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Visual, refractive and topographic results of progressive thickness vs stable thickness intrastromal corneal ring segment implantation for the eyes with asymmetric bow-tie type of keratoconus

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First Author: E.Coskunseven TURKEY

Co Author(s):    B. Kayhan                    

Abstract Details

Purpose:

To evaluate pre and postoperative visual, refractive and topographic outcomes of 32 eyes of 16 patients with asymmetric bow-tie type of keratoconus, who underwent a progressive thickness intrastromal corneal ring segment (ICRS) implantation in one eye and stable thickness ICRS implantation in the other eye.

Setting:

Dunya Eye Hospital, Istanbul, Turkey

Methods:

Patients who had unsatisfactory spectacle-corrected vision and contact lens-intolerance because of advanced asymmetric bow-tie keratoconus (Grade I, II and III) underwent the implantation of only one progressive thickness ICRS (Mediphacos, Brazil) in one eye and only one stable thickness ICRS (Mediphacos, Brazil) in the other eye. The complete refractive assessment including the measurement of uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), spherical equivalent (SE) was performed preoperatively and postoperatively. The corneal topographies of all patients were measured by Pentacam (Oculus, Wetzlar, Germany). The difference between maximum and minimum keratometry in 3 mm central area was evaluated.

Results:

In this retrospective case series, 32 eyes of 16 keratoconus patients were included. The mean age was 26 years. There were improvements postoperatively in mean UCVA, mean BCVA, mean cylindrical refraction and mean SE in both groups comparing with preoperative values. The mean keratometry (K) decreased to 45.92 D postoperatively from 51,25 D preoperatively in progressive thickness ICRS group. However, the mean K decreased to 47,24 D postoperatively from 52,1 D preoperatively in stable thickness ICRS group. The reduction of the mean K in the progressive thickness ICRS group was significantly better than the stable thickness ICRS group.

Conclusions:

The evaluation of the visual performance and topographic measurements revealed that the implantation of only one progressive thickness ICRS is more effective than the implantation of only one stable thickness ICRS for the asymmetric bow-tie type in eyes with keratoconus.

Financial Disclosure:

... receives consulting fees, retainer, or contract payments from a competing company