Incidence and Outcomes of Optical Zone Enlargement and Recentration After Previous Myopic LASIK by Topography-Guided Custom Ablation.

PURPOSE: To report the incidence, visual and refractive outcomes, optical zone enlargement, and recentration using topography-guided CRS-Master TOSCA II software with the MEL 80 excimer laser (Carl Zeiss Meditec AG, Jena, Germany) after primary myopic laser refractive surgery. METHODS: Retrospective analysis of 73 eyes (40 patients) with complaints of night vision disturbances due to either a decentration or small optical zone following a primary myopic laser refractive surgery procedure using the MEL 80 laser. Multiple ATLAS topography scans were imported into the CRS-Master software for topography-guided ablation planning. The topography-guided re-treatment procedure was performed as either a LASIK flap lift, a new LASIK flap, a side cut only, or photorefractive keratectomy. Axial curvature maps were analyzed using a fixed grid and set of concentric circles superimposed to measure the topographic optical zone diameter and centration. Follow-up was 12 months. RESULTS: The incidence of use in the population of myopic treatments during the study period was 0.79% (73 of 9,249). The optical zone diameter was increased by 11% from a mean of 5.65 to 6.32 mm, with a maximum change of 2 mm in one case. Topographic decentration was reduced by 64% from a mean of 0.58 to 0.21 mm. There was a 44% reduction in spherical aberration, 53% reduction in coma, and 39% reduction in total higher order aberrations. A subjective improvement in night vision symptoms was reported by 93%. Regarding efficacy, 82% of eyes reached 20/20 and 100% reached 20/32 (preoperative CDVA was 20/20 or better in 90%). Regarding safety, no eyes lost two lines of CDVA and 27% gained one line. Regarding predictability, 71% of re-treatments were within ±0.50 diopters. CONCLUSIONS: Topography-guided ablation was effective in enlarging the optical zone, recentering the optical zone, and reducing higher order aberrations. Topography-guided custom ablation appears to be an effective method for re-treatment procedures of symptomatic patients after myopic LASIK. [J Refract Surg. 2018;34(2):121-130.].

Threshold limit of postoperative astigmatism for patient satisfaction after refractive lens exchange and multifocal intraocular lens implantation.

PURPOSE: To determine the degree of tolerance toward different magnitudes of residual refractive astigmatism and corneal astigmatism and the angles of corneal astigmatism after implantation of an asymmetric multifocal intraocular lens (IOL). SETTING: Cathedral Eye Clinic, Belfast, United Kingdom. DESIGN: Retrospective comparative case series. METHODS: The study enrolled patients having refractive lens exchange and implantation of a Lentis Mplus LS-312 MF30 IOL. Uncorrected (UDVA) and corrected distance visual acuities, uncorrected near and intermediate visual acuities, and quality-of-vision questionnaires were evaluated. Groups were categorized based on the magnitude of refractive astigmatism and corneal residual astigmatism. Refractive astigmatism of less than 0.50 diopter (D) and more than 0.50 D and corneal astigmatism of 0.50 D or less, 0.51 to 0.75 D, 0.76 to 1.00 D, and more than 1.00 D were categorized. RESULTS: The study comprised 117 patients (234 eyes). There was a significant difference in UDVA (P = .003), refractive sphere (P = .001), and defocus equivalent (P ≤ .001) between the residual refractive astigmatism groups; however, there was no difference in quality of vision (P = .28). The same was found for corneal astigmatism with UDVA (P ≤ .001) and quality of vision (P = .16). The angle of corneal astigmatism in relation to IOL placement did not statistically affect postoperative outcomes. CONCLUSIONS: The IOL appeared to subjectively tolerate residual astigmatism well despite a statistically significant difference in UDVA with higher magnitudes of residual astigmatism. The angle of residual corneal astigmatism in relation to IOL placement did not have a significant effect on postoperative outcomes. FINANCIAL DISCLOSURE: None of the authors has a financial or proprietary interest in any material or method mentioned.