ABSTRACT
Purpose: To assess the role of Scheimpflug imaging in improving the accuracy of reference marking for toric IOL implantation. Methods: In this prospective, randomized, clinical trial all patients with cataract and pre-existing significant regular corneal astigmatism, who required implantation of a toric IOL were included in the study, and patients with any ocular pathology or abnormality were excluded. Patients were divided into two groups: For one group of patients, Group I (GI), reference marking was finalized using slit lamp only, and for the second group, Group II (GII), after slit lamp marking, the reference marks were checked using Goniometer of Scheimpflug imaging. The primary outcome was to determine the axis of toric intraocular lens (IOL) postoperatively (within 1 hour) and compare it with the desired axis of placement. Results: We found a statistically significant difference in the two groups (P < 0.001) suggesting Group II (4 step technique) is better than Group I (3 step technique). Conclusion: Scheimpflug imaging, an extra step preoperatively, is an effective measure to reduce errors in reference marking and thereby improving the refractive outcome of toric intraocular lens.
ABSTRACT
PURPOSE: There has been a difficulty in measuring angle kappa because special instrument was required. To measure the angle kappa conveniently, we designed a new method using slit lamp biomicroscope. METHODS: We measured the angle kappa in 124 eyes of 62 patients with newly designed method and compared the measurement by new method with those by T-shape ruler or the major amblyoscope. RESULTS: We found the average angle kappa was +3.12 degrees by slit lamp, +2.85 degrees by major amblyoscope and +3.04 degrees by T shape ruler method. There was no significant difference between slit lamp and either major amblyoscope method (p=0.48) or T shape ruler (p=0.18). CONCLUSIONS: The new method of measuring angle kappa using slit lamp biomicroscope seemed to be a convenient and relatively accurate method for measuring of angle kappa and appeared to be beneficial in measurement of ocular deviation.