Assessment for Macular Thickness after Uncomplicated Phacoemulsification Using Optical Coherence Tomography.

PURPOSE: Macular edema including cystoid macular edema is one of the main causes of unfavorable visual outcomes after cataract surgery. The macular thickness and the occurrence of macular edema after uncomplicated cataract surgery was evaluated using optical coherence tomography (OCT) in this study. METHODS: Macular map images were taken by OCT before surgery and at 1 week, 1 month, and 2 months postsurgery. The subjects were classified into two groups (group 1, patients with no macular edema; group 2, patients with macular edema). Group 2 was defined as increase in central macular thickness (CMT) by 30% compared with that before surgery. The risk factors for macular edema were evaluated. Group 2 was divided into two subgroups: subclinical macular edema (group 2A) and cystoid macular edema (group 2B) and they were assessed in terms of the clinical course of best-corrected visual acuity and CMT. RESULTS: A total of 376 patients were enrolled in this study, of which 36 (9.57%, group 2) showed macular edema measured by OCT after the surgery. Univariate analysis for group 1 and 2 revealed that intracameral injection of epinephrine during phacoemulsification was associated with the development of macular edema. In group 2, five patients (1.33%) developed cystoid macular edema. Statistically significant differences in the clinical course of CMT were observed at 2 months (201.2 ± 23.1, 250.0 ± 29.8, and 371.0 ± 160.3 in group 1, group 2A, and group 2B, respectively; p < 0.001) and 1 month postoperatively (198.5 ± 23.6, 237.8 ± 40.9, and 314.0 ± 104.5 in group 1, group 2A, and group 2B, respectively; p < 0.001). Group 2B required additional treatment and eventually achieved best-corrected visual acuity of >0.2 with CMT in the normal range. CONCLUSIONS: The intracameral injection of epinephrine may cause macular edema after uncomplicated cataract surgery. Examination of CMT using OCT is recommended for the early detection of macular edema.

Comparison of refractive outcomes using five devices for the assessment of preoperative corneal power.

BACKGROUND: To compare keratometric values obtained with a manual keratometer (Topcon), an automated keratometer (Canon), an Orbscan II (Bausch & Lomb), the IOLMaster keratometer (Carl-Zeiss) and the Pentacam rotating Scheimpflug camera (Oculus) in cataract surgery, and to characterize the refractive outcomes generated using each device. DESIGN: Retrospective study conducted at a tertiary university hospital. PARTICIPANTS: Sixty-nine eyes of 69 patients were analysed. METHODS: The keratometric values obtained with different devices (manual keratometer, automated keratometer, corneal topography, IOLMaster keratometer and Scheimpflug camera) were employed for intraocular lens power calculation. Multiple comparisons of averaged keratometric value were conducted, and the averaged keratometric value was used to calculate the predicted refraction. The absolute values of corneal astigmatism were calculated and also compared. MAIN OUTCOME MEASURES: Mean keratometric value, absolute value of astigmatism, mean error and mean absolute error from each device. RESULTS: The mean keratometric values generated by manual keratometer, automated keratometry, corneal topography, IOLMaster keratometer and the Pentacam Scheimpflug system were 43.95 ± 1.39, 43.91 ± 1.39, 44.67 ± 1.53, 44.03 ± 1.41 and 42.96 ± 1.39 diopter, respectively. The absolute value of astigmatism determined via manual keratometer, automated keratometer, corneal topography, IOLMaster keratometer and the Pentacam Scheimpflug system were 0.95 ± 0.60, 0.99 ± 0.69, 1.14 ± 0.74, 1.11 ± 0.65 and 1.03 ± 0.73 diopter, respectively. The corneal topography showed statistically significant differences with other devices and produced the greater value in mean absolute errors (all P < 0.05). CONCLUSION: Keratometric values with standard devices are a good choice for cataract surgery, whereas the corneal topography is not an appropriate method for the assessment of preoperative keratometric values.

Posterior corneal curvature assessment after Epi-LASIK for myopia: comparison of Orbscan II and Pentacam imaging.

PURPOSE: To compare the changes in posterior corneal curvature using scanning slit topography (Orbscan II) and Scheimpflug imaging (Pentacam) before and after Epi-laser in situ keratomileusis (LASIK) for myopia. METHODS: In a prospective observational case-series study, 20 myopic patients having undergone Epi-LASIK were examined serially with two different devices, Orbscan II and Pentacam, preoperatively and one month postoperatively. Posterior central elevation (PCE) and posterior maximal elevation (PME) were compared between the two devices, and the changes in parameters after Epi-LASIK were analyzed using a difference map. RESULTS: All parameters (preoperative and postoperative PCE and preoperative and postoperative PME) that were measured using the Orbscan II were significantly greater compared to those of the Pentacam (for all p < 0.001). PCE and PME were significantly increased one month postoperatively in the Orbscan II measurements (p < 0.05) but were not significantly increased in the Pentacam measurements. Also, ΔPCE and ΔPME, in the difference map obtained by each serial scanning, were significantly greater in the Orbscan II measurements than with the Pentacam (p = 0.012, p = 0.016). CONCLUSIONS: The Pentacam measurements displayed significantly reduced values in all parameters related to posterior corneal elevation compared to those of the Orbscan II. The Pentacam showed no significant change in posterior corneal curvature after Epi-LASIK, based on the difference map.