Abstract
Purpose: :
We have previously reported results of femtosecond laser-assisted intrastromal keratotomy induced corneal biometry changes along with analysis of refractive error and higher order aberration in a rabbit model (Gray B, et al. IOVS; 52:ARVO E-Abstract 5763). Here we evaluated postoperative wound healing response following manual, intrastromal and anterior penetrating arcuate corneal incisions in the rabbit model.
Methods: :
Thirty-one New Zealand White or Black rabbits (~6 months old) were treated with manual penetrating, laser-assisted intrastromal, or laser-assisted penetrating corneal arcuate incisions. The postoperative wound healing was monitored by corneal endothelial cell counts (CEEC), corneal pachymetry, slit lamp examinations and histopathological analysis up to 47 days.
Results: :
CEEC of the various treatments ranged from 3250±283 cells/mm2 preoperatively to 3285±152 cells/mm2 postoperatively. No significant difference was observed between the mean pre- and post-operative corneal endothelial cell density based on CEEC measurements from both intrastromal and anterior penetrating treatments (n=8). The mean peripheral corneal thickness changed from 361±13 µm preoperatively to 329±32 µm postoperatively for the intrastromal treatment and from 366±20 µm preoperatively to 359±19 µm postoperatively for the penetrating treatment (n=8, p<0.05). Recovery time from the laser treatment is faster (~1week) than the manual technique with respect to corneal wound healing. There were clear differences in the severity of scarring and epithelial hyperplasia with the intrastromal incisions producing no surface or posterior changes whereas the penetrating wounds were similar between the fs laser and diamond blade (epithelial plug formation, anterior wound gape).
Conclusions: :
The femtosecond laser is capable of making precisely delivered patterns within the corneas that cannot be achieved by manual techniques. The intrastromal incisions have the potential benefits of reducing the risk of postoperative infection. The histopathology of penetrating wounds were consistant with previous studies. Results from these studies support the safety of laser-assisted arcuate corneal incision procedures compared to penetrating incisions.
Keywords: cornea: basic science • refractive surgery • wound healing