Abstract
Purpose: :
To analize corneal epithelium behavior in patients who photorefractive keratectomy (PRK) were performed.
Methods: :
Patients with PRK based on regular protocol of surgery were included. Confocal microscopy (confoscan 3, Nidek) and panoramic pictures in the slit lamp were taken at the 1°,4°,5°,6° postoperative days, every week during 3 weeks and every month during 1 month. Findings were compared with clinical panoramic photographs to study the characteristics of epithelial grow (intercellular space, cellular size and color brightness). We also did a cellular count of the basal layers in a constant area of 0.0192 mm2 in the days listed before. Characteristics of nerves and Bowman’s layer were studied. Un–epithelialization Diameter and speed of re–epithelialization were measured.
Results: :
PRK surgery was performed in 23 patients. Forty one thousand confocal images were taken, 700 were selected for this study. Preoperative epithelial cell density in average was 139.3 cells/0.0192 mm2, no cell were seen at day 1, 59.2 at day 4, 88.1 at day 5, 113.7 at day 12, 122.5 at day 18, 135.4 at day 24 and 141.1 at the first month. We noticed a re–epithelialization in average of 1.5 mm per day, with a complete epithelial layers at day 25, 82 % of cases (17 eyes) prebasal cells first seen was at day 4, and in 96% (20 eyes) normal morphology of basal cells was seen at day 12, 82% had an organized basal cell layers at day 18, and we observed the superficial cells at day 12, we did not see Bowman’s layer and epithelial nerves. In the basal cell count we observed a similar number of basal cells at 1 month compared with control.
Conclusions: :
Clinical appearance of complete re–epithelialization was seen at day 6 even thought complete epithelial layers and normal cell density by confocal reached control parameters after day 24. Cell reorganization was normal after one month of follow up despite there is no Bowman’s layer.
Keywords: microscopy: confocal/tunneling • refractive surgery: PRK • imaging/image analysis: clinical