Corneal Topographic Change After PRK for Myopia: Follow-up Study Longer Than 15 Years
Narrative Responses:
Purpose
To investigate the long-term corneal topographic changes following photorefractive keratectomy (PRK) for the treatment of low to high myopia eyes.
Methods
This retrospective study involved 13 eyes of 8 patients that underwent PRK for myopia. All patients completed a 15-year or more follow-up, and the mean preoperative spherical equivalent was -5.61±2.36D. We evaluated the absolute power change in a differential map of the corneal topography. The yearly change of the central 4mm-diameter mean corneal power between 6-months and 1-year postoperative, between 1 and 5-years postoperative, and between 5 and 15-years or more postoperative were compared.
Results
The yearly change of central corneal power between 6-months and 1-year postoperative (0.61±0.30 D/year) was statistically significant greater than that of any later-year change. The yearly change of central corneal power between 1 and 5-years postoperative (0.21±0.10D/year) was statistically significantly greater than that of between 5 and 15-years postoperative (0.06±0.03 D/year). No statistically significant change occurred after 5-years postoperative.
Conclusion
The findings of this study show that in eyes that have undergone PRK for the treatment of myopia, the shape of the cornea does not change after 5-years postoperative.