title: A single 210-degree arc length intrastromal corneal ring implantation for the management of pellucid marginal corneal degeneration.
abstract: OBJECTIVE
  To determine the visual and refractive outcomes of 210-degree arc length intrastromal corneal ring segment (ICRS) implantation in eyes with pellucid marginal corneal degeneration (PMCD).
  
  
  METHODS
  Retrospective, consecutive case series.
  
  
  METHODS
  Sixteen consecutive eyes of 10 patients who underwent a single 210-degree ICRS implantation by femtosecond laser for the management of PMCD and completed at least 1 year follow-up were included. A complete ophthalmic examination was performed preoperatively and postoperatively, including uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifest spherical and cylindrical refractions, spherical equivalent, and keratometric readings.
  
  
  RESULTS
  The mean follow-up period was 30.7 months (range 12 to 36 months). No intraoperative complication was observed. White deposits around the segments were noted in 2 of 16 eyes (12.5%) at the first postoperative year. The mean UCVA showed significant improvement, from 1.69 +/- 1.02 logarithm of the minimal angle of resolution (logMAR) preoperatively to 0.64 +/- 0.43 logMAR at the 36th month (n = 11, P < .001). The mean preoperative BSCVA was 0.88 +/- 0.68 logMAR; after 36 months, this improved to 0.35 +/- 0.34 (P < .001). At the 36th month, UCVA was improved in all eyes (n = 11, range: gain of 1 to 6 lines), whereas BSCVA was improved in 9 eyes (81.8%, range: gain of 2 to 7 lines) and remained unchanged in 2 eyes (18.1%); UCVA was 20/40 or better in 3 eyes (27%) and BSCVA was 20/40 or better in 8 eyes (72.7%). There was a significant reduction in the spherical equivalent refractive error, from -4.40 +/- 1.85 diopters (D) preoperatively to -1.86 +/- 0.60 D (P < .001), and the mean maximum keratometric power decreased from 49.70 +/- 4.32 D to 46.08 +/- 2.84 D (P < .001) after 36 months. The mean cylindrical refraction decreased from -4.39 +/- 1.86 D preoperatively to -2.38 +/- 1.35 D at 36 months (P < .001).
  
  
  CONCLUSIONS
  A single 210-degree arc length ICRS implantation using a femtosecond laser for patients with PMCD provides good visual and refractive outcomes.
authors.affiliation: Dr Lütfi Kirdar Kartal Training and Research Hospital, Istanbul, Turkey.
authors.forename: Anil
authors.initials: A
authors.lastname: Kubaloglu
authors.forename: Esin Sogutlu
authors.initials: ES
authors.lastname: Sari
authors.forename: Yasin
authors.initials: Y
authors.lastname: Cinar
authors.forename: Arif
authors.initials: A
authors.lastname: Koytak
authors.forename: Ekrem
authors.initials: E
authors.lastname: Kurnaz
authors.forename: David P
authors.initials: DP
authors.lastname: Piñero
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Ozerturk
mesh_terms: D000328:Adult; D003317:Corneal Dystrophies, Hereditary / Q000503:physiopathology / Q000601:surgery*; D003319:Corneal Stroma / Q000601:surgery*; D019781:Corneal Topography; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D019736:Prostheses and Implants; D019919:Prosthesis Implantation; D012029:Refraction, Ocular / Q000502:physiology; D012189:Retrospective Studies; D014792:Visual Acuity / Q000502:physiology