VOL. 97, NO. 4
527
LETTERS TO THE JOURNAL
ler technique should make this possible in a greater number of cases.
2. Barr, C. C., and Mitchell, D.: Penetrating ocular injury caused by nylon cord fragment from electric lawn trimmer. Ophthalmic Surg. 14:741, 1983.
OPHTHALMIC HAZARDS
KERATOCONUS AND EYE RUBBING
RICHARD A. EIFERMAN, M.D. Department of Ophthalmology, University of Louisville. Inquiries to Richard A Eiferman, M. D. , Department of Ophthalmology, University of Louisville School of Medicine, 301 E. Muhammad Ali Blvd., Louisville, KY 40202.
The ophthalmic hazards of string lawn trimmers has been described by Spaeth.! Another recent report describes a penetrating injury caused by a fragment of nylon cord expelled from an electric rotary weed trimmer. 2 I have seen two severe cases of ocular infection caused by these devices. In the first, the patient had multiple linear penetrating injuries, which were infected with Helminthosporium sp., the eye developed endophthalmitis and was lost. In the second case, the patient developed corneal ulceration in a laceration because of Nocardia asteroides. Both patients were initially treated with aminoglyocide antibiotics without success; the correct diagnosis was made in both cases after appropriate cultures and scrapings were obtained. Because of the unusual nature of these infections, ophthalmologists should obtain bacteriologic studies on all patients with this type of injury. Additionally, safety glasses should be mandatory whenever these lawn tools are used. REFERENCES 1. Spaeth, G. L.: Weed trimmer. A new ocular hazard. Ophthalmic Surg. 14:727, 1983.
J.
TERRENCE COYLE,
M.D.
Eye Clinic of Bellevue. Inquiries to Eye Clinic of Bellevue, Ltd. , P.S. 1300 116th Ave. N.E, Bellevue, WA 98004.
Can external pressure against an eye cause or aggravate keratoconus?' Two observations suggest that it may. Firstly, 30% to 50% of patients with keratoconus have allergtes-" and patients with allergies tend to rub their eyes. Secondly, atypical keratoconus has been induced by prolonged wear of hard contact lenses.' The following case supported the suggestion that keratoconus may be mechanically induced in some instances. The patient had had an atrialventricular septal defect at birth and had undergone open heart surgery at the age of 2 years. The operation was successful, but a conduction defect developed, which resulting in many daily episodes of paroxysmal atrial tachycardia (Wolf-ParkinsonWhite syndrome). When he was 5 years old, the patient discovered that the tachycardia could be stopped by vigorously massaging his eye. Because he was righthanded it was more convenient for him to massage his left eye. When he was 7 years old, ophthalmologic findings were normal and his visual acuity was 20/20 in both eyes. He was examined at the age of 11 years because of blurred vision in his left eye. His visual acuity was then R. E.: 20/20 and L. E.: 20/200. He reported that he