Injuries to the eye associated with anesthesia care fit into two categories. They are much easier to prevent than to treat. The first category is that of mechanical injury. Mechanical injuries are caused by physical trauma to the eye, which occurs on induction, on securing apparatus to the patient, or from inappropriate taping of the eye during general anesthesia. The mechanism of prevention of mechanical injury is simply taking care to avoid the injury and appropriate padding when the eyes are not accessible. Not commonly recognized, but a frequent cause of ophthalmic injury is the inappropriate use of disposable pulse oximeter probes. A patient, upon awakening, will often rub or scratch his/her eye (particularly if protective ointment has been used in the eyes during the case). If the disposable probe has been placed upon the dominant index finger then, in the PACU, the patient may easily injure his or her eye with this probe. This is easy to prevent by simply not putting disposable pulse oximeter probes on either index finger. [A desirable alternative is to use the tip of the fifth finger, which is usually thinner and, thus, easier for the probe light to penetrate and is also a less intrusive location on awake patients.]
A subcategory of mechanical injury is associated with the use of lasers. These injuries are prevented by elaborate mechanical protection of the eyes involving taping them shut, placing wet sponges over the eye, taping the sponges on the face, and finally, taping metal shields over the eyes. Some practitioners also place laser goggles on the patient’s face to prevent any possibility of the laser beam actually getting to the cornea.
The other mechanism of injury to the eye is that of desiccation. In general, if the normal lacrimal mechanism is kept functioning and the eye is kept closed, there is not any risk of a desiccating injury to the cornea. This drying can be satisfactorily prevented with careful attention to keeping the normal eye shut and allowing normal lacrimation to occur and thus avoiding the risk of lubricant. Many practitioners will routinely use an ophthalmic lubricant ointment on the eye and then tape the eye shut. This may actually indirectly cause a corneal abrasion. Commonly, patients will partially awaken and not see clearly. In a completely normal, reflexive, manner, they will then scratch, or rub their eyes in an attempt to improve their vision. This occasionally results in corneal abrasion. Some patients have very long eyelashes, so when the eyes are taped closed it is common for the tape to pull out many of the eyelashes when it is removed at the end of the case. While this may not seem to be a significant injury, it can be very distressing, especially to select self-conscious patients. Depending on the surgical procedure, it is often possible to tape the eyes at the corner and avoid the lashes, or, in such a way that the upper lid (or upper tarsal plate) is stiffened, with the result that the eyes “actively close” while the patient is anesthetized. This is done by sliding the redundant skin of the upper lid downward, removing all wrinkles from the upper lid, then placing a piece of half-inch tape parallel to the lashes about a quarter centimeter above the lashes. When this is done properly there is a small amount of mounded up tissue between the tape and lashes. This bunched up tissue, plus the tape, appears to provide the mechanism for the “active” closing of the upper lid. Obviously, this method is only reasonable when the patient’s head is under total control of the anesthesiologist and the position does not put the eyes at risk.
Dr. Yost is Assistant Professor of Anesthesiology, University of Mississippi School of Medicine and Medical Center, Jackson, MS.
Method of noninvasive eye taping to minimize corneal drying during general anesthesia. Left: “Passively” closed eye of routine patient under general anesthesia. Right: Application of short strip of half-inch tape above small folds of “bunched up” skin of upper eyelid which holds the eye “actively” closed and prevents drying out of the cornea, thus minimizing this potential cause of corneal abrasion.