A LASIK Complication-Oil Gland Secretions
In the hands of a well trained, experienced, and seasoned refractive surgeon, LASIK is a very good procedure with excellent results. IntraLASIK which is the same procedure that employs a laser to create the flap is even. An often over looked complication of the procedure is the affect that the oil glands have on the final results.
Meibomian(oil) glands, or Tarsal glands as they are sometimes known are sebaceous glands located in the tarsal plate of the eye lids. These are found near the rim of the lids, and are responsible for the production of sebum which is an oily material. This very important component of the tear film prevents evaporation of the tears by maintaining tear /cornea contact evenly over the entire surface. Since it thickens the tears, it also functions to prevent the tears from spilling over the eye lids. The final affect of the sebum is creating a tight lid-lid seal keeping the eyes moist at night.
The upper eye lid has approximately 50 glands and the lower 25. These very important organs were first named in the late 1600s by the German physician Heinrich Meibom. So how and why do these glands affect LASIK?
The Meibomian glands produce the sebum 24 hours per day, and will secrete it into the eye upon every blink. Squeezing the eye lids tight will force out more sebum making the eyes oilier.
The cornea is completely transparent, and must remain that way in order to see clearly.
The most important point that must always be maintained during LASIK is to make sure that when the flap is placed back in position it goes back exactly as it was before, and that the area under it is clear of any debris. Unfortunately, if the patient squeezes his/her eyes during the surgery the Meibomian glands will secrete more sebum into the eye and coat the exposed surface. If this occurs while the flap is lifted up, the sebum will coat the inside area of the cornea and cause distorted vision. When the flap is put back into position, it traps this excessive sebum under the flap. While there is no health risk to this trapped sebum, is does leave an oily residue in the middle of the cornea.
The final result is an imperfect cornea. When examining these post operative patients one can see oily, hazy areas. The affect on one’s vision will vary from mild to severe haziness, photophobia (glare and light sensitivity), and decreased vision. If the oil slick is out of the visual axis then glare will be the only visual side affect. If it is in the line of sight then most patients complain of decreased vision. In severe cases, the surgeon must go back into surgery, lift the flap, and clean out the area.
The best way to prevent this surgical complication is to listen to the doctor during surgery and not force a blink or squirm around during the procedure. That is often much more easily said then done.
