HYPEROPIC THERMAL KERATOPLASTY PROCEDURE IN A CIVILIAN AIR-TRAFFIC-CONTROLLER

Hyperopic thermal keratoplasty (HTK), also referred to as radial therm okeratoplasty, is one of several refractive surgery procedures in use to correct significant visual acuity problems. The current procedure w as developed in the former Soviet Union, and was first performed in th e U.S. in the early 1980's. The thermocoagulating unit used for the su rgery is still considered an experimental device by the Food and Drug Administration, and as such requires a device exemption permit from th at Agency for its use. The unit is used to coagulate corneal protein, which alters the shape of the cornea and hence its refractive power. N o well-controlled series of patients followed over time exists to conc lusively state the pros and cons of the procedure. Excimer laser surge ry has been recently used as a substitute for the thermocoagulator, bu t experience is also limited. Lasers, nevertheless, show great promise for use in this procedure. While HTK has been shown to correct hypero pia, significant sequelae have been documented with the procedure; the y have included unstable visual acuity, under- and overcorrection of a cuity, damage to the cornea, and scarring. These sequelae may present a problem for individuals involved in aviation, where issues of visual acuity are critical. It is important to identify such individuals and monitor their vision status carefully prior to return to safety relat ed duties.