Full-Ring Intracorneal Implantation in Corneas With Pellucid Marginal Degeneration

BACKGROUND: Keratoconus (KCN) is a progressive, non-inflammatory ectacic disorder characterized by bilateral and asymmetrical conical protrusion of the cornea. MyoRing implantation and Collagen Crosslink (CXL) are two separate effective treatments for all stages of keratoconous. This study wants to show the effect of these treatments combination in patients with moderate and severe keratoconus. OBJECTIVES: The aim of this study was to report on the visual and refractive outcomes of corneas with pellucid marginal degeneration following MyoRing implantation (DIOPTEX GmbH). PATIENTS AND METHODS: This study included 15 eyes of 15 patients, with an age range from 22 to 49 years old, and pellucid marginal degeneration. An intrastromal corneal ring (MyoRing) was inserted by the means of mechanical dissection using a PocketMaker microkeratome. The main outcome measures were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction, and keratometry readings. The mean postoperative follow-up was ten months (range 6 - 12 months). RESULTS: The mean UDVA (LogMAR) improved significantly from 1.13 ± 0.21 preoperatively to 0.24 ± 0.13 postoperatively (P < 0.001), and the mean CDVA (LogMAR) improved significantly from 0.39 ± 0.12 to 0.19 ± 0.09 (P < 0.001). The mean cylinder of manifest refraction decreased significantly by 4.00 diopter (D) (P < 0.001). The mean spherical equivalent error (SE) decreased significantly from −6.00 ± 3.60 D to −0.70 ± 1.90 D, at the end of the follow-up period. Furthermore, with regards to corneal topography, a significant reduction was observed in keratometric values. The Kmax, Kmin and Kaverage decreased significantly by 5.00, 1.10 and 4.00 D, respectively (P < 0.001). CONCLUSIONS: MyoRing implantation using the PocketMaker microkeratome appears to provide an effective method for treating pellucid marginal degeneration. Both UDVA and CDVA improved significantly. The corneal steepening and astigmatism were reduced in all subjects after MyoRing implantation.