Abstract
In order to examine whether a myringotomy made with a CO2-laser might be an alternative of a ventilation tube, a perforation was made in the upper rear quadrant bilaterally, of 22 rats. The laser-made perforations showed a delayed healing pattern, about twice the closing time of a similar-sized perforation made with a myringotomy lancet. Serous effusion was constantly observed in the attic space during the first 9 days but only in one ear was there actual discharge through the perforation. The size of the perforation started to diminish when the hyperplastic keratinizing squamous epithelium reached the perforation border.