RK and LASIK may cause loss of contrast sensitivity

September 17, 2004

Contrast sensitivity has been neglected as an important aspect of visual function and should be measured routinely, said William Jory, MD, at the European Society of Cataract and Refractive Surgeons meeting. Because of the nature of excimer laser treatment, which affects the central cornea, contrast sensitivity may be impaired in these patients.

Paris—Contrast sensitivity has been neglected as an important aspect of visual function and should be measured routinely, said William Jory, MD, at the European Society of Cataract and Refractive Surgeons meeting. Because of the nature of excimer laser treatment, which affects the central cornea, contrast sensitivity may be impaired in these patients.

Dr. Jory, of the London Centre for Refractive Surgery, conducted studies of both radial keratotomy (RK) and LASIK procedures to compare the loss of contrast sensitivity. He found that contrast sensitivity was impaired in 2.43% of cases after RK 2 years after the procedure and in 56% of cases after excimer laser treatment 2 to 7 years after treatment.

The contrast sensitivity loss in RK patients was invariably associated with central corneal irregular astigmatism, Dr. Jory noted. With excimer laser treatments, the loss of contrast sensitivity resulted from damaged corneal architecture in the central visual field and to the corneal stroma in the ablation bed. He urged surgeons to conduct contrast sensitivity testing before and after refractive surgery and heralds the routine use of phakic implants.