New surgical technique for enhancing the astigmatic correction effect of Intacs SK corneal ring segments in keratoconus eyes with a central cone

Session Details

Session Title: Keratoconus and Phakic IOLs

Session Date/Time: Monday 12/09/2016 | 16:30-18:30

Paper Time: 17:12

Venue: Hall C4

First Author: : S.Awwad LEBANON

Co Author(s): :    R. Antonios   M. Abdul Fattah   M. Nasser   B. Abiad           

Abstract Details

Purpose:

To evaluate the refractive effect of 150° arc length intrastromal corneal ring segments (Intacs SK) placed in a larger tunnel to correct astigmatism in keratoconus eyes with a central cone. 150° arc length segments, implanted in a 7 mm tunnel instead of 6 mm, would yield an effective arc-length of 129°.

Setting:

American University of Beirut Medical Center

Methods:

6 keratoconus eyes with central bow-tie astigmatism, underwent implantation of two 450 μm Intacs SK segments at 7.0 mm (SK-7 group) instead of the usual 6.0 mm tunnel. The refractive effects of the SK-7 group were compared to a control arm of 6 consecutive keratoconus eyes with central bow-tie which underwent two symmetric 450 μm intacs SK implantation at the usual 6mm position, obtained by a retrospective chart review (SK-6 group).

Results:

There were no statistical significance between the baseline parameters of both groups, although mean SE was larger in SK-6 group and both refractive cylinder and corneal astigmatism were larger in SK-7 group. The average change in MRSE at 6 months was +2.21 ± 0.86 for the SK-7 group and +8.87 ± 3.22 for the SK-6 group (P=0.004). However, SK-7 group showed greater reduction in topographic surgical induced astigmatism (SIA) as compared to the SK-6 group (+5.55 ± 0.50 vs +2.47 ± 0.50, P=0.004). On corneal topography, the bow-tie shape was maintained in all eyes that underwent intacs SK implantation at 6mm (SK-6 group) while it became round in eyes that had the intacs SK implanted at 7mm.

Conclusions:

Placement of two Intacs SK segments in a larger tunnel in eyes with central Keratoconus leads to a greater astigmatism correction while having less effect on overall corneal flattening and spherical equivalent refraction.

Financial Disclosure:

NONE