimmerman MB. Cornea 1996;15:229-34.
T
HE AUTHORS EVALUATED TEAR FILM FUNCTION IN
normal subjects by measuring reflex tear capacity using the Schirmer test without anesthetic, steady state tear flow using fluorophotometry, meibomian gland function based on gland dropout, expressible lipid volume and viscosity, tear loss from evaporation, and tear osmolarity. The average tear flow and tear volume measurements were 0.19 μΐ/min and 2.74 μΐ, respectively, which were less than previously reported. With the exception of the decay constant and lipid volume, increasing subject age was associated with a decline in all measured variables. The highest corre lations with aging were tear volume, Schirmer test, and tear osmolarity. The authors concluded that tear film function declines throughout life and that tear flow is considerably less than previously estimated. —George B. Bartley 'Department of Ophthalmology, University of Iowa Hospitals and Clinics, 200 Hawkins Dr., Iowa City, IA 52242.
• Decrease in corneal sensitivity and change in tear function in dry eye. Xu K-P*, Yagi Y, Tsubota K. Cornea 1996;15:235-9.
D
ECREASED CORNEAL SENSITIVITY HAS BEEN Docu mented in patients with Herpes simplex keratitis, diabetes mellitus, and leprosy; in contact lens wearers; and in patients who have undergone intraocular surgery. In this investigation, the authors examined the relationship between decreased corneal sensitivity
290
and insufficient tear secretion. The study population comprised 59 patients with dry eye (15 of whom had Sjögren syndrome) and 26 normal subjects. Corneal sensitivity was measured with esthesiometry. Addi tionally, the Schirmer test with and without anesthe sia, the tear clearance rate, the tear function index, and staining with rose bengal and fluorescein were evaluated. The average corneal sensitivity of patients with dry eye (with or without Sjögren syndrome) was significantly less than that of control subjects. Corne al sensitivity correlated significantly with the Schirmer values with anesthesia and with the tear function index. There also were significant relation ships between corneal sensitivity and the rose bengal and fluorescein scores. Because hyposecretion of tears may lead to pathologic changes in corneal epithelium and a decline in corneal sensitivity, the authors advocate prompt treatment of keratoconjunctivitis sicca to maintain a normal corneal protective mech anism.—-George B. Bartley *Department of Ophthalmology, Tokyo Dental College, 5-11-13 Sugano, Ichikawa, Chiba 272, Japan.
• Occupational conjunctivitis associated with type IV allergy to methacrylates. Estlander T*, Kanerva L, Kari O, Jolanki R, Mölsa K. Allergy 1996;51:56-9.
A
STHMA AND OTHER MUCOSAL DISEASE OCCASION-
ally may be caused by exposure to methacrylates. The authors examined three patients who developed allergic contact dermatitis after working in dental or hearing aid laboratories. Two of the patients had conjunctivitis as well. Both of these individuals were exposed to chemically curable and light-curable
AMERICAN JOURNAL OF OPHTHALMOLOGY
AUGUST
1996
methacrylates, although the authors believe that the latter compounds may be more hazardous than the former. The conjunctivitis was ascribed to a type IV allergic reaction, although type I allergy, other hypersensitivity mechanisms, and irritation could not be excluded. The patients were able to return to work after modification of the ventilation system in the laboratories and with the use of sodium chromoglycate eyedrops.—George B. Bartley 'Finnish Institute of Occupational Health, Section of Occupational Dermatology, Topeliuksenkatu 41 a A, FIN-00250 Helsinki, Finland.
• Retinal blood flow changes in type I diabetes. A long-term, follow-up study. Konno S, Feke GT*, Yoshida A, Fujio N, Goger DG, Buzney SM. Invest Ophthalmol Vis Sci 1996;37:1140-8.
T
HE AUTHORS PREVIOUSLY REPORTED IN A CROSS-
sectional study that retinal blood flow was signifi cantly slower in patients with insulin-dependent (type I) diabetes mellitus than in healthy control subjects. In this longitudinal follow-up study, blood flow in a temporal retinal artery of 24 patients with type I diabetes was measured annually using a bidirec tional laser Doppler technique and monochromatic photography. Retinopathy was scored using standard ized color fundus photography and fluorescein angiography. Follow-up ranged from two to six years. Retinal blood flow slopes were negative in 15 patients and positive in nine patients. Multiple linear regres sion analysis demonstrated that the retinal blood flow slopes were significantly related to the retinal blood flow measured at the time of enrollment in the study and to the median duration of diabetes during the follow-up interval. Additionally, the retinal blood flow slopes and the median retinopathy score correlat ed positively over time. The transition from negative to positive retinal blood flow slopes as the duration of diabetes becomes longer and the retinopathy becomes more severe and reflects the complex pathologic changes that occur in the diabetic retina. One explanation for the decrease in resistance to flow is that areas of capillary nonperfusion become short-
VOL. 122, NO. 2
circuited by dilated anastomotic channels between arterioles and venules. Autoregulatory mechanisms, such as tissue Po2, also may play a role in increasing retinal blood flow.—George B. Bartley *Schepens Eye Research Institute, 20 Stamford St., Boston, MA 02114.
• Amelioration of vascular dysfunctions in diabetic rats by an oral PKC ß inhibitor. Ishii H, Jirousek MR, Koya D, Takagi C, Xia P, Clermont A, Bursell S-E, Kern TS, Ballas LM, Heath WF, Stramm LE, Feener EP, King GL*. Science 1996;272:728-31.
O
NE AVENUE BY WHICH HYERGLYCEMIA IS THOUGHT
to cause vascular complications in diabetes mellitus is by activation of protein kinase C, an enzyme that phosphorylates serine and threonine residues of intracellular proteins and effects blood vessel permeability. The authors previously had dem onstrated that the ß2 isoenzyme of protein kinase C is preferentially activated in the retina of diabetic rats. In this investigation, the authors synthesized a selec tive, reversible, orally effective inhibitor of protein kinase C ß (LY333531) and evaluated its effect on vascular functions in diabetic rats. The drug im proved the glomerular filtration rate, albumin excre tion rate, and retinal circulation in a dose-responsive manner, parallel with its inhibition of protein kinase C activities, suggesting that abnormal activation of protein kinase C, and particularly its ß isoenzymes, may underlie some of the vascular complications of diabetes mellitus.—George B. Bartley *]oslin Diabetes Center, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, 1 Joslin Place, Boston, MA 02215.
• Retinal degeneration in mice lacking the 7 subunit of the rod cGMP phosphodiesterase. Tsang SH, Gouras P, Yamashita CK, Kjeldbye H, Fisher J, Färber DB, Goff SP*. Science 1996;272:1026-9.
T
HE RETINAL CYCLIC GUANOSINE 3',5'-MONOPHOS-
phate (cGMP) phosphodiesterase (PDE) is a key regulator of phototransduction in the vertebrate visu-
ABSTRACTS
291