[Intracorneal Ring Segments to Treat Keratectasia - Interim Results and Potential Complications].
OBJECTIVE
Implantation of intracorneal ring segments (ICRS) using a femtosecond laser is a minimally invasive procedure which represents a reliable option to widen the spectrum of the stage-related therapy of keratoconus in patients with contact lens intolerance, or with post-LASIK-keratectasia or pellucide marginale degeneration (PMD).


METHODS
From August 2011 to September 2015, 84 eyes of 69 patients were implanted with ICRS. 74 eyes were implanted with INTACS-SK (Intacs, Addition Technology, Inc.), and 10 eyes were implanted with KeraRing SI6 (Mediaphacos Ltda.). The indication is taken in the presence of a clear central cornea and the patients had to fulfill the corneal diagnostic tests required for implantation. Tunnel creation should nowadays only be carried out by femtosecond laser, in order to avoid intra- and postoperative complications.


RESULTS
Three months after surgery, the INTACS-SK group showed an increase in uncorrected distance visual acuity (logMAR) from 0.99 ± 0.35 to 0.29 ± 0.17. The KeraRing SI6 group showed an increase in uncorrected distance visual acuity (logMAR) from 0.93 ± 0.4 to 0.41 ± 0.34. The keratometric values were reduced in both groups.


CONCLUSIONS
Uncorrected and corrected distance visual acuity can be improved by implantation of the ICRS. Progression of ectasia seems to be retarded. Consistent follow-up visits at close intervals are necessary to identify complications at an early stage. However, larger case series and a longer postoperative observation period are required. Complications after ICRS implantation are rare, due to strict patient selection and modern surgical techniques.
Klinik für Augenheilkunde, Universitätsklinikum des Saarlandes, Homburg.
M
M
El-Husseiny
Klinik für Augenheilkunde, Universitätsklinikum des Saarlandes, Homburg.
L
L
Daas
Experimentelle Ophthalmologie, Universitätsklinikum des Saarlandes, Homburg.
A
A
Langenbucher
Klinik für Augenheilkunde, Universitätsklinikum des Saarlandes, Homburg.
B
B
Seitz
D016039:Corneal Transplantation / Q000009:adverse effects* / Q000379:methods*; D019317:Evidence-Based Medicine; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000150:complications / Q000175:diagnosis* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D019736:Prostheses and Implants; D019919:Prosthesis Implantation / Q000009:adverse effects / Q000379:methods; D019738:Surgically-Created Structures / Q000009:adverse effects; D016896:Treatment Outcome; D014786:Vision Disorders / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control*; D014792:Visual Acuity