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CHAPTER VI EYE EXAMINATI0N STANDARDS AND TREATMENT H. Christian Zweng* and Heinrich Rose* EYE EXAMINATI0N STANDARDS The purpose of this chapter is to set forth the outline of an initial eye examination for one who is to be placed in a laser environment and subsequent eye examinations at regular intervals thereafter. It is im- portant that the following eye examination be carried out to establish a baseline on each eye from which all subsequent changes can be measured so that any possible laser injury can be well documented, both for the protection of the individual worker and for the firm or agency employing him. As with the introduction of any new physical modality, it is in- evitable that when laser light is widely used, problems will arise either because (a) damage is claimed which has not occurred or (b) damage is oc- curring which is not suspected by the worker in its early stages and which must be arrested as soon as possible and guarded against for the future. Consequently, the following eye examinations incorporate standards or pro- cedures which measure the functioning of the human eye and can be carried out in a reasonably well equipped ophthaImological center. Three standards attempt to obtain objective information as far as possible and record such information so that even if the same examiner does not carry out subsequent visits, the information will still be set out in a form which makes it possible to ascertain whether or not a change in the patient's ocular status has occurred. Since all the possible effects of laser energy on ocular tissue are certainly not known at this time, especially cumulative effects, the main- tenance of these records on each individual is of the greatest importance. Copies of these records should follow the worker, should he change places of employment. This is true even for copies of fundus photographs which may be made. The initial examination upon placement of a worker in a laser environ- ment should be as follows: 1. 0cular history: The patient's past eye history and family eye history are reviewed. Any current complaints which he now has about his eyes are checked. The patient's general health status should be inquired about with a special emphasis upon diseases (e.g., diabetes, hypertension) which can give ocular problems. 2. Visual acuity: This should be tested and recorded in Snellen figures for distance with an without lenses down to 20/15. The visual acuity at near should be tested at 35 cm and re- corded in Jaeger test figures with and without lenses, if any. 3. Determination of patient's lens correction with a lensometer. *Department of 0phthalmology, Standord University School of Medicine and Palo Alto Clinic, Palo Alto, California 87
k. External ocular examination: This includes examination of brows, lids, lashes, conjunctiva, sclera, cornea, iris, and pupillary size, equality and regularity. 5. Color vision screening: This is done with the American 0ptical Company Ishihara color vision plates. 6. Amsler grid: The Amsler grid sheet is presented to each eye separately and any distortion of the grid is noted by the patient and drawn by him. . I 7. Visual fields: The peripheral visual field is charted with a 1 mm white target at 33 cm distance and a central visual field involving the fixation area is charted with a 1 mm red target at 1 meter. The pupils should then be dilated by the instillation of one (1) drop of 1% Mydriacyl in each eye. The remainder of the examination should be carried out with the eye under this medication. *8. Cycloplegic refraction: This is to measure the patient's total refractive error and the new visual acuity of the patient must be noted if the visual acuity is improved over the patient's old lenticular prescription or if he has no lenses at the time of the exami nation. 9. Examination of the ocular fundus with a direct ophthalmoscope. In the recording of this portion of the examination the points to be covered are: The presence or absence of opacities in the media, the sharpness of outline of the optic nerve, the color of the optic nerve, the size of the physiological cup, if present, the ratio of the size of the retinal veins to that of the retinal arteries, the presence or absence of a well defined macula and the presence or absence of a foveolar reflex, and any other retinal pathology that can be seen with a direct ophthalmoscope. Even small deviations from normal should be described and carefully localized. 10. Examination by slit lamp: The cornea, iris and lens are examined with this bio-microscope and carefully described. *11. Photograph of the posterior pole of the fundus. This includes the area of the macula and head of the optic nerve and is to be taken in color film. Positive color photograph should be mounted in the patient's chart. Also, all areas of the retina which show significant abnormalities should be photographed. *12. Examination of the retina with the slit lamp and the Goldman 3-mirrcr lens: This examination allows all of the retina in- cluding the periphery to be surveyed with binocularity, high magnification, and excellent illumination to give a very definite examination of the retina. *Editor's note: Some members of the Working Group consider the starred procedures less important and have suggested that they be made optional. 88
The dilation of the pupil is neutralized by the instillation of 1 drop of 2% Pilocarpine solution in each eye. This eye examination should be repeated down to intervening twelve months. If any ocular symptoms are present, or if the worker is in a position of special laser hazard, he is to come in immediately for examination and treatment by an ophthalmologist. The last eye examination should be done upon termination of work in a laser environment. TREATMENT OF ACCIDENTAL LASER DAMAGE 0F THE EYE At the present time with wavelengths available, the retina appears to be the ocular tissue most sensitive to injury from laser radiation. Since the macula is responsible for sharp central vision, it is this central portion of the retina which must be most zealously examined in cases of suspected laser injuries to the eye. If areas of the retina outside the macula are injured by laser irradiation, effect on vision will in most cases be negligible, but even small injuries to the macula will result in visual loss. Until further evidence is accumulated, laser burns of the macula will best be treated as thermal effects and treatment should be effected with anti-inflammatory agents. At this time, therefore, it is recommended that any patient re- ceiving macular injury from laser irradiation in the acute phase be treated with cortical steroids in maximal doses compatible with usual restrictions necessary in using these agents upon human beings. Treat- ment should be instituted promptly and since evidence of healing persists for several weeks in the form of increased oigmentation, treatment should be carried on for at least that length of time. For the first two weeks after injury, the patient should be examined and evaluated daily; for the next one month, weekly; and for the following six months, monthly.
Security Classification j DOCUMENT CONTROL DATA - R & D 1 (Security classification of title, body of abstract and indexing annotation niusf be entered when the overall report is cltissilied) ll ORIGIN A TING ACTIVITY (Corporate author) 2*. REPORT SECURITY CLASSIFICATION [National Academy of Sciences-National Research formed Forces-NRC Committee on Vision plOJ Constitution Ave., N. W., Washington, D. Counci 1 C. 20M8 None 26. GROUP 13 REPORT TITLE LASER EYE EFFECTS 4. DESCRIPTIVE NOTES (Type of report and inclusive dates) 3- AUTHOR(S) (First name, middle initial, last name) Harry G. Sperling 6 REPORT DATE March 15, 1968 7B. TOTAL NO. OF PAGES 92 76. NO. OF REFS 153 Sa. CONTRACT OR GRANT NO. Nonr 2300(05) b. PROJEC T NO. d. 9a. ORIGINATOR'S REPORT NUMBER(S) 96. OTHER REPORT NO(S) (Any other numbers that may be assigned thle report) 10. DISTRIBUTION STATEMENT DISTRIBUTI0N 0F THIS D0CUMENT IS UNLIMITED II. SUPPLEMENTARY NOTES 12. SPONSORING MILI TARY ACTIVITY Physiological Psychology Branch 0ffice of Naval Research 13. ABSTRACT Describes technical properties of and retinal damage produced by lasers. Recommends safety measures and protective devices. DD FORM (PAGE 1) 90 i NOV as S/N 0101-807-6801 Security Classification
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