Evaluating the Progression of Keratoconus Patients With Intrastromal Corneal Ring Segments After Epithelial-on CXL
Purpose
To determine the early results of epithelial-on (Epi-ON) cross-linking (CXL) in patients with intrastromal corneal ring segments (intacs) for keratoconus or post-LASIK ectasia at a single center.
Methods
This is a retrospective study of 8 patients (13 eyes) with intacs that underwent Epi-ON CXL with a proprietary riboflavin formulation. A critical step was slit lamp verification that the corneal stroma was saturated with riboflavin prior to initiating the UV light. Once verified, UV light was applied for 30 minutes. Charts were reviewed to determine change in maximum keratometry (KMax) and change in best spectacle corrected visual acuity (BSCVA). Patients were divided into two groups for analysis; Group 1 included 6 eyes with 3-6 month follow-up and Group 2 included 7 eyes with greater than 6 months follow-up.
Results
The average age was 41 (range 32-46) in Group 1 and 37 (range 23-63) in Group 2. The average preoperative thinnest point on Pentacam was 449 microns (range 399 - 496) in Group 1 and 435 microns (range 399-482) in Group 2. The average preoperative KMax was 51.9 in Group 1 and 58.0 in Group 2. The average improvement in KMax was .450 D in Group 1 & 1.07 D in Group 2. BSCVA improved in 50% for Group 1 and 71% in Group 2. Only one eye (Group 2) lost BSCVA (1 line). There were no adverse events.
Conclusion
The early results of Epi-ON CXL with slit lamp verification of riboflavin saturation in the cornea was found to be both safe and effective for eyes with previous placement of intacs for keratoconus or post-LASIK ectasia.