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Mary Ann Croft - One of the best experts on this subject based on the ideXlab platform.
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Surgical intervention and accommodative responses, II: Forward ciliary body accommodative movement is facilitated by zonular attachments to the Lens Capsule. Invest Ophthalmol Vis Sci
2015Co-Authors: Rainer Wasilewski, Jared P Mcdonald, Gregg A Heatley, Mary Ann CroftAbstract:PURPOSE. To determine the role of the Lens and the Lens Capsule in the three-dimensional architecture of the ciliary muscle at rest and during accommodation, in live rhesus monkeys and in histologic sections, by removing the entire Lens, or only the Lens nucleus and cortex, while leaving the posterior Capsule in place. METHODS. In 15 rhesus monkey eyes, aged 6 to 27 years, accommodation was induced by central stimulation of the Edinger-Westphal nucleus before and after intra- or extracap-sular Lens extraction (ICLE, ECLE). Forward ciliary body move-ment and ciliary body width were measured by ultrasound biomicroscopy (UBM, 50 MHz). The monkeys were then killed, the eyes were examined morphologically in 1-m sections, and the shape of the ciliary muscle was compared with that ob-tained from UBM images. RESULTS. The shape of the ciliary muscle in eyes undergoing ECLE (n 5) did not differ from that in control eyes. In contrast, after ICLE (n 10), accommodative forward ciliary body movement (P 0.01) and thickness were decreased (P 0.001), length was increased (P 0.058), and the inner apex was located more posteriorly than in control eyes (P 0.005). Histologic and in vivo data were similar and showed that the ciliary muscle maintained its triangular shape only if the Lens Capsule (with or without the Lens substance) was present. CONCLUSIONS. The posterior Lens Capsule and anterior zonular attachments facilitate forward accommodative ciliary body movement. Lens substance extraction procedures that leave the posterior Capsule intact, similar to those used clinically, do not affect the Capsule/zonular/muscular system move-ments, an important finding for accommodating intraocula
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surgical intervention and accommodative responses ii forward ciliary body accommodative movement is facilitated by zonular attachments to the Lens Capsule
Investigative Ophthalmology & Visual Science, 2008Co-Authors: Rainer Wasilewski, Paul L. Kaufman, Jared P Mcdonald, Gregg A Heatley, Elke Lutjendrecoll, Mary Ann CroftAbstract:PURPOSE: To determine the role of the Lens and the Lens Capsule in the three-dimensional architecture of the ciliary muscle at rest and during accommodation, in live rhesus monkeys and in histologic sections, by removing the entire Lens, or only the Lens nucleus and cortex, while leaving the posterior Capsule in place. METHODS: In 15 rhesus monkey eyes, aged 6 to 27 years, accommodation was induced by central stimulation of the Edinger-Westphal nucleus before and after intra- or extracapsular Lens extraction (ICLE, ECLE). Forward ciliary body movement and ciliary body width were measured by ultrasound biomicroscopy (UBM, 50 MHz). The monkeys were then killed, the eyes were examined morphologically in 1-microm sections, and the shape of the ciliary muscle was compared with that obtained from UBM images. RESULTS: The shape of the ciliary muscle in eyes undergoing ECLE (n = 5) did not differ from that in control eyes. In contrast, after ICLE (n = 10), accommodative forward ciliary body movement (P < 0.01) and thickness were decreased (P < 0.001), length was increased (P = 0.058), and the inner apex was located more posteriorly than in control eyes (P < 0.005). Histologic and in vivo data were similar and showed that the ciliary muscle maintained its triangular shape only if the Lens Capsule (with or without the Lens substance) was present. CONCLUSIONS: The posterior Lens Capsule and anterior zonular attachments facilitate forward accommodative ciliary body movement. Lens substance extraction procedures that leave the posterior Capsule intact, similar to those used clinically, do not affect the Capsule/zonular/muscular system movements, an important finding for accommodating intraocular Lens development.
Paul B Henrich - One of the best experts on this subject based on the ideXlab platform.
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superior rim stability of the Lens Capsule following manual over femtosecond laser capsulotomy
Investigative Ophthalmology & Visual Science, 2016Co-Authors: Magaly Reyes Lua, Philipp Oertle, L C Camenzind, Alexandra Goz, Carsten H Meyer, Katarzyna Konieczka, Marko Loparic, Willi Halfter, Paul B HenrichAbstract:PURPOSE Cataract surgery requires the removal of a circular segment of the anterior Lens Capsule (LC) by manual or femtosecond laser (FL) capsulotomy. Tears in the remaining anterior LC may compromise surgical outcome. We investigated whether biophysical differences in the rim properties of the LC remaining in the patient after manual or FL capsulotomy (FLC) lead to different risks with regard to anterior tear formation. METHODS Lens Capsule samples obtained by either continuous curvilinear capsulorhexis (CCC) or FLC were investigated by light microscopy, laser scanning confocal microscopy, and scanning electron microscopy; atomic force microscopy (AFM) was used to test the biomechanical properties of the LC. The mechanical stability of the LC following either of the two capsulotomy techniques was simulated by using finite-element modeling. RESULTS Continuous curvilinear capsulorhexis produced wedge-shaped, uniform rims, while FLC resulted in nearly perpendicular, frayed rims with numerous notches. The LC is composed of two sublayers: a stiff epithelial layer that is abundant with laminin and a softer anterior chamber layer that is predominantly made from collagen IV. Computer models show that stress is uniformly distributed over the entire rim after CCC, while focal high stress concentrations are observed in the frayed profiles of LC after FLC, making the latter procedure more prone to anterior tear formation. CONCLUSIONS Finite-element modeling based on three-dimensional AFM maps indicated that CCC leads to a capsulotomy rim with higher stress resistance, leading to a lower propensity for anterior radial tears than FLC.
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superior rim stability of the Lens Capsule following manual over femtosecond laser capsulotomy
Investigative Ophthalmology & Visual Science, 2016Co-Authors: Reyes Lua M, Philipp Oertle, L C Camenzind, Carsten H Meyer, Katarzyna Konieczka, Marko Loparic, Willi Halfter, Paul B HenrichAbstract:Abstract Cataract surgery requires the removal of a circular segment of the anterior Lens Capsule (LC) by manual or femtosecond laser (FL) capsulotomy. Tears in the remaining anterior LC may compromise surgical outcome. We investigated whether biophysical differences in the rim properties of the LC remaining in the patient after manual or FL capsulotomy (FLC) lead to different risks with regard to anterior tear formation. Lens Capsule samples obtained by either continuous curvilinear capsulorhexis (CCC) or FLC were investigated by light microscopy, laser scanning confocal microscopy, and scanning electron microscopy; atomic force microscopy (AFM) was used to test the biomechanical properties of the LC. The mechanical stability of the LC following either of the two capsulotomy techniques was simulated by using finite-element modeling. Continuous curvilinear capsulorhexis produced wedge-shaped, uniform rims, while FLC resulted in nearly perpendicular, frayed rims with numerous notches. The LC is composed of two sublayers: a stiff epithelial layer that is abundant with laminin and a softer anterior chamber layer that is predominantly made from collagen IV. Computer models show that stress is uniformly distributed over the entire rim after CCC, while focal high stress concentrations are observed in the frayed profiles of LC after FLC, making the latter procedure more prone to anterior tear formation. Finite-element modeling based on three-dimensional AFM maps indicated that CCC leads to a capsulotomy rim with higher stress resistance, leading to a lower propensity for anterior radial tears than FLC.
Xinyi Chen - One of the best experts on this subject based on the ideXlab platform.
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Lens Capsule related complications of femtosecond laser assisted capsulotomy versus manual capsulorhexis for white cataracts
Journal of Cataract and Refractive Surgery, 2019Co-Authors: Xinyi Chen, Peiqing Chen, Wen Xu, Xingchao Shentu, Yibo YuAbstract:Purpose Comparison of Lens Capsule-related complications resulting from femtosecond laser–assisted capsulotomy and manual capsulorhexis in patients with white cataracts. Setting Eye Center, Second Affiliated Hospital, Zhejiang Medical School, Hangzhou, China. Design Prospective consecutive nonrandomized comparative cohort study. Methods Selected patients were divided into a femtosecond laser–assisted cataract surgery group (FLACS group) and a conventional phacoemulsification cataract surgery group (CPCS group). Each case was recorded as either a type I or type II white cataract. Here, type I was characterized by the presence of a liquefied cortex, whereas type II had a solid cortex. Five experienced phacoemulsification surgeons conducted all surgeries. Lens Capsule-related events, including anterior Capsule tears, posterior Capsule ruptures (PCRs), incomplete capsulotomies, and irregular capsulorhexes were recorded; surgical parameters, postoperative visual acuities, and intraocular Lens (IOL) decentrations were evaluated. Results The study comprised 132 eyes of 132 patients (66 in each group). Anterior Capsule tears were significantly more common in the CPCS group than the FLACS group (12.1% versus 0%). All 8 cases of anterior Capsule tears were type I cases. Six FLACS cases developed incomplete capsulotomies, four of which were type I cases. The incidences of PCRs and vitreous loss were the same. Capsulotomy produced better circularity index and diameter stability than capsulorhexis. IOLs were better centered in the FLACS group than the CPCS group. The mean ultrasound power, absolute phaco time, effective phaco time, and postoperative visual acuities were similar in both groups. Conclusions Compared with CPCS, FLACS decreased the risk for anterior Capsule tears in white cataracts, especially in type I cases. However, it did not reduce the incidence of PCR. Incomplete capsulotomy during FLACS could happen in white cataracts. Using FLACS on white cataracts enabled more precise capsulotomies and better-centered IOLs.
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Lens Capsule related complications of femtosecond laser assisted capsulotomy versus manual capsulorhexis for white cataracts
Journal of Cataract and Refractive Surgery, 2019Co-Authors: Yanan Zhu, Xinyi Chen, Peiqing Chen, Xingchao Shentu, Ke YaoAbstract:Purpose Comparison of Lens Capsule-related complications resulting from femtosecond laser–assisted capsulotomy and manual capsulorhexis in patients with white cataracts. Setting Eye Center, Second Affiliated Hospital, Zhejiang Medical School, Hangzhou, China. Design Prospective consecutive nonrandomized comparative cohort study. Methods Selected patients were divided into a femtosecond laser–assisted cataract surgery group (FLACS group) and a conventional phacoemulsification cataract surgery group (CPCS group). Each case was recorded as either a type I or type II white cataract. Here, type I was characterized by the presence of a liquefied cortex, whereas type II had a solid cortex. Five experienced phacoemulsification surgeons conducted all surgeries. Lens Capsule-related events, including anterior Capsule tears, posterior Capsule ruptures (PCRs), incomplete capsulotomies, and irregular capsulorhexes were recorded; surgical parameters, postoperative visual acuities, and intraocular Lens (IOL) decentrations were evaluated. Results The study comprised 132 eyes of 132 patients (66 in each group). Anterior Capsule tears were significantly more common in the CPCS group than the FLACS group (12.1% versus 0%). All 8 cases of anterior Capsule tears were type I cases. Six FLACS cases developed incomplete capsulotomies, four of which were type I cases. The incidences of PCRs and vitreous loss were the same. Capsulotomy produced better circularity index and diameter stability than capsulorhexis. IOLs were better centered in the FLACS group than the CPCS group. The mean ultrasound power, absolute phaco time, effective phaco time, and postoperative visual acuities were similar in both groups. Conclusions Compared with CPCS, FLACS decreased the risk for anterior Capsule tears in white cataracts, especially in type I cases. However, it did not reduce the incidence of PCR. Incomplete capsulotomy during FLACS could happen in white cataracts. Using FLACS on white cataracts enabled more precise capsulotomies and better-centered IOLs.
Paul L. Kaufman - One of the best experts on this subject based on the ideXlab platform.
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surgical intervention and accommodative responses ii forward ciliary body accommodative movement is facilitated by zonular attachments to the Lens Capsule
Investigative Ophthalmology & Visual Science, 2008Co-Authors: Rainer Wasilewski, Paul L. Kaufman, Jared P Mcdonald, Gregg A Heatley, Elke Lutjendrecoll, Mary Ann CroftAbstract:PURPOSE: To determine the role of the Lens and the Lens Capsule in the three-dimensional architecture of the ciliary muscle at rest and during accommodation, in live rhesus monkeys and in histologic sections, by removing the entire Lens, or only the Lens nucleus and cortex, while leaving the posterior Capsule in place. METHODS: In 15 rhesus monkey eyes, aged 6 to 27 years, accommodation was induced by central stimulation of the Edinger-Westphal nucleus before and after intra- or extracapsular Lens extraction (ICLE, ECLE). Forward ciliary body movement and ciliary body width were measured by ultrasound biomicroscopy (UBM, 50 MHz). The monkeys were then killed, the eyes were examined morphologically in 1-microm sections, and the shape of the ciliary muscle was compared with that obtained from UBM images. RESULTS: The shape of the ciliary muscle in eyes undergoing ECLE (n = 5) did not differ from that in control eyes. In contrast, after ICLE (n = 10), accommodative forward ciliary body movement (P < 0.01) and thickness were decreased (P < 0.001), length was increased (P = 0.058), and the inner apex was located more posteriorly than in control eyes (P < 0.005). Histologic and in vivo data were similar and showed that the ciliary muscle maintained its triangular shape only if the Lens Capsule (with or without the Lens substance) was present. CONCLUSIONS: The posterior Lens Capsule and anterior zonular attachments facilitate forward accommodative ciliary body movement. Lens substance extraction procedures that leave the posterior Capsule intact, similar to those used clinically, do not affect the Capsule/zonular/muscular system movements, an important finding for accommodating intraocular Lens development.
Ke Yao - One of the best experts on this subject based on the ideXlab platform.
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Lens Capsule related complications of femtosecond laser assisted capsulotomy versus manual capsulorhexis for white cataracts
Journal of Cataract and Refractive Surgery, 2019Co-Authors: Yanan Zhu, Xinyi Chen, Peiqing Chen, Xingchao Shentu, Ke YaoAbstract:Purpose Comparison of Lens Capsule-related complications resulting from femtosecond laser–assisted capsulotomy and manual capsulorhexis in patients with white cataracts. Setting Eye Center, Second Affiliated Hospital, Zhejiang Medical School, Hangzhou, China. Design Prospective consecutive nonrandomized comparative cohort study. Methods Selected patients were divided into a femtosecond laser–assisted cataract surgery group (FLACS group) and a conventional phacoemulsification cataract surgery group (CPCS group). Each case was recorded as either a type I or type II white cataract. Here, type I was characterized by the presence of a liquefied cortex, whereas type II had a solid cortex. Five experienced phacoemulsification surgeons conducted all surgeries. Lens Capsule-related events, including anterior Capsule tears, posterior Capsule ruptures (PCRs), incomplete capsulotomies, and irregular capsulorhexes were recorded; surgical parameters, postoperative visual acuities, and intraocular Lens (IOL) decentrations were evaluated. Results The study comprised 132 eyes of 132 patients (66 in each group). Anterior Capsule tears were significantly more common in the CPCS group than the FLACS group (12.1% versus 0%). All 8 cases of anterior Capsule tears were type I cases. Six FLACS cases developed incomplete capsulotomies, four of which were type I cases. The incidences of PCRs and vitreous loss were the same. Capsulotomy produced better circularity index and diameter stability than capsulorhexis. IOLs were better centered in the FLACS group than the CPCS group. The mean ultrasound power, absolute phaco time, effective phaco time, and postoperative visual acuities were similar in both groups. Conclusions Compared with CPCS, FLACS decreased the risk for anterior Capsule tears in white cataracts, especially in type I cases. However, it did not reduce the incidence of PCR. Incomplete capsulotomy during FLACS could happen in white cataracts. Using FLACS on white cataracts enabled more precise capsulotomies and better-centered IOLs.