The Alcon Research Institute

Comparison of novel digital microscope using integrated intraoperative OCT with Ngenuity 3D visualization system in phacoemulsification

To analyze the optical quality of aspheric toric intraocular lenses (IOLs) at different degrees of decentering. Wavefront aberrations of Acrysof IQ Toric IOLs (SN6AT3, SN6AT4, and SN6AT5; Alcon Laboratories Inc, Fort Worth, TX, USA) for different powers (15.00, 20.00 and 23.50 diopters [D]) and for different degrees of decentering (diagonal, horizontal, and vertical decentering of 0.3 and 0.6mm) were measured in vitro at 3- and 5-mm pupils. The Zernike coefficients of trefoil, coma, tetrafoil, secondary astigmatism, and spherical aberration were evaluated. The point spread functions (PSFs) and modulation transfer function (MTF) of each IOL evaluated were calculated from the wavefront aberrations. Coma aberration increased significantly with IOL decentration. Statistically significant differences were found between centered and all decentered positions in coma aberration (p < 0.05). Although, we only found visible differences between centered and decentered positions in PSF images and MTF curves for horizontal and vertical 0.6mm of decentering at 3- and 5-mm pupil. Despite the coma increment, these values were clinically negligible and have no effect on visual performance, except for vertical and horizontal 0.6mm of decentering, which could have a negative effect on visual quality.

To evaluate the clinical outcomes of custom topographic neutralizing technique in treating highly aberrated eyes using the WaveLight ALLEGRETTO WAVE Excimer Laser. A retrospective consecutive case series of 67 eyes with decentered ablations and 48 eyes with symptomatic small optical zones after previous LASIK underwent topography-guided retreatment with the ALLEGRETTO WAVE. Sixteen keratoconus eyes underwent topographic neutralizing technique photorefractive keratectomy (PRK). The study assessed preoperative and 6-month and 1-year postoperative results regarding best spectacle-corrected visual acuity (BSCVA), uncorrected visual acuity (UCVA), topography, and predictability. Sixty-seven eyes with previously decentered optical zones had an improvement of centration from 0.92 mm preoperatively to 0.30 mm postoperatively relative to pupil center (P<.01). Twenty-nine percent of these eyes gained 1 or more lines of BSCVA, whereas 71% had no change in BSCVA. Forty-eight eyes with previously small optical zones had an increase of the central monodioptric optical zone from 3.9 mm to 5.6 mm (P<.01). Nineteen percent of eyes had an improvement of at least 1 line, whereas 75% had no change in BSCVA and 6% lost 1 line. Sixteen keratoconus eyes had custom topographic neutralizing technique PRK as an alternative to penetrating keratoplasty. All eyes had improvement of astigmatism up to 5.00 diopters (D), with a mean change of 1.68+/-1.62 D. Best spectacle-corrected visual acuity was unchanged in 8 (50%) eyes, with 4 (25%) eyes gaining 1 line, 2 (12%) eyes gaining 2 lines, and 2 (12%) eyes losing 1 line of BSCVA at 6 months. Management of some highly aberrated eyes is now possible with topography-guided ablation using the WaveLight ALLEGRETTO platform and custom topographic neutralizing technique. Safety was acceptable for small optical zone and decentered ablation retreatments. The topography-guided ablation could be an alternative treatment for keratoconus patients if keratoplasty is otherwise indicated. The algorithms for custom topographic neutralizing technique need further refinement.

To evaluate visual quality differences among intraocular lenses (IOLs) in patients with previous hyperopic laser ablations and to assess the impact of decentration and tilt of IOLs on visual quality. An adaptive optics visual simulator was used to simulate the wavefront aberration pattern of one aberration-correcting IOL (AcrySof IQ SN60WF, Alcon Laboratories Inc) and two spherical IOLs with different amounts of positive spherical aberration (Akreos Adapt [Bausch & Lomb] and Triplato [AJL Ophthalmic]) in five situations-centered, 0.2 mm and 0.4 mm of decentration, and 2° and 4° of tilt-in two groups: simulated low hyperopic laser corneal ablation (low hyperopia group) and high hyperopic laser corneal ablation (high hyperopia group). Monocular distance visual acuity at 100%, 50%, and 10% contrast were measured. Ten eyes were evaluated. When the IOLs were centered, all IOLs obtained comparable results for the low hyperopia group, whereas for the high hyperopia group, the Akreos Adapt and AcrySof IQ SN60WF showed better visual acuity than the Triplato. When the IOLs were misaligned, for the low hyperopia group, the best visual acuity results were obtained with the Akreos Adapt and the most critical situation was at 0.4 mm of decentration. For the high hyperopia group, misalignments decreased visual acuity in a higher amount than for the low hyperopia group. Our results suggest that the IOLs studied offer good visual quality when they are centered for both groups. However, tilt and decentration of monofocal IOLs have an impact on visual function in patients with hyperopic ablations. For these patients, the Akreos Adapt is the most robust to misalignments.

To compare the optical performance of rigid spherical polymethylmethacrylate (PMMA), foldable spherical, and foldable aspheric intraocular lenses (IOLs). Measurements were obtained monocularly from pseudophakic patients with a PMMA IOL (Ophtec PC265y or Rayner 105U), spherical AcrySof MA30 IOL (Alcon Laboratories Inc), or aspheric Tecnis ZA9003 IOL (Abbott Medical Optics). Contrast sensitivity was measured using the Holladay automated contrast sensitivity test with 5.0-mm artificial pupil at 3 and 6 cycles per degree at optimal focus and at several defocus levels. The myopic shift (shift of the optimal focus toward more myopic values at lower spatial frequencies) and depth of focus were determined. Wavefront aberrations were assessed with a Hartmann-Shack wavefront analyzer; straylight was measured using the C-Quant meter (Oculus Optikgeräte GmbH). Nine patients with a spherical rigid PMMA IOL, 19 patients with a spherical foldable IOL, and 24 patients with an aspheric foldable IOL met the inclusion criteria. Eyes with an aspheric IOL showed less spherical aberration than eyes with other IOLs; no differences were found in overall higher order aberrations. No differences in contrast sensitivity at optimal focus and in straylight were found among the IOLs. Eyes with a PMMA IOL showed a larger depth of focus compared to eyes with an aspheric IOL. Eyes with an aspheric IOL had a smaller myopic shift than eyes with other IOLs. Optical performance differences among the IOLs in this study are small, concurring with similar higher order aberrations found in the three groups. Reduction in myopic shift appears to be the most obvious effect of aspheric IOLs.

To evaluate the efficacy of 2 ceruminolytic products, Cerumenex Eardrops (Purdue Frederick Company, Norwalk, Conn) and Murine Ear Drops (Abbott Laboratories, Abbott Park, Ill), in subjects with partial or complete occlusion of the ear canal due to cerumen. Randomized, subject- and observer-blind, placebo-controlled, clinical trial. Corporate research clinic. From among 230 volunteers screened, 74 subjects (age, 22-66 [mean, 45] years) were enrolled in the study. Participants had baseline occlusion levels of mild (n = 10), moderate (n = 26), or complete (n = 38) impairment of tympanic membrane visualization. Subjects were randomly assigned to 1 of 3 treatments: Cerumenex (10% triethanolamine polypeptide oleate-condensate), Murine (6.5% carbamide peroxide), and a placebo, BSS Sterile Irrigating Solution (Alcon Laboratories Inc, Ft Worth, Tex). The test medication was instilled into 1 occluded ear for up to two 15-minute applications. Following the treatment, the subject's ear was irrigated with 50 mL of lukewarm water delivered at low pressure via a WaterPik irrigator equipped with a Grossan irrigator tip. Main Outcome Measure The degree of occlusion, measured against a previously established 4-point scale, was assessed and recorded at baseline and after each instillation and irrigation procedure. Neither Cerumenex nor Murine was superior to saline placebo. By the end of treatment, 29.2%, 15.4%, and 41.7% of subjects treated with Cerumenex, Murine, and placebo, respectively, experienced resolution of cerumen occlusion. These values were not statistically significantly different from one another. The currently marketed ceruminolytic products, Cerumenex and Murine, are no more effective than a saline placebo in removing earwax.

To describe the outcomes of the first 285 eyes receiving LASIK or photorefractive keratectomy (PRK) using an optimized ablation profile at a refractive surgery practice experienced with customized ablation. A retrospective chart review was performed on all patients who underwent refractive treatments using the ALLEGRETTO WAVE Eye-Q platform (Alcon Laboratories Inc) between September 2008 and July 2009. Patients were divided into LASIK and PRK treatments, then further subdivided based on pre- and targeted postoperative refraction. Pre- and postoperative measures of uncorrected distance visual acuity (UDVA), corrected distance visual acuity, manifest refraction, keratometry, and wavefront values were taken and compared, and the average changes in keratometry and higher order aberrations were calculated. At 3 months postoperative, 92% of myopes and 63% of hyperopes undergoing LASIK with a target of emmetropia achieved UDVA of 20/20. Of PRK eyes targeted for emmetropia, 80% of myopic eyes achieved UDVA of 20/20 (the hyperopic subgroup was too small to analyze). In both LASIK and PRK subgroups, total wavefront aberrations decreased, as did some higher order aberrations. This group of patients, who all achieved excellent postoperative UDVA, represents our initial surgical experience with the ALLEGRETTO WAVE, using only a standard (global surgeon) nomogram. These results may serve as an estimate of what a practice could expect in terms of initial outcomes with this system.

To evaluate retinal straylight and patient complaint scores 18 months after implantation with the AcrySof ReSTOR diffractive multifocal intraocular lens (IOL) (Alcon Laboratories Inc). Retinal straylight was measured with the C-Quant (Oculus Optikgeräte GmbH) system in 40 eyes implanted with the AcrySof ReSTOR IOL (SA60D3) and in 40 eyes implanted with the AcrySof SA60AT monofocal IOL. Complaint scores were assessed by a questionnaire in both groups of patients at three different lighting conditions--day light, dimmed light, and at night. Seventy-five percent of eyes (30/40) of the ReSTOR group and 80% of eyes (32/40) of the SA60AT control group showed a retinal straylight value within or better than the normal range. No statistically significant differences between groups were found (P = .790). Patients of the ReSTOR group showed significantly more complaint scores at all assessed lighting conditions: increasing factors were 1.53, 2.02, and 2.66, for day light, dimmed light, and night, respectively (P < .0001). Comparing the amount of straylight, the multifocal group had 20% more straylight, albeit not significant at the 1% level. The AcrySof ReSTOR IOL showed similar retinal straylight values compared to the monofocal IOL. Subjectively, patients with the diffractive IOL claimed significantly more glare for all light conditions, especially at night.

To describe a case of a 52-year-old man with severe keratoconus who underwent femtosecond laser-assisted keratoplasty with the WaveLight FS200 femtosecond laser (Alcon Laboratories Inc). The donor and recipient corneas were cut in a mushroom-shaped pattern. The laser parameters used on this platform for the donor and recipient corneas are described. Corrected distance visual acuity improved by 3 weeks postoperatively. Mean keratometry decreased from 60.00 to 46.00 diopters. This patient underwent a mushroom-shaped keratoplasty with the femtosecond laser to maximize preservation of his own endothelium. Increased energy and/or decreased spot line separation may be required depending on the degree of corneal edema or scarring involved.

Medical therapy cost considerations for glaucoma

To compare the rate of epithelial healing following photorefractive keratectomy (PRK) with two commercially available fourth-generation fluoroquinolones, gatifloxacin (Zymar, Allergan, Irvine, California) and moxifloxacin (Vigamox, Alcon Laboratories, Fort Worth, Texas). Double-masked, randomized, prospective trial. Thirty-five subjects received gatifloxacin in one eye and moxifloxacin in the fellow eye following PRK with a 9.0-mm epithelial defect. Patients were examined daily after surgery until the epithelium had healed completely in both eyes. Beginning on post-operative day 3, photos were taken and used to confirm epithelial healing or measure the area of residual epithelial defects. Healing times and defect sizes were compared using the Wilcoxon signed-ranks test. Both eyes healed on the same day in 18 of the 35 subjects (51.4%). In 13 of 35 (37.1%) subjects, the moxifloxacin-treated eye healed first, compared with only four of 35 (11.4%) subjects whose gatifloxacin-treated eye healed first. All six of the eyes that took 2 days longer than their fellow eye to heal were gatifloxacin-treated. Median healing time for both groups was 4 days (moxifloxacin range: 3 to 7 days; gatifloxacin range: 3 to 9 days; P = .01), but only 69% of gatifloxacin-treated eyes had healed by day 4 compared with 80% of the moxifloxacin-treated eyes. Overall, on each post-operative day, defect sizes were greater for the gatifloxacin-treated eyes. This difference was statistically significant on day 4 (P = .027). Eyes treated with moxifloxacin healed faster and had smaller defects compared with those treated with gatifloxacin. This provides another factor to consider in selecting antibiotic prophylaxis for corneal refractive surgery.

BackgroundThe aim of this study was to compare the safety and efficacy of 20,000 cuts per minute (cpm) with 10,000 cpm in vitreous cutters.MethodsThis was a prospective, parallel, single masked randomized control trial comparing the 25 gauge 20,000 cpm HYPERVIT Dual Blade from Alcon Laboratories, Fort Worth, TX, USA and 10,000 cpm ULTRAVIT vitrectomy cutter from Alcon Laboratories, Inc, Fort Worth, TX. Standard T-test by SPSS version 27 was used to compare efficiency and safety between two groups.ResultsIn total 72 patients were recruited for the study and among them 71 patients completed the study. This study did not show any significant difference between 20,000 cpm probe and 10,000 cpm probe (p value = 0.347) for the core vitrectomy duration in all included eyes. The mean of core vitrectomy time was 269.28 s in the 25 gauge 20,000 cpm group and 289.44 s in the 25 gauge 10,000 cpm group. However, by comparing the two systems operated on epiretinal membrane eyes, 20,000 cpm probe had a significantly shorter mean core vitrectomy time than 10,000 cpm group (P = 0.03). The majority of all the patients had no intraoperative retinal tear (98.6.8%) and post-operative retinal tear (95.8%). There were no intraoperative iatrogenic breaks, and 3 postoperative retinal tears with rhegmatogenous retinal detachment (RRD) were documented. All the retinal tears belongs to the 20,000 cpm group but no significant difference was found between the two groups in terms of retinal tear and complications.Conclusions25-gauge 20,000 cpm Hypervit dual blade showed a faster trend in vitrectomy time although this was not statistically significant in all included eyes. By comparing vitrectomy time operated on epiretinal membrane eyes, a significant shorter time was found in 25-gauge 20,000 cpm. With more efficient and faster vitrectomy systems, the effect of surgeon factor likely plays a larger role. Our study suggest that the two devices may have a similar efficacy and safety. However, further studies may be needed to compare the core vitrectomy time between them after excluding the surgeon factor influence.

Outcomes of Bilateral Cataract Surgery in Tanzanian Children

Inferior Pseudophakic Retinal Detachment

Incidence of Dislocation of Intraocular Lenses and Pseudophakodonesis 10 Years after Cataract Surgery