Factors leading to realignment or exchange after implantable collamer lens implantation in 10 258 eyes.

PURPOSE: To evaluate the incidence, causes, and outcomes of implantable collamer lens (ICL) realignment or exchange after implantation of the EVO-ICL. SETTING: Eye and ENT Hospital of Fudan University, China. DESIGN: Retrospective study. METHODS: The study included 10 258 consecutive eyes after ICL implantation. Preoperative refractive and biometric measurements were compared between eyes with and without realignment or exchange. For eyes with ICL realignment or exchange, visual and biometric outcomes were also compared before and after ICL realignment or exchange. RESULTS: The overall incidence of ICL realignment or exchange was 0.21% 22 eyes. 12 eyes (0.12%) underwent ICL realignment by axis rotation (10 eyes) or ICL exchange (2 eyes) due to toric ICL (TICL) misalignment. After realignment, uncorrected distance visual acuity improved, and residual cylinder decreased from -1.75 ± 0.48 diopters (D) to -0.87 ± 0.59 D ( P = .01). 10 eyes (0.10%) underwent vertical rotation of ICL (3 eyes) or ICL exchange (7 eyes) due to excessive vault. After either vertical rotation or ICL exchange, vault decreased significantly ( P < .05). CONCLUSIONS: The incidence of ICL realignment or exchange after ICL implantation is low. TICL misalignment and excessive vault are 2 main causes. Implant exchange may be performed for excessive vault or misalignment with an insufficient vault. In addition, vertical rotation of an ICL may be a less invasive method to treat excessive vault in certain cases.

Visualization of Forward Light Scatter in Opacified Intraocular Lenses and Straylight Assessment.

BACKGROUND: Qualitative visualization of forward light scatter and quantitative straylight measurement of intraocular lenses (IOLs). METHODS: We analyzed two calcified IOL-explants, the Euromaxx ALI313Y (Argonoptics GmbH) and the LS-312 MF30 (Oculentis BV), one IOL with artificially induced glistenings (PC-60AD, Hoya), and one control (CT Asphina 409MP, Carl Zeiss Meditec AG) free of any opacification. Analysis included light microscopy, qualitative light scatter visualization using ray propagation imaging technique, and quantitative straylight measurement using C-Quant (Oculus). RESULTS: More light scattering effect-visible as increased light intensity outside the IOL's main focus-was evident in all opacified IOLs than the control. The highest straylight levels were observed in the Euromaxx (289.71 deg2/sr), which showed extensive granular deposits throughout its optic, followed by the MF30 (78.58 deg2/sr), which only showed opacification in its center. The glistenings-IOL demonstrated numerous microvacuoles within the optic and had straylight levels of 22.6 deg2/sr, while the control showed the lowest straylight levels (1.7 deg2/sr). CONCLUSIONS: Ray propagation imaging technique allowed qualitative assessment of off-axis veils of light that result from increased forward light scattering. Straylight was increased in all opacified lenses compared to the clear control lens. The IOL opacifications are significant sources of glare.

Corneal Incision Enlargement in Two Preloaded Intraocular Lens Injectors: An Intraindividual In Vivo Study.

PURPOSE: To assess enlargement of the clear corneal incision site and functional outcome in patients with cataract, following the use of two preloaded intraocular lens (IOL) injectors. METHODS: In this prospective, randomized, intraindividual comparative clinical study, 58 paired-eyes were randomly assigned for implantation with two preloaded injectors: AutonoMe with a Clareon IOL (Alcon Laboratories, Inc) and iSert with a Vivinex IOL (Hoya). The size of the corneal incision, 2 mm for the iSert and 2.2 mm for the AutonoMe, was measured before and after phacoemulsification and after IOL implantation. Patients were examined 3 months after surgery to assess keratometry, subjective refraction, and visual acuity. RESULTS: The incision enlargement was 0.20 ± 0.10 mm for the AutonoMe and 0.29 ± 0.10 mm for the iSert, with a statistically significant difference (P < .05). The final wound size after IOL implantation was 2.41 mm for the AutonoMe and 2.35 mm for the iSert. The mean absolute surgically induced astigmatism (SIA) was 0.50 ± 0.25 diopters (D) in the iSert eyes and 0.45 ± 0.20 D in the AutonoMe eyes (P > .05). The 3-month postoperative uncorrected and corrected distance visual acuity (UDVA and CDVA) were similar in both groups, with a UDVA of 0.10 and 0.12 logMAR and CDVA of -0.04 and -0.03 logMAR, respectively for the AutonoMe and iSert. CONCLUSIONS: The iSert injector caused more enlargement of the corneal wound during IOL implantation compared to the AutonoMe. Despite the initially different incision sizes, the final incision size and functional outcomes were similar in both groups. [J Refract Surg. 2021;37(5):331-336.].

Trifocality Achieved Through Polypseudophakia: Optical Quality and Light Loss Compared With a Single Trifocal Intraocular Lens.

PURPOSE: To compare the optical performance of a twointraocular lens (IOL) system with that of a single capsular bag trifocal IOL. METHODS: The two-IOL configuration of a monofocal RayOne Aspheric (Rayner Intraocular Lenses, Ltd) and a Sulcoflex Trifocal (Rayner Intraocular Lenses, Ltd) lens was compared in vitro with a single-lens option (RayOne Trifocal; Rayner Intraocular Lenses, Ltd). Two samples of each IOL model were studied with an optical metrology device. The optical quality was assessed using the area under the modulation transfer function (MTF). The impact of the supplementary lens mis-alignment on the MTF was tested. The light loss was also measured using a power meter. RESULTS: The two-IOL system produced three well-defined focal peaks comparable to those of the single lens. The MTF area of the single- and two-IOL configuration was, respectively, 22.5 and 20.7 at far, 16.4 and 15.4 at intermediate, and 14.9 for each configuration at near. A moderate decentration (up to 0.6 mm) had a minimal effect at intermediate and near on the supplementary lens MTF and no impact at far. A 5° tilt did not alter the MTF. The supplementary lens caused a 1.3% decrease in the optical power. CONCLUSIONS: The optical quality of the two-IOL system matched that of the single trifocal lens. A low-power supplementary IOL demonstrated high tolerance to misalignment and minimal light attenuation. The reversibility of the two-IOL approach may prove advantageous clinically. [J Refract Surg. 2020;36(9):570-577.].

Comparison Between Bilateral Implantation of a Trifocal IOL and Mix-and-Match Implantation of a Bifocal IOL and an Extended Depth of Focus IOL.

PURPOSE: To compare the clinical outcomes of mix-and-match implantation of a diffractive extended depth of focus intraocular lens (IOL) (TECNIS Symfony ZXR00; Johnson & Johnson Vision) and a diffractive bifocal IOL (TECNIS ZLB00 +3.25 diopters [D]; Johnson & Johnson Vision) and bilateral implantation of a diffractive trifocal IOL (AcrySof IQ PanOptix; Alcon Laboratories, Inc). METHODS: This prospective comparative study compares the clinical outcomes of patients with age-related cataract undergoing cataract surgery using the IOLs described. Patients were divided into the mix-and-match group and the trifocal group. Assessment included monocular and binocular uncorrected distance visual acuity (UDVA), intermediate visual acuity (UIVA at 60 cm), and near visual acuity (UNVA at 40 cm), uncorrected defocus curves, contrast sensitivity, and reading speed. Quality of vision was measured with the Visual Function Questionnaire (VFQ-25). RESULTS: A total of 50 patients (25 in each group) were enrolled. At 6 months postoperatively, outcomes of binocular UDVA, UIVA, and UNVA were similar in both groups. The binocular defocus curve only differed at vergences of -0.50 to -1.00 D (better for the mix-and-match group; P = .032 and .004, respectively) and at -4.00 D (better for the trifocal group; P = .001). Significantly higher reading speeds in the mix-and-match group were measured at 0.7 and 0.5 logMAR (P = .038 and .034, respectively). There were no significant differences between groups for contrast sensitivity and the results of the questionnaire. CONCLUSIONS: The mix-and-match implantation seemed to be a good option for patients with high demands for distance and intermediate visual acuity, whereas the trifocal IOL appeared to be more suitable for patients with enhanced near vision demands. [J Refract Surg. 2020;36(8):528-535.].

Semi-fluorinated Alkane Eye Drops Reduce Signs and Symptoms of Evaporative Dry Eye Disease After Cataract Surgery.

PURPOSE: To clinically evaluate the efficacy and tolerability of semi-fluorinated alkane eye drops (EvoTears; URSAPHARM GmbH) as ocular surface treatment after cataract surgery in patients with evaporative dry eye disease. METHODS: This prospective, monocentric, open-label clinical trial included 40 patients undergoing cataract surgery and showing symptoms of evaporative dry eye disease as measured by the Symptom Assessment in Dry Eye (Visual Analogue Scale [VAS]) questionnaire, Ocular Surface Disease Index (OSDI), and tear break-up time (TBUT) of less than 10 seconds. EvoTears was prescribed four times a day for 5 weeks and administered 15 minutes after the standard postoperative topical anti-inflammatory regimen. The primary endpoint was the change in TBUT. Secondary endpoints included assessment of the subjective symptoms (VAS), corrected distance visual acuity (CDVA), slit-lamp examination, intraocular pressure, and Schirmer's test, which were evaluated at 1 day, 1 week, and 5 weeks postoperatively. At 5 weeks postoperatively, the tolerability and efficacy of EvoTears were evaluated by physicians and patients. RESULTS: At 5 weeks postoperatively, the median TBUT increased from 6.8 (preoperative) to 14 seconds (P < .001) and the average total corneal staining score decreased from 3.53 (preoperative) to 2.36 (P < .001). The mean CDVA improved from 0.41 (preoperative) to 0.14 logMAR (P < .001) and there was a statistically significant decrease in all scores from the VAS questionnaire at 5 weeks postoperatively. There was no statistically significant change in Schirmer's test (P = .150). CONCLUSIONS: EvoTears improved tear film, ocular surface, and subjective impressions of patients with dry eye disease 5 weeks after cataract surgery. Patients' and physicians' assessment indicated good efficacy and high tolerability of EvoTears, suggesting its suitability in postoperative management of the ocular surface in patients with dry eye disease. [J Refract Surg. 2020;36(7):474-480.].

Intraocular pressure changes and corneal biomechanics after hyperopic small-incision lenticule extraction.

BACKGROUND: We aimed to compare the intraocular pressure (IOP) measurements by a dynamic Scheimpflug analyzer (Corvis ST), a non-contact tonometer, and an ocular response analyzer after hyperopic small-incision lenticule extraction (SMILE). METHODS: Thirteen patients who underwent hyperopic SMILE in one eye were enrolled prospectively. IOP and corneal biomechanical parameters were measured preoperatively and at 1 week, 1 month, and 3 months postoperatively with a non-contact tonometer (IOPNCT), Corvis ST (biomechanical corrected IOP [bIOP]), and ocular response analyzer (Goldmann-correlated intraocular pressure [IOPg] and cornea compensated IOP [IOPcc]). A linear mixed model was used to compare the IOPs and biomechanical values among methods at each time point. RESULTS: IOPNCT, IOPg, and IOPcc dropped significantly after surgery, with the amplitude being 3.15 ± 0.48 mmHg, 5.49 ± 0.94 mmHg, and 4.34 ± 0.97 mmHg, respectively, at the last follow-up visit. IOPNCT decreased by 0.11 ± 0.06 mmHg per µm of excised central corneal thickness. bIOP did not change significantly after surgery. Preoperatively, no difference was found among the four measurements (P > 0.05). Postoperatively, IOPNCT and bIOP were higher than IOPg and IOPcc. bIOP was independent of cornea thickness at last follow-up visit, whereas it correlated significantly with corneal biomechanics similar to the other three IOP values. CONCLUSION: bIOP is a relative accurate measure of IOP after hyperopic SMILE.

Three-Step Treatment of Keratoconus and Post-LASIK Ectasia: Implantation of ICRS, Corneal Cross-linking, and Implantation of Toric Posterior Chamber Phakic IOLs.

PURPOSE: To evaluate vision and corneal surface regularity after each step of a three-step surgical treatment of keratoconus and post-laser in situ keratomileusis (LASIK) ectasia (implantation of intracorneal ring segments [ICRS], corneal cross-linking [CXL], and implantation of toric intraocular contact lenses [ICLs]). METHODS: Thirty-one eyes of 24 patients with moderate to severe keratoconus and post-LASIK ectasia (stages II and III of Amsler-Krumeich classification) were included. All eyes underwent all three steps. The time interval between ICRS implantation and CXL was 4 to 6 weeks, and ICL implantation was performed 6 to 8 months after CXL. Visual acuity, refraction, and corneal topometric indices were evaluated with the Pentacam system (index of surface variance [ISV], index of vertical asymmetry [IVA], keratoconus index [KI], central keratoconus index [CKI], index of height asymmetry [IHA], index of height decentration [IHD], and corneal wavefront parameters [eg, higher order aberrations, spherical aberration, and coma]). RESULTS: Decimal uncorrected distance visual acuity (UDVA) improved from 0.13 ± 0.17 preoperatively to 0.69 ± 0.18 at 1 year, whereas corrected distance visual acuity (CDVA) improved from 0.56 ± 0.24 to 0.80 ± 0.18, respectively. The topometric indices ISV, IVA, KI, and IHD also improved significantly, whereas CKI and IHA showed no significant improvement. Higher order aberrations, spherical aberration, and coma improved significantly compared to baseline. CONCLUSIONS: The combined use of ICRS, CXL, and ICL implantation significantly improves visual acuity, higher order aberrations, and corneal shape in moderate and severe keratoconus and post-LASIK ectasia. [J Refract Surg. 2020;36(2):104-109.].

Impact of Primary Calcification in Segmented Refractive Bifocal Intraocular Lenses on Optical Performance Including Straylight.

PURPOSE: To describe and analyze the impact of calcification on the optical quality of segmented refractive bifocal intraocular lenses (IOLs). METHODS: Eight segmented refractive bifocal IOLs made of hydrophilic acrylic were explanted from 8 patients due to opacification (and one opacified IOL that was not explanted) and analyzed in a cross-sectional study with laboratory analysis. Nine cases comprised three IOL models: LS-313 MF30 (5 cases), LS-312 MF30 (3 cases), and LS-313 MF15 (1 case). Material analysis with scanning and transmission electron microscopy confirmed IOL calcification. Measurements of modulation transfer function (MTF) and straylight permitted assessment of the IOL optical quality. Values were compared to a control lens. RESULTS: Except for one case of Nd:YAG (neodymium:yttrium-aluminum-garnet) capsulotomy, there was no secondary surgical procedure in the patients' histories. Eight of nine patients reported deteriorated visual quality, ultimately requiring IOL exchange. Material evaluation revealed fine granules of a calcium phosphate. Despite calcification, all but one lens still showed two distinct foci on the MTF measurements. Straylight values were higher than in a cataractous lens (33.1 deg2/sr) in all cases, with an average value of 170.1 ± 71.5 deg2/sr. CONCLUSIONS: Optical quality assessment showed that IOL calcification had a small effect on the MTF of segmented refractive bifocal lenses but a large impact on the straylight levels. Accordingly, in the clinical case, straylight levels were elevated. [J Refract Surg. 2020;36(1):20-27.].

[Presbyopia Correction with Intraocular Lenses]. / Presbyopiekorrektur mittels Linsensystemen.

Surgical correction of presbyopia can be performed by refractive lens exchange, replacing the lens with a monofocal, a multifocal or an extended-depth-of-focus (EDOF) intraocular lens (IOL). Option 1, a monofocal IOL, must be combined with monovision, otherwise presbyopia cannot be corrected. Monovision in this context means one eye for distance and one eye targeted for - 1.5 D. With this concept glasses are still required for near (30 - 40 cm) and for driving, but intermediate distances and everyday life is usually possible without glasses. Option 2, a multifocal IOL, results in spectacle independence. Current multifocal IOL typically use three foci and are therefore called trifocal IOL. Distance vision and near vision are typically good, intermediate vision still acceptable but lower than distance and near, resulting in occasional problems while working on a computer. Option 3, EDOF-IOL, provide good distance and intermediate vision without glasses but near vision typically requires reading glasses.

Preoperative refraction, age and optical zone as predictors of optical and visual quality after advanced surface ablation in patients with high myopia: a cross-sectional study.

OBJECTIVE: To investigate the factors associated with optical and visual quality of advanced surface ablation in high myopia. DESIGN: A cross-sectional study of high myopic eyes treated with laser epithelial keratomileusis (LASEK)/epipolis laser in situ keratomileusis (Epi-LASIK). SETTING6: Eye and ENT Hospital of Fudan University in Shanghai. METHODS: One hundred and thirty-eight high myopic eyes (138 patients) (myopia -6 D or more) were examined more than 12 months after LASEK or Epi-LASIK with advanced surface ablation on the MEL 80 excimer laser (Zeiss AG, Jena, Germany). Refraction, higher order aberrations (HOAs) and contrast sensitivity before and after surgery were evaluated. Factors including preoperative refraction, age, gender, central corneal thickness, pupil size, optical diameter, ablation depth and flap creation method were analysed for association with postoperative high-order aberration, contrast and glare sensitivities, and different analytic diameters. RESULTS: HOAs increased significantly postoperatively (p<0.05), with the most significant change found in Z(spherical aberration). At a 5 mm analysis diameter, increased coma was associated with age; increased spherical aberration difference was associated with age, optical zone diameter and method of epithelial flap creation. At a 3 mm analysis diameter, none of the factors contributed to changes in HOAs. Higher preoperative refractive error was associated with decreased contrast and glare sensitivity at each spatial frequency. CONCLUSION: A larger optical zone diameter design is recommended to achieve better visual quality in advanced surface ablation for high myopia correction. Age and preoperative refraction may help predict postoperative visual quality.

Treatment of Corneal Ectasia by Implantation of an Allogenic Corneal Lenticule.

PURPOSE: To describe a case in which post-LASIK corneal ectasia was treated using an allogeneic lenticule implanted into the recipient eye. METHODS: A 29-year-old man presented with bilateral ectasia 10 years after LASIK. Manifest refraction was -1.50 -3.25 × 15° in the right eye and -13.50 -6.00 × 10° in the left eye. Because of contact lens intolerance in the left eye, the authors decided to implant an allogenic corneal lenticule, created by small incision lenticule extraction with the VisuMax laser (Carl Zeiss Meditec, Jena, Germany) in a donor eye with a refraction of +5.75 -0.50 × 15°. The intended peripheral thickness was 116 µm and the central thickness was 20 µm. The lenticule was placed under the original LASIK flap in the left eye. RESULTS: Ten months after surgery, refraction of the left eye had improved to -3.25 -1.50 × 10° with a corrected distance visual acuity of 20/40. The front corneal flat and steep values were decreased by 6.20 and 5.90 diopters (D), respectively, relative to corresponding preoperative values. The cornea remained clear throughout the follow-up. CONCLUSIONS: Implantation of an allogenic lenticule may be an option in the treatment of advanced ectasia. [J Refract Surg. 2018;34(5):347-350.].

Comparison of Color Light-Emitting Diode Corneal Topographer and Dual Rotating Scheimpflug-Placido Topographer.

PURPOSE: To compare measurements of anterior and posterior keratometric values, using a color light-emitting diode corneal topographer and a dual rotating Scheimpflug-Placido topographer. METHODS: Anterior and posterior corneal index measurements were performed using a color light-emitting diode corneal topographer (Cassini) and a dual rotating Scheimpflug-Placido topographer (Galilei G4) and then compared. The paired t-test, intraclass correlation coefficients (ICCs), and Bland-Altman plots were used to evaluate the agreement between measurements. RESULTS: Sixty postrefractive surgery eyes and 60 normal eyes were evaluated. Both the color light-emitting diode corneal topographer and the dual rotating Scheimpflug-Placido topographer provided highly repeatable corneal measurements (ICC > 0.969). The agreement levels between the 2 devices for anterior corneal power, astigmatism magnitude, and J0 and J45 values were ICC > 0.906 for the total group. However, the ICC values for posterior corneal power, astigmatism magnitude, and J0 and J45 values were lower than 0.681 for the total group. CONCLUSIONS: The anterior keratometric values obtained by the color light-emitting diode corneal topographer and the dual rotating Scheimpflug-Placido topographer showed high agreement levels, but the posterior keratometric values showed lower agreement levels.

Laboratory Evaluation of the Influence of Decentration and Pupil Size on the Optical Performance of a Monofocal, Bifocal, and Trifocal Intraocular Lens.

PURPOSE: To assess the influence of decentration and aperture size on the optical quality of different intraocular lenses (IOLs) of the same material, body design, and refractive power using standardized optical bench testing. METHODS: Using an optical bench set-up, an aspheric monofocal (CT ASPHINA 409M; Carl Zeiss Meditec, Jena, Germany), an aspheric diffractive bifocal (AT LISA 809M; Carl Zeiss Meditec), and an aspheric diffractive trifocal (AT LISA 839M; Carl Zeiss Meditec) intraocular lens (IOL) were evaluated, each with the same distance power, body design, and material. Modulation transfer function (MTF) values were measured at spatial frequencies of 50 lp/mm and aperture sizes of 3 and 4.5 mm. Each IOL was measured while centered, then decentered by 0.25, 0.5, 0.75, and 1 mm. RESULTS: MTF values for the monofocal IOL at far focus with 3- and 4.5-mm aperture size were 0.80/0.80 with maximum reduction to 0.77/0.73 for 1-mm decentration, respectively. Centered IOL MTFs of the bifocal and trifocal IOLs were lower for the far focus at 0.46/0.41 and 0.39/0.26, with reduction at 1-mm decentration to 0.35/0.25 and 0.25/0.18, respectively. Values for near focus of the bifocal and trifocal IOLs reduced from 0.27/0.31 and 0.19/0.18 to 0.2/0.21 and 0.12/0.13, respectively. The trifocal intermediate focus MTF reduced from 0.15/0.10 to 0.12/0.08. MTF values of all three lenses decreased significantly under all conditions with decentration of 0.5 to 0.75 mm. CONCLUSIONS: Monofocal lenses were least negatively affected by decentration, with mean optical quality reduction of less than 10% for 1-mm decentration at physiological pupil sizes. For diffractive bifocal and trifocal lenses, optical quality at all distances was significantly reduced if decentration exceeded 0.75 mm, with intermediate focus showing the least reduction. [J Refract Surg. 2017;33(12):808-812.].

Three-Year Stability of Posterior Corneal Elevation After Small Incision Lenticule Extraction (SMILE) for Moderate and High Myopia.

PURPOSE: To investigate long-term changes in posterior corneal elevation after small incision lenticule extraction (SMILE). METHODS: Thirty-six eyes of 20 patients (7 male, 13 female) who underwent SMILE were recruited for this prospective consecutive study. The mean preoperative manifest spherical equivalent was -6.24 ± 1.47 diopters (D) (range: -3.88 to -8.75 D). Posterior corneal surfaces were measured by a Scheimpflug camera (Pentacam; Oculus Optikgeräte GmbH, Wetzlar, Germany) preoperatively and at 1 month, 6 months, 12 months, 2 years, and 3 years after surgery. Posterior central elevation (PCE), posterior maximal elevation (PME), and posterior elevation at the thinnest corneal point (PTE) in the central 4-mm area above the best-fit sphere (BFS) were analyzed. The BFS was the same across all follow-up periods and determined by the preoperative data. A P value of less than .05 was considered statistically significant. RESULTS: All surgeries were executed without complications and no case of keratectasia was observed during the follow-up. An uncorrected distance visual acuity of 20/20 or better was achieved in 100% of eyes at the last visit. The mean change of PCE, PME, and PTE at 3 years after the operation was -2.39 ± 2.85, 0.50 ± 3.33, and -2.33 ± 2.90 µm, respectively. There were significant differences in the measurements of PCE and PTE before surgery and 3 years after surgery (P ≤ .009); however, there was no significant difference in PME before surgery and 3 years after surgery (P = 1.000). No correlation was found between changes in posterior corneal elevation and residual bed thickness, ablation depth, and preoperative thinnest corneal thickness. CONCLUSIONS: The posterior corneal surface, measured using the Pentacam, was stable after SMILE in the long-term follow-up. The cause of the slight backward change of PCE and PTE needs further study. [J Refract Surg. 2017;33(2):84-88.].

Change in Anterior and Posterior Curvature After Cataract Surgery.

PURPOSE: To analyze the change in anterior and posterior corneal curvature after cataract surgery using a Placido-dual rotating Scheimpflug device. METHODS: In a prospective cross-sectional study, corneal curvature was measured using the Galilei G4 device (Ziemer Ophthalmic Systems, Port, Switzerland) preoperatively and 1 week and 1, 3, and 6 months after cataract surgery with a temporal limbal self-sealing 2.2-mm incision. The surgically induced astigmatism (SIA) was determined on the anterior and posterior surfaces. RESULTS: Fifty-nine patients (68 eyes) were assessed. Based on the anterior corneal surface, 16 (23.5%) eyes had a vertically steep meridian (with-the-rule [WTR] astigmatism), 32 (47.1%) had a horizontally steep meridian (against-the-rule [ATR] astigmatism), and 20 (29.4%) had oblique astigmatism. Based on the posterior corneal surface, 2 (2.9%) eyes had a horizontally steep meridian (ATR astigmatism), 62 (91.2%) had a vertically steep meridian (WTR astigmatism), and 4 (5.9%) had oblique astigmatism. SIA of the anterior and posterior corneal surfaces was 0.61 ± 0.33 and 0.20 ± 0.17 diopters (D), respectively. However, there was no significant difference between the preoperative and the 6-month postoperative data in the Jackson coefficient orthogonal coordinate system for the anterior and posterior corneal surfaces. SIA of WTR astigmatism of the posterior cornea was 0.19 ± 0.16 D at 6 months. Sixty-one of 62 eyes with WTR astigmatism in the posterior corneal surface still showed WTR astigmatism after cataract surgery. CONCLUSIONS: The tendency of SIA of the posterior cornea may not be uniform, but type of posterior corneal astigmatism did not change in most cases after the 2.2-mm temporal limbal incision cataract surgery. [J Refract Surg. 2016;32(11):754-759.].

Posterior Corneal Elevation after Small Incision Lenticule Extraction for Moderate and High Myopia.

PURPOSE: To investigate the changes of posterior corneal elevation after small incision lenticule extraction (SMILE) for moderate and high myopia. METHODS: In this prospective study, fifty consecutive eyes of thirty patients (10 male, 20 female) who underwent SMILE for myopia and myopic astigmatism were included. Eyes were divided in two groups based on the preoperative spherical equivalent refraction: high myopia group (32 eyes, range -6.25D to -10.00D) and moderate myopia group (18 eyes, range -3.00D to -6.00D). Posterior corneal surfaces were measured by a Scheimpflug camera (Pentacam, Oculus Germany) preoperatively and 1 month, 3 months, 6 months and 12 months postoperatively. Posterior central elevation (PCE) and posterior mean elevation (PME) at 17 predetermined points in the central-4mm area above the best-fit sphere were analyzed. RESULTS: No significant difference in the amount of posterior corneal elevation changes in the high myopia group was noted over time (P = 0.23 and P = 0.94 for PCE and PME, respectively). Similarly, the changes in the moderate myopia group before and after SMILE were not significant either (P = 0.34 and P = 0.40 for PCE and PME). A statistically significant correlation was found between the residual bed thickness and the shift of the PCE in the high myopia group at 12 months postoperatively (r = 0.53, P = 0.01). CONCLUSIONS: The results of this study suggest that the posterior corneal surface remain stable within one year after SMILE for both moderate and high myopia. The changes of PCE correlate to the residual bed thickness for high myopia. Long-term changes of posterior corneal surface need further investigation.

Development of the continuous curvilinear lenticulerrhexis technique for small incision lenticule extraction.

PURPOSE: To develop and evaluate the new continuous curvilinear lenticulerrhexis (CCL) technique for small incision lenticule extraction. METHODS: Thirty-one eyes of 20 patients with myopia were included in the study. The CCL technique for lenticule extraction was developed and used in 16 eyes of 10 patients (CCL group). The traditional technique of lenticule extraction was used in 15 eyes of 10 patients (traditional group). Uncorrected and corrected distance visual acuity, manifest refraction, lenticule quality, the duration of the extraction procedure, microdistorsions in Bowman's layer under optical coherence tomography (Optovue OCT; Optovue, Inc., Fremont, CA), and adverse events were evaluated at 1 day and 1 month postoperatively. RESULTS: At the first postoperative month, all eyes in both groups had an uncorrected distance visual acuity of 1.0 or better. The safety indices were 1.12 and 1.09 for the CCL and traditional groups, respectively. The efficacy indices were 1.06 and 1.09 for the CCL and traditional groups, respectively. All lenticules in the CCL group had intact, round margins, whereas one lenticule in the traditional group had a microdefect margin. There was no statistically significant difference in duration of lenticule extraction or microdistorsions in Bowman's layer. No eyes in the CCL group developed diffuse lamellar keratitis, as compared to one eye in the traditional group. CONCLUSIONS: The CCL technique exhibited excellent safety and efficacy for myopia correction, suggesting CCL is a promising technique that merits further development and study.

The use of femtosecond lasers in cataract surgery: review of the published results with the LenSx system.

PURPOSE: To review the published literature describing the use of the LenSx femtosecond laser technology (Alcon Laboratories, Inc., Fort Worth, TX) in cataract surgery. METHODS: Literature review. RESULTS: The LenSx system has been used in more than 200,000 cataract surgery procedures to date. Pre-clinical evaluations have shown that this system produces accurate and reproducible capsulorhexes, and that both the energy required for phacoemulsification and total phacoemulsification time are less than with conventional phacoemulsification. In comparative studies, femtosecond lasers have been shown to produce more precise and reproducible capsulorhexes than manual procedures, and better intraocular lens placement; capsule overlap, circularity of capsulotomy, and centration of the intraocular lens are consistently better with femtosecond lasers than with manual procedures. The improved quality of capsulorhexis and intraocular lens positioning are reflected in favorable visual and refractive outcomes. As with any new technology, there is a significant learning curve: prospective cohort studies have shown that the incidence of intraoperative complications such as suction breaks or anterior capsular tears or tags decreases with experience. In general, the incidence of such complications is within the range (< 2%) considered in recent evidence-based guidelines to be feasible and desirable. CONCLUSIONS: Although femtosecond laser cataract surgery is in its infancy, the technology is evolving rapidly and offers the potential for more consistent and predictable results after cataract surgery.