Abstract
Abstract: :
Purpose:To characterize the extent, duration and location of corneal sensitivity loss after LASIK. Methods:This was a prospective study in which 17 patients (34 eyes) were enrolled. Preoperative corneal sensation measurements were performed in six separate locations on each cornea starting in the center or the cornea. This measurement was done using the Cochet-Bonnet esthesiometer at the slit lamp. Six separate measurements were taken at day zero, week 1, 1 month, 3 months, and six months. The values were then tabulated and the percentage of sensitivity was calculated and graphed. Exclusion criteria included: history of prior eye surgery, eye medication use, history of prior herpes infection, contact lens use, and presence of diabetes mellitus. Results:The results indicated that the corneal sensation is markedly depressed immediately after the LASIK procedure throughout the cornea. The central recovery of the cornea is slow (54% recovery to normal pre-operative values at 6 months). Hinge sensitivity is much less affected (85% recovery at 6 months). Intermediate data points showed good recovery (73% at 6 months). This documents that central sensation does not return to near normal after LASIK during the first six months. Conclusion: LASIK is a procedure which adversely affects the corneal sensation. Our study documents a decrease in central sensation at six months, however the peripheral areas are recovering sensation nicely. Corneas are more susceptible to delayed epithelial healing, decreased tear flow, and corneal ulceration as a reslult of decreased corneal sensation. This study suggests the need for agressive treatment of dry eye before and after LASIK as the normal protective mechanisms of the eye are altered.
Keywords: 442 innervation: sensation • 376 cornea: tears/tear film/dry eye • 548 refractive surgery: LASIK