No abstract

Consideration of less corneal thinning favours A-CXL, whereas the deeper demarcation line and greater changes in minimum keratometric values in C-CXL may indicate a higher treatment efficacy. Altogether, C-CXL, as well as A-CXL, provides successful results in the strengthening of corneal tissue.

Purpose: To evaluate the repeatability and validity of total corneal power measurements (total keratometry [TK]) obtained with a recently introduced optical biometer (IOLMaster 700, Carl Zeiss Meditec AG) to a Scheimpflug device (Pentacam, Oculus). Setting: Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany. Design: Prospective randomized controlled trial. Methods: The inclusion criteria were a corneal astigmatism of 3.00 diopters (D) or less, no previous ocular surgery, no known corneal irregularities, and no known dry eyes. All eyes were measured 3 times using the optical biometer and the Scheimpflug device. The results were statistically compared using Bland–Altman, within-subject SD, and astigmatism vector analysis. Results: Ninety-three eyes of 93 subjects were included. Overall, the repeatability of all eyes measured was 0.42 for standard K, 0.40 for TK, 0.45 for total corneal refractive power (TCRP), 0.43 for true net power (TNP), and 0.39 for simulated K. Bland–Altman analysis showed no significant difference between the optical biometer's TK compared with standard K and the Scheimpflug device's simulated K, TNP, and TCRP, the P value exceeding .05 in each case. A difference of >0.50 diopters between astigmatism measurements between TK and TCRP was found in 10 cases compared with standard K and TNP with 0 and 2 cases. Conclusions: Repeatability of both devices was high, although measurements of meridian showed a great variability, suggesting that numerous measurements are needed to enhance accuracy. TCRP measurements between recently introduced TK and TCRP cannot be used interchangeably. Future studies are necessary to evaluate which measurement will result in a better outcome when respective measurements are used for toric intraocular lens calculations.

Purpose: To compare the efficacy and safety of femtosecond laser–assisted cataract surgery (FLACS) with conventional cataract surgery (CCS). Setting: Department of Ophthalmology, Goethe-University, Frankfurt am Main, Germany. Design: Meta-analysis. Methods: PubMed, Cochrane Library, and EMBASE were systematically searched for studies comparing FLACS and CCS. Outcomes were efficacy and safety parameters. The effect measures were weighted mean differences or odds ratios with 95% CIs. Results: A total of 73 studies (25 randomized controlled, 48 observational) were reviewed with a total of 12 769 eyes treated with FLACS and 12 274 eyes treated with CCS. In eyes treated with FLACS, uncorrected and corrected distance visual acuities and spherical equivalent after 1 month to 3 months (P = .04, P = .005, and P = .007, respectively) were better, total and effective phacoemulsification times were shorter (P < .001 each), cumulative dissipated energy was less (P < .001), circularity was more accurate (P < .001), central corneal thickness after 1 day and 1 month to 3 months was less (P < .001 and P = .004, respectively), and endothelial cell loss after 3 to 6 weeks and 3 months was less (P = .002 and P < .001, respectively) compared with CCS. Anterior capsule ruptures occurred more often with FLACS. No significant differences among groups were found in visual acuity at 1 week and after 6 months or in posterior capsule rupture rates and endothelial cell loss after 6 months. Conclusions: Both FLACS and CCS are effective and safe. FLACS required less ultrasound energy and a more precise treatment. However, mid-term visual acuity did not show any difference between both methods.