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Updated: Jun 16, 2026

Three Different Protocols of Corneal Collagen Crosslinking in Keratoconus: Conventional, Accelerated and Iontophoresis
Published on: November 12, 2015
INTACS followed by KeraRing intrastromal corneal ring segment implantation for keratoconus
Efekan Coskunseven1, George D Kymionis, Michael A Grentzelos
1Dunya Eye Hospital, Istanbul, Turkey.
Purpose:
To describe the visual and refractive outcomes in three eyes (two keratoconic patients) with previous intrastromal corneal ring segments (INTACS, Addition Technology Inc) that underwent adjuvant single KeraRing (Mediphacos) intrastromal corneal ring segment implantation.
Methods:
Two keratoconic patients (three eyes) with implanted INTACS segments underwent an additional (without explanting previous INTACS) single KeraRing segment implantation.
Results:
No intraoperative complications occurred. Six months postoperatively, uncorrected distance visual acuity improved from 20/100 and 20/200 to 20/32 and 20/40 in the right and left eyes, respectively, of patient 1, and from 20/400 to 20/50 in the treated right eye of patient 2. Corrected distance visual acuity improved from 20/50 and 20/100 to 20/30 and 20/32 in the right and left eyes, respectively, of patient 1 and from 20/200 to 20/40 in patient 2. Keratometric measurements improved from 51.00/45.70 to 47.00/44.60 diopters (D) and from 50.80/48.80 to 42.70/40.30 D in the right and left eyes, respectively, of patient 1, and from 49.30/45.70 to 45.60/44.10 D in patient 2.
Conclusions:
In keratoconic patients with INTACS in place, adjuvant single intrastromal corneal ring segment (KeraRing) implantation could improve visual and refractive outcome.
