Purpose
The aim was to compare visual acuity, refraction of intrastromal segment 355, and two, 160° symmetrical segments in central keratoconus.
Setting
Al-Fath Eye Hospital, Zagazig, Egypt.
Design
Prospective case series.
Patients and methods
Surgeries were performed using a femtosecond laser for tunnel creation for the 355° near-total ring (group 1) and the 160° two-segment device (group 2). The preoperative and 6-month postoperative uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA) distance visual acuities were acquired.
Results
The study included 40 eyes. No statistically significant differences were found in the preoperative parameters between groups (>0.05). The postoperative UCVA and CDVA were statistically better than the preoperative parameters in all study groups (<0.001). A statistically significant increase in the median UCVA and BCVA occurred in group 2 compared with group 1 (<0.01).
Conclusions
All devices were effective in improving UCVA and BCVA. The UCVA results in the two separated 160° segment better than the 355 segment. Patients with high spherical than cylindrical power had better vision and satisfaction with the 355 segment, while the two separated segments had better vision in high cylindrical patients than spherical power patients.