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Sanmillan IL, Thumann G, Kropp M, Cvejic Z, Pajic B. Predictability of Astigmatism Correction by Arcuate Incisions with a Femtosecond Laser Using the Gaussian Approximation Calculation. MICROMACHINES 2023; 14:mi14051009. [PMID: 37241632 DOI: 10.3390/mi14051009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 05/01/2023] [Accepted: 05/04/2023] [Indexed: 05/28/2023]
Abstract
Planning astigmatic correction is a complex task. Biomechanical simulation models are useful for predicting the effects of the physical procedure on the cornea. Algorithms based on these models allow preoperative planning and simulate the outcome of patient-specific treatment. The objective of this study was to develop a customised optimisation algorithm and determine the predictability of astigmatism correction by femtosecond laser arcuate incisions. In this study, biomechanical models and Gaussian approximation curve calculations were used for surgical planning. Thirty-four eyes with mild astigmatism were included, and corneal topographies were evaluated before and after femtosecond laser-assisted cataract surgery with arcuate incisions. The follow-up time was up to 6 weeks. Retrospective data showed a significant reduction in postoperative astigmatism. A total of 79.4% showed a postoperative astigmatic value less than 1 D. Clinical refraction was significantly reduced from -1.39 ± 0.79 D preoperatively to -0.86 ± 0.67 D postoperatively (p 0.02). A positive reduction in topographic astigmatism was also observed (p < 0.00). The best-corrected visual acuity increased postoperatively (p < 0.001). We can conclude that customised simulations based on corneal biomechanics are a valuable tool for correcting mild astigmatism with corneal incisions in cataract surgery to improve postoperative visual outcomes.
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Affiliation(s)
| | - Gabriele Thumann
- Division of Ophthalmology, Department of Clinical Neurosciences, Geneva University Hospitals, 1205 Geneva, Switzerland
- Experimental Ophthalmology, University of Geneva, 1205 Geneva, Switzerland
| | - Martina Kropp
- Division of Ophthalmology, Department of Clinical Neurosciences, Geneva University Hospitals, 1205 Geneva, Switzerland
- Experimental Ophthalmology, University of Geneva, 1205 Geneva, Switzerland
| | - Zeljka Cvejic
- Faculty of Sciences, Department of Physics, University of Novi Sad, Trg Dositeja Obradovica 4, 21000 Novi Sad, Serbia
| | - Bojan Pajic
- Eye Clinic ORASIS, Swiss Eye Research Foundation, 5734 Reinach, Switzerland
- Division of Ophthalmology, Department of Clinical Neurosciences, Geneva University Hospitals, 1205 Geneva, Switzerland
- Experimental Ophthalmology, University of Geneva, 1205 Geneva, Switzerland
- Faculty of Sciences, Department of Physics, University of Novi Sad, Trg Dositeja Obradovica 4, 21000 Novi Sad, Serbia
- Faculty of Medicine of the Military Medical Academy, University of Defense, 11000 Belgrade, Serbia
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Jones M, Hovanesian JA, Keyser A. Accuracy of the LaserArcs Femtosecond Cataract Surgery Arcuate Incision Nomogram in Patients Undergoing Cataract Surgery and Astigmatism Reduction. Clin Ophthalmol 2023; 17:681-689. [PMID: 36880021 PMCID: PMC9984544 DOI: 10.2147/opth.s398334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Accepted: 02/10/2023] [Indexed: 03/03/2023] Open
Abstract
Purpose The purpose of this study is to evaluate the efficacy and safety of the laserarcs.com nomogram in reducing astigmatism among cataract patients that underwent astigmatism reduction with laser arcuate incisions. Methods In this retrospective study, 50 patients who underwent uncomplicated cataract surgery with laser arc incisions for the reduction of astigmatism with a single surgeon between the dates of January 23, 2021 and February 10, 2022 were evaluated in a single eye. Preoperative astigmatism was determined on the basis of keratometry from biometry (IOLmaster, Carl Zeiss Meditec or LenStar LS900, Haag-Streit, Bern, Switzerland) and was compared to the postoperative manifest astigmatism. The percent change in the absolute magnitude of astigmatism was calculated along with the percent of patients with various levels of postoperative astigmatism. Results Mean cylinder was 0.97 ± 0.49 D pre-op and 0.21 ± 0.28 D postop. Mean reduction in cylinder was 81.4 ± 47.7% (P < 0.00001, one-sample t-test compared to a hypothetical 60% reduction in cylinder). Residual cylinder was ≤0.5 D in 90%, 0.25 D in 72%, and 0 D in 58%. Postoperative uncorrected visual acuity was 20/30 or better in 92% and 20/20 or better in 40%. Subgroup analysis showed that residual astigmatism was not affected by patient age, magnitude of preoperative astigmatism, preoperative spherical equivalent, or corneal curvature. No adverse events related to the laser arcuate incisions were noted. Conclusion Use of the LaserArcs nomogram yielded a significant reduction in preoperative astigmatism. Postoperative uncorrected visual acuity was substantially similar to best-corrected visual acuity, suggesting that many patients undergoing treatment will function without correction for distance tasks.
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Mainguy A, Vabres B, Orignac I. Analyse vectorielle de la correction de l’astigmatisme par incisions arciformes au laser femtoseconde dans les astigmatismes géants post-kératoplastie transfixiante. J Fr Ophtalmol 2022; 45:640-646. [DOI: 10.1016/j.jfo.2021.09.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 07/10/2021] [Accepted: 09/08/2021] [Indexed: 10/18/2022]
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Abu-Ain MS, Al-Latayfeh MM, Khan MI. Do limbal relaxing incisions during cataract surgery still have a role? BMC Ophthalmol 2022; 22:102. [PMID: 35246091 PMCID: PMC8897932 DOI: 10.1186/s12886-022-02327-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 02/23/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Though Limbal Relaxing Incisions (LRI) were used widely to correct pre-existing corneal astigmatism during cataract surgery, they have been replaced recently with the more expensive methods like the use of toric Intra Ocular Lenses (IOL) and femtosecond during cataract surgery. We conducted our study to re-evaluate the role of (LRI) in correcting pre-existing moderate corneal astigmatism during cataract surgery in settings where other options are neither available nor affordable. METHODS Retrospective analysis of all consecutive cases of LRI performed by a single surgeon at the time of cataract surgery to correct moderate corneal astigmatism (1.5-3D) in a community hospital over a period of 6 months. Corneal astigmatism, uncorrected distance visual acuity (UDVA) and best corrected distance visual acuity (CDVA) were recorded pre-operatively, 4 weeks and 3 months post-operatively. Data on age, intraocular lens (IOL) power, predictive refraction and post-operative spherical equivalent was also collected and analyzed. The number and position of LRI was determined based on the pre-existing corneal astigmatism using online calculator. RESULTS 29 eyes of 25 patients with the mean age of 73.6 years (range: 46 to 90 years) and corneal astigmatism between 1.5 to 3D were included. Statistically significant reduction in the mean corneal astigmatism was recorded from 2.05 ± 0.45D preoperatively to 0.85 ± 0.56D postoperatively (P < 0.0001). All eyes showed reduction in astigmatism; 83% of eyes had < 1.0D post-operatively and 66% of eyes had < 0.75D. UDVA of 6/9 or better was recorded in 80% of eyes post-operatively (CDVA of 6/9 or better in 100%). The spherical equivalent was within 1.0D of the predictive refraction postoperatively in nearly all eyes (97%) and within 0.5D in 86% of the eyes. There were no peri-operative or post-operative complications were recorded in any case. CONCLUSION Combining LRI and cataract surgery to address moderate degrees of corneal astigmatism is a safe, reliable and predictable option especially in areas where more expensive methods such as toric IOL or excimer laser are not available or affordable. LRI has no significant effect on the spherical equivalent and is an excellent tool in reducing patient's spectacle dependence.
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Affiliation(s)
- Mohammad Saleh Abu-Ain
- Prince Hamzah Hospital, Amman, Jordan. .,Department of Special and General Surgery, The Hashemite University, Zarqa, Jordan.
| | - Motasem Mohammad Al-Latayfeh
- Prince Hamzah Hospital, Amman, Jordan.,Department of Special and General Surgery, The Hashemite University, Zarqa, Jordan
| | - Mohammad Irfan Khan
- Doncaster and Bassetlaw Teaching Hospitals NHS Foundation Trust, Armthorpe Road, Doncaster, UK
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Wendelstein JA, Hoffmann PC, Schwarzenbacher L, Fischinger IR, Hirnschall N, Menapace R, Langenbucher A, Findl O, Bolz M. Lasting Effects: Seven Year Results of the Castrop Nomogram for Femtosecond Laser-Assisted Paired Corneal Arcuate Incisions. Curr Eye Res 2021; 47:225-232. [PMID: 34464547 DOI: 10.1080/02713683.2021.1975761] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
PURPOSE Long-term results of arcuate incisions are rarely reported. This is unfortunate as long-term stability of astigmatic correction is of great interest to surgeons performing astigmatic correction. This study investigates the 7 year stability of results after application of femtosecond laser-assisted arcuate incisions with the Castrop nomogram. METHODS Prospective interventional case series at the Augen- und Laserklinik, Castrop-Rauxel, Germany. Single site, single surgeon study. Seven year results of cataract patients with low to moderate corneal astigmatism receiving femtosecond laser-assisted arcuate incisions using a TechnolasVictus SW 2.7 (Bausch & Lomb Inc, Dornach, Germany) were assessed and compared to 1 year results. Outcome evaluation was based on astigmatic vector analysis, manifest refraction, and visual acuity. RESULTS The study analyzed 19 eyes of 19 patients 7 years after surgery. Ocular residual astigmatism changed from -0.26 to -0.39 D. Preoperative corneal astigmatism was -1.51 D. Correction Index changed from 1.0 to 1.16. The magnitude of difference vector changed from 0.26 to 0.39 D. The index of success changed from 0.20 to 0.29. Spherical equivalent remained stable. A slight tendency to change toward astigmatic overcorrection was mainly observed for patients with preoperative with the rule astigmatism, but not with patients with against the rule astigmatism. CONCLUSIONS The Castrop nomogram showed stable results 7 years after surgery. Similar to toric IOL surgery, it is advisable to be less aggressive when correcting with the rule astigmatism, to avoid overcorrection over a long period.
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Affiliation(s)
- Jascha A Wendelstein
- Department of Ophthalmology and Optometry, Kepler University Hospital GmbH, Johannes Kepler University Linz, Linz, Austria
| | - Peter C Hoffmann
- Department of Ophthalmology, Augen-und Laserklinik, Castrop-Rauxel, Germany
| | - Luca Schwarzenbacher
- Department of Ophthalmology and Optometry, Medical University Vienna, Vienna, Austria
| | - Isaak R Fischinger
- Department of Ophthalmology and Optometry, Kepler University Hospital GmbH, Johannes Kepler University Linz, Linz, Austria.,Department of Ophthalmology, Augentagesklinik Spreebogen Berlin, Berlin, Germany
| | - Nino Hirnschall
- Department of Ophthalmology, Viros - Vienna Institute for Research in Ocular Surgery, Karl Landsteiner Institute, Hanusch Hospital, Vienna, Austria
| | - Rupert Menapace
- Department of Ophthalmology and Optometry, Medical University Vienna, Vienna, Austria
| | - Achim Langenbucher
- Institute of Experimental Ophthalmology, Saarland University, Homburg, Germany
| | - Oliver Findl
- Department of Ophthalmology, Viros - Vienna Institute for Research in Ocular Surgery, Karl Landsteiner Institute, Hanusch Hospital, Vienna, Austria
| | - Matthias Bolz
- Department of Ophthalmology and Optometry, Kepler University Hospital GmbH, Johannes Kepler University Linz, Linz, Austria
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Angermann R, Palme C, Segnitz P, Dimmer A, Schmid E, Hofer M, Steger B. Surgically induced astigmatism and coupling effect-mediated keratometric changes after conventional phacoemulsification cataract surgery. SPEKTRUM DER AUGENHEILKUNDE 2021. [DOI: 10.1007/s00717-021-00488-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Summary
Background
The aim of the present study was to describe surgically induced astigmatism (SIA) and the coupling effect after conventional phacoemulsification cataract surgery (CPS) in relation to the incisional axis.
Material and methods
A total of 42 patients were included in the retrospective case series study. Corneal topography was obtained for patients with significant cataract before and 6 weeks after CPS with a main clear corneal incision size of 2.4 mm. Patients were grouped according to the relationship of the incisional axis to the position of the steep axis into a steep incisional group and a flat incisional group.
Results
In total, 46 eyes were included in the study. While the steep incisional group showed an SIA of −0.15 D (± 0.35), the flat incisional group had a significantly higher SIA of 0.20 D (± 0.51) (p = 0.03). The coupling ratio (CR) in the steep incisional group was −0.38 (± 1.41) and in the flat incisional group it was 0.16 (± 0.97). Correspondingly, a coupling constant (CC) of −0.25 was found for group 1 and a CC of 0.0 for group 2.
Conclusion
Our results suggest that the location of the main incision should be decided with consideration of the corneal astigmatism in order to minimize the SIA. The CR helps to understand the effect of induced astigmatism and the change in spherical equivalent.
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Truffer O, Abler D, Pajic B, Grabner G, Kraker H, Büchler P. Optimization of surgical parameters based on patient-specific models: Application to arcuate keratotomy. J Cataract Refract Surg 2020; 45:1084-1091. [PMID: 31371005 DOI: 10.1016/j.jcrs.2019.02.022] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 02/12/2019] [Accepted: 02/15/2019] [Indexed: 11/28/2022]
Abstract
PURPOSE To determine surgical parameters for arcuate keratotomy by simulating the intervention with a patient-specific model. SETTING University Eye Clinic Salzburg, Paracelsus Medical University, Austria, and Institute for Surgical Technology and Biomechanics, University of Bern, Switzerland. DESIGN Computational modeling study. METHODS A new approach to plan arcuate keratotomy based on personalized finite element simulations was developed. Using this numeric tool, an optimization algorithm was implemented to determine the incision parameters that best met the surgeon's requirements while preserving the orientation of the astigmatism. Virtual surgeries were performed on patients to compare the performance of the simulation-based approach with results based on the Lindstrom and Donnenfeld nomograms and with intrastromal interventions. RESULTS Retrospective data on 28 patients showed that personalized simulation reproduced the surgically induced change in astigmatism (Pearson correlation = 0.8). Patient-specific simulation was used to examine strategies for arcuate interventions on 621 corneal topographies. The Lindstrom nomogram resulted in low postoperative astigmatism (mean 0.03 diopter [D] ± 0.3 [SD]) but frequent overcorrections (20%). The Donnenfeld nomogram and intrastromal incisions resulted in a small amount of overcorrection (1.5%) but a wider spread in astigmatism (mean 0.63 ± 0.35 D and 0.48 ± 0.50 D, respectively). In contrast, the new numeric parameter optimization approach led to postoperative astigmatism values (mean 0.40 ± 0.08 D, 0.20 ± 0.08 D, and 0.04 ± 0.13 D) that closely matched the target astigmatism (0.40 D, 0.20 D, and 0.00 D), respectively, while keeping the number of overcorrections low (<1.5%). CONCLUSION Using numeric modeling to optimize surgical parameters for arcuate keratotomy led to more reliable postoperative astigmatism, limiting the risk for overcorrection.
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Affiliation(s)
- Oskar Truffer
- Institute for Surgical Technology and Biomechanics, University of Bern, Switzerland.
| | - Daniel Abler
- Institute for Surgical Technology and Biomechanics, University of Bern, Switzerland
| | - Bojan Pajic
- Eye Clinic Orasis, Swiss Eye Research Foundation, Switzerland; Division of Ophthalmology, Department of Clinical Neurosciences, Geneva University Hospitals, Switzerland; Department of Physics, Faculty of Sciences, University of Novi Sad, Serbia; Faculty of Medicine of the Military Medical Academy, University of Defense, Serbia
| | - Günther Grabner
- University Eye Clinic Salzburg, Paracelsus Medical University, Austria
| | - Hannes Kraker
- University Eye Clinic Salzburg, Paracelsus Medical University, Austria
| | - Philippe Büchler
- Institute for Surgical Technology and Biomechanics, University of Bern, Switzerland
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Byun YS, Kim S, Lazo MZ, Choi MH, Kang MJ, Lee JH, Yoo YS, Whang WJ, Joo CK. Astigmatic correction by intrastromal astigmatic keratotomy during femtosecond laser-assisted cataract surgery: Factors in outcomes. J Cataract Refract Surg 2019; 44:202-208. [PMID: 29587975 DOI: 10.1016/j.jcrs.2017.11.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 11/09/2017] [Accepted: 11/30/2017] [Indexed: 11/30/2022]
Abstract
PURPOSE To evaluate the 6-month outcomes of femtosecond laser astigmatic keratotomy (AK) combined with femtosecond laser-assisted cataract surgery and identify factors affecting the efficacy of astigmatic correction. SETTING Seoul St. Mary's Hospital, Catholic University of Korea, Seoul, South Korea. DESIGN Retrospective case series. METHODS Femtosecond laser AK was performed during femtosecond laser-assisted cataract surgery. The keratometric astigmatism, refractive cylinder, corneal hysteresis (CH), and corneal resistance factor (CRF) were measured preoperatively and postoperatively at 1 week, 2 months, and 6 months. Vector analysis to evaluate the 6-month outcomes of femtosecond laser AK and univariable regression analysis to determine the factors influencing the correction index were performed. RESULTS The study enrolled 89 eyes of 89 patients. The stigmatism type, CH, CRF, and absolute angle of error showed significant correlations with the correction index (P = .041, P = .029, P = .044, and P < .001, respectively). There was a significant difference in the correction index and no difference in keratometric astigmatism between with-the-rule (WTR), against-the-rule (ATR), and oblique astigmatism (P = .044). The keratometric astigmatism with ATR and oblique astigmatism (0.66 diopter [D] ± 0.42 [SD] and 0.46 ± 0.27 D, respectively) was significantly lower than the refractive cylinder (0.92 ± 0.56 D and 0.78 ± 0.43 D, respectively) (P < .05); this was not the case for WTR astigmatism. CONCLUSIONS The efficacy of femtosecond laser AK was affected by the biomechanical properties of the cornea and astigmatism type. Further studies incorporating the individual biomechanical properties of the cornea and total corneal astigmatism in a nomogram are recommended.
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Affiliation(s)
- Yong-Soo Byun
- From the Department of Ophthalmology and Visual Science, College of Medicine, Seoul St. Mary's Hospital, Catholic University of Korea, and the Catholic Institute of Visual Science, Catholic University of Korea, Seoul, South Korea
| | - Seonjoo Kim
- From the Department of Ophthalmology and Visual Science, College of Medicine, Seoul St. Mary's Hospital, Catholic University of Korea, and the Catholic Institute of Visual Science, Catholic University of Korea, Seoul, South Korea
| | - Marjorie Z Lazo
- From the Department of Ophthalmology and Visual Science, College of Medicine, Seoul St. Mary's Hospital, Catholic University of Korea, and the Catholic Institute of Visual Science, Catholic University of Korea, Seoul, South Korea
| | - Mi-Hyun Choi
- From the Department of Ophthalmology and Visual Science, College of Medicine, Seoul St. Mary's Hospital, Catholic University of Korea, and the Catholic Institute of Visual Science, Catholic University of Korea, Seoul, South Korea
| | - Min-Ji Kang
- From the Department of Ophthalmology and Visual Science, College of Medicine, Seoul St. Mary's Hospital, Catholic University of Korea, and the Catholic Institute of Visual Science, Catholic University of Korea, Seoul, South Korea
| | - Jee-Hye Lee
- From the Department of Ophthalmology and Visual Science, College of Medicine, Seoul St. Mary's Hospital, Catholic University of Korea, and the Catholic Institute of Visual Science, Catholic University of Korea, Seoul, South Korea
| | - Young-Sik Yoo
- From the Department of Ophthalmology and Visual Science, College of Medicine, Seoul St. Mary's Hospital, Catholic University of Korea, and the Catholic Institute of Visual Science, Catholic University of Korea, Seoul, South Korea
| | - Woong-Joo Whang
- From the Department of Ophthalmology and Visual Science, College of Medicine, Seoul St. Mary's Hospital, Catholic University of Korea, and the Catholic Institute of Visual Science, Catholic University of Korea, Seoul, South Korea
| | - Choun-Ki Joo
- From the Department of Ophthalmology and Visual Science, College of Medicine, Seoul St. Mary's Hospital, Catholic University of Korea, and the Catholic Institute of Visual Science, Catholic University of Korea, Seoul, South Korea.
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Wang J, Zhao J, Xu J, Zhang J. Evaluation of the effectiveness of combined femtosecond laser-assisted cataract surgery and femtosecond laser astigmatic keratotomy in improving post-operative visual outcomes. BMC Ophthalmol 2018; 18:161. [PMID: 29970039 PMCID: PMC6029423 DOI: 10.1186/s12886-018-0823-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 06/13/2018] [Indexed: 11/13/2022] Open
Abstract
Background To determine postoperative refractive and visual outcomes and astigmatic changes after femtosecond laser astigmatic keratotomy in femtosecond laser-assisted cataract surgery (FLACS). Methods This was a prospective interventional case series. Patients with age-related cataract and corneal astigmatism (1.0–3.0D) were treated with FLACS and femtosecond laser astigmatic keratotomy (FSAK). All patients underwent examinations before and 3 months after surgery; visual acuity, subjective and objective refraction, and corneal astigmatism were evaluated and recorded for all patients by using an OPD-Scan III topographer. Vector analysis of astigmatic changes was performed by using the Alpins vector method. Results Twenty-five patients were included in the study. Postoperatively, refractive and corneal astigmatism were both reduced significantly (P < 0.05), concurrent with improved uncorrected distance visual acuity and corrected distance visual acuity. The rate of spectacle use was significantly reduced at 3 months postoperatively (P = 0.001). The mean magnitude of the target-induced astigmatism vector (1.40 ± 0.37D) was slightly higher than the mean magnitude of the surgically induced astigmatism vector (1.22 ± 0.46D). The magnitude of error (− 0.18 ± 0.36D), as well as the correction index (0.88 ± 0.29), demonstrated slight undercorrection. The angle of error was 0.85 ± 13.69°, which was close to zero. Conclusions Combined femtosecond laser-assisted cataract surgery and astigmatic keratotomy may be an effective approach to manage preoperative astigmatism in cataract surgery, although slight undercorrection may exist during short-term follow-up. Trial registration ChiCTR-TRC-14004977
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Affiliation(s)
- Jing Wang
- Department of Ophthalmology, the Fourth Affiliated Hospital of China Medical University, Eye Hospital of China Medical University,The Key Lenticular Laboratory of Liaoning Province, Shenyang, 110005, China
| | - Jiangyue Zhao
- Department of Ophthalmology, the Fourth Affiliated Hospital of China Medical University, Eye Hospital of China Medical University,The Key Lenticular Laboratory of Liaoning Province, Shenyang, 110005, China
| | - Jun Xu
- Department of Ophthalmology, the Fourth Affiliated Hospital of China Medical University, Eye Hospital of China Medical University,The Key Lenticular Laboratory of Liaoning Province, Shenyang, 110005, China
| | - Jinsong Zhang
- Department of Ophthalmology, the Fourth Affiliated Hospital of China Medical University, Eye Hospital of China Medical University,The Key Lenticular Laboratory of Liaoning Province, Shenyang, 110005, China.
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11
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St. Clair RM, Sharma A, Huang D, Yu F, Goldich Y, Rootman D, Yoo S, Cabot F, Jun J, Zhang L, Aldave AJ. Development of a nomogram for femtosecond laser astigmatic keratotomy for astigmatism after keratoplasty. J Cataract Refract Surg 2016; 42:556-62. [DOI: 10.1016/j.jcrs.2015.12.053] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 11/26/2015] [Accepted: 12/05/2015] [Indexed: 11/15/2022]
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Fung SSM, Aiello F, Maurino V. Outcomes of femtosecond laser-assisted mushroom-configuration keratoplasty in advanced keratoconus. Eye (Lond) 2016; 30:553-61. [PMID: 26795410 DOI: 10.1038/eye.2015.273] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 11/13/2015] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To evaluate the long-term outcomes after femtosecond laser (FSL)-assisted mushroom-configuration keratoplasty in advanced keratoconus. PATIENTS AND METHODS Thirteen eyes with Amsler-Krumeich stage IV keratoconus underwent FSL-assisted mushroom-configuration penetrating keratoplasty (PKP) and deep anterior lamellar keratoplasty (DALK) at a tertiary referral centre. Preoperative risk factors included low orneal thickness, high keratometry measurements, previous hydrops, and central stromal scarring. Main outcome measures were visual acuity and refractive outcome. RESULTS The median follow-up was 33 months (range: 4-43). Preoperatively, the mean corrected distance visual acuity (CDVA) was 1.22±0.47 LogMAR (range: 0.5-1.9 LogMAR), mean minimum corneal thickness was 282±100.8 μm (range: 147-478 μm), and mean average keratometric (K) value was 63.4±7.63 dioptre (D; range: 57.0-75.7 D). Four patients underwent PKP and nine underwent DALK (two converted to PKP). Five patients subsequently underwent a modified arcuate mushroom interface dissection (AMID) procedure for astigmatic correction. At the final follow-up, the mean CDVA was 0.05±0.13 LogMAR (range: -0.10 to 0.20 LogMAR), mean spherical equivalent was -3.21±3.21D, mean cylindrical refractive error was 3.23±2.20 D, and mean average K was 43.1±1.53 D. Complications included early graft dehiscence, corneal vascularisation, stromal rejection, and sclerokeratitis. Sutures were completely removed at the mean 18.4 months for PKP and 9.1 months for DALK postoperatively. CONCLUSION FSL-assisted mushroom-configuration keratoplasty is feasible and safe in patients with stage IV keratoconus. AMID could further enhance the refractive outcome safely.
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Affiliation(s)
- S S M Fung
- Cornea and External Disease Service, Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - F Aiello
- Cornea and External Disease Service, Moorfields Eye Hospital NHS Foundation Trust, London, UK.,Department of Experimental Medicine and Surgery, Ophthalmology Unit, University of Rome 'Tor Vergata', Rome, Italy
| | - V Maurino
- Cornea and External Disease Service, Moorfields Eye Hospital NHS Foundation Trust, London, UK
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Aristeidou A, Taniguchi EV, Tsatsos M, Muller R, McAlinden C, Pineda R, Paschalis EI. The evolution of corneal and refractive surgery with the femtosecond laser. EYE AND VISION 2015; 2:12. [PMID: 26605365 PMCID: PMC4655461 DOI: 10.1186/s40662-015-0022-6] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Accepted: 06/20/2015] [Indexed: 01/12/2023]
Abstract
The use of femtosecond lasers has created an evolution in modern corneal and refractive surgery. With accuracy, safety, and repeatability, eye surgeons can utilize the femtosecond laser in almost all anterior refractive procedures; laser in situ keratomileusis (LASIK), small incision lenticule extraction (SMILE), penetrating keratoplasty (PKP), insertion of intracorneal ring segments, anterior and posterior lamellar keratoplasty (Deep anterior lamellar keratoplasty (DALK) and Descemet's stripping endothelial keratoplasty (DSEK)), insertion of corneal inlays and cataract surgery. As the technology matures, it will push surgical limits and open new avenues for ophthalmic intervention in areas not yet explored. As we witness the transition from femto-LASIK to femto-cataract surgery it becomes obvious that this innovation is here to stay. This article presents some of the most relevant advances of femtosecond lasers to modern corneal and refractive surgery.
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Affiliation(s)
| | - Elise V Taniguchi
- Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA USA ; Massachusetts Eye and Ear Infirmary/Schepens Eye Research Institute, Boston Keratoprosthesis Laboratory, Harvard Medical School, Boston, 02114 MA USA
| | | | - Rodrigo Muller
- Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA USA
| | - Colm McAlinden
- Flinders University, Adelaide, South Australia Australia ; Wenzhou Medical University, Wenzhou, Zhejiang China
| | - Roberto Pineda
- Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA USA
| | - Eleftherios I Paschalis
- Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, MA USA ; Massachusetts Eye and Ear Infirmary/Schepens Eye Research Institute, Boston Keratoprosthesis Laboratory, Harvard Medical School, Boston, 02114 MA USA
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Sáles CS, Manche EE. Managing residual refractive error after cataract surgery. J Cataract Refract Surg 2015; 41:1289-99. [DOI: 10.1016/j.jcrs.2015.05.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 10/07/2014] [Accepted: 10/13/2014] [Indexed: 11/26/2022]
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Miyake T, Kamiya K, Amano R, Iida Y, Tsunehiro S, Shimizu K. Long-term clinical outcomes of toric intraocular lens implantation in cataract cases with preexisting astigmatism. J Cataract Refract Surg 2014; 40:1654-60. [PMID: 25149554 DOI: 10.1016/j.jcrs.2014.01.044] [Citation(s) in RCA: 107] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Revised: 01/28/2014] [Accepted: 01/29/2014] [Indexed: 11/28/2022]
Abstract
PURPOSE To evaluate the long-term clinical outcomes and rotational stability of toric intraocular lenses (IOLs) to correct preexisting astigmatism in cataract patients. SETTING Kitasato University Hospital, Kanagawa, Japan. DESIGN Prospective observational study. METHODS Phacoemulsification with implantation of a toric IOL (Acrysof IQ toric SN6AT) was performed in cataract patients with corneal astigmatism. The postoperative follow-up was up to 2 years. RESULTS This study enrolled 378 eyes of 302 patients with a mean age of 63.4 years ± 16.9 (SD). The corrected distance visual acuity 3 months postoperatively was 20/25 or better in 94.7% of eyes. The mean refractive cylinder was -1.92 ± 1.45 diopters (D) preoperatively, -0.59 ± 0.62 D 3 months postoperatively (322 eyes), and -0.67 ± 0.90 D at 2 years (73 eyes). There were statistically significant differences between the preoperative and 3-month postoperative measurements (P<.001, Wilcoxon signed-rank test). The mean IOL misalignment was 4.1 ± 3.0 degrees 2 years postoperatively. The mean IOL rotation was 4.5 ± 4.9 degrees within 1 day postoperatively. The rotation was more than 20 degrees in 6 eyes, all of which had an axial length (AL) of more than 25.0 mm. All rotations occurred within 10 days postoperatively. CONCLUSIONS Toric IOLs were effective in reducing preexisting corneal astigmatism and had overall good rotational stability. A large degree of IOL rotation might occur in eyes with a relatively long AL, especially during the early postoperative period. The 6 rotated IOLs were implanted to correct with-the-rule astigmatism. FINANCIAL DISCLOSURE No author has a financial or proprietary interest in any material or method mentioned.
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Affiliation(s)
- Toshiyuki Miyake
- From the Department of Ophthalmology, University of Kitasato School of Medicine, Kanagawa, Japan.
| | - Kazutaka Kamiya
- From the Department of Ophthalmology, University of Kitasato School of Medicine, Kanagawa, Japan
| | - Rie Amano
- From the Department of Ophthalmology, University of Kitasato School of Medicine, Kanagawa, Japan
| | - Yoshihiko Iida
- From the Department of Ophthalmology, University of Kitasato School of Medicine, Kanagawa, Japan
| | - Shuntaro Tsunehiro
- From the Department of Ophthalmology, University of Kitasato School of Medicine, Kanagawa, Japan
| | - Kimiya Shimizu
- From the Department of Ophthalmology, University of Kitasato School of Medicine, Kanagawa, Japan
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Kankariya VP, Diakonis VF, Goldberg JL, Kymionis GD, Yoo SH. Femtosecond laser-assisted astigmatic keratotomy for postoperative trabeculectomy-induced corneal astigmatism. J Refract Surg 2014; 30:502-4. [PMID: 24892377 DOI: 10.3928/1081597x-20140527-01] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Accepted: 03/17/2014] [Indexed: 11/20/2022]
Abstract
PURPOSE To describe a case of postoperative trabeculectomy-induced corneal astigmatism treated with femtosecond laser-assisted astigmatic keratotomy. METHODS After trabeculectomy, the patient demonstrated change in manifest refraction from -0.5 diopters preoperatively to mixed astigmatism of -3.5 + 5.25@100 postoperatively and a decrease in uncorrected distance visual acuity from 20/60 preoperatively to 20/200 at 1 month postoperatively. Because the patient was intolerant to spectacle use, she underwent femtosecond laser-assisted astigmatic keratotomy. RESULTS After astigmatic keratotomy there was improvement in corneal topographic astigmatism from 4.15 to 0.81 diopters with uncorrected distance visual acuity of 20/60(-2) and manifest refraction of -0.75 + 1.0@90 at 3 months postoperatively. There were no intraoperative or postoperative complications. CONCLUSIONS Femtosecond laser-assisted astigmatic keratotomy may be considered in eyes with postoperative trabeculectomy-induced mixed astigmatism.
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Gao H, Shi W, Liu M, Gao Y, Xie L. Advanced Topography-Guided (OcuLink) Treatment of Irregular Astigmatism After Epikeratophakia in Keratoconus With the WaveLight Excimer Laser. Cornea 2012; 31:140-4. [DOI: 10.1097/ico.0b013e31822018a0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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21
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Kératotomies arciformes périphériques et correction de l’astigmatisme dans la chirurgie de la cataracte. J Fr Ophtalmol 2009; 32:390-5. [DOI: 10.1016/j.jfo.2009.04.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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22
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Long-term refractive stability following combined astigmatic keratotomy and phakoemulsification. Int Ophthalmol 2007; 29:109-15. [PMID: 18080094 DOI: 10.1007/s10792-007-9178-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2007] [Accepted: 11/19/2007] [Indexed: 10/22/2022]
Abstract
BACKGROUND To determine whether combined astigmatic keratotomy and cataract surgery induces a sustained reduction in astigmatism. METHODS Patients who had previously undergone combined cataract surgery and astigmatic keratotomy for naturally occurring astigmatism were identified and their notes reviewed. Mean final follow-up was 34 months (30-42 months). Fourteen eyes of 11 patients were eligible for study. Arcuate corneal incisions had been employed using the Buzard nomogram. Using power vector analysis, the post-operative refractive change at 6 months and final follow-up was determined. RESULTS The mean preoperative manifest cylindrical refractive error was 2.88 D (1.50-5.50 D). The mean postoperative manifest cylindrical refractive error was 1.89 and 1.79 D at 6 months and final follow-up, respectively. Power vector analysis demonstrated a significant postoperative reduction in refractive blur at 6 months and final follow-up (P = 0.006, P = 0.004, respectively): mean preoperative blur strength was 2.90 D and mean postoperative blur strength was 1.33 and 1.25 D at 6 months and final follow-up, respectively. Sustained postoperative reduction in astigmatism was noted in 12 of 14 eyes at final follow-up. CONCLUSIONS Astigmatic keratotomy is a well-established treatment for astigmatism. In this series, the refractive benefit from combined astigmatic keratotomy and cataract surgery is maintained for several years. No surgical complications were observed.
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Jankov MR, Panagopoulou SI, Tsiklis NS, Hajitanasis GC, Aslanides LM, Pallikaris LG. Topography-guided Treatment of Irregular Astigmatism With the WaveLight Excimer Laser. J Refract Surg 2006; 22:335-44. [PMID: 16629063 DOI: 10.3928/1081-597x-20060401-07] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE To evaluate the feasibility, safety, and predictability of correcting high irregular astigmatism in symptomatic eyes with the use of topography-guided photoablation. METHODS In a prospective, non-comparative case series, 16 consecutive symptomatic eyes of 11 patients with small hyperopic and myopic excimer laser optical zones, decentered and irregular ablation after corneal graft, and corneal scars were operated. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifest and cycloplegic refraction, and corneal topography, with asphericity and regularity, were analyzed. LASIK (n = 10) and photorefractive keratectomy (n = 6) were performed using the ALLEGRETTO WAVE excimer laser and T-CAT software (Topography-guided Customized Ablation Treatment; WaveLight Laser Technologie AG, Erlangen, Germany). RESULTS In the LASIK group, UCVA improved from 0.81 +/- 0.68 IogMAR (20/130) (range: 0.2 to 2.0) to 0.29 +/- 0.21 logMAR (20/39) (range: 0.1 to 0.7) at 6 months. In the PRK group, mean UCVA improved from 0.89 +/- 0.87 IogMAR (20/157) (range: 0.1 to 2.0) to 0.42 +/- 0.35 logMAR (20/53) (range: 0.1 to 1.0) at 6 months. Best spectacle-corrected visual acuity did not change significantly in either group. One PRK patient lost one line of BSCVA. Refractive cylinder for the LASIK group improved from -2.53 +/- 1.71 diopters (D) (range: -0.75 to -5.75 D) to -1.28 +/- 0.99 D (range: 0 to -2.50 D) at 6 months. Refractive cylinder in the PRK group improved from -2.21 +/- 2.11 D (range: -0.25 to -5.50 D) to -1.10 +/- 0.42 D (range: -0.50 to -1.50 D). Index of surface irregularity showed a decrease from 60 +/- 12 (range: 46 to 89) to 50 +/- 9 (range: 32 to 63) at 6 months in the LASIK group whereas no significant change was noted in the PRK group. Subjective symptoms, such as glare, halos, ghost images, starbursts, and monocular diplopia, were not present postoperatively. CONCLUSIONS Topography-guided LASIK and PRK resulted in a significant reduction of refractive cylinder and increase of UCVA, without a significant loss of BSCVA.
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Affiliation(s)
- Mirko R Jankov
- Vardinoyiannion Eye Institute of Crete, University of Crete, PO Box 1352, 71110 Voutes, Heraklion Crete, Greece.
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Alió JL, Belda JI, Osman AA, Shalaby AMM. Topography-guided Laser in situ Keratomileusis (TOPOLINK) to Correct Irregular Astigmatism After Previous Refractive Surgery. J Refract Surg 2003; 19:516-27. [PMID: 14518740 DOI: 10.3928/1081-597x-20030901-06] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE To assess whether topography-driven laser in situ keratomileusis (LASIK) can correct induced corneal irregular astigmatism. METHODS A prospective non-comparative case series of 41 eyes (38 patients) with irregular astigmatism following corneal refractive surgery, included two groups: Group 1 (26 eyes) with a defined topographic pattern and Group 2 (15 eyes) with no pattern. Ablation was performed using the Technolas 217C excimer laser with a software ablation program (TOPOLINK) based on corneal topography. Uncorrected and best spectacle-corrected visual acuity, manifest and cycloplegic refraction, corneal topography, superficial corneal surface quality, and image distortion were measured. RESULTS At 6 months follow-up in Group 1 eyes (defined topographic pattern) mean preoperative BSCVA improved from 0.16 +/- 0.11 LogMAR (0.4 to 0) to 0.09 +/- 0.10 LogMAR (0.2 to 0) (P = .001) (safety index of 1.1). In Group 2 eyes (no pattern), mean preoperative BSCVA was 0.18 +/- 0.11 LogMAR (0.4 to 0), similar to the postoperative BSCVA of 0.17 +/- 0.10 LogMAR (0.3 to 0) (safety index of 0.98). Mean postoperative UCVA was > or = 0.3 LogMAR in 25 eyes (96.2%) in Group 1 (efficacy index of 0.8) and 7 eyes (46.6%) in Group 2 (efficacy index of 0.5). Both superficial corneal surface quality and image distortion significantly improved in Group 1; there were no significant changes in Group 2. We reoperated nine eyes (21.9%). CONCLUSIONS Topographic-assisted LASIK was helpful in selected cases where irregular astigmatism showed a pattern. It was ineffective in undefined irregular astigmatism. Partial correction of the irregularity and regression of the obtained effect was common.
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Affiliation(s)
- Jorge L Alió
- Instituto Oftalmológico de Alicante, Alicante - Miguel Hernández University, Alicante, Spain
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Titiyal JS, Baidya KP, Sinha R, Ray M, Sharma N, Vajpayee RB, Dada VK. Intraoperative Arcuate Transverse Keratotomy With Phacoemulsification. J Refract Surg 2002; 18:725-30. [PMID: 12458867 DOI: 10.3928/1081-597x-20021101-10] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE To evaluate the efficacy of paired intraoperative arcuate transverse keratotomy at a 7-mm-diameter zone along with a 3.5-mm clear corneal phaco tunnel in the steeper axis to correct pre-existing astigmatism. METHODS A prospective randomized case-control study was conducted on 34 eyes of 28 patients with immature senile cataract. They were divided into two groups; in one group (17 eyes) intraoperative arcuate keratotomy was coupled with phacoemulsification in the steeper meridian (arcuate keratotomy group; mean preoperative astigmatism 2.28 +/- 0.89 D) and the other group (17 eyes) phacoemulsification was performed in the steeper meridian without arcuate keratotomy (control group; mean preoperative astigmatism 2.04 +/- 0.50 D). The patients were examined at 1 day, and 1, 4, and 8 weeks postoperatively. Correction of keratometric astigmatism, surgically induced refractive changes, magnitude and axis of cylinder, spherical equivalent refraction, with and against the wound change, and coupling ratio were evaluated. RESULTS Mean reduction in keratometric astigmatism in the keratotomy group was 1.26 +/- 0.54 D (P = .0067) and in the control group was 0.48 +/- 0.60 D (P = .0423). The difference in reduction of keratometric astigmatism between the two groups was statistically significant (P = .0296). Surgically induced refractive change at 8 weeks follow-up was 2.15 +/- 1.13 D in the keratotomy group and 1.50 +/- 1.32 D in the control group (P = .046). Coupling ratio was -1.10 +/- 0.43 in the keratotomy group at 8 weeks after surgery while the control group was -0.82 +/- 0.38. CONCLUSION A combination of intraoperative arcuate keratotomy with steep axis phacoemulsification incision is more effective than steep axis phacoemulsification incision alone in reducing pre-existing astigmatism.
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Affiliation(s)
- Jeewan S Titiyal
- Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Ophthalmic Sciences, New Delhi, India.
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Abstract
The use of incisional refractive surgery has become limited due to the widespread use of the excimer laser to correct myopia, hyperopia and astigmatism. Laser in situ keratomileusis and photorefractive keratectomy have proven to be much more accurate and predictable in correcting refractive error. This has made some forms of incisional refractive surgery practically obsolete. Radial keratotomy should not be considered a primary refractive procedure in the modern world, as RK has become "RKhaic". There are still indications for incisional refractive surgery in cataract and post-surgical patients for the treatment of astigmatism. However, with the advent of the toric intraocular lens and the use of LASIK in such aforementioned patients, these indications for incisional surgery will likely become more limited. In this review, we go over the past history of incisional refractive surgery and also report the current uses and advancements of this technique in today's practice environment.
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Affiliation(s)
- David M Choi
- Price Vision Group/Corneal Consultants of Indiana and The Cornea Research Foundation of America, Indianapolis, Indiana, USA
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Akura J, Matsuura K, Hatta S, Kaneda S, Kadonosono K. Clinical application of full-arc, depth-dependent, astigmatic keratotomy. Cornea 2001; 20:839-43. [PMID: 11685062 DOI: 10.1097/00003226-200111000-00012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To report a case series of the first clinical application of a new method of astigmatic keratotomy termed full-arc, depth-dependent astigmatic keratotomy (FDAK). METHODS The type of astigmatism was analyzed by corneal topography. If the astigmatism was regular, paired arcuate incisions of 90 degrees length were used. Incision depth varied between 40% and 75% of local corneal thickness for controlling the level of astigmatic correction. RESULTS All 13 cases had regular astigmatism, and paired arcuate incisions of 90 degrees length were used. Four cases with incisions at 40% depth, five cases at 50% depth, three cases at 60% depth, and one case at 75% depth induced vector astigmatic change of 0.93 +/- 0.33 D, 1.92 +/- 0.24 D, 3.17 +/- 0.26 D, and 4.44 D, respectively, 3 months after surgery. From 3 months to 1 year or 3 years, the postoperative astigmatism was stable, and no cases showed astigmatic regression of 0.50 D or more. Every topographic difference map indicated effective flattening and steepening occurring with a 1:1 coupling ratio. All postoperative color maps showed a marked improvement in corneal sphericity. CONCLUSIONS In FDAK using paired 90 degrees incisions at 40-75% depth, an almost linear relationship between the incision depth and degree of astigmatic change was observed. FDAK may be an effective and safe method of astigmatic keratotomy that accurately controls the level of astigmatic correction. More clinical applications are necessary for drawing final conclusions and making a nomogram.
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Affiliation(s)
- J Akura
- Kushimoto Rehabilitation Center, Kushimoto, Japan.
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Inoue T, Maeda N, Sasaki K, Watanabe H, Inoue Y, Nishida K, Inoue Y, Yamamoto S, Shimomura Y, Tano Y. Factors that influence the surgical effects of astigmatic keratotomy after cataract surgery. Ophthalmology 2001; 108:1269-74. [PMID: 11425686 DOI: 10.1016/s0161-6420(01)00629-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To determine the factors affecting the surgical effect of astigmatic keratotomy (AK) when against-the-rule astigmatism is present following cataract surgery. DESIGN Prospective interventional noncomparative case series. PARTICIPANTS Twenty eyes of 19 patients from four medical centers who had against-the-rule astigmatism following cataract surgery. INTERVENTION AK with a 6 mm optical zone, two linear 3-mm length incisions (T-cut) and a depth of 90% of the central thickness was performed on all subjects. MAIN OUTCOME MEASURES Vector analysis of astigmatic correction. Multiple regression analysis for seven covariates including age, spherical equivalent of the manifest refraction, preoperative astigmatism, corneal diameter, corneal thickness, mean radius of corneal curvature and axial misalignment. RESULTS Multiple regression analysis showed that the preoperative astigmatism (p = 0.014) and the axis deviation (p = 0.005) were significantly correlated with the surgical effects. CONCLUSIONS Even with a uniform surgical procedure, the surgical effects of AK in eyes with against-the-rule astigmatism can be affected by the amount of preoperative astigmatism and the intraoperative axis misalignment. Adding the amount of preoperative astigmatism to the nomogram and improvement of surgical procedures will be required to obtain better surgical predictability of AK following cataract surgery.
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Affiliation(s)
- T Inoue
- Department of Ophthalmology, Osaka University Medical School, Osaka, Japan
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Porta A, Sobha S, Claoué C. Can We Combine Astigmatic Keratotomy and Multifocal Lens Implantation? J Refract Surg 2001; 17:474-5. [PMID: 11472010 DOI: 10.3928/1081-597x-20010701-14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Alió JL, Belda JI, Shalaby AM. Correction of irregular astigmatism with excimer laser assisted by sodium hyaluronate. Ophthalmology 2001; 108:1246-60. [PMID: 11425683 DOI: 10.1016/s0161-6420(01)00602-9] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
Abstract
PURPOSE To demonstrate the usefulness of excimer laser surgery assisted by sodium hyaluronate for the correction of irregular astigmatism after previous corneal refractive surgery. DESIGN Prospective noncomparative case series. PARTICIPANTS Fifty eyes with surgically induced irregular astigmatism. All the patients had been subjected previously to one or more of the following: laser in situ keratomileusis (LASIK), incisional keratotomy, photorefractive keratotomy, phototherapeutic keratotomy, laser thermokeratoplasty, and corneal trauma. Irregular astigmatism developed thereafter. METHODS Stability of the corneal topography pattern before surgical decision was observed for at least 6 months with the C-SCAN corneal topography with Ray Tracing (Technomed GmbH, Germany) and the Eye-Sys 2000 Corneal Analysis System (Eye Sys Co., Houston, TX). The lowest pachymetry value was 310 microm in the thinnest portion of the cornea. Ablation was performed with the Technolas 217 C-LASIK excimer laser (Bausch and Lomb Chiron Technolas GmbH, Dornach, Germany), in phototherapeutic keratectomy mode, assisted by a mask of 0.25% sodium hyaluronate. We performed our ablation either on the surface or under a flap, whether elevated or newly cut. MAIN OUTCOME MEASURES Uncorrected and best-corrected visual acuity, manifest and cycloplegic refraction, superficial corneal surface quality, image distortion, and predicted corneal visual acuity. RESULTS At 3 months of follow-up, the irregular corneal surface was significantly improved in all cases (n = 50). The superficial corneal surface quality improved from 70.5% +/- 9.16% to 75.6% +/- 10.38 (P < 0.0001). Six eyes lost 1 line of best-corrected visual acuity, three eyes lost 2 lines, and five eyes lost 3 or more lines. The real corneal ablation depth obtained was equal to 63% of that programmed because of the influence of masking substance. Mean uncorrected visual acuity improved from 20/80 +/- 20/125 to 20/63 +/- 20/100 (P = 0.01). Predicted corneal visual acuity improved from a mean of 20/32 +/- 20/80 to 20/25 +/- 20/63 (P = 0.004). Image distortion improved from a mean of 13.95 +/- 3.64 to 12.16 +/- 3.92 (P < 0.0001). We obtained a hyperopic shift in 56% and myopic shift in 40% of eyes. After 6 months of follow-up the irregular corneal surface continued to improve in all cases (n = 32). The superficial corneal surface quality improved from 69.38% +/- 9.48% to 73.13% +/- 8.87 (P = 0.002). Two eyes lost 2 lines of best-corrected visual acuity, and 3 eyes lost 1 line. Ray tracing was significantly improved in all cases at the end of follow-up regarding superficial corneal surface quality (P = 0.002) and the image distortion (P = 0.05). Improvement of predicted corneal visual acuity was not significant (P = 0.11). The procedure proved to be safe, with a safety index of 1.1. Differences between the surface and stromal treatments and between pattern and nonpattern irregular astigmatism were not statistically significant. CONCLUSION It is possible to produce a more regular corneal surface and to improve best-corrected visual acuity in patients with irregular astigmatism using plano-scan excimer laser assisted by viscous masking solution of 0.25% sodium hyaluronate.
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Affiliation(s)
- J L Alió
- Instituto Oftalmológico De Alicante, Alicante, Spain.
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Akura J, Matsuura K, Hatta S, Kaneda S, Ikeda T. Experimental study using pig eyes for realizing ideal astigmatic keratotomy. Cornea 2001; 20:325-8. [PMID: 11322425 DOI: 10.1097/00003226-200104000-00017] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE The effects of varying the incision length and depth were analyzed using pig eyes to acquire information for realizing an ideal method of astigmatic keratotomy (AK). METHODS Single and paired arcuate incisions were made on pig corneas using a diamond knife. Incisions with varying lengths of 40 degrees, 60 degrees, and 90 degrees were made with the incision depth fixed at 90% of corneal thickness. Next, paired incisions with varying incision depth from 20% to 95% of corneal thickness were made with the incision length fixed at 90 degrees. The changes in corneal shape were analyzed using corneal topography and the degrees of astigmatic change were measured using a surgical keratometer. RESULTS For short single and paired incisions (40 degrees or 60 degrees in length), narrow areas of flattenings occurred, and steepenings were observed on both sides adjacent to the flattened areas. For long paired incisions of 90 degrees length, wide areas of flattenings and steepenings were observed with an approximately 1:1 coupling ratio, and a positive linear relationship between the incision depth and degree of astigmatic change was observed in the range of incision depth between 40% and 80% of corneal thickness. CONCLUSION This experimental study suggests that for achieving ideal corneal sphericity after AK, long incisions covering the entire steep areas (paired 90 degrees incisions for regular astigmatism) should be used and the degree of astigmatic correction may be controlled by varying the incision depth.
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Affiliation(s)
- J Akura
- Kushimoto Rehabilitation Center, Kushimoto, Japan
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Alió JL, Artola A, Rodriguez-Mier FA. Selective zonal ablations with excimer laser for correction of irregular astigmatism induced by refractive surgery. Ophthalmology 2000; 107:662-73. [PMID: 10768327 DOI: 10.1016/s0161-6420(99)00152-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
OBJECTIVE To demonstrate the safety and efficacy of selective zonal ablations with excimer laser for the correction of irregular astigmatism induced by refractive surgery. DESIGN Thirty-one eyes of 26 patients. Retrospective and noncomparative case series. METHODS The authors reviewed the medical results of the two series of consecutive cases of irregular astigmatism induced by refractive surgery. One group showed a topography map with a defined pattern: decentered ablation, decentered steep central island, central irregularity, and peripheral irregularity. The other group showed an irregular astigmatism without defined pattern. Selective zonal ablation was performed with a broad-beam excimer laser. Laser ablations were adjusted according to the Munnerlyn formula. A phototherapeutic keratectomy (PTK) mode was used in all cases without using viscous masking solution. MAIN OUTCOME MEASURES Uncorrected visual acuity, best spectacle-corrected visual acuity (BCVA), and Holladay diagnostic summary (Eye Sys 2.000) were considered before and after surgery to obtain the qualitative and quantitative characteristics of the visual acuity and corneal topography. The corneal uniformity index (CUI) was used to evaluate the corneal surface changes induced by the selective zonal ablations in the correction of irregular astigmatism. It proved to be a useful tool in the understanding of astigmatic changes when it is not possible to apply the vector analysis. RESULTS In group 1, the irregular astigmatism was significantly improved in 96.4% of cases. The CUI was improved from 58+/-0.3% to 87+/-0.8%, P < 0.005 (Student's t-test). The improvement of the BCVA was from 20/40+/-20/100 to 20/25+/-20/100, P < 0.005 (Student's t-test). The results obtained in group 2 were not clinically significant in terms of improvement of CUI and BCVA. CONCLUSIONS Using the corneal topographic map as a guide, selective zonal ablations with excimer laser can be used to create a more regular corneal surface, when a defined pattern of topographic irregularities can be defined.
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Affiliation(s)
- J L Alió
- Instituto Oftalmológico de Alicante, Spain.
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Akura J, Matsuura K, Hatta S, Otsuka K, Kaneda S. A new concept for the correction of astigmatism: full-arc, depth-dependent astigmatic keratotomy. Ophthalmology 2000; 107:95-104. [PMID: 10647726 DOI: 10.1016/s0161-6420(99)00021-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
OBJECTIVE The purpose of this study is to introduce and evaluate a new concept in astigmatic keratotomy (AK) named full-arc, depth-dependent AK (FDAK). DESIGN Noncomparative interventional case series. PARTICIPANTS FDAK was performed on a total of 37 eyes with regular astigmatism; of these, 16 eyes received FDAK alone, and 21 eyes received FDAK combined with cataract surgery. METHODS Corneal topography was used to divide the cornea into two discreet regions of "steep" and "flat." Then, paired arcuate incisions, 90 degrees in length, were placed along the full arc of the steep area. The level of astigmatic correction was controlled by varying the incision depth from 40% to 80% on the basis of a provisional nomogram developed by the authors. MAIN OUTCOME MEASURES Keratometries, corneal topographies, and visual acuities were measured. RESULTS The FDAK alone group showed a significant improvement from a preoperative corneal astigmatism of 2.90 +/- 0.78 diopters (D) to a postoperative value of 0.89 +/- 0.52 D. The "combined" group also showed significant improvement from a preoperative corneal astigmatism of 2.97 +/- 1.01 D, to a postoperative value of 1.02 +/- 0.45 D. The deviation of achieved correction from attempted correction using vector analysis was between 1.37 D of undercorrection and 0.98 D of overcorrection, with 91.9% of cases within the range of +/- 1.0 D. Slight oblique change caused by axis deviation was observed in seven cases. Both uncorrected and corrected visual acuity showed statistically significant improvement. No serious complications were encountered. CONCLUSIONS Controlling the level of correction by varying the incision depth allowed the surgeon to use long incisions (90 degrees in length in regular astigmatism) covering the entire steep area, minimizing the undesirable changes induced by conventional deep and narrow incision AK and resulting in an ideal corneal sphericity after surgery. FDAK enabled the surgeon to accurately control the level of astigmatic correction with minimal risk of corneal perforation.
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Affiliation(s)
- J Akura
- Department of Ophthalmology, Kushimoto Rehabilitation Center, Wakayama, Japan
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Oshika T, Shimazaki J, Yoshitomi F, Oki K, Sakabe I, Matsuda S, Shiwa T, Fukuyama M, Hara Y. Arcuate keratotomy to treat corneal astigmatism after cataract surgery: a prospective evaluation of predictability and effectiveness. Ophthalmology 1998; 105:2012-6. [PMID: 9818598 DOI: 10.1016/s0161-6420(98)91117-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Abstract
OBJECTIVE Although several nomograms are available for the incisional keratotomy to correct naturally occurring astigmatism, astigmatic keratotomy in eyes after cataract surgery has not been well analyzed. The predictability and effectiveness of arcuate keratotomy in pseudophakic eyes were studied. DESIGN A prospective, multicenter study. PARTICIPANTS One hundred four eyes of 86 patients with residual corneal astigmatism of 1.5 diopters (D) or more after cataract surgery were examined. INTERVENTION Arcuate keratotomy was performed in nine centers by nine surgeons. MAIN OUTCOME MEASURES The amount of astigmatic correction was calculated using the vector analysis of preoperative and 6-month postoperative refractive cylinder results. RESULTS Multiple regression analysis showed that optical zone size, number of incisions, and incision length had significant correlations with the amount of astigmatic correction. The regression equation was expressed as effects = (-0.643 x optical zone size) + (0.998 x incision number) + (0.057 x incision length) + 2.356. The parameter of predictability (r2: 35%) was lower than that reported for congenital astigmatism (48 to approximately 56%). A new nomogram was derived based on the multiple regression equation. CONCLUSIONS Astigmatic keratotomy in pseudophakic eyes is less predictable than that in eyes with idiopathic astigmatism, but the procedure is sufficiently effective in reducing the residual astigmatism after cataract surgery. Individual nomograms are necessary for astigmatic keratotomy in eyes with naturally occurring and postsurgical astigmatism.
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Affiliation(s)
- T Oshika
- Department of Ophthalmology, University of Tokyo School of Medicine, Japan
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Abstract
BACKGROUND In anisometropia, the asymmetry of refractive error produces disparity of image magnification (aniseikonia) that can create visual discomfort, especially when asymmetry is 3.00 diopters or more. METHODS A prospective study of 20 eyes of 20 patients between 18 and 61 years of age who underwent unilateral radial and/or transverse keratotomy was conducted; results of at least 12 months follow-up are presented. The efficacy of keratotomy was evaluated by the following criteria: 1) change in spherical and cylindrical refraction, 2) decrease in refraction difference between two eyes of each patient, 3) change in spectacle-corrected visual acuity, and 4) change in binocular vision functions and asthenopic complaints. RESULTS Mean decrease in spherical refractive error was 3.66 +/- 1.58 D (range, 1.25 to 7.50 D) and 2.08 +/- 0.81 D (range, 1.00 to 3.50 D) in astigmatic refraction. The mean refraction difference between two eyes was 4.90 +/- 2.20 D preoperatively, and this difference regressed to 1.79 +/- 1.42 D postoperatively. Spectacle-corrected visual acuity increased in seven eyes (35%), remained the same in 12 eyes (60%) and decreased in one eye (5%). All patients reported relief of asthenopic complaints. Fusion amplitudes increased in 12 (60%) patients. Stereoscopic vision improved in five (25%) patients. CONCLUSION Monocular refractive keratotomy can significantly decrease anisometropia.
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Affiliation(s)
- A Maden
- Department of Ophthalmology, Dokuz Eylul University, Izmir, Turkey
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Abstract
BACKGROUND Four basic types of irregular astigmatism are described: central elevation, central flat area, eccentric elevation, and eccentric flat area. METHODS The importance of the Munnerlyn formula is shown for the treatment of irregular astigmatism. A new diagnostic entity is described, the steep/flat ratio, modeled on the inferior/superior ratio described previously in keratoconus. Calculation of the steep/flat ratio is described using the cross sectional view of videokeratography, leading to specific treatments for the four types of irregular astigmatism. Surgical technique using the VISX Star excimer laser for repeated laser in situ keratomileusis (LASIK) is described. RESULTS Case studies are given for each of the forms of irregular astigmatism showing improved topographic appearance and indicating treatment parameters. In each case, improvement of both uncorrected and spectacle-corrected visual acuity is demonstrated. CONCLUSIONS Irregular astigmatism is an important complication of refractive surgery. Four basic forms of irregular astigmatism can be treated with a broad beam excimer laser.
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Affiliation(s)
- K A Buzard
- Buzard Eye Institute, Department of Surgery, University of Nevada School of Medicine, Las Vegas, USA
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Flanagan GW, Binder PS. Refractive outcome following radial keratotomy and combined radial and astigmatic keratotomy. J Cataract Refract Surg 1997; 23:1057-63. [PMID: 9379377 DOI: 10.1016/s0886-3350(97)80080-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
PURPOSE To determine whether the visual and refractive outcomes of combined astigmatic and radial keratotomy (AK/RK) procedures was different from that following RK for the correction of naturally occurring compound myopic astigmatism and spherical myopia. SETTING Private professional practice, San Diego, California, USA. METHODS The computer database of all incisional procedures performed by one surgeon over 10 years was reviewed to compare the visual acuity outcome of AK/RK and RK procedures. Enhancement procedures were excluded. Only data from the last office visits were analyzed to establish the relationship between visual acuity and type of keratotomy procedure performed. A multiple regression model was constructed, which included covariates of age, postoperative keratometric cylinder, and postoperative refraction. RESULTS After controlling for covariates, the AK/RK population had significantly lower postoperative uncorrected visual acuity levels than the RK population (P < .03) after one operation (prior to enhancement surgery). CONCLUSIONS Using the nomograms for myopia correction for unenhanced RK cases, combined AK and RK procedures appeared to reduce the expected visual results. Surgeons may consider modifying surgical nomograms to account for the expected spherical undercorrection that can occur when myopia and astigmatism are corrected simultaneously.
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Affiliation(s)
- G W Flanagan
- Ophthalmology Research Laboratory, National Vision Research Institute, San Diego, California, USA
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Richard L. Lindstrom, MD 1995 Barraquer Lecturer Biographical Sketch. J Refract Surg 1997; 13:285-6. [PMID: 9244595 DOI: 10.3928/1081-597x-19970501-14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Buzard KA, Laranjeira E, Fundingsland BR. Clinical results of arcuate incisions to correct astigmatism. J Cataract Refract Surg 1996; 22:1062-9. [PMID: 8915803 DOI: 10.1016/s0886-3350(96)80119-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
PURPOSE To evaluate the effectiveness of arcuate incisions for correcting congenital, post-cataract, post-radial keratotomy, and post-trapezoidal keratotomy astigmatism. SETTING Buzard Eye Institute, Las Vegas, Nevada. METHODS In this retrospective study, 46 eyes of 29 patients had arcuate incisions to correct astigmatism. The average age of patients was 52 years. RESULTS Mean preoperative astigmatism was 3.51 +/- 1.57 D (keratometric) and 3.41 +/- 1.44 D (manifest). Mean preoperative uncorrected visual acuity was 20/80, ranging from 20/30 to 20/400. Thirty eyes had a pair of 45-degree arcuate incisions, 10 eyes had a pair of 60-degree arcuate incisions, and 6 eyes had a pair of 90-degree arcuate incisions. Mean follow-up was 6 months. Mean postoperative astigmatism was 1.46 +/- 1.07 D (keratometric) and 1.05 +/- 0.94 D (manifest), with a reduction of astigmatism in all operated eyes. Mean postoperative uncorrected visual acuity was 20/32, ranging from 20/20 to 20/60. The analysis of the vector astigmatic change showed that only two patients were overcorrected after the procedure. CONCLUSION The predictability and safety of arcuate incisions are reflected in these results.
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Affiliation(s)
- K A Buzard
- Department of Ophthalmology, Ruprecht-Karls-University of Heidelberg, Germany
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Manche EE, Maloney RK. Astigmatic keratotomy combined with myopic keratomileusis in situ for compound myopic astigmatism. Am J Ophthalmol 1996; 122:18-28. [PMID: 8659595 DOI: 10.1016/s0002-9394(14)71960-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
PURPOSE Myopic keratomileusis in situ by an automated microkeratome corrects myopia but not astigmatism, which is traditionally corrected by astigmatic keratotomy months after keratomileusis. We developed a technique for simultaneously correcting astigmatism and severe myopia, and examined its effectiveness in a retrospective case-control study. METHODS Thirty-four eyes (23 patients) underwent myopic keratomileusis in situ combined with one or two arcuate keratotomy incisions performed after the refractive cut, in the bed of the primary keratectomy flap. The myopic keratomileusis control group consisted of 34 matched eyes (30 patients) undergoing keratomileusis without astigmatic keratotomy. The astigmatic control group consisted of 117 unmatched eyes (85 patients) undergoing astigmatic keratotomy combined with radial keratotomy. RESULTS Mean refractive astigmatism in the study group decreased from 2.4 diopters (range, 1.0 to 4.0 diopters) preoperatively to 1.7 diopters (range, 1.0 to 4.0 diopters) at three months postoperatively, and increased by 0.4 diopter in the myopic keratomileusis control group at three months postoperatively (P < .005). Eighteen of 27 eyes in the study group showed decreased refractive astigmatism compared with ten of 34 eyes in the myopic keratomileusis control group (P < .0001). Combining astigmatic keratotomy with myopic keratomileusis produced 0.2 +/- 0.9 diopter less astigmatic correction than that expected from the astigmatic control group. One of 27 eyes lost two or more lines of best spectacle-corrected visual acuity at the three-month postoperative visit. No eye lost two or more lines of best spectacle-corrected visual acuity at postoperative month 6. CONCLUSION Eyes with substantial preoperative refractive astigmatism that undergo myopic keratomileusis in situ may benefit from simultaneous astigmatic keratotomy to reduce residual post-operative refractive astigmatism.
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Affiliation(s)
- E E Manche
- Department of Ophthalmology, UCLA School of Medicine, USA
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Niles C, Culp B, Teal P. Excimer laser photorefractive keratectomy using an erodible mask to treat myopic astigmatism. J Cataract Refract Surg 1996; 22:436-40. [PMID: 8733846 DOI: 10.1016/s0886-3350(96)80038-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
PURPOSE To evaluate the results of excimer laser photorefractive keratectomy (PRK) using an erodible mask to treat myopic astigmatism. SETTING Douglas Memorial Hospital Medical Centre, Fore Erie, Ontario, Canada. METHODS Photorefractive keratectomy was done on 25 consecutive eyes of 25 patients with myopic astigmatism using the OmniMed excimer laser and a compound single-use myopic erodible mask manufactured to produce a specific spherical and cylindrical correction for each individual patient. Follow-up ranged from 6 months for 25 patients to 1 year for 5 patients. RESULTS Six months after PRK, the mean preoperative sphere of -7.46 diopters (D) decreased to -0.17 D and the mean preoperative cylinder of 2.31 D dropped to 0.69 D; 73% of astigmatism was corrected. In the five eyes followed for 1 year, 94% of astigmatism was corrected. Correction of the myopic component was less predictable, with a wider than anticipated range of overcorrection. CONCLUSIONS Excimer laser PRK successfully corrected myopic astigmatism in patients with low and high myopia. The less predictable myopia results may have been secondary to increased procedure time, corneal dehydration, and difficulty in patient fixation and thus alignment.
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Affiliation(s)
- C Niles
- Douglas Memorial Hospital Medical Centre, Fort Erie, Ontario, Canada
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Abstract
PURPOSE To determine the efficacy and safety of the Casebeer transverse nomogram for correcting idiopathic astigmatism using transverse incisions (T-incisions) with variable optical zones. SETTING Rancho Bernardo Eye Center, San Diego, California. METHODS This retrospective study comprised 173 eyes of 100 consecutive patients who had T-incisions according to the Casebeer transverse nomogram to correct mixed or myopic astigmatism. Preoperative cylinder ranged from 0.75 to 6.00 diopters (D). The nomogram was modified for eyes with preoperative cylinder from 1.75 to 6.00 D. Principal outcome measures were net residual astigmatism for all eyes and uncorrected visual acuity in eyes with the highest preoperative cylinder (3.25 to 6.00 D). RESULTS A comparison of preoperative astigmatism (mean 3.07 D +/- 1.53 [SD]) and net residual astigmatism showed significant reduction in all diopter categories. Enhancements were done in 16.2% of eyes, mostly those with high preoperative cylinder. Patient age did not seem to affect results. No patient, including those with smaller optical zones, lost two or more Snellen lines of best corrected visual acuity. CONCLUSION Use of the Casebeer transverse nomogram with T-incisions and variable optical zones effectively and safely reduced most idiopathic astigmatism between 0.75 and 5.50 D. Modifications to the nomogram yielded similar results in eyes with a higher preoperative cylinder.
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Price FW, Grene RB, Marks RG, Gonzales JS. Arcuate Transverse Keratotomy for Astigmatism Followed by Subsequent Radial or Transverse Keratotomy. J Refract Surg 1996; 12:68-76. [PMID: 8963820 DOI: 10.3928/1081-597x-19960101-14] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND We studied the safety and efficacy of arcuate transverse keratotomy performed for the primary correction of naturally occurring corneal astigmatism. METHODS A multicenter, prospective evaluation of one-stage arcuate transverse keratotomy was conducted in 160 eyes with 1.00 to 6.00 diopters (D) of naturally occurring astigmatism. Vector analysis was used. After 1 month, those eyes that needed further refractive surgery received radial keratotomy for myopia and second-stage arcuate transverse keratotomy for residual astigmatism. RESULTS Mean preoperative refractive cylinder was 2.80 D. At 1 month, the vector-corrected change was 2.30 D. Eighty-eight (61%) eyes had at least 1.00 D of residual refractive cylinder and 24 (17%) had at least 2.00 D. Eyes undergoing a second surgery averaged 1.60 D of vector-corrected effect, for a total effect of 2.90 D from both surgeries, indicating the astigmatic refractive effects were not additive. Eyes that had radial keratotomy alone as the second surgery demonstrated a similar change in refractive cylinder as eyes that had both radial and transverse keratotomies. Two eyes lost two lines of spectacle-corrected visual acuity, 29 eyes lost one line, 84 showed no change, and 26 eyes improved one line. CONCLUSION Arcuate transverse keratotomy reduced refractive astigmatism. Both overcorrection and undercorrection were common. Complications were infrequent but occasionally caused significant irregular astigmatism. Arcuate transverse keratotomy appears to be a safe procedure with few complications.
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Affiliation(s)
- F W Price
- Cornea Research Foundation of America, Indianapolis, Ind, USA
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Chavez S, Chayet A, Celikkol L, Parker J, Celikkol G, Feldman ST. Analysis of astigmatic keratotomy with a 5.0-mm optical clear zone. Am J Ophthalmol 1996; 121:65-76. [PMID: 8554082 DOI: 10.1016/s0002-9394(14)70535-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
PURPOSE To investigate the surgically induced refractive change after astigmatic keratotomy with a 5.0-mm optical clear zone in patients with severe naturally occurring astigmatism. METHODS We analyzed surgically induced refractive change in 40 consecutive eyes undergoing astigmatic keratotomy with a 5.0-mm optical clear zone. The surgically induced refractive change was calculated according to the method of Holladay, Cravy, and Koch with some modifications. Eyes were divided into two groups: Group I included eyes with mixed astigmatism and a maximum preoperative spherical equivalent of +1.25 diopters that underwent arcuate keratotomy, and Group II included eyes with compound myopic or simple myopic astigmatism (maximum preoperative spherical equivalent of -3.00 diopters) or mixed astigmatism with low minus spherical equivalent that underwent four-incision radial keratotomy and arcuate keratotomy. RESULTS After refractive surgery, all eyes experienced a reduction of astigmatism when examined three months or more after surgery. Only one eye from each group was overcorrected. The magnitude of refractive astigmatism of surgically induced refractive change was 3.25 +/- 0.90 diopters for eyes in Group I and 3.25 +/- 0.80 diopters for eyes in Group II. There was minimal axis deviation. Eyes in Group I had more flattening with the wound than steepening against the wound, with a coupling ratio of -0.86 +/- 0.36, whereas in Group II, there was flattening both with the wound and against the wound. The net effect of surgery (sum of the primary and secondary effects) was more flattening than steepening in Group I eyes, and flattening of the circumference of the eye in Group II. A decrease of one line of best-corrected visual acuity was observed in one (6.6%) of 15 eyes in Group I and in two (8%) of 25 eyes in Group II. CONCLUSIONS A 5.0-mm optical clear zone arcuate keratotomy is an effective method for correcting moderate to severe naturally occurring astigmatism. Further investigation of this optical clear zone size on glare and contrast sensitivity testing is necessary and is underway.
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Affiliation(s)
- S Chavez
- Department of Ophthalmology, University of California, San Diego School of Medicine, La Jolla 92093-0684, USA
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Affiliation(s)
- G O Naumann
- Department of Ophthalmology, University of Erlangen-Nürnberg, Germany
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46
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Abstract
Radial keratotomy (RK) is a common surgical technique for correcting myopia. The RK incisions, like any corneal incisions, permanently weaken the cornea and this structural weakening can cause several complications and side effects, including diurnal fluctuation, progressive hyperopic shift, and the potential for traumatic rupture of the keratotomy scars. I describe a new technique--minimally invasive RK (mini-RK)--that reduces the millimeters of cornea incised and present preliminary laboratory and clinical results. In a cadaver eye study, eight short, deep incisions extending from the 3.0 mm optical zone to the 7.0 mm optical zone produced 92% of the efficacy of full-length incisions to the 11.0 mm optical zone. This finding was confirmed by intraoperative surgical keratometry in six patients in whom a 1% increase in central corneal flattening was achieved when incisions were extended from the mini-RK configurations to full length. In a retrospective evaluation of 100 patients with -1.0 to -6.0 diopters (D) of myopia, 92% of eyes were within 1.0 D of emmetropia and 94% had 20/40 or better uncorrected visual acuity. No significant complications were encountered. Mini-RK may be a useful alternative to reduce the invasiveness of RK but retain its efficacy in eyes with low to moderate myopia.
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Affiliation(s)
- R L Lindstrom
- Phillips Eye Institute Center for Teaching and Research, Minneapolis, Minnesota, USA
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Gibralter R, Trokel SL. Correction of irregular astigmatism with the excimer laser. Ophthalmology 1994; 101:1310-4; discussion 1314-5. [PMID: 8035996 DOI: 10.1016/s0161-6420(94)31174-2] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND Correction of irregular astigmatism has not been possible using available keratorefractive technology. METHODS The authors used a topographic map as a guide and created a custom excimer ablation program, designed to create a more regular surface. The program consisted of a combination of phototherapeutic and photorefractive ablation patterns. The amount of tissue to be removed was calculated on the basis of the diameter and steepness of the irregular areas of the corneal surface. RESULTS A more regular surface, as evidenced by topographic analysis, reduced astigmatism, and improved uncorrected visual acuity, was produced. CONCLUSION Using the corneal topographical map as a guide, excimer laser ablation can be used to create a more regular optical surface with improved visual function.
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Affiliation(s)
- R Gibralter
- Manhattan Eye, Ear and Throat Hospital, New York
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Sabates MA, Buzard KA, Friedlander MH, Cortinas MB. Induction of Astigmatism by Straight Transverse Corneal Incisions, 45° Long, at Different Clear Zones in Human Cadaver Eyes. J Refract Surg 1994. [DOI: 10.3928/1081-597x-19940501-05] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Ring CP, Hadden OB, Morris AT. Transverse Keratotomy Combined with Spherical Photorefractive Keratectomy for Compound Myopic Astigmatism. J Refract Surg 1994. [DOI: 10.3928/1081-597x-19940302-14] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Spigelman AV, Albert WC, Cozean CH, Johnson DG, McDonnell PJ, Pender PM, Shimmick J. Treatment of myopic astigmatism with the 193 nm excimer laser utilizing aperture elements. J Cataract Refract Surg 1994; 20 Suppl:258-61. [PMID: 8006797 DOI: 10.1016/s0886-3350(13)80763-8] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
In this paper, we examine the 193 nm excimer laser's efficacy and safety in treating myopic astigmatism. The VISX Twenty/Twenty excimer laser uses aperture elements to effect astigmatic photorefractive keratectomy. In 70 patients with six months follow-up, the average postoperative sphere was -0.14 and the average postoperative cylinder was -0.54. Seventy-one percent of these patients had uncorrected visual acuity of 20/40 or better at six months. In 12 patients with one year follow-up, the average postoperative sphere was -0.05 and the average postoperative cylinder was -0.59. Eighty-three percent of these patients had uncorrected acuities of 20/40 or better; none had a clinically significant loss of best corrected acuity. This investigation demonstrates that the excimer laser can be used to treat myopic astigmatism successfully.
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