Résumé : | SIGNIFICANCE: The development of confocal microscopy allows one to obtain high-resolution corneal images like
its optical density. Some studies have evaluated the optical density with Scheimpflug cameras in the early
post-operative period after photorefractive keratectomy, but no studies have evaluated the long-term evolution of
optical density after surface ablation when mitomycin C is used.
PURPOSE: This work aimed to study the changes in corneal optical density measured with confocal microscopy in
eyes treated with laser-assisted subepithelial keratectomy (LASEK) and intraoperative mitomycin C (MMC) to
correct myopia.
METHODS: A study of 24 consecutive myopic eyes that underwent LASEK with 0.02% MMC and a control group of
24 healthy nontreated eyes was performed. Optical density was measured using the images by the confocal microscopy
of the Heidelberg Retina Tomograph II with the Rostock Cornea Module. An analysis of confocal microscopy images was
performed using the ImageJ software to obtain the optical density, in gray-scale units (GSU). The optical density of the
stromal bed was evaluated 3 months, 15 months, and 3 years after surgery and was compared with the optical density at
the equivalent depth of the stroma in controls.
RESULTS: The mean values of optical density for the LASEK group were 81.7 ± 9.7, 78.6 ± 11.7, and
73.6 ± 18.7 GSU at 3 months, 15 months, and 3 years, respectively, and it was 61.8 ± 8.2 GSU for the control
group. A statistically higher optical density 3 and 15 months after LASEK with MMC was found compared with controls (P < .001). No significant difference was found in optical density at 3 years post-operatively.
CONCLUSIONS: Our study suggests that, after LASEK with MMC, the anterior corneal stroma has a higher optical
density at 3 and 15 months post-operatively, which gradually returns to normal values 3 years after surgery. |