Outcome of complete intrastromal ring implantation using femtosecond laser in pellucid marginal degeneration

Purpose

To evaluate the effect of complete intrastromal corneal ring implantations on patients with pellucid marginal degeneration (PMD).

Design

Prospective interventional case series

Patients and Methods

Thirty-three eyes with PMD were included into the study. After pocket creation with femtosecond laser (Femtec; 20/10 PerfectVision), MyoRing implantation was performed. Uncorrected and corrected distance visual acuity (UDVA, CDVA), subjective refraction, keratometry, central corneal thickness, corneal biomechanical profile (Ocular Response Analysis), and whole-eye wavefront aberrometry (iTrace) were evaluated preoperatively and also postoperatively, 1 month, 3 months, 6 months, and 1 year after the operation.

Results

One month after surgery, significant improvements were observed in UDVA (ANOVA; P=0.02), mean keratometry, sphere (ANOVA; P <0.001), and cylinder (ANOVA; P=0.04) with no significant changes afterwards. No significant change occurred in the corneal biomechanical profile. Primary coma and trefoil reduced after 1 year (ANOVA; P values were 0.02 and 0.06, respectively). Primary spherical aberration significantly increased according to the 1-year follow-up (ANOVA; P<0.001). No significant complication was observed.

Conclusion

MyoRing is considered as a treatment modality for spherocylindrical correction in patients with PMD, with an acceptable safety and efficacy profile.