LASIK is a refractive surgical procedure that reshapes the cornea to focus light on to the retina. It is performed by creating a flap in the epithelium (outer) layer of the eye with either a lathe or laser, called Intralase. The underlying tissue is then reshaped with a laser to a predetermined arrangement in order to eliminate refractive conditions. It is designed to treat nearsightedness (Myopia), farsightedness ( Hyperopia) and astigmatism. It does not, however eliminate the need for reading glasses in those over forty. The surgery can only correct one distance at a time.
The procedure is a very effective, however there is no guarantee that there will not be any residual refractive power, or that the person my not regress requiring glasses in the future. While there are several possible deleterious side affects of the surgery, one of the most serious and potentially vision threatening is called DLK which stands for Diffuse Lamellar Keratitis. It is also know as Sand of the Sahara since it often appears like sand dunes in the Sahara desert.
This condition arises when inflammatory cells migrate into, and under the corneal flap. Depending on the location of the cells, the vision may be normal or severely reduced. Glare is often present, and in some cases the individual will present with ocular discomfort. Traditional therapy has been to prescribe strong steroid eye drops such as Pred-Forte every hour, and closely follow the patient for a reduction in these inflammatory cells. This may take days or even weeks to completely resolve. In some cases, the cells remain under the flap indefinitely.
In cases where the flap was created by a lathe, there is a gradual slope from the point of contact between the lathe and the corneal bed. This slope permitted this cell migration under the flap. It was a fairly constant degree of DLK in cases that were predisposed to acquiring this condition. Intralase, by comparison results in a step off the peripheral cornea to the corneal bed. One would think that this sharp step would reduce the number of cases and severity of DLK as compared to those with the lathe. Interestingly, DLK is more prevalent in patients who have had Intralase performed, as compared to the lathe. In either situation the cells present a problem that must be addressed.
According to Dr. Theirry Hufnagel of the Stahl Eye Center located in New York, the best treatment is to go back into surgery and lift the flap. Once the flap is once again separated from the corneal bed, the underlying area is washed and bathed with saline physically removing all the cells. This is a simple procedure, but the most effective way to completely, quickly and safely eliminate all the inflammatory cells. It also prevents any secondary complication that might arise from use of the steroid eye drops. In Dr Hufnagle’s opinion, it is the best way to remediate the DLK .
This procedure is not performed by most refractive surgeons, and only those very skilled and experienced employ it. As always, one should only have surgery with doctors who know all the techniques to deal with post surgical complications.
Dr. Jay B Stockman is a contributing editor for
VisionUpdate.net, and a practicing doctor for New York Vision Associates, http://newyorkvisionassociates.com,
