Intraocular lens power calculation in a posterior chamber phakic intraocular lens implanted eye.

PURPOSE: To evaluate the effect of Eyecryl posterior chamber phakic intraocular lens (pIOL) on axial length measurement and intraocular lens power calculation. METHODS: Axial length (AL), keratometry (K), and IOL power calculations were compared at monthly preoperative and postoperative visits (preoperative vs 1-month). Preoperative IOL power (calculated using preoperative K and AL) was compared with a re-calculation where the pIOL was assumed to be in the posterior chamber (calculated using preoperative K value and postoperative AL). RESULTS: Thirty-nine eyes of 39 patients were included. The mean preoperative AL and postoperative AL were 27.02 ± 1.50 and 27.17 ± 1.52 mm (p < 0.001), respectively. The mean preoperative and recalculated IOL powers to achieve emmetropia were 9.40 ± 3.35 and 8.98 ± 3.37 D (p < 0.001) with SRK-T formula, 8.82 ± 3.54 and 8.47 ± 3.60 (p = 0.02) with Holladay I formula, and 9.78 ± 3.43 and 9.44 ± 3.50 (p = 0.013) with Hoffer Q formula. CONCLUSION: The presence of Eyecryl pIOL in the posterior chamber results in a small increase in the AL measurement, and this might result in a corresponding hypermetropic shift in the desired refraction.

Death and Dying: Grapevine Survival, Cold Hardiness, and BLUPs and Winter BLUEs in North Dakota Vineyards.

A total of fourteen diverse, interspecific hybrid grapevines (Vitis spp.) were evaluated for their adaptability to North Dakota winter conditions using differential thermal analysis (DTA) of low-temperature exotherms (LTE) and bud cross-sectional assessment of survival techniques. This research was conducted in two vineyard locations in eastern North Dakota. This work demonstrates the use of DTA for monitoring and selecting cultivars capable of withstanding sub-zero temperatures. These results were assessed for quantitative genetic traits. High heritability was observed for bud LTE traits and may thus be a useful target for cold hardiness breeding programs; however, it is necessary to ensure that variance is reduced when pooling multiple sample events. After DTA sampling, grapevines were assessed for survival of primary and secondary dormant buds using cross-sectional visual evaluation of death. 'Valiant' had the greatest primary bud survival (68%), followed by 'Frontenac gris', 'Crimson Pearl', and 'King of the North'. These varieties are among those with potential for production in eastern North Dakota's environment. The newly evaluated relationships between traits and the heritability of DTA results provide valuable tools to grapevine breeders for the development of cold-tolerant genotypes for future climatic challenges.

Comparison of refractive and visual outcomes between image-guided system-assisted small-incision lenticule extraction and wavefront-optimized FS-LASIK in treatment of high astigmatism.

PURPOSE: To compare the refractive and visual results of image-guided system-assisted small-incision lenticule extraction (IGA-SMILE) and wavefront-optimized femtosecond laser in situ keratomileusis (FS-LASIK) in the treatment of high astigmatism. SETTINGS: Osmangazi Aritmi Hospital, Bursa, Turkey. DESIGN: Retrospective. METHODS: This retrospective case-matched study included 64 eyes that had undergone IGA-SMILE and 64 eyes that had undergone wavefront-optimized FS-LASIK. The mean preoperative myopia and astigmatism were -4.05 ± 1.98 diopter (D) and 3.11 ± 1.06 D in the IGA-SMILE group and -4.21 ± 2.23 D and -3.15 ± 0.62 D in the FS-LASIK group, respectively. One year later, visual and refractive results were compared in the groups. Vector analysis based on Alpins method was performed to evaluate astigmatic treatment. RESULTS: 128 eyes of 128 patients were included in this study. At 1 year, the residual astigmatism was -0.21 ± 0.25 D in the IGA-SMILE group and -0.21 ± 0.24 D in the FS-LASIK group ( P = .305). In the IGA-SMILE group, 57 eyes (89.1%) achieved uncorrected distance visual acuity of 20/20 or better, as did 56 eyes (85.9%) in the FS-LASIK group. Vector analysis results demonstrated that the difference vectors were 0.22 ± 0.24 D and 0.21 ± 0.22 D ( P = .230), the correction indexes were 0.95 ± 0.08 and 0.95 ± 0.08 ( P = .239), and the indices of success were 0.08 ± 0.09 and 0.08 ± 0.09 ( P = .248) in the IGA-SMILE and the FS-LASIK groups, respectively. CONCLUSIONS: The combination of an image-guided system with SMILE resulted in high efficacy and safety indices that were comparable with FS-LASIK surgery.

Agreement between swept-source optical biometry and Scheimpflug-based topography measurements of posterior corneal curvature.

PURPOSE: To evaluate agreement of posterior corneal curvature parameters between a swept-source optical coherence tomography-based biometer (IOLMaster 700) and Scheimpflug topography (Pentacam HR) in healthy, myopic eyes. SETTING: Department of Ophthalmology, Osmangazi Aritmi Hospital, Bursa, Turkey. DESIGN: Retrospective study. METHODS: In this study, 59 eyes of 59 patients who applied as candidates for refractive surgery were included. Measurements of the posterior corneal curvature were performed using IOLMaster 700 and Pentacam HR. J0 and J45 vector components were calculated using astigmatic values. Posterior corneal keratometry (K) measurements at flat (K flat) and steep (K steep) axes and J0 and J45 values were compared between the 2 devices. The agreement between the devices was analyzed using the Bland-Altman method. Intraclass correlation coefficients and within-subject SD were calculated to assess the repeatability. RESULTS: 59 eyes of 59 patients were included in this study. The IOLMaster 700 provided significantly flatter K flat and K steep values (P < .001, for both). Significant differences were found in J0 and J45 values (P = 0.13 and P < .001, respectively). The mean differences between K flat, K steep, and J0 and J45 values were 0.49 diopter (D), 0.53 D, 0.04 D, and -0.05 D, respectively. CONCLUSIONS: The IOLMaster 700 and the Pentacam HR could not be used interchangeably to measure K flat, K steep, and J0 and J45 values of the posterior corneal curvature in healthy, myopic eyes. Both devices showed high repeatability for posterior corneal curvature measurement.

A Comparison of Two Foldable Phakic Intraocular Lenses Implanted in Different Anatomical Compartments: Artiflex Versus Eyecryl.

OBJECTIVES: The aim of this study was to compare the refractive results and safety of Artiflex (Ophtec BV, Groningen, Netherlands) and Eyecryl (BioTech Healthcare GmbH, Luzern, Switzerland) phakic intraocular lenses (pIOL). METHODS: The medical records of patients who underwent implantation of Artiflex or Eyecryl pIOL were retrospectively reviewed. Patients with a follow-up of 3 years were included in the study. Manifest refractive error, uncorrected and corrected visual acuity, intraocular pressure (IOP) and central endothelial cell density (ECD) data were evaluated preoperatively and at 1 and 3 years after surgery. RESULTS: In all 79 eyes (Artiflex group: 35 eyes; Eyecryl group: 44 eyes) were included in the study. The preoperative spherical equivalent (SE) of manifest refractive error was -11.53±3.46 in the Artiflex group and -13.08±3.01 in the Eyecryl group. Three years after the operation, the efficacy index was 1.06±0.55 and 1.15±0.85 in the Artiflex and Eyecryl groups, respectively. The safety index was in 1.32±0.49 and 1.46±0.95 the Artiflex and Eyecryl groups, respectively. The SE refractive error, efficacy index, safety index UDVA, CDVA, IOP, and ECD were not significantly different between groups during follow-up. CONCLUSION: Both the Artiflex and Eyecryl foldable pIOLs were found to be safe and effective up to 3 years after implantation. Prospective longitudinal studies are needed to assess and compare the rate of cataract formation.

Detection of and Compensation for Static Cyclotorsion With an Image-Guided System in SMILE.

PURPOSE: To evaluate the effect of cyclotorsion compensation with an image-guided system (Callisto eye; Carl Zeiss Meditec AG, Jena, Germany) on the visual and refractive outcomes of small incision lenticule extraction (SMILE) surgery for astigmatism. METHODS: The medical records of 124 right eyes of 124 patients with astigmatism of 0.75 diopters (D) or greater who underwent SMILE for myopic astigmatism were reviewed. Patients were treated with cyclotorsion compensated SMILE or standard SMILE. After the sitting position reference axis was registered with IOLMaster 700 (Carl Zeiss Meditec AG), these data were transferred to the Callisto eye system, which was connected to the operating VisuMax microscope (Carl Zeiss Meditec AG). Cyclotorsion was measured by activating the Z-align function and compensated for by repositioning the patient's body or tilting the head until the reference axis from the IOLMaster 700 (0-180) was parallel to a manually drawn reference axis on the screen (0-180) before docking. The visual and refractive results were studied preoperatively and postoperatively. Astigmatic changes were interpreted using the Alpins method. RESULTS: Six months after surgery, the results showed that the astigmatic eyes in the cyclotorsion compensated group had improved axial alignment, more precise astigmatic correction, and better postoperative uncorrected distance visual acuity (UDVA) compared with the standard group. The mean logMAR UDVA was 0.02 ± 0.10 (range: -0.15 to 0.30) and 0.06 ± 0.11 (range: -0.15 to 0.30) (P = .13) and the mean astigmatic error was -0.19 ± 0.17 D (range: -0.50 to 0.00 D) and -0.45 ± 0.38 D (range: -1.50 to 0.00 D) (P < .001) in the cyclotorsion compensated group and the standard group, respectively. In regard to vector analysis, the mean index of success was 0.00 ± 0.00 (range: 0.00 to 0.00) and 0.40 ± 0.48 (range: 0.00 to 2.72) (P < .001), and the mean absolute angle of error in degrees was 1.18 ± 2.23 (range: 0.00 to 13.00) and 3.76 ± 3.80 (range: 0.00 to 14.00) (P < .001) in the cyclotorsion compensated group and the standard group, respectively. CONCLUSIONS: The combination of the Callisto eye system with a VisuMax laser might be an efficacious and reliable approach to enhance astigmatism treatment with SMILE surgery. [J Refract Surg. 2020;36(3):142-149.].

Results of Callisto Eye System in Toric Intraocular Lens Alignment.

OBJECTIVES: This study was an evaluation of the effectiveness of the Callisto eye image-guided, markerless system (Carl Zeiss Meditec AG, Jena, Germany) in toric intraocular lens (IOL) positioning. METHODS: The results of a novel, markerless, alignment system used for IOL positioning were analyzed in this retrospective study. Preoperatively, reference image registration was performed with the IOLMaster 700 biometer (Carl Zeiss Meditec AG, Jena, Germany) and transferred to the Callisto eye system, which was used in conjunction with an Opmi Lumera 700 microscope (Carl Zeiss Meditec AG, Jena, Germany). Using the Callisto Z Align technology, a toric IOL was aligned precisely with the steep axis. One day after surgery, the pupil was fully dilated and a thin slit was placed on the marker of the toric IOL and the angle was measured using an axis calculator smartphone application. The degree of the measured angle and the preoperatively determined angle were compared. RESULTS: Sixty eyes of 46 patients were included. The difference in the absolute angle between the intended and the postoperative (at day 1) axes was a mean of 2.71±1.64°. CONCLUSION: The Callisto eye image-guided, markerless system successfully provided assistance in precisely positioning the toric IOL.

Comparison of Toric Intraocular Lens Alignment Using Image-Guided System and Manual Marking Technique.

OBJECTIVES: The aim of this study was to compare the accuracy of an image-guided system (Callisto eye; Carl Zeiss, Oberkochen, Germany) with the manual marking technique in the positioning of a toric intraocular lens (IOL). METHODS: A total of 80 eyes of 80 patients who underwent cataract surgery with a monofocal, single-piece, hydrophobic, biconvex, toric, aspheric IOL (Acrysof IQ SN6AT, Alcon Laboratories, Inc., Fort Worth, TX, USA) implantation were included. Before surgery, all of the patients underwent a complete eye examination that included evaluation of uncorrected (UCVA) and corrected distance visual acuity (CDVA), spherical equivalent (SE), astigmatic refraction (AR), keratometry, biometry, as well as meridian registration with the IOLMaster 700 (Carl Zeiss, Oberkochen, Germany), slit lamp examination, intraocular pressure measurement, and dilated retinal examination. The diopter of the toric IOL was calculated with an online calculator (Alcon, Fort Worth, TX, USA). At 3 months post surgery, the UCVA, CDVA, SE, and residual astigmatism were recorded, and the pupils of all of the patients were fully dilated to determine the toric IOL marker positions. RESULTS: Group 1, the Callisto eye system group, comprised 45 eyes, and Group 2, the manual marking technique group, was composed of 35 eyes. The preoperative values of both groups were statistically similar in terms of the SE, corneal cylinder, axial length, logMAR UDVA, and logMAR CDVA. At postoperative 3 months, there were no significant differences between the 2 groups in the logMAR UDVA, logMAR CDVA, degree of misalignment of toric IOL, or mean deviation from target-induced astigmatism values. The mean deviation degree from the intended axis was 2.04±1.84 in the Callisto eye system group (Group 1) and 3.24±2.64 in the manual marking technique group (Group 2). However, this difference did not have any effect on the logMAR UDVA. CONCLUSION: The image-guided markerless system was found to be as effective as manual marking in the positioning of toric IOLs.

Rotational Stability of a New Posterior Chamber Toric Phakic Intraocular Lens.

PURPOSE: To evaluate the refractive results and rotational stability of Eyecryl toric phakic intraocular lens (pIOL). METHODS: In this retrospective single-surgeon case series, manifest refraction, visual acuities, endothelial cell density (ECD), and pIOL rotation were evaluated over 6 months. RESULTS: 43 eyes from 23 patients were included. At 6 months, the SE was within ±0.50 D of emmetropia in 30 (70%) eyes and within ±1.00 D of emmetropia in 39 (91%) eyes. The efficacy and safety indices were 1.25 ± 0.38 and 1.41 ± 0.34, respectively. Mean ECD was 2719 ± 296 cells/mm2 at the preoperative visit and 2779.42 ± 422 cells/mm2 at the 6-month visit (p > 0.05). The mean value of absolute axis orientation error was 4.95 ± 5.28°. Mean absolute change in axis orientation between visits was less than 3° for all visit intervals. Ninety percent or more of lenses were found to rotate 5° or less between all visit intervals. None of the patients experienced a vision-threatening complication, and no patient required secondary IOL repositioning. CONCLUSION: The pIOL appears to effectively reduce subjective manifest astigmatism and provide good visual acuity. Its position was found to be stable throughout the follow-up.