Abstract
Purpose: :
To compare two- and three-steps architecture of cataract clear corneal incisions measurements using Fourier-Domain Optical Coherence Tomography.
Methods: :
Prospective study included 44 eyes of 36 patients. A Fourier-domain OCT system (RTVue, Optovue Inc., Fremont, CA) with a corneal adaptor module (CAM) was used to image the corneal incisions. A line scan pattern was used to measure the corneal incisions positioning the caliper mark perpendicularly to the limbus. Postoperative measurements were taken for each eye at 1 day, 1 week and 4 weeks after phacoemulsification. Length, location, angle, architecture, and anatomic imperfections of the incisions were analyzed.
Results: :
All incisions were located superiorly. The groups presented average measurements: a. three-steps incision group (22 eyes): incision length=2.046 +/-289mm (range, 1.320-2.575), incision angle=30 +/-4 degree (range, 24-34); b. two-steps incision group (22 eyes): incision length=1.687 +/-256mm (range, 1.333-2.330), incision angle=34 +/-5 degree (range, 27-44). Comparing both techniques for incision length and angle, the measurements were statistically significant (P<0.005). At first postoperative day, epithelial irregularity was observed: a. two-steps incision group, 8 cases (36%), diameter=0.106 +/-46 mm; b. three-steps incision group, 10 cases (45%), diameter=0.151 +/-0.082mm, P=0.188. No epithelial imperfection was observed at seven days postoperative.
Conclusions: :
The three-steps clear cornea incision group presented higher incidence of epithelial irregularity at early postoperative, and the incision was proved to be larger and with a smaller angle of entrance. A reduced incision length and inappropriate construction may be determinant risk factors. Further studies evaluating a greater number of patients with an architectural analysis of clear corneal incisions are needed to confirm these preliminary results.
Keywords: anterior segment • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)