Evolution of corneal epithelial remodeling after myopic laser in situ keratomileusis surgery measured by anterior segment optical coherence tomography combined with Placido disk.

PURPOSE: To investigate patterns of short- and long-term variations in corneal epithelial thickness (CET) after myopic laser in situ keratomileusis (LASIK) using anterior segment optical coherence tomography (AS-OCT) combined with Placido disk-based topography. METHODS: In this retrospective study, 36 subjects (72 eyes) who underwent LASIK myopic surgery and 53 healthy subjects (106 eyes) who served as controls were enrolled. AS-OCT (MS-39) was performed in all patients before, 1 day, 1 month, and 6 months after surgery. Statistical analysis was performed to analyze CET changes over time after LASIK and to detect patterns of definitive CET remodeling compared to healthy subjects. Multivariate analysis was performed to look for possible predictors of final CET. RESULTS: There was no statistically significant difference between groups in terms of demographic and anterior segment parameters (all P > 0.05). After LASIK, all sectors and rings got thicker over time (1.62-8.32 µm; P < 0.01). Except for the central sector, all areas achieved the thickest CET value one day after surgery with a progressive epithelial thinning between 1 and 6 months of follow-up. Changes on CET occurred independently of the grade of myopia before LASIK or final refraction (P > 0.05). None of the clinical variables studied, including diopters corrected, were found to be correlated with final CET (P > 0.05). CONCLUSION: Independent of anterior segment parameters and diopters corrected, CET becomes thicker after LASIK surgery. Central and inner ring sectors thicken more than those more peripheral. CET remodeling after myopic LASIK should be taken into consideration when planning refractive surgery.

FACE MASK CONTAMINATION DURING COVID-19 PANDEMIA. A STUDY ON PATIENTS RECEIVING INTRAVITREAL INJECTIONS.

PURPOSE: To investigate the bacterial growth in the surgical face masks used by patients who received intravitreal injections and study the effect of povidone-iodine on the periocular area (PA) of masks. METHODS: Forty patients who attended for intravitreal injections were divided in those with less (<4 hours) and more (>4 hours) than 4 hours of mask use. Each group was divided depending on the application or not of povidone-iodine in the PA of the mask. Bacterial load was studied on PA and mouth area samples. RESULTS: The bacterial load in the PA was higher in the >4 hours group compared with the <4 hours group (13.2 vs. 48.75 colony-forming units/µL; P = 0.03). The contamination in the PA significantly decreased after applying povidone-iodine in the >4 hours group (P = 0.01). The use or not of povidone-iodine was strongly correlated to a positive culture (OR = 9.0, P = 0.00. CI 1.63-49.44). CONCLUSION: Surgical face masks worn for more than 4 hours present higher contamination in the PA than those with less use. Bacterial load in the PA is reduced with povidone-iodine on masks used for more than 4 hours. This contamination should be considered in the asepsis protocol of intravitreal injections.