G. Sutton et al., EXCIMER RETREATMENT FOR SCARRING AND REGRESSION AFTER PHOTOREFRACTIVEKERATECTOMY FOR MYOPIA, British journal of ophthalmology, 79(8), 1995, pp. 756-759
Aims/Background-Scarring associated with regression of refractive effe
ct can occur after photorefractive keratectomy (PRK) for myopia. The e
xperience of treating these complications is reported. Methods-Eightee
n of 285 eyes (6 . 3%) were retreated with the excimer laser. Age, sex
, preoperative primary treatment keratometry, pre-primary treatment, p
re-retreatment and post-retreatment spherical equivalents, best correc
ted and uncorrected visual acuities were recorded and analysed. Result
s-At 6 months post-retreatment, the mean spherical equivalent was -2 .
07 dioptres (D) (SD 4 . 60 D). This spherical equivalent persisted in
eyes followed for 12 months (-2 . 85 D, SD 4 . 09 D). Nine of 18 eyes
(50%) had uncorrected visual acuity of 6/12 (20/40) or better. If ret
reatment was undertaken within 6 . 5 months of the initial PRK, then s
carring was likely to recur (p=0 . 035). Nine of 10 eyes (90%) which h
ad a retreatment spherical equivalent less than two thirds of their pr
imary treatment spherical equivalent were within plus or minus 1 . 25
D from emmetropia after retreatment. Four of 11 eyes (36%) followed fo
r 12 months after retreatment rescarred with further regression. Concl
usion-The data showed that eyes with scarring and regression of myopia
should not be treated with PRK within 6 months of the initial procedu
re. Eyes with the highest percentage of regression towards their initi
al myopia tend to have a poor response to retreatment.