Fluctuating Vision

"The unsutured wounds in the avascular cornea heal slowly, requiring at least 4 to 5 years to completely eject the epithelial plug  and to remodel the stroma adjacent to the incision scar.  Persistent diurnal fluctuation of vision occurs up to 3 years after surgery, and some patients notice it as long as 5 years after surgery."

Statement on Radial Keratotomy, George O Waring III - 1988

Corneal topography and fluctuating visual acuity after radial keratotomy

A high-resolution photokeratoscope using computer graphics to model corneal topography was used on patients who had undergone radial keratotomy. After radial keratotomy, central optical zones are created that can be characterized as round, oval or band-like, or dumbbell-shaped or split. The dumbbell form of optical zone was associated with larger amounts of refractive and keratometric astigmatism than the round or band-like zones. The authors correlated the shape of the optical zone with the presence or absence of diurnal variation (fluctuation) in visual acuity. Of the 26 eyes studied, 11 experienced fluctuation and 15 did not. Of those 11 eyes with fluctuating visual acuity, 10 (91%) had dumbbell-shaped or split optical zones and 1 (9%) had a round optical zone. Of the 15 eyes without fluctuation, 12 (80%) had round optical zones and 3 (20%) had band-like zones. The presence of a split or dumbbell-shaped optical zone after radial keratotomy indicates that the patient is likely to experience diurnal fluctuation of visual acuity.