Posters

Progressive thickness intrastromal corneal ring segments (Keraring® AS) implantation for paracentral keratoconus with non-coincident topographic and coma axis (Duck phenotype)

Poster Details

First Author: A.Soares PORTUGAL

Co Author(s):    T. Monteiro   N. Franqueira   F. Faria-Correia   F. Vaz           

Abstract Details

Purpose:

To evaluate the efficacy and safety of implantation of progressive thickness intracorneal ring segments (ICRS) Keraring® AS (Mediphacos®, Brazil) segments for the correction of paracentral keratoconus with non coincident topographic and coma axis.

Setting:

Hospital de Braga

Methods:

This retrospective study included patients with paracentral keratoconus with non coincident topographic and coma axis (coma axis between 30° and 60° of the flat topographic axis) submitted to Keraring® AS implantation. Parameters evaluated at preoperative and 6 months after surgery were: uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), manifest refraction, corneal topography and corneal aberrometry with Pentacam (Oculus®, Germany).

Results:

The study included 14 eyes of 13 patients. The mean CDVA preoperatively was 0.35±0.14 and postoperatively was 0.80±0.22 (p=0.002). The mean UDVA preoperatively was 0.10±0.08 and postoperatively was 0.35±0.3 (p=0.03). The subjective refractive cylinder improved from a mean preoperatively value of -2,65±1.11D to -1,124±0.48D after surgery (p=0.00041); topographic cylinder improved from 3.78±1.22 before surgery to 2.10±1.8 after surgery (p=0.14). The value of coma improved significantly from 3.15±0.94 to 1.83±0.86 μm (p=0.018). No intraoperative or postoperative complications occurred; no eyes lost lines of BCVA and 77,8% of eyes gained 2 or more lines of BCVA.

Conclusions:

The implantation of progressive thickness intrastromal corneal ring segments (Keraring AS) in eyes with paracentral keratoconus with non coincident topographic and coma axis was safe and effective. They produce a progressive flattening effect, allowing a better customization of the corneal remodelling, specially in patients with significant difference between the flat topographic axis and the coma axis.

Financial Disclosure:

None