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Corneal Ulcer Caused by a Biologic Insecticide (Bacillus thuringiensis)
258
AMERICAN JOURNAL OF OPHTHALMOLOGY
the sutures to be relaxed individually, the eye to be massaged at the slit lamp, and a bleb to appear. Because there is no inci sion in the conjunctiva, there is no risk of leakage or infection through the conjunc tiva. Similarly, patients with postcataract astigmatism can be seated at the laser and the sutures lysed with the four-mirror lens, avoiding the minimal bleeding or antibiotic treatment. I do not know whether treating the sutures at the corneoscleral limbus or more posteriorly at the knot would affect the degree of reduced astigmatism quali tatively. A conjunctival perforation might possibly occur in an area that was already thinned. Nevertheless, I have found no complications in more than 20 such treat ments. MARC F. LIEBERMAN,
Redwood City,
M.D.
California
An Open Letter to Physicians With Physical Impairments For the past two years, the St. PaulRamsey Medical Center has been in volved in compiling a resource directory for physicians with physical impairments. The purpose is to list physicians with various physical disabilities who are will ing to provide information and referral services to physicians who incur similar disabilities and need specific information. Existing rehabilitation programs are sim ply not equipped to deal with the situa tion and "Impaired Physician" services within the medical profession are direct ed exclusively to those physicians with various drug dependencies. The biggest problem we have encoun tered is poor participation. About 4% of all physicians are not in active practice because of physically disabling condi tions; of these, about 25% have the poten tial to practice medicine again. In real numbers this constitutes 1% of the li
FEBRUARY, 1983
censed physicians in this country or 4,500 physicians. Our goal is to identify these physicians and to encourage their participation. To date we have placed ad vertisements in over 100 major medical journals but fewer than 200 physicians have responded. In retrospect, it ap pears this was the result of using inap propriate terminology in the advertise ments. Physical disability does not imply inability. Our use of the term "handi capped physician" was inappropriate be cause most physically disabled physicians are not handicapped in their practice of medicine. We apologize for the inappro priate terminology and again ask that all physicians, active or inactive, with any type of physical disability write to Frank C. Zondlo, M . D . , St. Paul-Ramsey Hos pital Medical and Education Research Foundation, 640 Jackson St., St. Paul, MN 55101. The directory will be com pleted in six to eight months and at that time it will be sent to only those physi cians who are listed therein. Upon re ceipt of your initial response, information forms will be mailed. All correspondence is confidential. We encourage all physicians with a physical disability, no matter how small, to respond. Information from a doctor with even a minor disability may be of value to another doctor with multiple disabilities. The cornerstone of this proj ect is your participation. FRANK C. ZONDLO,
Saint Paul,
M.D.
Minnesota
Corneal Ulcer Caused by a Biologic Insecticide (Bacillus thuringiensis) Environmental concerns are prompt ing an increased interest in the use of biologic insecticides in agriculture. We observed a corneal ulcer following the exposure of an eye to Dipel, a biologic insecticide containing Bacillus thurin giensis as the active ingredient. This in-
VOL. 95, NO. 2
CORRESPONDENCE
secticide is used to control the larvae of certain lepidopterous insects. A previously healthy 18-year-old farm er accidentally splashed a suspension con taining B. thuringiensis in his right eye. After immediate irrigation with water the eye was treated with antibiotic oint ment. When the eye was still irritated three days later, treatment with a corticosteroid ointment was begun. Ten days after the accident an ulcer was noted in the lower part of the right cornea (Fig. 1) and the patient was referred to us. At this time the ulcer was cultured and treated with 0.5-ml subconjunctival in jections containing 20 mg of gentamicin and 25 mg of cefazolin sodium. Gentami cin ointment and 1% atropine eyedrops were also administered three times a day.
Fig. 1 (Samples and Buettner). Slit lamp photo graph of corneal ulcer near the inferior corneoscleral limbus.
259
Three days later, a bacillus resembling B. thuringiensis (Fig. 2) was identified in the cultures from the corneal ulcer. The ba cillus was susceptible to gentamicin at a concentration of 1 μg/ml. After two weeks of topical treatment with gentami cin the ulcer had healed. Dr. Ruth E. Gordon, of the American Type Culture Collection, Rockville, Maryland, and Dr. Oleg Lysenko, of the Institute of Entomology, Prague, Czech oslovakia, identified the recovered orga nism as B. thuringiensis.w Both the cul tures of the organism recovered from the patient and the cultures of the organism contained in Dipel showed strains of typi cal gram-positive rods producing ellip soidal subterminal spores under aerobic
Fig. 2 (Samples and Buettner). Bacillus thuringiensis recovered from the corneal ulcer. Characteristic ellipsoidal subterminal spores are present within (arrow) and outside the organism (Gram stain, X 1,600).
260
AMERICAN JOURNAL OF OPHTHALMOLOGY
conditions (Fig. 2), contained parasporal inclusions, and had identical biochemical properties. Both stock strains from Dipel and strains from the ulcer of our patient demonstrated similar pathogenicity for the Mediterranean flour moth, the great er wax moth, and the Southern house mosquito. Bacillus thuringiensis has been report ed to be a mammalian pathogen in only one case in which it was identified as the causal agent in a fatal case of bovine mastitis. 2 We believe that our patient's corneal ulcer is the first reported occur rence of an infectious process in humans caused by B. thuringiensis. Biologic in secticides, generally considered to be safe to humans, apparently can present a health hazard. Caution should be exer cised when working with active biologic insecticides, and using some form of ocu lar protection when handling them seems to be warranted. J O H N R. SAMPLES, H E L M U T BUETTNER,
Rochester,
FEBRUARY, 1983
jection 1 or intravitreous gas tamponade 2 are used. However, the safety of intravit reous silicone oil has yet to be proven and intravitreous gas must be injected while the patient is in the prone position. Other techniques using nylon sutures for retinal flap transvitreoretinal fixation have been described 3,4 but are not widely accepted because they are hazardous. To alleviate some of these difficulties, we developed a special tack for fixing an inverted retinal flap on the choroid. The technique is fairly easy to use and is well tolerated by the eye. The retinal tack is made of polyacetal, 0.8mm
M.D. M.D.
Minnesota
1.5 mm
REFERENCES 1. Smith, N. R., Gordon, R. E., and Clark, F. E.: Aerobic, Spore Forming Bacteria. U.S. Department of Agriculture, Monograph No. 16, 1952. 2. Gordon, R. E.: Some taxonomic observations on the genus Bacillus. In Briggs, J. D. (ed.): Biologi cal Regulation of Vectors. The Saprophytic and Aero bic Bacteria and Fungi. U.S. Department of Health, Education, and Welfare, Publication No. NIH 771180, 1977, pp. 67-82. 3. Lysenko, O. : Some thoughts to the taxonomy of Bacillus thuringiensis. Entomophaga Mem. Hors Serie 2:239, 1962. 4. Gordon, R. E., Haynes, W. C , and Pang, H.-N.: The Genus Bacillus. U.S. Department of Agriculture, Handbook No. 427, 1973.
A Plastic Tack for the Treatment of Retinal D e t a c h m e n t With Giant Tear Treating a retinal detachment caused by a giant tear with an inverted retinal flap is difficult unless such special tech niques as intravitreous silicone oil in
3.0mm
1.5mm
0.8mm
0.8mm
Fig. 1 (Ando and Kondo). Schematic drawing of the retinal tack. This plastic tack is about 3 mm long and 0.8 mm in diameter. A pair of grooves in the posterior half allows the tack to be grasped easily. A small barb on the tip prevents it from coming out of the sclera.
AMERICAN JOURNAL OF OPHTHALMOLOGY
the sutures to be relaxed individually, the eye to be massaged at the slit lamp, and a bleb to appear. Because there is no inci sion in the conjunctiva, there is no risk of leakage or infection through the conjunc tiva. Similarly, patients with postcataract astigmatism can be seated at the laser and the sutures lysed with the four-mirror lens, avoiding the minimal bleeding or antibiotic treatment. I do not know whether treating the sutures at the corneoscleral limbus or more posteriorly at the knot would affect the degree of reduced astigmatism quali tatively. A conjunctival perforation might possibly occur in an area that was already thinned. Nevertheless, I have found no complications in more than 20 such treat ments. MARC F. LIEBERMAN,
Redwood City,
M.D.
California
An Open Letter to Physicians With Physical Impairments For the past two years, the St. PaulRamsey Medical Center has been in volved in compiling a resource directory for physicians with physical impairments. The purpose is to list physicians with various physical disabilities who are will ing to provide information and referral services to physicians who incur similar disabilities and need specific information. Existing rehabilitation programs are sim ply not equipped to deal with the situa tion and "Impaired Physician" services within the medical profession are direct ed exclusively to those physicians with various drug dependencies. The biggest problem we have encoun tered is poor participation. About 4% of all physicians are not in active practice because of physically disabling condi tions; of these, about 25% have the poten tial to practice medicine again. In real numbers this constitutes 1% of the li
FEBRUARY, 1983
censed physicians in this country or 4,500 physicians. Our goal is to identify these physicians and to encourage their participation. To date we have placed ad vertisements in over 100 major medical journals but fewer than 200 physicians have responded. In retrospect, it ap pears this was the result of using inap propriate terminology in the advertise ments. Physical disability does not imply inability. Our use of the term "handi capped physician" was inappropriate be cause most physically disabled physicians are not handicapped in their practice of medicine. We apologize for the inappro priate terminology and again ask that all physicians, active or inactive, with any type of physical disability write to Frank C. Zondlo, M . D . , St. Paul-Ramsey Hos pital Medical and Education Research Foundation, 640 Jackson St., St. Paul, MN 55101. The directory will be com pleted in six to eight months and at that time it will be sent to only those physi cians who are listed therein. Upon re ceipt of your initial response, information forms will be mailed. All correspondence is confidential. We encourage all physicians with a physical disability, no matter how small, to respond. Information from a doctor with even a minor disability may be of value to another doctor with multiple disabilities. The cornerstone of this proj ect is your participation. FRANK C. ZONDLO,
Saint Paul,
M.D.
Minnesota
Corneal Ulcer Caused by a Biologic Insecticide (Bacillus thuringiensis) Environmental concerns are prompt ing an increased interest in the use of biologic insecticides in agriculture. We observed a corneal ulcer following the exposure of an eye to Dipel, a biologic insecticide containing Bacillus thurin giensis as the active ingredient. This in-
VOL. 95, NO. 2
CORRESPONDENCE
secticide is used to control the larvae of certain lepidopterous insects. A previously healthy 18-year-old farm er accidentally splashed a suspension con taining B. thuringiensis in his right eye. After immediate irrigation with water the eye was treated with antibiotic oint ment. When the eye was still irritated three days later, treatment with a corticosteroid ointment was begun. Ten days after the accident an ulcer was noted in the lower part of the right cornea (Fig. 1) and the patient was referred to us. At this time the ulcer was cultured and treated with 0.5-ml subconjunctival in jections containing 20 mg of gentamicin and 25 mg of cefazolin sodium. Gentami cin ointment and 1% atropine eyedrops were also administered three times a day.
Fig. 1 (Samples and Buettner). Slit lamp photo graph of corneal ulcer near the inferior corneoscleral limbus.
259
Three days later, a bacillus resembling B. thuringiensis (Fig. 2) was identified in the cultures from the corneal ulcer. The ba cillus was susceptible to gentamicin at a concentration of 1 μg/ml. After two weeks of topical treatment with gentami cin the ulcer had healed. Dr. Ruth E. Gordon, of the American Type Culture Collection, Rockville, Maryland, and Dr. Oleg Lysenko, of the Institute of Entomology, Prague, Czech oslovakia, identified the recovered orga nism as B. thuringiensis.w Both the cul tures of the organism recovered from the patient and the cultures of the organism contained in Dipel showed strains of typi cal gram-positive rods producing ellip soidal subterminal spores under aerobic
Fig. 2 (Samples and Buettner). Bacillus thuringiensis recovered from the corneal ulcer. Characteristic ellipsoidal subterminal spores are present within (arrow) and outside the organism (Gram stain, X 1,600).
260
AMERICAN JOURNAL OF OPHTHALMOLOGY
conditions (Fig. 2), contained parasporal inclusions, and had identical biochemical properties. Both stock strains from Dipel and strains from the ulcer of our patient demonstrated similar pathogenicity for the Mediterranean flour moth, the great er wax moth, and the Southern house mosquito. Bacillus thuringiensis has been report ed to be a mammalian pathogen in only one case in which it was identified as the causal agent in a fatal case of bovine mastitis. 2 We believe that our patient's corneal ulcer is the first reported occur rence of an infectious process in humans caused by B. thuringiensis. Biologic in secticides, generally considered to be safe to humans, apparently can present a health hazard. Caution should be exer cised when working with active biologic insecticides, and using some form of ocu lar protection when handling them seems to be warranted. J O H N R. SAMPLES, H E L M U T BUETTNER,
Rochester,
FEBRUARY, 1983
jection 1 or intravitreous gas tamponade 2 are used. However, the safety of intravit reous silicone oil has yet to be proven and intravitreous gas must be injected while the patient is in the prone position. Other techniques using nylon sutures for retinal flap transvitreoretinal fixation have been described 3,4 but are not widely accepted because they are hazardous. To alleviate some of these difficulties, we developed a special tack for fixing an inverted retinal flap on the choroid. The technique is fairly easy to use and is well tolerated by the eye. The retinal tack is made of polyacetal, 0.8mm
M.D. M.D.
Minnesota
1.5 mm
REFERENCES 1. Smith, N. R., Gordon, R. E., and Clark, F. E.: Aerobic, Spore Forming Bacteria. U.S. Department of Agriculture, Monograph No. 16, 1952. 2. Gordon, R. E.: Some taxonomic observations on the genus Bacillus. In Briggs, J. D. (ed.): Biologi cal Regulation of Vectors. The Saprophytic and Aero bic Bacteria and Fungi. U.S. Department of Health, Education, and Welfare, Publication No. NIH 771180, 1977, pp. 67-82. 3. Lysenko, O. : Some thoughts to the taxonomy of Bacillus thuringiensis. Entomophaga Mem. Hors Serie 2:239, 1962. 4. Gordon, R. E., Haynes, W. C , and Pang, H.-N.: The Genus Bacillus. U.S. Department of Agriculture, Handbook No. 427, 1973.
A Plastic Tack for the Treatment of Retinal D e t a c h m e n t With Giant Tear Treating a retinal detachment caused by a giant tear with an inverted retinal flap is difficult unless such special tech niques as intravitreous silicone oil in
3.0mm
1.5mm
0.8mm
0.8mm
Fig. 1 (Ando and Kondo). Schematic drawing of the retinal tack. This plastic tack is about 3 mm long and 0.8 mm in diameter. A pair of grooves in the posterior half allows the tack to be grasped easily. A small barb on the tip prevents it from coming out of the sclera.