Abstract
Purpose :
Pterygium is a common ocular surface disorder. Conjunctival autografting (CAG) following pterygium resection is the gold standard treatment. CAGs without Tenon’s tissue provide better results but are more technically difficult to achieve. In this study, we evaluated the feasibility and reproducibility of femtosecond laser (FSL)-assisted CAG preparation first in a porcine model, then in a clinical trial (NCT02866968).
Methods :
Fifteen porcine globes were fixed in a suction holder and ellipsoid CAGs created by 1) an experienced consultant and 2) a less experienced fellow using the Ziemer LDV Z8 set to 100% energy for the horizontal conjunctival stroma and 130% for the side cuts. The CAG’s dimension was measured and thickness analyzed by optical coherence tomography. In a clinical trial we treated 6 eyes of 5 patients with FLAPS. Statistical analysis was performed by Mann-Whitney-U and Wilcoxon test.
Results :
Porcine FSL-assisted CAGs prepared at 100 µm (146.4 ±45.7µm) showed a significantly higher deviation from desired depth (p=.04) and a higher variability (p=.03) in thickness than those prepared at 60 µm (71.4 ±12.7µm). The experienced (68.3 ±14.3µm) and inexperienced surgeon (73.9 ±11.9µm) produced 60 µm grafts of comparable thickness (p=.6) and variability (p=.7). In patients following standard pterygium resection the Z8 was programmed to dissect ellipses of 60 µm thickness and a mean CAG area of 51.4 ±6.9mm2. The CAG area measured after dissection in the patients was 42.2 ±8.3mm2, 17.9% smaller than the settings (p=.03). Intraoperative central (75.6 ±13.7µm) and peripheral (77.7 ±13.2µm) CAG thickness did not differ significantly (p=.3). No buttonholes or CAG tags occurred during surgery. The mean FSL dissection time was 19.5 ±1.2 s and the time to lift the prepared CAG and to unfold it onto the cornea was 10.3 ±3.8 s. Mean follow-up was 35.8 ±38.0 days and the epithelium had healed at the CAG resection side within 1 week in all patients. During the time of follow-up no postoperative complication or recurrence occurred.
Conclusions :
FLAPS is a new technique, in which the preparation of an ultra-thin CAG is done by FSL. Following optimization in porcine eyes, the clinical trial in the first 6 eyes was performed without any complications and the FSL might assist in further standardizing the surgical procedure. Longer follow-ups and larger cohorts are needed to assess recurrence rates.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.