Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 17 de 17
Filter
2.
Graefes Arch Clin Exp Ophthalmol ; 260(9): 2941-2948, 2022 Sep.
Article in English | MEDLINE | ID: mdl-35380269

ABSTRACT

PURPOSE: A new femtosecond laser assisted deep anterior lamellar keratoplasty technique (Clear Cornea Femto DALK or CCF DALK) can be performed with less technical challenges compared to conventional procedures. This paper reports on a preliminary case series to evaluate the technique. METHOD: First, through a clear cornea approach, Descemet's membrane (DM) is completely separated from posterior stroma by injection of balanced salt solution/viscoelastic substance through a special cannula inserted into the deep stroma and positioned right above the DM without perforating. The injection creates a liquid chamber that detaches the DM while preserving a reasonably transparent corneal stroma. Afterwards, a complete posterior/anterior trephination of the stroma, from the liquid chamber to the epithelium, is done using a femtosecond laser system under optical coherence tomography control. RESULTS: This technique was successfully performed in a preliminary series of 10 eyes/10 patients. All patients had the DM completely bared and kept their own endothelial cell population with minimal cell loss (< 15%) after 6 months. Postoperative interface reaction was minimal, and no immune reactions were observed thus far. CONCLUSION: Clear Cornea Femto DALK is a promising alternative to previous Femto DALK procedures with good acceptance of the tissue seen to date.


Subject(s)
Corneal Transplantation , Keratoconus , Cornea , Corneal Stroma , Humans , Lasers , Tomography, Optical Coherence
3.
J Cataract Refract Surg ; 42(9): 1255-1261, 2016 09.
Article in English | MEDLINE | ID: mdl-27697242

ABSTRACT

We describe a technique that uses a femtosecond laser (femtosecond laser pseudophakic capsulotomy) to treat capsule contraction syndrome (capsule phimosis) that may occur after cataract surgery and intraocular lens (IOL) implantation. Enlarging the capsulotomy with a femtosecond laser may offer advantages over the existing treatment methods, neodymium:YAG laser capsulotomy and manual extension of the capsulorhexis. FINANCIAL DISCLOSURE: None of the authors has a financial or proprietary interest in any material or method mentioned.


Subject(s)
Cataract Extraction , Laser Therapy , Lens Implantation, Intraocular , Capsulorhexis , Humans , Lasers, Solid-State , Postoperative Complications
4.
J Refract Surg ; 32(9): 618-25, 2016 Aug 01.
Article in English | MEDLINE | ID: mdl-27598732

ABSTRACT

PURPOSE: To conduct a material analysis of spontaneously subluxated iris-fixated phakic intraocular lenses (IOLs) using light and scanning electron microscopy. METHODS: Six explanted Artisan/Verisyse and Artiflex/Veriflex IOLs (Ophtec, Groningen, Netherlands/AMO, Santa Ana, CA) were analyzed in a laboratory using light and scanning electron microscopy. Four of the IOLs had been explanted after spontaneous subluxation leading to a decrease in visual acuity, whereas the remaining two IOLs did not demonstrate signs of disenclavation but had been explanted in the course of planned cataract surgery and thus served as the control in this study. RESULTS: Light microscopy enabled the detection of clear deformations of the fixation arms on one or both haptics of the lens that had subluxated, and scanning electron microscopy revealed micro-cracks in the material. The deformations, which appeared to have been caused by some form of manipulation of the fixation arms, meant that adequate closure of the fixation arms was no longer possible and a reliable fixation in the iris stroma was unattainable. At least three of the lenses had been implanted with the use of an IOL haptic expander for enclavation, which may have contributed to the malformation of the haptics. The two control lenses exhibited no signs of material deformation or subsequent disenclavation. CONCLUSIONS: Deformations of the haptics of iris-fixated phakic IOLs can cause irreversible damage leading to disenclavation and inadequate re-enclavation. In such cases, explantation appears to be the only therapeutic option. It is important to adhere to an appropriate implantation technique to reduce the risk of spontaneous subluxation. [J Refract Surg. 2016;32(9):618-624.].


Subject(s)
Artificial Lens Implant Migration/etiology , Equipment Failure Analysis , Iris/surgery , Phakic Intraocular Lenses , Prosthesis Failure , Adult , Aged , Artificial Lens Implant Migration/surgery , Biocompatible Materials , Device Removal , Female , Humans , Microscopy, Electron, Scanning , Middle Aged , Myopia/surgery , Reoperation , Visual Acuity/physiology
5.
JAMA Ophthalmol ; 132(10): 1192-8, 2014 Oct.
Article in English | MEDLINE | ID: mdl-24993643

ABSTRACT

IMPORTANCE: Surgeons starting to perform Descemet membrane endothelial keratoplasty (DMEK) should be informed about the learning curve and experience of others. OBJECTIVE: To document the clinical outcome of standardized "no-touch" DMEK and its complications during the learning curves of experienced surgeons. DESIGN, SETTING, AND PARTICIPANTS: Retrospective multicenter study. A total of 431 eyes from 401 patients with Fuchs endothelial dystrophy (68.2%) and bullous keratopathy (31.8%) underwent DMEK performed by 18 surgeons in 11 countries. EXPOSURES: Descemet membrane endothelial keratoplasty. MAIN OUTCOMES AND MEASURES: Best-corrected visual acuity (BCVA), endothelial cell density, and intraoperative and postoperative complications. RESULTS: Of 275 eyes available for BCVA pooled analysis, BCVA improved in 258 eyes (93.8%), remained unchanged in 12 (4.4%), and deteriorated in 5 (1.8%). Two hundred seventeen eyes (78.9%) reached a BCVA of at least 20/40 (≥0.5), 117 (42.5%) at least 20/25 (≥0.8), and 61 (22.2%) at least 20/20 (≥1.0). Eyes with at least 6 months of follow-up (n = 176) reached similar BCVA outcomes. Mean (SD) decrease in endothelial cell density at 6 months was 47% (20%) (n = 133 [P = .02]). Intraoperative complications were rare, including difficulties in inserting, unfolding, or positioning of the graft (1.2%) and intraoperative hemorrhage (0.5%). The main postoperative complication was graft detachment (34.6%); 20.4% underwent a single rebubbling procedure, occasionally requiring a second (2.6%) and a third rebubbling (0.7%), and 17.6% underwent a second keratoplasty. CONCLUSIONS AND RELEVANCE: Our multicenter study showed that the standardized no-touch DMEK technique was feasible in most hands. The main challenges for surgeons starting to perform the procedure may be (1) to decide whether graft preparation is outsourced or performed during surgery, (2) to limit the number of graft detachments and secondary procedures, and (3) to obtain organ cultured donor corneal tissue.


Subject(s)
Descemet Stripping Endothelial Keratoplasty/methods , Learning Curve , Ophthalmology , Adult , Aged , Aged, 80 and over , Blister/surgery , Cell Count , Corneal Diseases/surgery , Endothelium, Corneal/pathology , Female , Fuchs' Endothelial Dystrophy/surgery , Humans , Intraoperative Complications , Male , Middle Aged , Organ Preservation , Postoperative Complications , Retrospective Studies , Specimen Handling , Tissue Donors , Treatment Outcome , Visual Acuity/physiology , Young Adult
6.
J Refract Surg ; 29(6): 390-4, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23739831

ABSTRACT

PURPOSE: To evaluate the rotational stability of an acrylic angle-supported phakic intraocular lens (PIOL) 12 months after implantation in myopic eyes. METHODS: Patients with a history of moderate to high myopia underwent unilateral or bilateral implantation of an acrylic angle-supported PIOL (AcrySof Cachet; Alcon Laboratories, Inc., Fort Worth, TX). All were followed up for 12 months. IOL rotation was assessed using digital overlay of ocular photographs captured within 2 weeks of implantation and at postoperative month 12. The secondary outcomes of refractive power (spherical equivalent, refractive sphere, and cylinder) and uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) were assessed preoperatively and again at 3 months after implantation. RESULTS: Fifty eyes of 28 patients with a mean age of 32 years were included in this retrospective cohort study. All underwent successful IOL implantation and follow-up. A mean 12-month rotation of 11° was observed (standard deviation: 15.1°, range: 0 to 60°). All preoperative measures (mean) of refractive power improved by 3 months postoperatively (spherical equivalent = -0.35 ± 0.79 diopters [D], spherical refraction = 0.04 ± 0.82 D, and cylindrical refraction = -0.77 ± 0.91 D). Two percent of eyes requiring additional laser adjustment by postoperative month 12, primarily due to corneal astigmatism. CONCLUSION: The study findings suggest that AcrySof Cachet angle-supported PIOLs offer moderate 1-year rotational stability. Because this type of IOL also corrects myopia effectively, it appears to be a good treatment option for myopic eyes. However, the rotation that occurs makes it unsuitable for cylinder corrections.


Subject(s)
Myopia/surgery , Phakic Intraocular Lenses/standards , Suture Techniques , Adolescent , Adult , Female , Follow-Up Studies , Humans , Male , Middle Aged , Myopia/physiopathology , Postoperative Period , Prosthesis Design , Refraction, Ocular , Retrospective Studies , Rotation , Treatment Outcome , Young Adult
7.
J Biophotonics ; 3(5-6): 265-8, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20437418

ABSTRACT

Based on Helmholtz Theory for accommodation the increasing sclerosis of lens nucleus and cortex is the main cause for the developments of presbyopia. Existing therapies, however, do not reverse the stiffness of the crystalline lens and thus do not regain real accommodation ability. A new approach to restore the flexibility of the lens could be realized by photodisruption using ultrafast laser pulses. This process, known as fs-lentotomy, was used to create micro-incisions which act as gliding planes inside the crystalline lens without opening the eye globe.


Subject(s)
Accommodation, Ocular , Laser Therapy/methods , Lens, Crystalline/surgery , Animals , Feasibility Studies , Follow-Up Studies , Lens, Crystalline/physiology , Models, Theoretical , Rabbits , Time Factors
8.
J Cataract Refract Surg ; 35(12): 2136-43, 2009 Dec.
Article in English | MEDLINE | ID: mdl-19969220

ABSTRACT

PURPOSE: To evaluate a new diffractive multifocal intraocular lens (IOL) as an additional (add-on) IOL for sulcus-based implantation. SETTING: Augenklinik am Neumarkt, Köln, Germany. METHODS: In this prospective study, cataract patients had phacoemulsification and IOL implantation. After phacoemulsification, an aspheric silicone monofocal IOL (MS 612 ASP-Y) with a power range of +4.00 to +27.00 diopters [D]) was implanted in the capsular bag. This was followed by sulcus placement of an add-on multifocal IOL (MS 714 PB) with a +3.50 D diffractive element for near but zero refractive power for distance. RESULTS: The study included 56 eyes of 30 patients. Three months postoperatively, the mean monocular uncorrected distance visual acuity was 0.10 logMAR +/- 0.11 (SD) (median 1.00 decimal; 20/20 Snellen), with a remaining mean postoperative spherical equivalent of 0.01 +/- 0.51 D. The mean uncorrected intermediate visual acuity was 0.20 +/- 0.15 logMAR (median 0.63 decimal; 20/30 Snellen) with a luminance of 500 lux at 1 m. The mean uncorrected near visual acuity (Early Treatment Diabetic Retinopathy chart) was 0.16 +/- 0.13 logMAR (median 0.80 decimal; Jaeger 2). No major complications (eg, iris chafing, iris capture, lens epithelial cell ingrowth, glaucoma) were associated with the add-on IOL in the sulcus. CONCLUSIONS: Combined implantation of an add-on diffractive sulcus IOL and a monofocal capsular bag IOL was safe and effective in improving far and near visual acuity in cataract surgery. Preliminary visual acuity results were similar to those in eyes with a single 1-piece diffractive multifocal IOL.


Subject(s)
Lens Implantation, Intraocular/methods , Lenses, Intraocular , Phacoemulsification , Aged , Female , Humans , Lens Capsule, Crystalline/surgery , Male , Prospective Studies , Pseudophakia/physiopathology , Visual Acuity/physiology
10.
Vision Res ; 49(14): 1853-9, 2009 Jul.
Article in English | MEDLINE | ID: mdl-19427880

ABSTRACT

BACKGROUND: According to the Helmholtz theory of accommodation the loss of accommodation amplitude is caused by the growing sclerosis of the crystalline lens, whereas the ciliary muscle and the lens capsule are mainly uneffected by age. A permanent treatment method for presbyopia which offers a dynamic accommodation ability is a recent field of study. The concept followed in this paper uses femtosecond laser pulses to potentially overcome the loss of deformation ability of the crystalline lens by creating gliding planes inside the lens tissue to improve its flexibility. METHODS: The aim of the study is to show that the flexibility of human donor lenses can be increased by applying tightly focused near infrared femtosecond laser pulses into the lens tissue. Thereby the tissue is separated by the photodisruption effect. A certain pattern of gliding planes is cut inside the tissue of 41 human donor lenses and the deformation ability of the lenses are compared using the Fisher spinning test before and after laser treatment. RESULTS: The laser treatment results in an increased deformation ability of the crystalline lens. The lens a-p thickness increases on average by 97 microm+/-14 microm after the treatment. The Fisher spinning test shows an increase of 16% in deformation ability of the lens at a rotational speed of 1620 rpm. CONCLUSION: The creation of gliding planes with a fs laser inside the crystalline lens tissue can change the deformation ability of the lens. This might be an indication for a possible method to treat presbyopia in future.


Subject(s)
Laser Therapy/methods , Lens, Crystalline/surgery , Presbyopia/surgery , Accommodation, Ocular , Adult , Aged , Equipment Design , Humans , Laser Therapy/instrumentation , Lens, Crystalline/physiopathology , Lens, Crystalline/transplantation , Middle Aged , Presbyopia/physiopathology , Rheology , Tissue Donors , Transplantation, Homologous , Young Adult
11.
J Refract Surg ; 25(1 Suppl): S98-103, 2009 01.
Article in English | MEDLINE | ID: mdl-19248536

ABSTRACT

PURPOSE: To report refractive outcomes of hyperopic LASIK with automated centration on the visual axis compared with centration on the line of sight (LOS). METHODS: The NIDEK Advanced Vision Excimer Laser platform (NAVEX) was used to treat 181 hyperopic eyes with centration on the LOS (LOS group) and 64 hyperopic eyes with centration on the visual axis (visual axis group). The coordinates of the visual axis were digitally transferred to the excimer laser system based on the positional relationship between the LOS and the coaxially sighted corneal light reflex. All eyes were treated with a 6.5-mm optical zone and 9.0-mm transition zone. Three-month postoperative outcomes were retrospectively analyzed. RESULTS: The preoperative manifest refraction spherical equivalent (MRSE) was +2.57+/-1.26 diopters (D) (range: 0.13 to 5.63 D) in the visual axis group and +2.46+/-1.32 D (range: 0.38 to 5.63 D) in the LOS group. The postoperative MRSE was +0.29+/-0.70 D (range: -1.00 to 1.75 D) in the visual axis group and +0.19+/-0.57 D (range: -0.75 to 1.75 D) in the LOS group. Postoperatively, 81% (38/47) of eyes in the visual axis group and 64% (74/116) of eyes in the LOS group were +/-0.50 D. In the visual axis group, 91% (44/52) of eyes and 92% (102/109) of eyes in the LOS group maintained best spectacle-corrected visual acuity within one line compared with preoperatively. CONCLUSIONS: Initial experience with hyperopic LASIK centered on the visual axis indicated safe and predictable outcomes.


Subject(s)
Hyperopia/surgery , Keratomileusis, Laser In Situ/methods , Lasers, Excimer/therapeutic use , Cornea/anatomy & histology , Female , Follow-Up Studies , Humans , Male , Pupil , Retrospective Studies , Treatment Outcome , Visual Acuity/physiology
12.
J Refract Surg ; 24(9): 991-5, 2008 11.
Article in English | MEDLINE | ID: mdl-19044246

ABSTRACT

PURPOSE: According to the Helmholtz theory of accommodation, one major cause of the development of presbyopia is the increasing sclerosis of the crystalline lens. One concept for regaining the elasticity of the sclerosing lens is intralenticular treatment by femtosecond laser pulses. METHODS: The feasibility of applying and imaging in vivo microincisions by femtosecond laser pulses was evaluated in five rabbit lenses with a new high repetition rate (100 kHz) femtosecond laser unit. The treated eyes were monitored using optical coherence tomography (OCT) and Scheimpflug imaging for localizing and studying the tissue effects of the incisions. The rabbits were investigated preoperatively, immediately postoperatively, and 14 days after treatment. RESULTS: The procedure, termed femtosecond-lentotomy, was successfully applied to the left lens of each rabbit. The laser microincisions within the crystalline lens were detectable with OCT and Scheimpflug imaging, which emphasizes the integral role these technologies play in targeting and characterizing postoperative tissue effects. The imaging within the lens showed a progressive fading of the incisional opacities generated by the femtosecond laser after 14 days with no detectable cataract formation. CONCLUSIONS: It is possible to create microincisions inside the crystalline lens within an acceptably short treatment time (<30 seconds). The 14-day follow-up did not show undesirable side effects, such as cataract formation, after intralenticular laser treatment.


Subject(s)
Accommodation, Ocular , Laser Therapy/methods , Lens, Crystalline/surgery , Animals , Rabbits , Tomography, Optical Coherence
13.
Cornea ; 27(10): 1195-9, 2008 Dec.
Article in English | MEDLINE | ID: mdl-19034142

ABSTRACT

PURPOSE: Two eyes with corneal neovascularization were treated with argon laser and bevacizumab (Avastin) to enhance transplant survival after penetrating keratoplasty. PATIENTS AND METHODS: Before penetrating keratoplasty, pathologic corneal vessels were treated with argon laser coagulation and a simultaneous, subconjunctival bevacizumab injection. Four to 6 weeks after this treatment, corneal transplantation was performed, followed by an intraocular injection of bevacizumab. RESULTS: A marked reduction of corneal neovascularization was observed in both eyes after the combined argon laser coagulation and subconjunctival bevacizumab injection. No major bleeding from corneal vessels occurred during the recipients' cornea trephination. At the end of the transplantation, bevacizumab was injected into the anterior chamber, the posterior chamber, and subconjunctivally without any immediate side effects. No recurrence of pathologic vessels' spreading into the graft was observed. Both transplants have remained clear without signs of rejection for more than 6 months. CONCLUSIONS: The combination of argon laser coagulation and bevacizumab injections may be a promising tool in treatment of neovascularization in association with corneal transplant surgery. Antivascular endothelial growth factor substances may increasingly play a role in anterior segment surgery in the future.


Subject(s)
Angiogenesis Inhibitors/therapeutic use , Antibodies, Monoclonal/therapeutic use , Cornea/blood supply , Corneal Transplantation/adverse effects , Laser Coagulation , Neovascularization, Pathologic/therapy , Adult , Aged , Angiogenesis Inhibitors/administration & dosage , Antibodies, Monoclonal/administration & dosage , Antibodies, Monoclonal, Humanized , Bevacizumab , Cornea/drug effects , Cornea/pathology , Humans , Intraoperative Care , Lasers, Gas , Male , Neovascularization, Pathologic/etiology , Treatment Outcome
14.
Graefes Arch Clin Exp Ophthalmol ; 246(6): 897-906, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18030488

ABSTRACT

BACKGROUND: According to the Helmholtz theory of accommodation, one of the major reasons for the development of presbyopia is the progressive sclerosis of the crystalline lens. However, both the ciliary muscle and the lens capsule stay active and elastic. Thus, the concept for regaining the deformation-ability of the crystalline lens is to create microincisions inside lens tissue to achieve gliding planes. METHODS: For the preparation of the microincisions, near-infrared femtosecond laser pulses are used, generating laser-induced optical breakdowns. Different cutting patterns were performed, and the elasticity regain of the lenses were measured with Fisher's spinning test for thickness determination. RESULTS: The creation of gliding planes inside lens tissue shows very good results in terms of increasing the deformation-ability. The optimization of laser parameters leads to a minimally invasive surgery with no remarkable side effects like residual gas bubbles. Furthermore, ex vivo elasticity measurements of untreated and treated pig lenses show an improvement in the flexibility of the lens. The deformation-ability increases up to 26% with a very low standard deviation (1.6%) and a high significance (p < 0.05). CONCLUSION: Generating particular cutting patterns inside lens tissue can increase the deformation-ability of the crystalline lens. Thus, it might be one possible way to treat presbyopia.


Subject(s)
Accommodation, Ocular/physiology , Laser Therapy , Lens, Crystalline/surgery , Presbyopia/surgery , Animals , Elasticity , Lens, Crystalline/pathology , Presbyopia/physiopathology , Swine
15.
J Refract Surg ; 22(8): 754-63, 2006 Oct.
Article in English | MEDLINE | ID: mdl-17061712

ABSTRACT

PURPOSE: To assess refractive outcomes, changes in the total higher order root mean square (RMS) aberration, and changes in higher order wavefront aberrations after LASIK for myopia and myopic astigmatism with the NIDEK Advanced Vision Excimer Laser platform (NAVEX) using either an aspheric or topography-based or whole eye wavefront ablation algorithm. METHODS: This was a retrospective study of 1459 eyes that underwent LASIK for myopia and myopic astigmatism. The mean preoperative spherical equivalent refraction was -4.68 diopters (D) (range: -0.50 to -9.63 D) with astigmatism up to -4.50 D. Treatments were classified into three categories depending on the type of ablation algorithm used--optimized aspheric transition zone (OATz) denoted eyes that underwent aspheric treatment zones; customized aspheric treatment zone (CATz) denoted eyes that underwent customized ablations based on corneal topography; and OPDCAT denoted eyes that underwent customized ablation based on the whole eye wavefront profile. Follow-up data are reported at 3 months (69%) and 12 months (17%) postoperatively. RESULTS: Three months after LASIK, the predictability (10.5 D from target refraction) was 80% for OATz, 91% for CATz, and 76% for OPDCAT. Of all eyes, 96% were within +/- 1.0 D of intended refraction 3 months postoperatively and 100% after 12 months (87% +/- 0.5 D). In the aspheric and custom groups, a notable improvement of uncorrected visual acuity was noted between 3 and 12 months after LASIK. No eye lost >1 line of best spectacle-corrected visual acuity. Mean higher order RMS increased in all groups. CONCLUSIONS: The data support that the treatment of myopia and myopic astigmatism is safe and effective with NAVEX. Customized ablation based on corneal topography rather than on total wavefront error was more predictable.


Subject(s)
Cornea/pathology , Corneal Topography/methods , Keratomileusis, Laser In Situ/methods , Myopia/surgery , Adolescent , Adult , Aged , Cornea/surgery , Female , Follow-Up Studies , Humans , Male , Middle Aged , Myopia/pathology , Myopia/physiopathology , Refraction, Ocular , Retrospective Studies , Treatment Outcome , Visual Acuity
16.
J Refract Surg ; 21(1): 52-8, 2005.
Article in English | MEDLINE | ID: mdl-15724685

ABSTRACT

PURPOSE: To evaluate the results of laser in situ keratomileusis (LASIK) for the correction of hyperopia and hyperopic astigmatism using a large 7.0-mm optical zone and to compare them with treatments using a 5.5- and 6.5-mm optical zone. METHODS: One hundred sixty-one eyes of 89 patients with a mean preoperative spherical equivalent refraction of +2.44 +/- 1.32 diopters (D) (range: +0.00 to +5.62 D, cylinder 5.25 to 0.00 D) were treated for hyperopia and hyperopic astigmatism using a 7.0-mm optical zone and were analyzed retrospectively. Postoperatively, patients were examined after 1 day, 1 week, 1 month, 3 months, and 1 year. Eyes treated previously at the same center by the same surgeons with 5.5- and 6.5-mm optical zone applications were used as controls. All treatments were performed with the Nidek EC 5000 CXII excimer laser system (Nidek, Gamagori, Japan). A nasal hinged flap was created using the Nidek MK 2000 microkeratome in all cases. RESULTS: The mean postoperative spherical equivalent refraction after 1 month (n=89) was +0.12 +/- 0.72 D (range: -1.75 to +2.75 D), +0.13 +/- 0.74 D (range: -1.88 to +1.62 D) at 3 months (n=70), and +0.20 +/- 0.69 D (range: -1.62 to +1.12 D) at 1 year (n=33). Regression between 1 month and 1 year was 0.08 D in the 7.0-mm optical zone group. Regression was 0.25 D in the 5.5-mm group and 0.02 D in the 6.5-mm optical zone group between 1 month and 1 year. In both the 5.5- and 6.5-mm optical zone groups, 13% of eyes lost one line in visual acuity (2% in the 7.0-mm optical zone group). The gain of one or more lines in visual acuity was 19% in the 5.5-mm group, 17% in the 6.5-mm group, and 27% in the 7.0-mm optical zone group. All data represent primary cases without retreatment. CONCLUSIONS: Increasing the optical zone size from 5.5 mm to 6.5 mm and to 7.0 mm seems to improve refractive results, stability, and safety of hyperopic and hyperopic-astigmatic LASIK treatments. Although some hyperopic and astigmatic eyes are endangered by loss of lines in best spectacle-corrected visual acuity, more eyes gain one or more lines.


Subject(s)
Cornea/surgery , Hyperopia/surgery , Keratomileusis, Laser In Situ/methods , Adult , Astigmatism/surgery , Corneal Topography , Female , Humans , Male , Middle Aged , Refraction, Ocular , Retrospective Studies , Treatment Outcome , Visual Acuity
17.
J Refract Surg ; 19(2 Suppl): S190-4, 2003.
Article in English | MEDLINE | ID: mdl-12699171

ABSTRACT

PURPOSE: Standard ablation profiles for myopia and myopic astigmatism are spherical in shape and usually induce spherical aberration, often resulting in glare, halo, and other night vision problems. New ablation algorithms with aspheric transition zones may help reduce the amount of induced spherical aberrations in refractive surgery. METHODS: Between September and November 2002, 52 eyes were treated with bilateral laser in situ keratomileusis (LASIK) using a new ablation profile with customized aspherical transition zone (CATz). Results were analyzed from examinations performed 1 day, 1 and 3 months (if available) after surgery, and compared to a standard LASIK patient group. RESULTS: Refractive outcome of patients was within +/- 0.50 D of intended correction in 72% on day 1, and 82% at 1 month after surgery. At 1 month after LASIK, mean spherical equivalent refraction was changed from preoperative mean -6.73 +/- 2.04 D to postoperative mean -0.43 +/- 0.80 D (range -2.00 to +1.50 D). No eye lost more than 1 line of visual acuity; 10% gained 1 line and 80% remained unchanged 1 month after surgery. The topographically visible effective optical zone size was larger than in comparable treatments with standard ablation profiles. Spherical aberration was reduced and no patient complained about night vision problems after surgery. CONCLUSIONS: Customized aspheric transition zones may help reduce induction of spherical aberration in refractive surgical correction of myopia and myopic astigmatism.


Subject(s)
Astigmatism/surgery , Keratomileusis, Laser In Situ/methods , Myopia/surgery , Adolescent , Adult , Aged , Algorithms , Corneal Stroma/pathology , Corneal Stroma/surgery , Corneal Topography , Female , Humans , Keratomileusis, Laser In Situ/instrumentation , Male , Middle Aged , Postoperative Complications/prevention & control , Refraction, Ocular , Treatment Outcome , Visual Acuity
SELECTION OF CITATIONS
SEARCH DETAIL
...