Purchase this article with an account.
T Tervo, MH Vesaluoma, JA O Moilanen; Long-term corneal subbasal nerve recovery after PRK and LASIK . Invest. Ophthalmol. Vis. Sci. 2002;43(13):2096.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: To characterize and compare regeneration of corneal subbasal nerves after PRK and LASIK. Methods: The patients were examined clinically and their corneas by in vivo confocal microscopy two years after LASIK (14 eyes of 14 patients; mean age 35.5, 9 women, 5 men, mean correction -9.9 D, range -6.6 - -13.9 D) and five years after PRK (14 eyes of 14 patients; mean age 40.1, 5 women, 9 men, mean correction -4.6 D, range -2.5 - -8.0 D). Nine healthy unoperated individuals served as controls (mean age 39.0, 4 women, 5 men). Results: The number of regenerated subbasal nerve fiber bundles was 3.6 +/- 2.1 (range 1-8) after LASIK, 4.2 +/- 2.1 (range 1-7) after PRK, and 4.9 +/- 1.1 (range 3-6) in the control group; insignificantly lower subbasal nerve density was observed after LASIK (p=0.055, Mann-Whitney) and PRK (p=0.562) compared to controls. In the LASIK group the nerves showed branching and interconnections almost comparable with the control group. In the PRK group the subbasal nerves appeared at the same level with the most anterior keratocytes and showed less branching. The mean epithelial thickness (µm) was 61.9 +/- 5.1, 51.5 +/- 4.0, and 50.7 +/- 3.5 in LASIK, PRK, and control group, respectively. The mean corneal thickness (µm) was 471.4 +/- 36.0, 494.1 +/- 40.6, and 526.8 +/- 24.7, respectively. Two patients in the LASIK group and one patient in the PRK group had BCVA of 20/25, the others showed 20/20 or better. Four PRK corneas showed a trace of haze, the rest were clinically devoid of haze. There was no haze in the LASIK group but 13/14 flaps presented with microfolds. Conclusion: The subbasal nerve morphology appeared mildly altered in the PRK group possibly due to altered/absent Bowman´s layer. The number of nerve fiber bundles showed no differences after PRK or LASIK. Faint haze sometimes complicates PRK, whereas microfolds are found in most LASIK corneas.
This PDF is available to Subscribers Only