Abstract
Purpose :
To compare the morphological cellular changes found in confocal microscopy in eyes that underwent SMILE surgery, before the procedure and 7 postoperative days.
Methods :
Patients of 21 years and older who wished refractive surgery were included. All patients who freely volunteered to be part of this program, signed a consent before to start the study. All eye surgeries were performed with VisuMax by a single surgeon.
The HRT3 Rostock Cornea Module (RCM) equipment was used to get confocal microscopy images. These Images were taken preoperatively and 7 days after surgery. The basal epithelium, subepithelial nerve plexus, anterior stroma, posterior stroma, and corneal endothelium were captured. These images were reviewed with ImageJ program and make it possible to quantify the basal epithelial cells, the subepithelial nerve plexuses, the keratocytes and the endothelial cells.
Results :
40 eyes from 20 patients were performed. Preoperative visual acuity was 0.059 on a decimal scale, while postoperatively it was 0.96. The cell density of the pre-surgical basal epithelium was 5,820 cells/mm2, and seven days after of the surgery was 5,090 cells/mm2 (p<0.0001) without any evident finding of morphological changes. The number of nerve branches observed in the confocal microscope photograph in the preoperative period was 8.8, while in the postoperative period it was 2.2 (p<0.0001). Similarly, the diameter of the nerves was 3.084 mm to 1.132 mm (p<0.0001). Regarding the keratocytes, it showed the cap level (120 mm), the nucleus of the keratocytes showed greater hyperreflectivity, finding 122.5 in the preoperative and 189.2 in the postoperative on the gray scale (p<0.0001). In addition, a lower keratocyte density was found at this level compared to the preoperative one, 247.1 cell/mm2 vs 136.1 cell/mm2 (p<0.0001).
Conclusions :
There are cellular changes that it cannot always seen by routine slit lamp examination. Confocal microscopy allows us to observe microscopic level the behavior of cells in real time. The HRT3 allowed us to observe these cellular changes clearly with a good resolution, while the ImageJ program is a tool to allows us to analyze different cells that make up the cornea. Despite finding the previously described changes at the cellular level, they have no impact on the final visual result of the patient. However, it helps us to have a better understand the behavior of cell dynamics at the corneal level.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.