AIM:To explore the effect of Alpha angle and Kappa angle before multifocal intraocular lenses(MIOLs)implantation on postoperative visual quality of patients.METHODS:Before and 3mo after cataract surgery,Alpha angle an...AIM:To explore the effect of Alpha angle and Kappa angle before multifocal intraocular lenses(MIOLs)implantation on postoperative visual quality of patients.METHODS:Before and 3mo after cataract surgery,Alpha angle and Kappa angle were collected using IOL Master 700,iTrace,and Pentacam for clinical observation.Postoperative visual quality indicators,including high-order aberrations(HOA),modulation transfer function(MTF)and point spread function(PSF),were collected using iTrace.multiple linear regression analysis was used to analyze the correlation of the Kappa angle and the Alpha angle with age,axial length(AL),anterior chamber depth(ACD),keratometry(K),lens thickness(LT)and corneal white to white distance(WTW).Pearson correlation coefficient was used to analyze the correlation between Alpha angle and Kappa angle;Bland Altman analysis was used to evaluate the consistency of pairwise detection results of three instruments.RESULTS:The Alpha angle was modeled as Alpha=2.230+0.003×age-0.036×AL-0.025×K-0.058×WTW and the Kappa angle was modeled as Kappa=0.685+0.003×age-0.013×K-0.061×WTW.The correlation between the total Alpha angle and Kappa angle of the three instruments was weakly positive(r=0.291,P=0.000).Comparing the measurement of Alpha angle and Kappa angle using three instruments,only IOL Master 700 and iTrace showed good consistency in measuring Kappa angle(P=0.4254).After 3mo of surgery,the Alpha angle and Kappa angle significantly decreased(P=0.011,0.018;P=0.008,0.036).△Kappa=1.136-0.021×AL-0.013×K.Kappa angle could positively predict HOA(β=0.18,P=0.000),MTF(β=0.171,P=0.000),PSF(β=0.088,P=0.000),Alpha angle cannot(P>0.05).CONCLUSION:The patients with older age,flatter K and shorter WTW should be alert to the possibility of larger Alpha angle and Kappa angle.Alpha angle should also consider the factor of AL.When selecting patients with MIOLs implantation,there is no need to consider the Alpha angle.Careful consideration should be given to the Kappa angle,and the preoperative standard of<0.5 mm can refer to△Kappa=1.136-0.021×AL-0.013×K and be appropriately relaxed.展开更多
AIM： To investigate the difference in kappa angle between sitting and supine positions during laser-assisted in situ keratomileusis（LASIK）.·METHODS： A retrospective study was performed on395 eyes from 215 pat...AIM： To investigate the difference in kappa angle between sitting and supine positions during laser-assisted in situ keratomileusis（LASIK）.·METHODS： A retrospective study was performed on395 eyes from 215 patients with myopia that received LASIK. Low, moderate, and high myopia groups were assigned according to diopters. The horizontal and vertical components of kappa angle in sitting position were measured before the operation, and in supine position during the operation. The data from the two positions were compared and the relationship between kappa angle and diopters were analyzed.· RESULTS： Two hundred and twenty-three eyes（56.5%） in sitting position and 343 eyes（86.8%） in supine position had positive kappa angles. There were no significant differences in horizontal and vertical components of kappa angle in the sitting position or horizontal components of kappa angle in the supine position between the three groups（P 〉0.05）. A significant difference in the vertical components of kappa angle in the supine position was seen in the three groups（P 〈0.01）. Differences in both horizontal and vertical components of kappa angles were significant between the sitting and supine positions. Positive correlations in both horizontal and vertical components of kappa angles（P 〈0.05） were found and vertical components of kappa angle in sitting and supine positions were negatively correlated with the degree of myopia（sitting position： r =-0.109; supine position： r =-0.172; P 〈0.05）.·CONCLUSION： There is a correlation in horizontal and vertical components of kappa angle in sitting and supine positions. Positive correlations in both horizontal and vertical components of kappa angle in sitting and supine positions till the end of the results. This result still needs further observation. Clinicians should take into account different postures when excimer laser surgery needs to be performed.展开更多
AIM:To investigate how angles kappa and alpha affect postoperative visual quality in patients with multifocal intraocular lens(mIOLs)implantation.METHODS:Retrospective cases series.A total of 46 patients(46 eyes)who u...AIM:To investigate how angles kappa and alpha affect postoperative visual quality in patients with multifocal intraocular lens(mIOLs)implantation.METHODS:Retrospective cases series.A total of 46 patients(46 eyes)who underwent phacoemulsification were subsumed.The correlation between Preoperative angles kappa and alpha,wave-front aberrations and objective visual quality of cornea,internal,and total eye after surgery were analyzed using iTrace.RESULTS:The magnitude of angle kappa was negatively correlated with internal and total modulation transfer function(MTF)at 3 mm;the magnitude of angle kappa was positively correlated with astigmatism,trefoil,higher-order aberrations(HOAs)of both internal and total eye at 3 mm.The magnitude of angle alpha was negatively correlated with total MTF and total Strehl ratio at 3 mm.The magnitude of angle alpha was positively correlated with corneal coma at 5 mm,internal astigmatism at both 3 mm and 5 mm,and total spherical aberration(SA)at 3 mm.Multivariate linear regression analysis showed that,among candidate independent variables(kappa,alpha,astigmatism,SA,coma,trefoil,and HOAs),astigmatism is the only independent factor for altering corneal MTF at 3 mm and 5 mm;astigmatism and HOAs emerged as independent factors for altering internal MTF at 3 mm and 5 mm,and total MTF at 3 mm;astigmatism,SA and HOAs emerged as independent factors for altering total MTF at 5 mm.CONCLUSION:With greater preoperative angle kappa or angle alpha,patients who accept mIOL implantation tend to have larger internal astigmatism and HOAs,which resulting in poor visual quality,especially those with small pupil size.展开更多
AIM： To evaluate and compare the uniformity of angle Kappa adjustment between Oculyzer and Topolyzer Vario topography guided ablation of laser in situ keratomileusis（LASIK） by EX500 excimer laser for myopia.METHODS...AIM： To evaluate and compare the uniformity of angle Kappa adjustment between Oculyzer and Topolyzer Vario topography guided ablation of laser in situ keratomileusis（LASIK） by EX500 excimer laser for myopia.METHODS： Totally 145 cases（290 consecutive eyes）with myopia received LASIK with a target of emmetropia. The ablation for 86 cases（172 eyes） was guided manually based on Oculyzer topography（study group）, while the ablation for 59 cases（118 eyes） was guided automatically by Topolyzer Vario topography（control group）. Measurement of adjustment values included data respectively in horizontal and vertical direction of cornea. RESULTS： Horizontally, synclastic adjustment between manually actual values（dx_（manu）） and Oculyzer topography guided data（dx_（ocu）） accounts 35.5% in study group, with mean dx_（manu）/dx_（ocu） of 0.78±0.48; while in control group, synclastic adjustment between automatically actual values（dx_（auto）） and Oculyzer topography data（dx_（ocu）） accounts 54.2%, with mean dx_（auto）/dx_（ocu） of 0.79±0.66. Vertically, synclastic adjustment between dy_（manu） and dy_（ocu） accounts 55.2% in study group, with mean dy_（manu）/dy_（ocu） of 0.61±0.42; while in control group, synclastic adjustment between dy_（auto） and dy_（ocu） accounts 66.1%, with mean dy_（auto）/dy_（ocu） of 0.66±0.65. There was no statistically significant difference in ratio of actual values/Oculyzer topography guided data in horizontal and vertical direction between two groups（P=0.951, 0.621）.CONCLUSION： There is high consistency in angle Kappa adjustment guided manually by Oculyzer and guided automatically by Topolyzer Vario topography during corneal refractive surgery by Wave Light EX500 excimer laser.展开更多
AIM： To investigate the independent factors associated with photic phenomena in patients implanted with refractive,rotationally asymmetric,multifocal intraocular lenses（MIOLs）.METHODS： Thirty-four eyes of 34 patie...AIM： To investigate the independent factors associated with photic phenomena in patients implanted with refractive,rotationally asymmetric,multifocal intraocular lenses（MIOLs）.METHODS： Thirty-four eyes of 34 patients who underwent unilateral cataract surgery,followed by implantation of rotationally asymmetric MIOLs were included.Distance and near visual acuity outcomes,intraocular aberrations,preferred reading distances,preoperative and postoperative refractive errors,mesopic and photopic pupil diameters,and the mesopic and photopic kappa angles were assessed.Patients were also administered a satisfaction survey.Photic phenomena were graded by questionnaire.Independent-related factors were identified by correlation and bivariate logistic regression analyses.RESULTS： The distance from the photopic to the mesopic pupil center（pupil center shift） was significantly associated with glare/halo symptoms [odds ratio（OR）=2.065,95% confidence interval（CI）=0.916-4.679,P=0.006] and night vision problems（OR=1.832,95% CI=0.721-2.158,P=0.007）.The preoperative photopic angle kappa was significantly associated with glare/halo symptoms（OR=2.155,95% CI=1.065-4.362,P=0.041）.The photopic angle kappa was also significantly associated with glare/halo symptoms（OR=2.155,95% CI=1.065-4.362,P=0.041） and with night vision problems（OR=1.832,95% CI=0.721-2.158,P=0.007） in patients implanted with rotationally asymmetric MIOLs.CONCLUSION： A large pupil center shift and misalignment between the visual and pupillary axis（angle kappa）may play a role in the occurrence of photic phenomena after implantation of rotationally asymmetric MIOLs.展开更多
The human eye is an asymmetric optical system and the real cornea is not a rotationally symmetrical volume.Each optical element in the eye has its own optical and neural axes.Defining the optimum center for laser abla...The human eye is an asymmetric optical system and the real cornea is not a rotationally symmetrical volume.Each optical element in the eye has its own optical and neural axes.Defining the optimum center for laser ablation is difficult with many available approaches.We explain the various centration approaches(based on these reference axes)in refractive surgery and review their clinical outcomes.The line-of-sight(LOS)(the line joining the entrance pupil center with the fixation point)is often the recommended reference axis for representing wavefront aberrations of the whole eye(derived from the definition of chief ray in geometrical optics);however pupil centration can be unstable and change with the pupil size.The corneal vertex(CV)represents a stable preferable morphologic reference which is the best approximate for alignment to the visual axis.However,the corneal light reflex can be considered as non-constant,but dependent on the direction of gaze of the eye with respect to the light source.A compromise between the pupil and CV centered ablations is seen in the form of an asymmetric offset where the manifest refraction is referenced to the CV while the higher order aberrations are referenced to the pupil center.There is a need for a flexible choice of centration in excimer laser systems to design customized and non-customized treatments optimally.展开更多
基金Supported by National Natural Science Foundation of China(No.81902751).
文摘AIM:To explore the effect of Alpha angle and Kappa angle before multifocal intraocular lenses(MIOLs)implantation on postoperative visual quality of patients.METHODS:Before and 3mo after cataract surgery,Alpha angle and Kappa angle were collected using IOL Master 700,iTrace,and Pentacam for clinical observation.Postoperative visual quality indicators,including high-order aberrations(HOA),modulation transfer function(MTF)and point spread function(PSF),were collected using iTrace.multiple linear regression analysis was used to analyze the correlation of the Kappa angle and the Alpha angle with age,axial length(AL),anterior chamber depth(ACD),keratometry(K),lens thickness(LT)and corneal white to white distance(WTW).Pearson correlation coefficient was used to analyze the correlation between Alpha angle and Kappa angle;Bland Altman analysis was used to evaluate the consistency of pairwise detection results of three instruments.RESULTS:The Alpha angle was modeled as Alpha=2.230+0.003×age-0.036×AL-0.025×K-0.058×WTW and the Kappa angle was modeled as Kappa=0.685+0.003×age-0.013×K-0.061×WTW.The correlation between the total Alpha angle and Kappa angle of the three instruments was weakly positive(r=0.291,P=0.000).Comparing the measurement of Alpha angle and Kappa angle using three instruments,only IOL Master 700 and iTrace showed good consistency in measuring Kappa angle(P=0.4254).After 3mo of surgery,the Alpha angle and Kappa angle significantly decreased(P=0.011,0.018;P=0.008,0.036).△Kappa=1.136-0.021×AL-0.013×K.Kappa angle could positively predict HOA(β=0.18,P=0.000),MTF(β=0.171,P=0.000),PSF(β=0.088,P=0.000),Alpha angle cannot(P>0.05).CONCLUSION:The patients with older age,flatter K and shorter WTW should be alert to the possibility of larger Alpha angle and Kappa angle.Alpha angle should also consider the factor of AL.When selecting patients with MIOLs implantation,there is no need to consider the Alpha angle.Careful consideration should be given to the Kappa angle,and the preoperative standard of<0.5 mm can refer to△Kappa=1.136-0.021×AL-0.013×K and be appropriately relaxed.
文摘AIM： To investigate the difference in kappa angle between sitting and supine positions during laser-assisted in situ keratomileusis（LASIK）.·METHODS： A retrospective study was performed on395 eyes from 215 patients with myopia that received LASIK. Low, moderate, and high myopia groups were assigned according to diopters. The horizontal and vertical components of kappa angle in sitting position were measured before the operation, and in supine position during the operation. The data from the two positions were compared and the relationship between kappa angle and diopters were analyzed.· RESULTS： Two hundred and twenty-three eyes（56.5%） in sitting position and 343 eyes（86.8%） in supine position had positive kappa angles. There were no significant differences in horizontal and vertical components of kappa angle in the sitting position or horizontal components of kappa angle in the supine position between the three groups（P 〉0.05）. A significant difference in the vertical components of kappa angle in the supine position was seen in the three groups（P 〈0.01）. Differences in both horizontal and vertical components of kappa angles were significant between the sitting and supine positions. Positive correlations in both horizontal and vertical components of kappa angles（P 〈0.05） were found and vertical components of kappa angle in sitting and supine positions were negatively correlated with the degree of myopia（sitting position： r =-0.109; supine position： r =-0.172; P 〈0.05）.·CONCLUSION： There is a correlation in horizontal and vertical components of kappa angle in sitting and supine positions. Positive correlations in both horizontal and vertical components of kappa angle in sitting and supine positions till the end of the results. This result still needs further observation. Clinicians should take into account different postures when excimer laser surgery needs to be performed.
文摘AIM:To investigate how angles kappa and alpha affect postoperative visual quality in patients with multifocal intraocular lens(mIOLs)implantation.METHODS:Retrospective cases series.A total of 46 patients(46 eyes)who underwent phacoemulsification were subsumed.The correlation between Preoperative angles kappa and alpha,wave-front aberrations and objective visual quality of cornea,internal,and total eye after surgery were analyzed using iTrace.RESULTS:The magnitude of angle kappa was negatively correlated with internal and total modulation transfer function(MTF)at 3 mm;the magnitude of angle kappa was positively correlated with astigmatism,trefoil,higher-order aberrations(HOAs)of both internal and total eye at 3 mm.The magnitude of angle alpha was negatively correlated with total MTF and total Strehl ratio at 3 mm.The magnitude of angle alpha was positively correlated with corneal coma at 5 mm,internal astigmatism at both 3 mm and 5 mm,and total spherical aberration(SA)at 3 mm.Multivariate linear regression analysis showed that,among candidate independent variables(kappa,alpha,astigmatism,SA,coma,trefoil,and HOAs),astigmatism is the only independent factor for altering corneal MTF at 3 mm and 5 mm;astigmatism and HOAs emerged as independent factors for altering internal MTF at 3 mm and 5 mm,and total MTF at 3 mm;astigmatism,SA and HOAs emerged as independent factors for altering total MTF at 5 mm.CONCLUSION:With greater preoperative angle kappa or angle alpha,patients who accept mIOL implantation tend to have larger internal astigmatism and HOAs,which resulting in poor visual quality,especially those with small pupil size.
基金Supported by 215 High Level Talent Fund of Beijing Health Government(No.2013-2-023)
文摘AIM： To evaluate and compare the uniformity of angle Kappa adjustment between Oculyzer and Topolyzer Vario topography guided ablation of laser in situ keratomileusis（LASIK） by EX500 excimer laser for myopia.METHODS： Totally 145 cases（290 consecutive eyes）with myopia received LASIK with a target of emmetropia. The ablation for 86 cases（172 eyes） was guided manually based on Oculyzer topography（study group）, while the ablation for 59 cases（118 eyes） was guided automatically by Topolyzer Vario topography（control group）. Measurement of adjustment values included data respectively in horizontal and vertical direction of cornea. RESULTS： Horizontally, synclastic adjustment between manually actual values（dx_（manu）） and Oculyzer topography guided data（dx_（ocu）） accounts 35.5% in study group, with mean dx_（manu）/dx_（ocu） of 0.78±0.48; while in control group, synclastic adjustment between automatically actual values（dx_（auto）） and Oculyzer topography data（dx_（ocu）） accounts 54.2%, with mean dx_（auto）/dx_（ocu） of 0.79±0.66. Vertically, synclastic adjustment between dy_（manu） and dy_（ocu） accounts 55.2% in study group, with mean dy_（manu）/dy_（ocu） of 0.61±0.42; while in control group, synclastic adjustment between dy_（auto） and dy_（ocu） accounts 66.1%, with mean dy_（auto）/dy_（ocu） of 0.66±0.65. There was no statistically significant difference in ratio of actual values/Oculyzer topography guided data in horizontal and vertical direction between two groups（P=0.951, 0.621）.CONCLUSION： There is high consistency in angle Kappa adjustment guided manually by Oculyzer and guided automatically by Topolyzer Vario topography during corneal refractive surgery by Wave Light EX500 excimer laser.
文摘AIM： To investigate the independent factors associated with photic phenomena in patients implanted with refractive,rotationally asymmetric,multifocal intraocular lenses（MIOLs）.METHODS： Thirty-four eyes of 34 patients who underwent unilateral cataract surgery,followed by implantation of rotationally asymmetric MIOLs were included.Distance and near visual acuity outcomes,intraocular aberrations,preferred reading distances,preoperative and postoperative refractive errors,mesopic and photopic pupil diameters,and the mesopic and photopic kappa angles were assessed.Patients were also administered a satisfaction survey.Photic phenomena were graded by questionnaire.Independent-related factors were identified by correlation and bivariate logistic regression analyses.RESULTS： The distance from the photopic to the mesopic pupil center（pupil center shift） was significantly associated with glare/halo symptoms [odds ratio（OR）=2.065,95% confidence interval（CI）=0.916-4.679,P=0.006] and night vision problems（OR=1.832,95% CI=0.721-2.158,P=0.007）.The preoperative photopic angle kappa was significantly associated with glare/halo symptoms（OR=2.155,95% CI=1.065-4.362,P=0.041）.The photopic angle kappa was also significantly associated with glare/halo symptoms（OR=2.155,95% CI=1.065-4.362,P=0.041） and with night vision problems（OR=1.832,95% CI=0.721-2.158,P=0.007） in patients implanted with rotationally asymmetric MIOLs.CONCLUSION： A large pupil center shift and misalignment between the visual and pupillary axis（angle kappa）may play a role in the occurrence of photic phenomena after implantation of rotationally asymmetric MIOLs.
文摘The human eye is an asymmetric optical system and the real cornea is not a rotationally symmetrical volume.Each optical element in the eye has its own optical and neural axes.Defining the optimum center for laser ablation is difficult with many available approaches.We explain the various centration approaches(based on these reference axes)in refractive surgery and review their clinical outcomes.The line-of-sight(LOS)(the line joining the entrance pupil center with the fixation point)is often the recommended reference axis for representing wavefront aberrations of the whole eye(derived from the definition of chief ray in geometrical optics);however pupil centration can be unstable and change with the pupil size.The corneal vertex(CV)represents a stable preferable morphologic reference which is the best approximate for alignment to the visual axis.However,the corneal light reflex can be considered as non-constant,but dependent on the direction of gaze of the eye with respect to the light source.A compromise between the pupil and CV centered ablations is seen in the form of an asymmetric offset where the manifest refraction is referenced to the CV while the higher order aberrations are referenced to the pupil center.There is a need for a flexible choice of centration in excimer laser systems to design customized and non-customized treatments optimally.
