Comparative study of 3 intracorneal implant types to manage central keratoconus.

PURPOSE

To compare the visual acuity, refraction, corneal topography, and corneal asphericity of intrastromal corneal implantation of Keratacx 160-degree 2 symmetrical ring segment, the Keratacx 320-degree near-total ring, and the Myoring continuous intracorneal ring (ICR) in central keratoconus.

SETTING

Ophthalmology Department, Ain Shams University, Cairo, Egypt.

DESIGN

Prospective case series.

METHODS

Surgeries were performed using a femtosecond laser for tunnel creation for the 160-degree 2-segment device (Group 1) and the 320-degree near-total ring (Group 2), and for pocket creation for the ICR (Group 3). The preoperative and 6-month postoperative uncorrected (UDVA) and corrected (CDVA) distance visual acuities, spherical equivalent (SE), corneal and refractive astigmatism, keratometry (K) readings, and Q value using topography images were acquired.

RESULTS

The study included 73 eyes. No statistically significant differences were found in the preoperative parameters between groups (P > .05). The postoperative UDVA, CDVA, SE, corneal and refractive astigmatisms, K readings, and Q value were statistically better than the preoperative parameters in all study groups (P < .01). A statistically significant increase in the median UDVA and CDVA occurred in Group 2 compared with Group 1 (P < .01). Groups 2 and 3 had a more effective reduction in SE (P < .01). No statistically significant difference was found in the postoperative changes in the corneal and refractive cylinders, mean and maximum K readings, and corneal asphericity between the study groups (P > .05).

CONCLUSIONS

All devices were effective in improving UDVA, CDVA, refraction, K readings, and corneal asphericity. The 320-degree segment and ICR improved UDVA and SE more than the 2-segment device.