Posters

Intrastromal corneal ring segments (210 degree arc length) in central hyperprolate keratoconus

Poster Details

First Author: L. Fernandez-Vega Cueto SPAIN

Co Author(s):    C. Lisa   J. Merayo-Lloves   D. Madrid-Costa   J. Alfonso           

Abstract Details

Purpose:

To assess the efficacy outcomes (visual, refractive and in terms of corneal aberrometry) of implanting intrastromal corneal ring segments (ICRS) to correct central keratoconus.

Setting:

Instituto Universitario Fernández-Vega (Oviedo). Spain.

Methods:

Forty-one eyes with central keratoconus were evaluated before and after implanting inferior 210 degree arc length Ferrara-type AFR5 ICRS (AJL Ophtalmic, Spain). LogMAR uncorrected (UDVA) and best corrected (CDVA) distance visual acuity, corneal spherical aberration (Z(4,0)), horizontal coma (Z(3,1)), vertical coma (Z(3,-1)), root mean square (RMS) of higher-order aberrations (HOAs) and residual refractive errors analysed using vector analysis were recorded before and 6 months after ICRS implantation.

Results:

The mean UDVA (LogMAR scale) rose from 0.87 ± 0.33 before to 0.52 ± 0.29 after ICRS implantation (P< 0.0001). The mean pre-operative CDVA was 0.31 ± 0.28 and the post-operative value 0.16 ± 0.11 (P=0.0004). The CDVA remained unchanged or improved in all eyes after surgery. The safety index was 1.32. The spherical equivalent declined steeply after ICRS implantation (P< 0.0001). The RMS values for HOAs and Zernike coefficients Z(4,0) and Z(3,-1) exhibited statistically significant decreases 6 months after ICRS implantation (P=0.004, 0.03 and 0.0002, for the RMS of HOAs, Z(4,0) and Z(3,-1), respectively).

Conclusions:

A single, inferior, 210 degree arc length Ferrara-type AFR5 ICRS may lower the spherical equivalent, RMS of HOAs and Zernike coefficients Z(4,0) and Z(3,-1) in central keratoconic eyes, with a concomitant improvement in post-surgery UDVA and CDVA values.

Financial Disclosure:

NONE