Background:Femtosecond laser astigmatic keratotomy(FSAK)and toric intraocular lens(IOL)implantation have been studied individually for comparison to treat astigmatism at cataract surgery.We report a case of surgically...Background:Femtosecond laser astigmatic keratotomy(FSAK)and toric intraocular lens(IOL)implantation have been studied individually for comparison to treat astigmatism at cataract surgery.We report a case of surgically induced high corneal astigmatism by laser thermal keratoplasty(LTK)in a patient with cataract who was successfully treated with simultaneous combination of FSAK and toric IOL implantation with femtosecond laser-assisted cataract surgery(FLACS).This is the first report of both procedures combined simultaneously,with or without history of LTK.Case Description:A 68-year-old male presented with a history of LTK with two enhancements each eye in 2004,with subsequent surgically induced high corneal astigmatism,and with age-related nuclear cataract of both eyes.IOL master demonstrated+7.71 diopters of astigmatism at 163 degree right eye and+3.29 diopters of astigmatism at 4 degree left eye.After extensive discussion of the risks and benefits,the patient agreed to undergo FLACS with FSAK with two 61 degrees of relaxation incisions(RIs)and toric IOL(Alcon SN6AT9)right eye;FLACS with toric IOL(Alcon SN6AT7)alone left eye.At 2-year follow-up,uncorrected visual acuity was 20/30 right eye,20/25 left eye.His best corrected visual acuity was 20/25(+0.25+1.00 axis 21)right eye and 20/20(plano+0.25 axis 90)left eye;his best corrected near visual acuity was J1+with add+2.50 diopters right eye and left eye.Conclusions:Patients with age-related cataract and LTK induced high corneal astigmatism can hardly be sufficiently treated with FSAK or toric IOL alone at the time of cataract surgery.An effective way is to combine large FSAK and toric IOL of the highest cylindrical power of T9,in our case,simultaneously,which can achieve an excellent long term visual outcome.展开更多
Background:To evaluate the accuracy and safety of micro radial and arcuate keratotomy incisions constructed by a femtosecond laser system with a curved contact patient interface in porcine eyes.Methods:Partial thickne...Background:To evaluate the accuracy and safety of micro radial and arcuate keratotomy incisions constructed by a femtosecond laser system with a curved contact patient interface in porcine eyes.Methods:Partial thickness micro radial and arcuate keratotomy incisions were constructed in porcine eyes with a femtosecond laser system and evaluated for precision of depth,quality,and consistency.Optical coherence tomography was used to determine the accuracy and precision of incision depth.Corneal endothelial safety was assessed by a fluorescent live/dead cell viability assay to demonstrate laser-induced endothelial cell loss.Quality was evaluated by ease of opening and examination of interfaces.Results:In two micro radial incision groups,intended incision depths of 50%and 80%resulted in mean achieved depths of 50.01%and 77.69%,respectively.In three arcuate incision groups,intended incision depths of 80%,600μm or 100μm residual uncut bed thickness resulted in mean achieved depths of 80.16%,603.03μm and residual bed of 115μm,respectively.No loss of endothelial cell density occurred when the residual corneal bed was maintained at a minimum of 85-116μm.The incisions were easy to open,and interfaces were smooth.Conclusions:A femtosecond laser system with curved contact interface created precise and reproducible micro radial and arcuate keratotomy incisions.Accuracy and precision of the incision depth and preservation of endothelial cell density demonstrated the effectiveness and safety of the system.展开更多
AIM:To evaluate corneal astigmatic outcomes of femtosecond laser-assisted arcuate keratotomies(FAKs)combined with femtosecond-laser assisted cataract surgery(FLACS)over 12mo follow-up.METHODS:Totally 145 patients with...AIM:To evaluate corneal astigmatic outcomes of femtosecond laser-assisted arcuate keratotomies(FAKs)combined with femtosecond-laser assisted cataract surgery(FLACS)over 12mo follow-up.METHODS:Totally 145 patients with bilateral cataracts and no ocular co-morbidities were recruited to a singlecentre,single-masked,prospective randomized controlled trial(RCT)comparing two monofocal hydrophobic acrylic intraocular lenses.Eyes with corneal astigmatism(CA)of>0.8 dioptres(D)received unpaired,unopened,surface penetrating FAKs at the time of FLACS.Visual acuity,subjective refraction and Scheimpflug tomography were recorded at 1,6,and 12mo.Alpins vectoral analyses were performed.RESULTS:Fifty-one patients(61 eyes),mean age 68.2±9.6y[standard deviation(SD)],received FAKs.Sixty eyes were available for analysis,except at 12mo when 59 attended.There were no complications due to FAKs.Mean pre-operative CA was 1.13±0.20 D.There was a reduction of astigmatism at all post-operative visits(residual CA 1mo:0.85±0.42 D,P=0.0001;6mo:0.86±0.35 D,P=0001;and 12mo:0.90±0.39,P=0.0001).Alpins indices remained stable over 12mo.Overall,the cohort was under-corrected at all time points.At 12mo,61%of eyes were within±15 degrees of pre-operative astigmatic meridian.CONCLUSION:Unpaired unopened penetrating FAKs combined with on-axis phacoemulsification are safe but minimally effective.CA is largely under-corrected in this cohort using an existing unmodified nomogram.The effect of arcuate keratotomies on CA remained stable over 12mo.展开更多
AIM:To evaluate the effect of symmetrical arc incision correcting corneal astigmatism in femtosecond laserassisted phacoemulsification(FLACS).METHODS:This study enrolled patients with cataract combined with regular co...AIM:To evaluate the effect of symmetrical arc incision correcting corneal astigmatism in femtosecond laserassisted phacoemulsification(FLACS).METHODS:This study enrolled patients with cataract combined with regular corneal astigmatism of>0.75 D,who underwent FLACS.Symmetrical arc incision was set at 8 mm diameter and 85%depth.The follow-up time was 3-24mo(4.92±3.49mo).Pentacam recorded the corneal astigmatism and higher-order aberration at pre-operation and post-operation.The changes in corneal astigmatism were analyzed by Alpins method.The correlation of astigmatism type,age,corneal horizontal diameter,corneal thickness,arc incision length,and correction index(CI)was analyzed,and the residual corneal astigmatism was compared with the residual whole eye astigmatism.RESULTS:Totally 79 patients(102 eyes)were enrolled,10 patients had corneal epithelial injury,1 patient occurred corneal epithelial hyperplasia.The corneal astigmatism was 1.23±0.38 D pre-operation,and decreased to 0.76±0.39 D post-operation(t=10.146,P=0.000).Corneal high-order aberration was 0.17±0.08μm pre-operation and 0.24±0.11μm post-operation(t=-5.186,P=0.000).The residual corneal astigmatism and residual whole eye astigmatism were no significant difference(t=-0.347,P=0.729).Using Alpin’s method,the following were determined:target-induced astigmatism(TIA)=1.23±0.38 D,surgeryinduced astigmatism(SIA)=0.77±0.45 D,difference vector(DV)=0.77±0.39 D,and CI=0.54±0.28.Age,astigmatism size,corneal horizontal diameter,corneal thickness,and arc incision length were not correlated with CI.The CI for against the rule astigmatism(ATR)was better than that for with the rule astigmatism(WTR;P=0.001).CONCLUSION:Femtosecond laser-assisted astigmatic keratotomy has better CI of ATR,but increase higher-order corneal aberration.CI is not ideal,it’s not a perfect choice if we pursue ideal correction effect.展开更多
Femtosecond time-resolved fluorescence depletion spectroscopy was used in the study of the orientation relaxation of Rhodamine 700(LD700) and Oxazine 750(OX750) in DMSO. The anisotropy functions of the dye molecules w...Femtosecond time-resolved fluorescence depletion spectroscopy was used in the study of the orientation relaxation of Rhodamine 700(LD700) and Oxazine 750(OX750) in DMSO. The anisotropy functions of the dye molecules were obtained from the fluorescence depletion spectra, as the polarization of probe pulse is parallel and perpendicular respectively. The results show that the transition dipole moment of the pump and the probe of LD700 and OX750 are parallel. The time constants of the orientation relaxation of these dye molecules in DMSO are 1.8 and 1.9 ps for LD700 and OX750, respectively.展开更多
Anisotropic shapes of gold nanoparticles are prepared using a modified seed method in the presence of silver ions or clusters in order to study the thermal stability and the dynamics of the hot carriers induced by fem...Anisotropic shapes of gold nanoparticles are prepared using a modified seed method in the presence of silver ions or clusters in order to study the thermal stability and the dynamics of the hot carriers induced by femtosecond laser pulses. Although gold nanospheres are stable towards thermal treatment, the decomposition of the gold nanorods into spherical nanoparticle aggregates upon thermal treatment is mechanistically different from the case of nanoprisms. Great enhancement of thermal stability is achieved by modifying the surface of the nanoparticles by adding specific amounts of polyvinyl pyrrolidone (PVP) after preparation of gold particles of different shapes capped with cetyltrimethylammonium bromide (CTAB). The surface plasmon resonance spectra of the gold nanostructures are used to monitor their morphological changes. In regards to the hot carrier dynamics, it is found that the phonon-phonon (ph-ph) coupling is much slower in dots than in rods and prisms while electron-phonon (e-ph) coupling is almost the same in these particles.展开更多
Postoperative visual acuity can be limited by post-keratoplasty astigmatism,even with a clear corneal graft.Astigmatism management can be performed by selective suture removal,adjustment of sutures,optical correction,...Postoperative visual acuity can be limited by post-keratoplasty astigmatism,even with a clear corneal graft.Astigmatism management can be performed by selective suture removal,adjustment of sutures,optical correction,photorefractive procedures,wedge resection,intra-ocular lens implantation,intracorneal ring segments,relaxing incisions with or without compression sutures and repeated keratoplasty.Relaxing incisions can be made in the graft,graft-host interface or host cornea.Despite the unpredictability of the method because the flat and steep meridians are usually not orthogonal after penetrating keratoplasty,with asymmetric power distribution,all the studies showed an overall reduction of refractive,keratometric or topographic astigmatism,ranging from 30%to 72%with manual or femtosecond-assisted techniques.Most patients with astigmatism higher than 6 diopters had residual cylinder less than or equal to 3 diopters,which can be treated by laser excimer ablation or secondary intraocular lens implantation.展开更多
文摘Background:Femtosecond laser astigmatic keratotomy(FSAK)and toric intraocular lens(IOL)implantation have been studied individually for comparison to treat astigmatism at cataract surgery.We report a case of surgically induced high corneal astigmatism by laser thermal keratoplasty(LTK)in a patient with cataract who was successfully treated with simultaneous combination of FSAK and toric IOL implantation with femtosecond laser-assisted cataract surgery(FLACS).This is the first report of both procedures combined simultaneously,with or without history of LTK.Case Description:A 68-year-old male presented with a history of LTK with two enhancements each eye in 2004,with subsequent surgically induced high corneal astigmatism,and with age-related nuclear cataract of both eyes.IOL master demonstrated+7.71 diopters of astigmatism at 163 degree right eye and+3.29 diopters of astigmatism at 4 degree left eye.After extensive discussion of the risks and benefits,the patient agreed to undergo FLACS with FSAK with two 61 degrees of relaxation incisions(RIs)and toric IOL(Alcon SN6AT9)right eye;FLACS with toric IOL(Alcon SN6AT7)alone left eye.At 2-year follow-up,uncorrected visual acuity was 20/30 right eye,20/25 left eye.His best corrected visual acuity was 20/25(+0.25+1.00 axis 21)right eye and 20/20(plano+0.25 axis 90)left eye;his best corrected near visual acuity was J1+with add+2.50 diopters right eye and left eye.Conclusions:Patients with age-related cataract and LTK induced high corneal astigmatism can hardly be sufficiently treated with FSAK or toric IOL alone at the time of cataract surgery.An effective way is to combine large FSAK and toric IOL of the highest cylindrical power of T9,in our case,simultaneously,which can achieve an excellent long term visual outcome.
文摘Background:To evaluate the accuracy and safety of micro radial and arcuate keratotomy incisions constructed by a femtosecond laser system with a curved contact patient interface in porcine eyes.Methods:Partial thickness micro radial and arcuate keratotomy incisions were constructed in porcine eyes with a femtosecond laser system and evaluated for precision of depth,quality,and consistency.Optical coherence tomography was used to determine the accuracy and precision of incision depth.Corneal endothelial safety was assessed by a fluorescent live/dead cell viability assay to demonstrate laser-induced endothelial cell loss.Quality was evaluated by ease of opening and examination of interfaces.Results:In two micro radial incision groups,intended incision depths of 50%and 80%resulted in mean achieved depths of 50.01%and 77.69%,respectively.In three arcuate incision groups,intended incision depths of 80%,600μm or 100μm residual uncut bed thickness resulted in mean achieved depths of 80.16%,603.03μm and residual bed of 115μm,respectively.No loss of endothelial cell density occurred when the residual corneal bed was maintained at a minimum of 85-116μm.The incisions were easy to open,and interfaces were smooth.Conclusions:A femtosecond laser system with curved contact interface created precise and reproducible micro radial and arcuate keratotomy incisions.Accuracy and precision of the incision depth and preservation of endothelial cell density demonstrated the effectiveness and safety of the system.
基金Supported by independent research grant from Alcon(IIT#34114517)。
文摘AIM:To evaluate corneal astigmatic outcomes of femtosecond laser-assisted arcuate keratotomies(FAKs)combined with femtosecond-laser assisted cataract surgery(FLACS)over 12mo follow-up.METHODS:Totally 145 patients with bilateral cataracts and no ocular co-morbidities were recruited to a singlecentre,single-masked,prospective randomized controlled trial(RCT)comparing two monofocal hydrophobic acrylic intraocular lenses.Eyes with corneal astigmatism(CA)of>0.8 dioptres(D)received unpaired,unopened,surface penetrating FAKs at the time of FLACS.Visual acuity,subjective refraction and Scheimpflug tomography were recorded at 1,6,and 12mo.Alpins vectoral analyses were performed.RESULTS:Fifty-one patients(61 eyes),mean age 68.2±9.6y[standard deviation(SD)],received FAKs.Sixty eyes were available for analysis,except at 12mo when 59 attended.There were no complications due to FAKs.Mean pre-operative CA was 1.13±0.20 D.There was a reduction of astigmatism at all post-operative visits(residual CA 1mo:0.85±0.42 D,P=0.0001;6mo:0.86±0.35 D,P=0001;and 12mo:0.90±0.39,P=0.0001).Alpins indices remained stable over 12mo.Overall,the cohort was under-corrected at all time points.At 12mo,61%of eyes were within±15 degrees of pre-operative astigmatic meridian.CONCLUSION:Unpaired unopened penetrating FAKs combined with on-axis phacoemulsification are safe but minimally effective.CA is largely under-corrected in this cohort using an existing unmodified nomogram.The effect of arcuate keratotomies on CA remained stable over 12mo.
基金Supported by the Natural Science Foundation of Guangdong Province,China(No.2022A1515010742)Hunan Provincial Natural Science Foundation of China(No.2021JJ30045)the Science Research Grant of Aier Eye Hospital Group(No.AF2102D5,No.AF2201D06,No.AF2201D05).
文摘AIM:To evaluate the effect of symmetrical arc incision correcting corneal astigmatism in femtosecond laserassisted phacoemulsification(FLACS).METHODS:This study enrolled patients with cataract combined with regular corneal astigmatism of>0.75 D,who underwent FLACS.Symmetrical arc incision was set at 8 mm diameter and 85%depth.The follow-up time was 3-24mo(4.92±3.49mo).Pentacam recorded the corneal astigmatism and higher-order aberration at pre-operation and post-operation.The changes in corneal astigmatism were analyzed by Alpins method.The correlation of astigmatism type,age,corneal horizontal diameter,corneal thickness,arc incision length,and correction index(CI)was analyzed,and the residual corneal astigmatism was compared with the residual whole eye astigmatism.RESULTS:Totally 79 patients(102 eyes)were enrolled,10 patients had corneal epithelial injury,1 patient occurred corneal epithelial hyperplasia.The corneal astigmatism was 1.23±0.38 D pre-operation,and decreased to 0.76±0.39 D post-operation(t=10.146,P=0.000).Corneal high-order aberration was 0.17±0.08μm pre-operation and 0.24±0.11μm post-operation(t=-5.186,P=0.000).The residual corneal astigmatism and residual whole eye astigmatism were no significant difference(t=-0.347,P=0.729).Using Alpin’s method,the following were determined:target-induced astigmatism(TIA)=1.23±0.38 D,surgeryinduced astigmatism(SIA)=0.77±0.45 D,difference vector(DV)=0.77±0.39 D,and CI=0.54±0.28.Age,astigmatism size,corneal horizontal diameter,corneal thickness,and arc incision length were not correlated with CI.The CI for against the rule astigmatism(ATR)was better than that for with the rule astigmatism(WTR;P=0.001).CONCLUSION:Femtosecond laser-assisted astigmatic keratotomy has better CI of ATR,but increase higher-order corneal aberration.CI is not ideal,it’s not a perfect choice if we pursue ideal correction effect.
文摘Femtosecond time-resolved fluorescence depletion spectroscopy was used in the study of the orientation relaxation of Rhodamine 700(LD700) and Oxazine 750(OX750) in DMSO. The anisotropy functions of the dye molecules were obtained from the fluorescence depletion spectra, as the polarization of probe pulse is parallel and perpendicular respectively. The results show that the transition dipole moment of the pump and the probe of LD700 and OX750 are parallel. The time constants of the orientation relaxation of these dye molecules in DMSO are 1.8 and 1.9 ps for LD700 and OX750, respectively.
文摘Anisotropic shapes of gold nanoparticles are prepared using a modified seed method in the presence of silver ions or clusters in order to study the thermal stability and the dynamics of the hot carriers induced by femtosecond laser pulses. Although gold nanospheres are stable towards thermal treatment, the decomposition of the gold nanorods into spherical nanoparticle aggregates upon thermal treatment is mechanistically different from the case of nanoprisms. Great enhancement of thermal stability is achieved by modifying the surface of the nanoparticles by adding specific amounts of polyvinyl pyrrolidone (PVP) after preparation of gold particles of different shapes capped with cetyltrimethylammonium bromide (CTAB). The surface plasmon resonance spectra of the gold nanostructures are used to monitor their morphological changes. In regards to the hot carrier dynamics, it is found that the phonon-phonon (ph-ph) coupling is much slower in dots than in rods and prisms while electron-phonon (e-ph) coupling is almost the same in these particles.
文摘Postoperative visual acuity can be limited by post-keratoplasty astigmatism,even with a clear corneal graft.Astigmatism management can be performed by selective suture removal,adjustment of sutures,optical correction,photorefractive procedures,wedge resection,intra-ocular lens implantation,intracorneal ring segments,relaxing incisions with or without compression sutures and repeated keratoplasty.Relaxing incisions can be made in the graft,graft-host interface or host cornea.Despite the unpredictability of the method because the flat and steep meridians are usually not orthogonal after penetrating keratoplasty,with asymmetric power distribution,all the studies showed an overall reduction of refractive,keratometric or topographic astigmatism,ranging from 30%to 72%with manual or femtosecond-assisted techniques.Most patients with astigmatism higher than 6 diopters had residual cylinder less than or equal to 3 diopters,which can be treated by laser excimer ablation or secondary intraocular lens implantation.
