The Experts below are selected from a list of 888 Experts worldwide ranked by ideXlab platform
Vishal Jhanji - One of the best experts on this subject based on the ideXlab platform.
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effects and risks of 3 2 mm transparent corneal incision phacoemulsification for cataract after radial Keratotomy
Journal of International Medical Research, 2020Co-Authors: Jinda Wang, Xue Liu, Jingshang Zhang, Ying Xiong, Jing Zhao, Qisheng You, Yao Huang, Mark Espina, Vishal JhanjiAbstract:ObjectiveThis study was performed to analyze the visual outcomes and complications of phacoemulsification using a 3.2-mm transparent corneal incision in eyes with cataract after radial Keratotomy (...
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corneal astigmatism and aberrations after combined femtosecond assisted phacoemulsification and arcuate Keratotomy two year results
American Journal of Ophthalmology, 2016Co-Authors: George P M Cheng, Tommy C. Y. Chan, Vishal Jhanji, Victor C P Woo, Z WangAbstract:Purpose To investigate the stability of corneal astigmatism and higher-order aberrations after combined femtosecond-assisted phacoemulsification and arcuate Keratotomy. Design Retrospective, interventional case series. Methods Surgery was performed using a VICTUS (Bausch & Lomb Inc, Dornach, Germany) platform. A single, 450-μm deep, arcuate Keratotomy was paired at the 8-mm zone with the main phacoemulsification incision in the opposite meridian. The Keratotomy incisions were not opened. Corneal astigmatism and higher-order aberration measurements obtained preoperatively and at 2 months and 2 years postoperatively were analyzed. Results Fifty eyes of 50 patients (mean age 66.2 ± 10.5 years) were included. The mean preoperative corneal astigmatism was 1.35 ± 0.48 diopters (D). This was reduced to 0.67 ± 0.54 D at 2 months and 0.74 ± 0.53 D at 2 years postoperatively ( P P = .392). Both magnitude of error and absolute angle of error were comparable between the 2 postoperative time points ( P > .283). At postoperative 2 months and 2 years, 72% and 70% of eyes were within 15 degrees of preoperative meridian of astigmatism, respectively. All wavefront measurements increased significantly at 2 months and 2 years ( P P > .150). There was no significant difference in higher-order aberrations between 2 months and 2 years postoperatively ( P > .486). Conclusions Our study showed the stability of femtosecond-assisted arcuate Keratotomy. Further studies using other platforms and nomograms are needed to corroborate the findings of this study.
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vector analysis of corneal astigmatism after combined femtosecond assisted phacoemulsification and arcuate Keratotomy
American Journal of Ophthalmology, 2015Co-Authors: George P M Cheng, Tommy C. Y. Chan, Vishal Jhanji, Clement C Y Tham, Victor C P WooAbstract:Purpose To evaluate the outcomes of femtosecond-assisted arcuate Keratotomy combined with cataract surgery in eyes with low to moderate corneal astigmatism. Design Retrospective, interventional case series. Methods This study included patients who underwent combined femtosecond-assisted phacoemulsification and arcuate Keratotomy between March 2013 and August 2013. Keratometric astigmatism was evaluated before and 2 months after the surgery. Vector analysis of the astigmatic changes was performed using the Alpins method. Results Overall, 54 eyes of 54 patients (18 male and 36 female; mean age, 68.8 ± 11.4 years) were included. The mean preoperative (target-induced astigmatism) and postoperative astigmatism was 1.33 ± 0.57 diopters (D) and 0.87 ± 0.56 D, respectively ( P Conclusions Combined phacoemulsification with arcuate Keratotomy using femtosecond laser appears to be a relatively easy and safe means for management of low to moderate corneal astigmatism in cataract surgery candidates. Misalignment at an individual level can reduce its effectiveness. This issue remains to be elucidated in future studies.
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vector analysis of corneal astigmatism after combined femtosecond assisted phacoemulsification and arcuate Keratotomy
American Journal of Ophthalmology, 2015Co-Authors: George P M Cheng, Tommy C. Y. Chan, Vishal Jhanji, Clement C Y ThamAbstract:PURPOSE: To evaluate the outcomes of femtosecond-assisted arcuate Keratotomy combined with cataract surgery in eyes with low to moderate corneal astigmatism. DESIGN: Retrospective, interventional case series. METHODS: This study included patients who underwent combined femtosecond-assisted phacoemulsification and arcuate Keratotomy between March 2013 and August 2013. Keratometric astigmatism was evaluated before and 2 months after the surgery. Vector analysis of the astigmatic changes was performed using the Alpins method. RESULTS: Overall, 54 eyes of 54 patients (18 male and 36 female; mean age, 68.8 ± 11.4 years) were included. The mean preoperative (target-induced astigmatism) and postoperative astigmatism was 1.33 ± 0.57 diopters (D) and 0.87 ± 0.56 D, respectively (P < .001). The magnitude of error (difference between surgically induced and target-induced astigmatism) (-0.13 ± 0.68 D), as well as the correction index (ratio of surgically induced and target-induced astigmatism) (0.86 ± 0.52), demonstrated slight undercorrection. The angle of error was very close to 0, indicating no significant systematic error of misaligned treatment. However, the absolute angle of error showed a less favorable range (17.5 ± 19.2 degrees), suggesting variable factors such as healing or alignment at an individual level. There were no intraoperative or postoperative complications. CONCLUSIONS: Combined phacoemulsification with arcuate Keratotomy using femtosecond laser appears to be a relatively easy and safe means for management of low to moderate corneal astigmatism in cataract surgery candidates. Misalignment at an individual level can reduce its effectiveness. This issue remains to be elucidated in future studies.
Tommy C. Y. Chan - One of the best experts on this subject based on the ideXlab platform.
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five year changes in corneal astigmatism after combined femtosecond assisted phacoemulsification and arcuate Keratotomy
American Journal of Ophthalmology, 2020Co-Authors: Tommy C. Y. Chan, Z Wang, John Sm Chang, George P M ChengAbstract:Purpose To investigate the long-term stability of corneal astigmatism after combined femtosecond (fs)-assisted phacoemulsification and arcuate Keratotomy. Design Retrospective, interventional case series. Methods Surgery was performed using a Victus (Bausch & Lomb) platform. A single, 450-μm-deep arcuate Keratotomy was paired at the 8-mm zone with the main phacoemulsification incision in the opposite meridian. The Keratotomy incisions were not opened. Corneal astigmatism measurements obtained preoperatively and at 2 and 5 years postoperatively were analyzed using vector analysis. Results A total of 44 eyes of 44 patients (mean age 66.0 ± 10.1 years) were included. The mean preoperative corneal astigmatism was 1.40 ± 0.66 diopters (D). This was reduced to 0.74 ± 0.54 D at 2 years and 0.70 ± 0.50 at 5 years postoperatively (P .805). At the end of 5 years, 65% of the eyes were within 15 degrees of the preoperative astigmatic meridian. Comparative analysis showed significantly higher surgically induced astigmatism, lower differences in vector and absolute angles of error for the eyes with preoperative with-the-rule (WTR) astigmatism than eyes with against-the-rule (ATR) astigmatism at 5 years (P Conclusions Our study showed the stability of femtosecond (fs)-assisted arcuate Keratotomy was well-maintained over 5 years. There was a tendency of increasing overcorrection of preoperative WTR astigmatism and undercorrection of ATR astigmatism over time.
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corneal astigmatism and aberrations after combined femtosecond assisted phacoemulsification and arcuate Keratotomy two year results
American Journal of Ophthalmology, 2016Co-Authors: George P M Cheng, Tommy C. Y. Chan, Vishal Jhanji, Victor C P Woo, Z WangAbstract:Purpose To investigate the stability of corneal astigmatism and higher-order aberrations after combined femtosecond-assisted phacoemulsification and arcuate Keratotomy. Design Retrospective, interventional case series. Methods Surgery was performed using a VICTUS (Bausch & Lomb Inc, Dornach, Germany) platform. A single, 450-μm deep, arcuate Keratotomy was paired at the 8-mm zone with the main phacoemulsification incision in the opposite meridian. The Keratotomy incisions were not opened. Corneal astigmatism and higher-order aberration measurements obtained preoperatively and at 2 months and 2 years postoperatively were analyzed. Results Fifty eyes of 50 patients (mean age 66.2 ± 10.5 years) were included. The mean preoperative corneal astigmatism was 1.35 ± 0.48 diopters (D). This was reduced to 0.67 ± 0.54 D at 2 months and 0.74 ± 0.53 D at 2 years postoperatively ( P P = .392). Both magnitude of error and absolute angle of error were comparable between the 2 postoperative time points ( P > .283). At postoperative 2 months and 2 years, 72% and 70% of eyes were within 15 degrees of preoperative meridian of astigmatism, respectively. All wavefront measurements increased significantly at 2 months and 2 years ( P P > .150). There was no significant difference in higher-order aberrations between 2 months and 2 years postoperatively ( P > .486). Conclusions Our study showed the stability of femtosecond-assisted arcuate Keratotomy. Further studies using other platforms and nomograms are needed to corroborate the findings of this study.
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vector analysis of corneal astigmatism after combined femtosecond assisted phacoemulsification and arcuate Keratotomy
American Journal of Ophthalmology, 2015Co-Authors: George P M Cheng, Tommy C. Y. Chan, Vishal Jhanji, Clement C Y Tham, Victor C P WooAbstract:Purpose To evaluate the outcomes of femtosecond-assisted arcuate Keratotomy combined with cataract surgery in eyes with low to moderate corneal astigmatism. Design Retrospective, interventional case series. Methods This study included patients who underwent combined femtosecond-assisted phacoemulsification and arcuate Keratotomy between March 2013 and August 2013. Keratometric astigmatism was evaluated before and 2 months after the surgery. Vector analysis of the astigmatic changes was performed using the Alpins method. Results Overall, 54 eyes of 54 patients (18 male and 36 female; mean age, 68.8 ± 11.4 years) were included. The mean preoperative (target-induced astigmatism) and postoperative astigmatism was 1.33 ± 0.57 diopters (D) and 0.87 ± 0.56 D, respectively ( P Conclusions Combined phacoemulsification with arcuate Keratotomy using femtosecond laser appears to be a relatively easy and safe means for management of low to moderate corneal astigmatism in cataract surgery candidates. Misalignment at an individual level can reduce its effectiveness. This issue remains to be elucidated in future studies.
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vector analysis of corneal astigmatism after combined femtosecond assisted phacoemulsification and arcuate Keratotomy
American Journal of Ophthalmology, 2015Co-Authors: George P M Cheng, Tommy C. Y. Chan, Vishal Jhanji, Clement C Y ThamAbstract:PURPOSE: To evaluate the outcomes of femtosecond-assisted arcuate Keratotomy combined with cataract surgery in eyes with low to moderate corneal astigmatism. DESIGN: Retrospective, interventional case series. METHODS: This study included patients who underwent combined femtosecond-assisted phacoemulsification and arcuate Keratotomy between March 2013 and August 2013. Keratometric astigmatism was evaluated before and 2 months after the surgery. Vector analysis of the astigmatic changes was performed using the Alpins method. RESULTS: Overall, 54 eyes of 54 patients (18 male and 36 female; mean age, 68.8 ± 11.4 years) were included. The mean preoperative (target-induced astigmatism) and postoperative astigmatism was 1.33 ± 0.57 diopters (D) and 0.87 ± 0.56 D, respectively (P < .001). The magnitude of error (difference between surgically induced and target-induced astigmatism) (-0.13 ± 0.68 D), as well as the correction index (ratio of surgically induced and target-induced astigmatism) (0.86 ± 0.52), demonstrated slight undercorrection. The angle of error was very close to 0, indicating no significant systematic error of misaligned treatment. However, the absolute angle of error showed a less favorable range (17.5 ± 19.2 degrees), suggesting variable factors such as healing or alignment at an individual level. There were no intraoperative or postoperative complications. CONCLUSIONS: Combined phacoemulsification with arcuate Keratotomy using femtosecond laser appears to be a relatively easy and safe means for management of low to moderate corneal astigmatism in cataract surgery candidates. Misalignment at an individual level can reduce its effectiveness. This issue remains to be elucidated in future studies.
David Huang - One of the best experts on this subject based on the ideXlab platform.
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beveled femtosecond laser astigmatic Keratotomy for the treatment of high astigmatism post penetrating keratoplasty
Cornea, 2013Co-Authors: Catherine Cleary, Maolong Tang, Habeeb Ahmed, David HuangAbstract:Astigmatism is a major factor compromising visual recovery after penetrating keratoplasty (PKP), with magnitudes greater than 5 diopters (D) occurring in up to 38% of cases.1 Numerous approaches have been used to address this problem, including manual2 and mechanized arcuate Keratotomy,3,4 compression sutures,5 photorefractive keratectomy (PRK),6 and laser in situ keratomileusis.7,8 Until recently, the technique of manual curved astigmatic Keratotomy, originally popularized by Merlin,9,10 has been the most widely used procedure for the treatment of astigmatism greater than 6 D. However manual astigmatic Keratotomy is associated with poor reliability and predictability in terms of astigmatism reduction, and associated complications include perforation, infection, gaping of the incision, and irregular astigmatism. The advent of the femtosecond laser has brought promise of improved accuracy, safety, and reproducibility in the treatment of high postkeratoplasty astigmatism.11 The same program settings on the femtosecond laser, which are used to create precise graft–host matching in femtosecond-enabled keratoplasty, can be used to create astigmatic Keratotomy stromal incisions with precisely customized shape, depth, and orientation.12 Several authors have reported positive results with femtosecond laser astigmatic Keratotomy (FLAK) at 90 degrees to the corneal surface, and complication rates such as full thickness perforation are lower with this technique.11–15 However, FLAK with a 90-degree incision orientation is still associated with the same problem of wound gaping that occurs with manual astigmatic Keratotomy incisions. The gaping astigmatic incision becomes filled with an epithelial plug (Fig. 1A), followed by gradual extrusion of the plug, and replacement with hypercellular scar tissue, a process that can take from 6 months to 5 years.16 This process may explain late changes in corneal curvature, which occur because of increased separation of the edges of the wound. A gaping Keratotomy incision is also a potential site for infectious keratitis and causes sensations of grittiness and discomfort for the patient. FIGURE 1 OCT of (A) perpendicular astigmatic Keratotomy incision and (B) beveled incision. A, FLAK incisions were made perpendicular to the corneal surface in one patient. Postoperatively this patient had marked discomfort due to gaping of the incision, and required ... In this preliminary study, we evaluated the effect on postkeratoplasty astigmatism of a FLAK incision, which is beveled at a 135-degree angle. We hypothesized that by creating a beveled incision, the anterior cornea would slide forward for a short distance relative to the cornea posterior to the incision, thereby leading to an increase in curvature of the anterior cornea and a corresponding reduction in astigmatism while simultaneously avoiding wound gape (Fig. 1B). Therefore, we conducted a small pilot study to test the efficacy and safety of beveled FLAK incisions for the correction of post-keratoplasty astigmatism.
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beveled femtosecond laser astigmatic Keratotomy for the treatment of high astigmatism post penetrating keratoplasty
Cornea, 2013Co-Authors: Catherine Cleary, Maolong Tang, Habeeb Ahmed, Martin Fox, David HuangAbstract:Purpose To use beveled femtosecond laser astigmatic Keratotomy (FLAK) incisions to treat high astigmatism after penetrating keratoplasty.
Catherine Cleary - One of the best experts on this subject based on the ideXlab platform.
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beveled femtosecond laser astigmatic Keratotomy for the treatment of high astigmatism post penetrating keratoplasty
Cornea, 2013Co-Authors: Catherine Cleary, Maolong Tang, Habeeb Ahmed, David HuangAbstract:Astigmatism is a major factor compromising visual recovery after penetrating keratoplasty (PKP), with magnitudes greater than 5 diopters (D) occurring in up to 38% of cases.1 Numerous approaches have been used to address this problem, including manual2 and mechanized arcuate Keratotomy,3,4 compression sutures,5 photorefractive keratectomy (PRK),6 and laser in situ keratomileusis.7,8 Until recently, the technique of manual curved astigmatic Keratotomy, originally popularized by Merlin,9,10 has been the most widely used procedure for the treatment of astigmatism greater than 6 D. However manual astigmatic Keratotomy is associated with poor reliability and predictability in terms of astigmatism reduction, and associated complications include perforation, infection, gaping of the incision, and irregular astigmatism. The advent of the femtosecond laser has brought promise of improved accuracy, safety, and reproducibility in the treatment of high postkeratoplasty astigmatism.11 The same program settings on the femtosecond laser, which are used to create precise graft–host matching in femtosecond-enabled keratoplasty, can be used to create astigmatic Keratotomy stromal incisions with precisely customized shape, depth, and orientation.12 Several authors have reported positive results with femtosecond laser astigmatic Keratotomy (FLAK) at 90 degrees to the corneal surface, and complication rates such as full thickness perforation are lower with this technique.11–15 However, FLAK with a 90-degree incision orientation is still associated with the same problem of wound gaping that occurs with manual astigmatic Keratotomy incisions. The gaping astigmatic incision becomes filled with an epithelial plug (Fig. 1A), followed by gradual extrusion of the plug, and replacement with hypercellular scar tissue, a process that can take from 6 months to 5 years.16 This process may explain late changes in corneal curvature, which occur because of increased separation of the edges of the wound. A gaping Keratotomy incision is also a potential site for infectious keratitis and causes sensations of grittiness and discomfort for the patient. FIGURE 1 OCT of (A) perpendicular astigmatic Keratotomy incision and (B) beveled incision. A, FLAK incisions were made perpendicular to the corneal surface in one patient. Postoperatively this patient had marked discomfort due to gaping of the incision, and required ... In this preliminary study, we evaluated the effect on postkeratoplasty astigmatism of a FLAK incision, which is beveled at a 135-degree angle. We hypothesized that by creating a beveled incision, the anterior cornea would slide forward for a short distance relative to the cornea posterior to the incision, thereby leading to an increase in curvature of the anterior cornea and a corresponding reduction in astigmatism while simultaneously avoiding wound gape (Fig. 1B). Therefore, we conducted a small pilot study to test the efficacy and safety of beveled FLAK incisions for the correction of post-keratoplasty astigmatism.
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beveled femtosecond laser astigmatic Keratotomy for the treatment of high astigmatism post penetrating keratoplasty
Cornea, 2013Co-Authors: Catherine Cleary, Maolong Tang, Habeeb Ahmed, Martin Fox, David HuangAbstract:Purpose To use beveled femtosecond laser astigmatic Keratotomy (FLAK) incisions to treat high astigmatism after penetrating keratoplasty.
Habeeb Ahmed - One of the best experts on this subject based on the ideXlab platform.
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beveled femtosecond laser astigmatic Keratotomy for the treatment of high astigmatism post penetrating keratoplasty
Cornea, 2013Co-Authors: Catherine Cleary, Maolong Tang, Habeeb Ahmed, David HuangAbstract:Astigmatism is a major factor compromising visual recovery after penetrating keratoplasty (PKP), with magnitudes greater than 5 diopters (D) occurring in up to 38% of cases.1 Numerous approaches have been used to address this problem, including manual2 and mechanized arcuate Keratotomy,3,4 compression sutures,5 photorefractive keratectomy (PRK),6 and laser in situ keratomileusis.7,8 Until recently, the technique of manual curved astigmatic Keratotomy, originally popularized by Merlin,9,10 has been the most widely used procedure for the treatment of astigmatism greater than 6 D. However manual astigmatic Keratotomy is associated with poor reliability and predictability in terms of astigmatism reduction, and associated complications include perforation, infection, gaping of the incision, and irregular astigmatism. The advent of the femtosecond laser has brought promise of improved accuracy, safety, and reproducibility in the treatment of high postkeratoplasty astigmatism.11 The same program settings on the femtosecond laser, which are used to create precise graft–host matching in femtosecond-enabled keratoplasty, can be used to create astigmatic Keratotomy stromal incisions with precisely customized shape, depth, and orientation.12 Several authors have reported positive results with femtosecond laser astigmatic Keratotomy (FLAK) at 90 degrees to the corneal surface, and complication rates such as full thickness perforation are lower with this technique.11–15 However, FLAK with a 90-degree incision orientation is still associated with the same problem of wound gaping that occurs with manual astigmatic Keratotomy incisions. The gaping astigmatic incision becomes filled with an epithelial plug (Fig. 1A), followed by gradual extrusion of the plug, and replacement with hypercellular scar tissue, a process that can take from 6 months to 5 years.16 This process may explain late changes in corneal curvature, which occur because of increased separation of the edges of the wound. A gaping Keratotomy incision is also a potential site for infectious keratitis and causes sensations of grittiness and discomfort for the patient. FIGURE 1 OCT of (A) perpendicular astigmatic Keratotomy incision and (B) beveled incision. A, FLAK incisions were made perpendicular to the corneal surface in one patient. Postoperatively this patient had marked discomfort due to gaping of the incision, and required ... In this preliminary study, we evaluated the effect on postkeratoplasty astigmatism of a FLAK incision, which is beveled at a 135-degree angle. We hypothesized that by creating a beveled incision, the anterior cornea would slide forward for a short distance relative to the cornea posterior to the incision, thereby leading to an increase in curvature of the anterior cornea and a corresponding reduction in astigmatism while simultaneously avoiding wound gape (Fig. 1B). Therefore, we conducted a small pilot study to test the efficacy and safety of beveled FLAK incisions for the correction of post-keratoplasty astigmatism.
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beveled femtosecond laser astigmatic Keratotomy for the treatment of high astigmatism post penetrating keratoplasty
Cornea, 2013Co-Authors: Catherine Cleary, Maolong Tang, Habeeb Ahmed, Martin Fox, David HuangAbstract:Purpose To use beveled femtosecond laser astigmatic Keratotomy (FLAK) incisions to treat high astigmatism after penetrating keratoplasty.
