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Brendan J. Vote - One of the best experts on this subject based on the ideXlab platform.
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cystoid macular edema after Femtosecond Laser assisted versus phacoemulsification cataract surgery
Journal of Cataract and Refractive Surgery, 2015Co-Authors: Shaun Y P Ewe, Robin G Abell, Penelope L Allen, Carmen L Oakley, Brendan J. VoteAbstract:Purpose To evaluate the incidence of postoperative clinical cystoid macular edema (CME) associated with Femtosecond Laser–assisted cataract surgery (Catalys Laser system) versus phacoemulsification cataract surgery. Setting Launceston Eye Institute, Launceston, Tasmania, Australia. Design Nonrandomized, single-surgeon, prospective, comparative cohort case series. Methods Patients who had Femtosecond Laser–assisted cataract surgery and phacoemulsification cataract surgery between March 2012 and July 2014 were included in the study. The Femtosecond Laser–assisted cataract surgery group had anterior capsulotomy, lens fragmentation, with or without corneal incisions via Femtosecond Laser pretreatment. Standard phacoemulsification surgery and foldable acrylic intraocular lens insertion proceeded in all cases. All patients received topical nonsteroidal drops commencing 2 days preoperatively and continuing for 4 weeks postoperatively. The incidence of postoperative clinical CME (confirmed by optical coherence tomography) and comparison between groups were measured. The main outcome measure was the clinical CME rates. Results Of the eyes, 833 had Femtosecond Laser–assisted cataract surgery amd 458 had standard phacoemulsification cataract surgery. Both groups had similar baseline parameters. There were 7 cases of postoperative CME (0.8%) in the Femtosecond Laser–assisted cataract surgery group compared to 1 case (0.2%) in the phacoemulsification cataract surgery group, highlighting a trend toward greater cystoid macular edema in the Femtosecond Laser–assisted cataract surgery group. This correlated with a change in Laser treatment speed (due to a software upgrade), suggesting that retinal safety thresholds need further careful analysis. Conclusion Increased CME might be a subthreshold retinal injury safety signal after Femtosecond Laser pretreatment and warrants further study. Financial Disclosure There are no financial or conflicts of interest for any author.
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anterior chamber flare after Femtosecond Laser assisted cataract surgery
Journal of Cataract and Refractive Surgery, 2013Co-Authors: Robin G Abell, Penelope L Allen, Brendan J. VoteAbstract:Purpose To determine whether postoperative ocular inflammation is less after Femtosecond Laser–assisted cataract surgery than after conventional phacoemulsification (manual) cataract surgery. Setting Private clinic, Launceston, Tasmania, Australia. Design Prospective consecutive investigator-masked nonrandomized parallel cohort study. Methods Consecutive cataract patients who had Femtosecond Laser–assisted cataract surgery or manual cataract surgery by the same surgeon at a single center were assessed. The primary endpoint was postoperative aqueous flare measured by Laser flare photometry at 1 day and 4 weeks. Secondary endpoints included retinal thickness measured by optical coherence tomography and slitlamp examination findings at 4 weeks. Results The per-protocol population comprised 176 patients (100 in Laser group; 76 in manual group). Postoperative aqueous flare was significantly greater in the manual cataract surgery group at 1 day (P=.0089) and at 4 weeks (P=.003). There was a significant correlation between effective phacoemulsification time and 1-day postoperative aqueous flare (r = 0.35, P Conclusion Anterior segment inflammation was less after Femtosecond Laser–assisted cataract surgery than after manual cataract surgery, and this appeared to be due to a reduction in phacoemulsification energy. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.
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Femtosecond Laser assisted cataract surgery compared with conventional cataract surgery
Clinical and Experimental Ophthalmology, 2013Co-Authors: Robin G Abell, Nathan M. Kerr, Brendan J. VoteAbstract:Abstract To investigate the safety and efficacy of the Catalys (Optimedica, Santa Clara, CA, USA) Femtosecond Laser-assisted cataract surgery system compared with conventional phacoemulsification cataract extraction. Prospective, consecutive, parallel cohort study. The first 200 eyes undergoing conventional cataract surgery to the first 200 eyes undergoing Femtosecond Laser-assisted cataract surgery between April and July 2012. Femtosecond Laser-assisted cataract surgery involved anterior capsulotomy and lens fragmentation based on optical coherence tomography-guided treatment mapping. Conventional cataract surgery involved manual continuous curvilinear capsulorhexis. Both procedures were completed by standard phacoemulsification and insertion of an intraocular lens. Effective phacoemulsification time and intraoperative complication rates. Patient demographics were similar between both groups. There was no statistically significant difference in intraoperative complications between Femtosecond Laser-assisted cataract surgery and conventional surgery. There was one posterior capsule rupture in both groups (0.5%; not significant). One hundred per cent of cases treated with the Femtosecond Laser had a complete capsulotomy. Vacuum time decreased with experience. Effective phacoemulsification time was reduced by 70% in the Femtosecond group (P
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toward zero effective phacoemulsification time using Femtosecond Laser pretreatment
Ophthalmology, 2013Co-Authors: Robin G Abell, Nathan M. Kerr, Brendan J. VoteAbstract:Objective To compare effective phacoemulsification time after Femtosecond Laser pretreatment with conventional phacoemulsification and the associated effect on visual outcomes and endothelial cell loss. Design Prospective, consecutive, single-surgeon case-control study. Controls Controls underwent phacoemulsification cataract extraction plus insertion of an intraocular lens (IOL). Cases underwent pretreatment with the Femtosecond Laser followed by phacoemulsification cataract extraction and IOL insertion. Methods Two hundred one eyes underwent cataract surgery between April 2012 and July 2012. Data collected included patient demographics, preoperative characteristics, Femtosecond lens fragmentation method, effective phacoemulsification time (EPT), intraoperative complications, and postoperative outcomes. Main Outcome Measures Effective phacoemulsification time, intraoperative complications, corneal endothelial cell loss, as well as postoperative best-corrected visual acuity, intraocular pressure, and refractive outcomes. Results Patient demographics were similar between groups. There was no difference between baseline cataract grades (2.59±0.71 vs. 2.52±0.72, not significant). One hundred percent of cases pretreated with the Femtosecond Laser had complete capsulotomy. Mean EPT was reduced by 83.6% in the Femtosecond pretreatment group ( P P Conclusions Femtosecond Laser pretreatment results in a significant reduction in effective phacoemulsification time, including the possibility of 0 EPT. Further reductions may be achieved using optimization of lens fragmentation patterns and surgical technique. Financial Disclosure(s) The author(s) have no proprietary or commercial interest in any materials discussed in this article.
Ya Cheng - One of the best experts on this subject based on the ideXlab platform.
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metal surface structuring with spatiotemporally focused Femtosecond Laser pulses
Journal of Optics, 2018Co-Authors: Zhiwei Fang, Ya Cheng, Yang LiaoAbstract:Femtosecond Laser micromachining provides high precision and less thermal diffusion in surface structuring as a result of the ultrashort duration and ultrahigh peak intensity of the Femtosecond Laser pulses. To increase the throughput of surface patterning, the focal spot size can be expanded with loose focusing, which, however, could lead to nonlinear self-focusing of the pulses when the pulses propagate in air. We solve the problem by use of spatiotemporally focused Femtosecond Laser pulses for ablation of metal surfaces, which gives rise to improved surface quality as compared with that obtained with the conventional focusing scheme.
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high performance materials processing using tailored Femtosecond Laser pulses
Conference on Lasers and Electro-Optics, 2015Co-Authors: Koji Sugioka, Katsumi Midorikawa, Ya ChengAbstract:Tailored Femtosecond Laser pulses can enhance the performance for materials processing. Temporarily tailored Femtosecond Laser pulses are employed for high efficiency glass welding, while the spatially one, for formation of taper-free through Si vias.
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fabrication of high q lithium niobate microresonators using Femtosecond Laser micromachining
Scientific Reports, 2015Co-Authors: Yingxin Xu, Zhiwei Fang, Min Wang, Jiangxin Song, Nengwen Wang, Lingling Qiao, Wei Fang, Ya ChengAbstract:We report on fabrication of high-Q lithium niobate (LN) whispering-gallery-mode (WGM) microresonators suspended on silica pedestals by Femtosecond Laser direct writing followed by focused ion beam (FIB) milling. The micrometer-scale (diameter ~82 μm) LN resonator possesses a Q factor of ~2.5 × 105 around 1550 nm wavelength. The combination of Femtosecond Laser direct writing with FIB enables high-efficiency, high-precision nanofabrication of high-Q crystalline microresonators.
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Femtosecond Laser three dimensional micro and nanofabrication
Applied physics reviews, 2014Co-Authors: Koji Sugioka, Ya ChengAbstract:The rapid development of the Femtosecond Laser has revolutionized materials processing due to its unique characteristics of ultrashort pulse width and extremely high peak intensity. The short pulse width suppresses the formation of a heat-affected zone, which is vital for ultrahigh precision fabrication, whereas the high peak intensity allows nonlinear interactions such as multiphoton absorption and tunneling ionization to be induced in transparent materials, which provides versatility in terms of the materials that can be processed. More interestingly, irradiation with tightly focused Femtosecond Laser pulses inside transparent materials makes three-dimensional (3D) micro- and nanofabrication available due to efficient confinement of the nonlinear interactions within the focal volume. Additive manufacturing (stereolithography) based on multiphoton absorption (two-photon polymerization) enables the fabrication of 3D polymer micro- and nanostructures for photonic devices, micro- and nanomachines, and microfluidic devices, and has applications for biomedical and tissue engineering. Subtractive manufacturing based on internal modification and fabrication can realize the direct fabrication of 3D microfluidics, micromechanics, microelectronics, and photonic microcomponents in glass. These microcomponents can be easily integrated in a single glass microchip by a simple procedure using a Femtosecond Laser to realize more functional microdevices, such as optofluidics and integrated photonic microdevices. The highly localized multiphoton absorption of a tightly focused Femtosecond Laser in glass can also induce strong absorption only at the interface of two closely stacked glass substrates. Consequently, glass bonding can be performed based on fusion welding with Femtosecond Laser irradiation, which provides the potential for applications in electronics, optics, microelectromechanical systems, medical devices, microfluidic devices, and small satellites. This review paper describes the concepts and principles of Femtosecond Laser 3D micro- and nanofabrication and presents a comprehensive review on the state-of-the-art, applications, and the future prospects of this technology.
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Femtosecond Laser 3d micromachining a powerful tool for the fabrication of microfluidic optofluidic and electrofluidic devices based on glass
Lab on a Chip, 2014Co-Authors: Koji Sugioka, Ya Cheng, Jian Xu, Dong Wu, Yasutaka Hanada, Zhongke Wang, Katsumi MidorikawaAbstract:Femtosecond Lasers have unique characteristics of ultrashort pulse width and extremely high peak intensity; however, one of the most important features of Femtosecond Laser processing is that strong absorption can be induced only at the focus position inside transparent materials due to nonlinear multiphoton absorption. This exclusive feature makes it possible to directly fabricate three-dimensional (3D) microfluidic devices in glass microchips by two methods: 3D internal modification using direct Femtosecond Laser writing followed by chemical wet etching (Femtosecond Laser-assisted etching, FLAE) and direct ablation of glass in water (water-assisted Femtosecond Laser drilling, WAFLD). Direct Femtosecond Laser writing also enables the integration of micromechanical, microelectronic, and microoptical components into the 3D microfluidic devices without stacking or bonding substrates. This paper gives a comprehensive review on the state-of-the-art Femtosecond Laser 3D micromachining for the fabrication of microfluidic, optofluidic, and electrofluidic devices. A new strategy (hybrid Femtosecond Laser processing) is also presented, in which FLAE is combined with Femtosecond Laser two-photon polymerization to realize a new type of biochip termed the ship-in-a-bottle biochip.
Burkhard H Dick - One of the best experts on this subject based on the ideXlab platform.
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nsaid pretreatment inhibits prostaglandin release in Femtosecond Laser assisted cataract surgery
Journal of Refractive Surgery, 2015Co-Authors: Tim Schultz, Stephanie C Joachim, Marek Szuler, Mathias Stellbogen, Burkhard H DickAbstract:PURPOSE: To investigate whether short-term nonsteroidal anti-inflammatory drug (NSAID) pretreatment on the day of surgery inhibits prostaglandin release. Previous studies detected elevated prostaglandin levels after Femtosecond Laser treatment and identified them as a potential mediator for Laser-induced miosis. METHODS: Patients underwent either image-guided Femtosecond Laser cataract surgery or conventional cataract surgery (n = 75). Half of the eyes per group received topical NSAID treatment on the day of surgery. Aqueous humor was collected from all patients. ELISA measurements were performed to detect aqueous humor prostaglandin levels. RESULTS: Femtosecond Laser cataract surgery led to higher prostaglandin levels than conventional cataract surgery (P = .007). In both groups, NSAID pretreatment led to reduced prostaglandin release. In the Femtosecond Laser group, patients pretreated with NSAIDs had significantly lower prostaglandin values (65.3 ± 13.2 pg/mL) than patients not pretreated with NSAIDs (294.4 ± 66.5 pg/mL) (P = .0009). CONCLUSIONS: The short-term NSAID treatment prevented prostaglandin release in patients treated with image-guided Femtosecond Laser. Therefore, it has potential to limit intraoperative Laser-induced miosis.
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changes in prostaglandin levels in patients undergoing Femtosecond Laser assisted cataract surgery
Journal of Refractive Surgery, 2013Co-Authors: Tim Schultz, Stephanie C Joachim, Mathias Kuehn, Burkhard H DickAbstract:PURPOSE: To investigate the intraocular prostaglandin concentrations after Femtosecond Laser treatment and the potential relationship to miosis. METHODS: Aqueous humor was collected from patients after Femtosecond Laser pretreatment and at the beginning of routine cataract surgery. The total prostaglandin and the prostaglandin E 2 concentrations were measured in two independent studies using an enzyme-linked immunoassay. RESULTS: A significantly higher level of prostaglandins was noted in the aqueous humor of patients immediately after Femtosecond Laser treatment. This could be confirmed in two studies consisting of independent pa tient populations (study I: control = 17.3 ± 4.0 pg/mL [n = 22], Femtosecond Laser [femto] = 182.1 ± 38.1 pg/mL [n = 22], P = .0001, and study II: control = 17.5 ± 1.4 pg/mL [n = 37], femto: 377.1 ± 83.6 pg/ mL [n = 35], P = .00004). A significant increase of prostaglandin E 2 was noted in two measurements (study III: control = 4.5 ± 1.9 pg/mL [n = 13], femto: 19.2 ± 2.5 pg/mL [n = 20], P = .0002, and study IV: control = 11.3 ± 1.6 pg/mL [n = 35], femto: 60.3 ± 16.1 pg/mL [n = 36], P = .004). No correlation was noted between age or cataract density and prostaglandin/prostaglandin E 2 level or between corneal incision, suction time, or Laser time in the femto groups and prostaglandin/prostaglandin E 2 level. CONCLUSIONS: Prostaglandins rise immediately after Femtosecond Laser treatment. Future patients should perhaps be treated with non-steroidal anti-inflammatory drugs to maintain mydriasis before undergoing Femtosecond Laser treatment for cataract surgery.
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Femtosecond Laser assisted cataract surgery in pediatric marfan syndrome
Journal of Refractive Surgery, 2013Co-Authors: Tim Schultz, Edak Ezeanosike, Burkhard H DickAbstract:PURPOSE To report Femtosecond Laser-assisted cataract surgery in pediatric Marfan syndrome. METHODS Case report. RESULTS A 10-year-old boy with ectopia lentis due to Marfan syndrome underwent Femtosecond Laser-assisted cataract surgery (Catalys Precision Laser System; OptiMedica, Sunnyvale, CA) under general anesthesia. Anterior capsulotomy was performed on the decentered lens. Routine irrigation/aspiration devices were used for lens and cortex removal. Centration of the capsular bag was achieved using a Cionni scleral fixation ring. A foldable intraocular lens was implanted. A free-positioned and precise sized capsulotomy was cut by the Femtosecond Laser. No intraoperative or postoperative complications were observed within the 10 weeks of follow-up. CONCLUSIONS The use of a Femtosecond Laser has potential to perform a circular, well-centered capsulotomy for subsequent capsular tension ring and intraocular lens implantation without decentration in patients with Marfan syndrome.
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effect of Femtosecond Laser fragmentation on effective phacoemulsification time in cataract surgery
Journal of Refractive Surgery, 2012Co-Authors: Ina Conradhengerer, Tim Schultz, Fritz H Hengerer, Burkhard H DickAbstract:Purpose To compare the effect of Femtosecond Laser-assisted cataract surgery on effective phacoemulsification time (EPT) with standard cataract surgery. Methods This prospective clinical trial evaluated the feasibility of using a Femtosecond Laser system (Catalys Precision Laser System, OptiMedica) to perform capsulotomy and lens fragmentation in the treatment of patients with senile cataract. Patients were evaluated preoperatively with the Lens Opacities Classification System III (LOCS III). Fifty-two patients underwent standard cataract surgery and 57 patients underwent Femtosecond Laser-assisted cataract surgery in December 2011. Both groups underwent phacoemulsification using pulsed ultrasound energy and EPT was evaluated. Results Preoperative LOCS III grades were 3.4±0.9 in the Femtosecond Laser-assisted cataract surgery group and 3.1±0.9 in the standard group. In the Femtosecond Laser-assisted cataract surgery group, mean Laser treatment time was 54.9 seconds and EPT was 0.16±0.21 seconds compared to 4.07±3.14 seconds in the standard group. Conclusions The use of the Femtosecond Laser-assisted system in cataract surgery led to a lower EPT compared to the standard procedure.
Robin G Abell - One of the best experts on this subject based on the ideXlab platform.
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cystoid macular edema after Femtosecond Laser assisted versus phacoemulsification cataract surgery
Journal of Cataract and Refractive Surgery, 2015Co-Authors: Shaun Y P Ewe, Robin G Abell, Penelope L Allen, Carmen L Oakley, Brendan J. VoteAbstract:Purpose To evaluate the incidence of postoperative clinical cystoid macular edema (CME) associated with Femtosecond Laser–assisted cataract surgery (Catalys Laser system) versus phacoemulsification cataract surgery. Setting Launceston Eye Institute, Launceston, Tasmania, Australia. Design Nonrandomized, single-surgeon, prospective, comparative cohort case series. Methods Patients who had Femtosecond Laser–assisted cataract surgery and phacoemulsification cataract surgery between March 2012 and July 2014 were included in the study. The Femtosecond Laser–assisted cataract surgery group had anterior capsulotomy, lens fragmentation, with or without corneal incisions via Femtosecond Laser pretreatment. Standard phacoemulsification surgery and foldable acrylic intraocular lens insertion proceeded in all cases. All patients received topical nonsteroidal drops commencing 2 days preoperatively and continuing for 4 weeks postoperatively. The incidence of postoperative clinical CME (confirmed by optical coherence tomography) and comparison between groups were measured. The main outcome measure was the clinical CME rates. Results Of the eyes, 833 had Femtosecond Laser–assisted cataract surgery amd 458 had standard phacoemulsification cataract surgery. Both groups had similar baseline parameters. There were 7 cases of postoperative CME (0.8%) in the Femtosecond Laser–assisted cataract surgery group compared to 1 case (0.2%) in the phacoemulsification cataract surgery group, highlighting a trend toward greater cystoid macular edema in the Femtosecond Laser–assisted cataract surgery group. This correlated with a change in Laser treatment speed (due to a software upgrade), suggesting that retinal safety thresholds need further careful analysis. Conclusion Increased CME might be a subthreshold retinal injury safety signal after Femtosecond Laser pretreatment and warrants further study. Financial Disclosure There are no financial or conflicts of interest for any author.
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anterior chamber flare after Femtosecond Laser assisted cataract surgery
Journal of Cataract and Refractive Surgery, 2013Co-Authors: Robin G Abell, Penelope L Allen, Brendan J. VoteAbstract:Purpose To determine whether postoperative ocular inflammation is less after Femtosecond Laser–assisted cataract surgery than after conventional phacoemulsification (manual) cataract surgery. Setting Private clinic, Launceston, Tasmania, Australia. Design Prospective consecutive investigator-masked nonrandomized parallel cohort study. Methods Consecutive cataract patients who had Femtosecond Laser–assisted cataract surgery or manual cataract surgery by the same surgeon at a single center were assessed. The primary endpoint was postoperative aqueous flare measured by Laser flare photometry at 1 day and 4 weeks. Secondary endpoints included retinal thickness measured by optical coherence tomography and slitlamp examination findings at 4 weeks. Results The per-protocol population comprised 176 patients (100 in Laser group; 76 in manual group). Postoperative aqueous flare was significantly greater in the manual cataract surgery group at 1 day (P=.0089) and at 4 weeks (P=.003). There was a significant correlation between effective phacoemulsification time and 1-day postoperative aqueous flare (r = 0.35, P Conclusion Anterior segment inflammation was less after Femtosecond Laser–assisted cataract surgery than after manual cataract surgery, and this appeared to be due to a reduction in phacoemulsification energy. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.
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Femtosecond Laser assisted cataract surgery compared with conventional cataract surgery
Clinical and Experimental Ophthalmology, 2013Co-Authors: Robin G Abell, Nathan M. Kerr, Brendan J. VoteAbstract:Abstract To investigate the safety and efficacy of the Catalys (Optimedica, Santa Clara, CA, USA) Femtosecond Laser-assisted cataract surgery system compared with conventional phacoemulsification cataract extraction. Prospective, consecutive, parallel cohort study. The first 200 eyes undergoing conventional cataract surgery to the first 200 eyes undergoing Femtosecond Laser-assisted cataract surgery between April and July 2012. Femtosecond Laser-assisted cataract surgery involved anterior capsulotomy and lens fragmentation based on optical coherence tomography-guided treatment mapping. Conventional cataract surgery involved manual continuous curvilinear capsulorhexis. Both procedures were completed by standard phacoemulsification and insertion of an intraocular lens. Effective phacoemulsification time and intraoperative complication rates. Patient demographics were similar between both groups. There was no statistically significant difference in intraoperative complications between Femtosecond Laser-assisted cataract surgery and conventional surgery. There was one posterior capsule rupture in both groups (0.5%; not significant). One hundred per cent of cases treated with the Femtosecond Laser had a complete capsulotomy. Vacuum time decreased with experience. Effective phacoemulsification time was reduced by 70% in the Femtosecond group (P
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toward zero effective phacoemulsification time using Femtosecond Laser pretreatment
Ophthalmology, 2013Co-Authors: Robin G Abell, Nathan M. Kerr, Brendan J. VoteAbstract:Objective To compare effective phacoemulsification time after Femtosecond Laser pretreatment with conventional phacoemulsification and the associated effect on visual outcomes and endothelial cell loss. Design Prospective, consecutive, single-surgeon case-control study. Controls Controls underwent phacoemulsification cataract extraction plus insertion of an intraocular lens (IOL). Cases underwent pretreatment with the Femtosecond Laser followed by phacoemulsification cataract extraction and IOL insertion. Methods Two hundred one eyes underwent cataract surgery between April 2012 and July 2012. Data collected included patient demographics, preoperative characteristics, Femtosecond lens fragmentation method, effective phacoemulsification time (EPT), intraoperative complications, and postoperative outcomes. Main Outcome Measures Effective phacoemulsification time, intraoperative complications, corneal endothelial cell loss, as well as postoperative best-corrected visual acuity, intraocular pressure, and refractive outcomes. Results Patient demographics were similar between groups. There was no difference between baseline cataract grades (2.59±0.71 vs. 2.52±0.72, not significant). One hundred percent of cases pretreated with the Femtosecond Laser had complete capsulotomy. Mean EPT was reduced by 83.6% in the Femtosecond pretreatment group ( P P Conclusions Femtosecond Laser pretreatment results in a significant reduction in effective phacoemulsification time, including the possibility of 0 EPT. Further reductions may be achieved using optimization of lens fragmentation patterns and surgical technique. Financial Disclosure(s) The author(s) have no proprietary or commercial interest in any materials discussed in this article.
David S. Rootman - One of the best experts on this subject based on the ideXlab platform.
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development of a nomogram for Femtosecond Laser astigmatic keratotomy for astigmatism after keratoplasty
Journal of Cataract and Refractive Surgery, 2016Co-Authors: Ryan M St Clair, Sonia H Yoo, David S. Rootman, Florence Cabot, Anushree Sharma, David Huang, Yakov Goldich, Jason Jun, Lijun Zhang, Anthony J AldaveAbstract:Purpose To develop a nomogram for Femtosecond Laser astigmatic keratotomy (AK) to treat post-keratoplasty astigmatism. Setting Three academic medical centers. Design Retrospective interventional case series. Methods A review of post-keratoplasty Femtosecond Laser AK was performed. Uncorrected (UDVA) and corrected (CDVA) distance visual acuities, manifest refraction, and keratometry were recorded preoperatively and 1, 3, 6, and 12 months postoperatively. The location, length, depth, and diameter of the AK incisions were recorded, and the surgically induced astigmatic correction was related to these variables using regression analysis. Results One hundred forty Femtosecond Laser AK procedures were performed after penetrating keratoplasty (PKP) (n = 129) or deep anterior lamellar keratoplasty (DALK) (n =11), with 89 procedures (80 PKP, 9 DALK) included in the analysis. The mean CDVA improved from 20/59 (0.47 logMAR ± 0.38 [SD]) preoperatively to 20/45 (0.35 ± 0.31 logMAR) postoperatively ( P = .013) (n = 46). The mean keratometric astigmatism decreased from 8.26 ± 2.90 diopters (D) preoperatively to 3.62 ± 2.59 D postoperatively ( P P Conclusions Femtosecond Laser AK significantly improved UDVA and CDVA and significantly reduced keratometric astigmatism and refractive cylinder after keratoplasty. The nomogram generated should improve the accuracy of post-keratoplasty Femtosecond Laser AK. Financial Disclosure None of the authors has a financial or proprietary interest in any material or method mentioned.
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Applications of the Femtosecond Laser in corneal refractive surgery
Current opinion in ophthalmology, 2011Co-Authors: Peter Kim, Gerard Sutton, David S. RootmanAbstract:PURPOSE OF REVIEW The Femtosecond Laser has become a rapidly and widely adopted technology for surgeons performing refractive surgery. With the advances in Femtosecond Lasers, clinical outcomes and safety with their use have improved. The purpose of this review is to outline the current surgical applications of the Femtosecond Laser in corneal refractive surgery. RECENT FINDINGS Many surgeons have adopted Femtosecond technology for the creation of the Laser in-situ keratomileusis flap secondary to its improved safety, precision and reproducibility. Other applications include astigmatic keratotomy, channel creation for the insertion of intrastromal corneal ring segments, Femtosecond lenticule extraction, facilitating the insertion of corneal inlays as well as in intrastromal presbyopia correction (IntraCOR). Further novel applications continue to be developed. SUMMARY This review outlines the recent advances and applications of the Femtosecond Laser in corneal refractive surgery.
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Femtosecond Laser assisted mushroom configuration deep anterior lamellar keratoplasty
Cornea, 2010Co-Authors: Clara C Chan, Rusty J Ritenour, Nikhil L Kumar, Wiwan Sansanayudh, David S. RootmanAbstract:PURPOSE To review patient outcomes after Femtosecond Laser-assisted mushroom configuration deep anterior lamellar keratoplasty. METHODS Seven eyes of seven patients with a mean age of 30 years underwent Femtosecond Laser-assisted mushroom configuration deep anterior lamellar keratoplasty from April 2008 to September 2008. Patients had keratoconus, corneal ectasia or scarring. Set for 100 mum of residual cornea, the Femtosecond Laser was used to create a mushroom-shaped recipient bed and donor button (having a larger anterior than posterior diameter). The posterior central lamella was manually dissected using Melles technique. RESULTS Mean follow up was 4 months (range, 3-6.5 months). Preoperative mean best-corrected visual acuity was 20/95 (range, 20/40-20/400). Intraoperative complications included two cases (28.6%) of small Descemet membrane perforation. Postoperatively, there was one case of stromal rejection that resolved with topical steroids and two cases of steroid-related intraocular pressure rise that were treated with a prostaglandin analog. At 3 months, mean best-corrected visual acuity was 20/40 (range, 20/25-20/60), mean spherical equivalent refraction was -3.21 D (range, -6.75 D to plano), mean cylindrical refractive error was 3.57 D (range, 1.5-7 D), and mean keratometric cylinder measured 5.56 D (range, 3.79-7.00 D). Selective suture removal occurred in six patients (86%) at a mean of 3.8 months (range, 2-6 months) postoperatively. CONCLUSIONS This preliminary series demonstrates that the use of the Femtosecond Laser to perform corneal cuts in a mushroom configuration for deep anterior lamellar keratoplasty is feasible. The mechanical stability and wound healing advantages for stepped corneal wounds should be considered in lamellar surgery.