AIM:To evaluate the visual outcomes of implantable collamer lenses(ICLs)and identify the possible risk factors for ICL axis misalignment,and consequently,repositioning,explanting,or exchanging at a specialized eye hos...AIM:To evaluate the visual outcomes of implantable collamer lenses(ICLs)and identify the possible risk factors for ICL axis misalignment,and consequently,repositioning,explanting,or exchanging at a specialized eye hospital in Saudi Arabia.METHODS:The medical records of 813 eyes with different refractive errors corrected with ICL implantation were identified and included in this single-arm retrospective cohort study.The following data were collected:demographic characteristics,primary diagnosis,preoperative refraction,anterior chamber depth(ACD),white-to-white(WTW)measurement,endothelial cell density(ECD),and axial length.Patients’satisfaction and complaints,and their postoperative refraction,vault depth,and axis alignment with the preoperative target,were reviewed during the postoperative period.Collectively,these data were correlated with symptomatic axis rotation and the need for repositioning,explantation,or exchange due to high or low ICL vaults.RESULTS:Of 813 eyes,27(3.32%),13(1.59%),and 11(1.35%)required ICL repositioning,ICL explantation only without exchange,and ICL explantation with the placement of a new ICL,respectively.The mean follow-up period was 37.5mo.The main cause of explanation or exchange was incorrect WTW measurement in seven(29.17%)eyes,followed by high vault in four(16.56%)eyes.ICL repositioning was required in 27(3.32%)eyes with considerable rotation.Only 2(0.24%)eyes developed cataracts that required ICL removal,and retinal complications were reported in 7(0.86%)eyes.Long-term glaucoma and corneal decompensation were not observed in this cohort.CONCLUSION:With a high safety profile and reversibility,ICL implantation is a good alternative to corneal-based refractive surgery in eyes unsuitable for laser vision correction.The rate of secondary procedures in our study was 6.26%.Old age is a risk factor for secondary surgical interventions in the repositioning group,whereas abnormal vault and toric ICL rotation in the explantation group necessitated subsequent surgical procedures.Overall,ICL implantation demonstrates a good efficacy index and safety profile in patients with diverse refractive errors.展开更多
AIM： To analyze the clinical factors influencing the human vision corrections via the changing of ocular components of human eye in various applications; and to analyze refractive state via a new effective axial leng...AIM： To analyze the clinical factors influencing the human vision corrections via the changing of ocular components of human eye in various applications; and to analyze refractive state via a new effective axial length.METHODS： An effective eye model was introduced by the ocular components of human eye including refractive indexes, surface radius（r1, r2, R1, R2） and thickness（t, T） of the cornea and lens, the anterior chamber depth（S1） and the vitreous length（S2）. Gaussian optics was used to calculate the change rate of refractive error per unit amount of ocular components of a human eye（the rate function M）. A new criterion of myopia was presented via an effective axial length.RESULTS： For typical corneal and lens power of 42 and 21.9 diopters, the rate function Mj（j=1 to 6） were calculated for a 1% change of r1, r2, R1, R2, t, T（in diopters） M1=＋0.485, M2=-0.063, M3=＋0.053, M4=＋0.091, M5=＋0.012, and M6=-0.021 diopters. For 1.0 mm increase of S1 and S2, the rate functions were M7=＋1.35, and M8=-2.67 diopter/mm, respectively. These rate functions were used to analyze the clinical outcomes in various applications including laser in situ keratomileusis surgery, corneal cross linking procedure, femtosecond laser surgery and scleral ablation for accommodation.CONCLUSION： Using Gaussian optics, analytic formulas are presented for the change of refractive power due to various ocular parameter changes. These formulas provide useful clinical guidance in refractive surgery and other related procedures.展开更多
文摘AIM:To evaluate the visual outcomes of implantable collamer lenses(ICLs)and identify the possible risk factors for ICL axis misalignment,and consequently,repositioning,explanting,or exchanging at a specialized eye hospital in Saudi Arabia.METHODS:The medical records of 813 eyes with different refractive errors corrected with ICL implantation were identified and included in this single-arm retrospective cohort study.The following data were collected:demographic characteristics,primary diagnosis,preoperative refraction,anterior chamber depth(ACD),white-to-white(WTW)measurement,endothelial cell density(ECD),and axial length.Patients’satisfaction and complaints,and their postoperative refraction,vault depth,and axis alignment with the preoperative target,were reviewed during the postoperative period.Collectively,these data were correlated with symptomatic axis rotation and the need for repositioning,explantation,or exchange due to high or low ICL vaults.RESULTS:Of 813 eyes,27(3.32%),13(1.59%),and 11(1.35%)required ICL repositioning,ICL explantation only without exchange,and ICL explantation with the placement of a new ICL,respectively.The mean follow-up period was 37.5mo.The main cause of explanation or exchange was incorrect WTW measurement in seven(29.17%)eyes,followed by high vault in four(16.56%)eyes.ICL repositioning was required in 27(3.32%)eyes with considerable rotation.Only 2(0.24%)eyes developed cataracts that required ICL removal,and retinal complications were reported in 7(0.86%)eyes.Long-term glaucoma and corneal decompensation were not observed in this cohort.CONCLUSION:With a high safety profile and reversibility,ICL implantation is a good alternative to corneal-based refractive surgery in eyes unsuitable for laser vision correction.The rate of secondary procedures in our study was 6.26%.Old age is a risk factor for secondary surgical interventions in the repositioning group,whereas abnormal vault and toric ICL rotation in the explantation group necessitated subsequent surgical procedures.Overall,ICL implantation demonstrates a good efficacy index and safety profile in patients with diverse refractive errors.
基金Supported by an Internal Research of New Vision Inc.,Taipei,Taiwan
文摘AIM： To analyze the clinical factors influencing the human vision corrections via the changing of ocular components of human eye in various applications; and to analyze refractive state via a new effective axial length.METHODS： An effective eye model was introduced by the ocular components of human eye including refractive indexes, surface radius（r1, r2, R1, R2） and thickness（t, T） of the cornea and lens, the anterior chamber depth（S1） and the vitreous length（S2）. Gaussian optics was used to calculate the change rate of refractive error per unit amount of ocular components of a human eye（the rate function M）. A new criterion of myopia was presented via an effective axial length.RESULTS： For typical corneal and lens power of 42 and 21.9 diopters, the rate function Mj（j=1 to 6） were calculated for a 1% change of r1, r2, R1, R2, t, T（in diopters） M1=＋0.485, M2=-0.063, M3=＋0.053, M4=＋0.091, M5=＋0.012, and M6=-0.021 diopters. For 1.0 mm increase of S1 and S2, the rate functions were M7=＋1.35, and M8=-2.67 diopter/mm, respectively. These rate functions were used to analyze the clinical outcomes in various applications including laser in situ keratomileusis surgery, corneal cross linking procedure, femtosecond laser surgery and scleral ablation for accommodation.CONCLUSION： Using Gaussian optics, analytic formulas are presented for the change of refractive power due to various ocular parameter changes. These formulas provide useful clinical guidance in refractive surgery and other related procedures.
