Abstract
Purpose :
Keratoplasty is the gold standard for keratoconus management but invasiveness, high post-operative astigmatism and risk of rejection remain the major complication related to surgery.
We investigate the restoration of corneal architecture in ectatic corneas (keratoconus) by intrastromal lenticule implantation (intrastromal keratoplasty), shaped by femtosecond laser (FSL).
Methods :
Experimental ex vivo study in 20 donor human corneas (DHC) not eligible for transplantation was carried out. All corneoscleral rims were mounted on an artificial anterior chamber. Ten ectatic corneas were created by decentralized myopic excimer laser treatment of 200 μm, performed on the posterior surface. Keratoconic corneas so obtained were evaluated by means of pachimetry, corneal topography and anterior segment optical coherence tomography.
Subsequently, from the remaining 10 DHC, ten stromal meniscus shaped lenticules, having the same diameter and thickness of the created ectasias, were cut out by FSL. Keratoconic corneas were underwent intrastromal pocket creation within ectatic area using the same FSL. After intrastromal lenticule implantation, the changes of corneal architecture and keratometric parameters were investigated.
Results :
All ectasias were performed succesfully. All stromal lenticules have been implanted without complications and anterior segment –OCT confermed the correct lenticular profile inside the stromal pocket. Central corneal thickness and thinnest corneal thickness showed statistically significant differences between pre and postoperative evaluations (p = <0.0001). Posterior Elevation is significantly reduced (p = 0.036). Corneal Irregularity Measurement (CIM) was significantly increased (p = 0.02). The other keratometric parameters were improved but not statistically significant.
Conclusions :
Datas obtained by stromal lenticules implantation in ectatic corneas show a remarkable improvement in architecture and corneal stability with restoration of the physiological posterior corneal elevation. These goals are achieved through a mini invasive surgical technique low immune risk. Anterior keratometric data do not show significant change in this study, probably due to high corneal surface irregularity at the end of treatment, as is shown by the statistical significance found in CIM.
In our experience, intrastromal keratoplasty could open new perspectives to the treatment of corneal ectasia.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.