Keratoconus is an ectatic condition characterized by gradual corneal thinning,corneal protrusion,progressive irregular astigmatism,corneal fibrosis,and visual impairment.The therapeutic options regarding improvement o...Keratoconus is an ectatic condition characterized by gradual corneal thinning,corneal protrusion,progressive irregular astigmatism,corneal fibrosis,and visual impairment.The therapeutic options regarding improvement of visual function include glasses or soft contact lenses correction for initial stages,gas-permeable rigid contact lenses,scleral lenses,implantation of intrastromal corneal ring or corneal transplants for most advanced stages.In keratoconus cases showing disease progression corneal collagen crosslinking(CXL)has been proven to be an effective,minimally invasive and safe procedure.CXL consists of a photochemical reaction of corneal collagen by riboflavin stimulation with ultraviolet A radiation,resulting in stromal crosslinks formation.The aim of this review is to carry out an examination of CXL methods based on theoretical basis and mathematical models,from the original Dresden protocol to the most recent developments in the technique,reporting the changes proposed in the last 15y and examining the advantages and disadvantages of the various treatment protocols.Finally,the limits of non-standardized methods and the perspectives offered by a customization of the treatment are highlighted.展开更多
Purpose:To assess clinical results of the 9 mW/5.4 J/cm^(2) accelerated crosslinking(ACXL)in the treatment of progressive keratoconus(KC)over a span of 5 years.Methods:The prospective open non-randomized interventiona...Purpose:To assess clinical results of the 9 mW/5.4 J/cm^(2) accelerated crosslinking(ACXL)in the treatment of progressive keratoconus(KC)over a span of 5 years.Methods:The prospective open non-randomized interventional study(Siena Eye-Cross Study 2)included 156 eyes of 112 patients with early progressive KC undergoing the Epi-Off 9 mW/5.4 J/cm^(2) ACXL at the Siena Crosslinking Centre,Italy.The mean age was 18.05±5.6 years.The 20-min treatments were performed using the New KXL I(Avedro,Waltham,USA),10 min of 0.1%HPMC Riboflavin soaking(VibeX Rapid,Avedro,Waltham,USA)and 10 min of continuous-light UV-A irradiation.Uncorrected distance visual acuity(UDVA),corrected distance visual acuity(CDVA),Kmax,coma,minimum corneal thickness(MCT),surface asymmetry index(SAI),endothelial cell count(ECC)were measured,and corneal OCT performed.Results:UDVA and CDVA improved significantly at the 3rd(P=0.028),Δ+0.17 Snellen lines and 6th postoperative month,respectively(P<0.001),Δ+0.23 Snellen lines.Kmax improved at the 6th postoperative month(P=0.03),Δ−1.49 diopters from the baseline value.Also,coma aberration value improved significantly(P=0.004).A mild temporary haze was recorded in 14.77%of patients without affecting visual acuity and without persistent complications.Corneal OCT revealed a mean demarcation line depth at 332.6±33.6μm.Conclusion:The 5-year results of Epi-Off 9 mW/5.4 J/cm^(2) ACXL demonstrated statistically significant improvements in UCVA and CDVA,corneal curvature and corneal higher-order aberrations which confers a long-term stability for progressive ectasia.Based on the results of the Siena Eye-Cross Study 2,the 9 mW/5.4 J/cm^(2) ACXL is a candidate to be the natural evolution of Epi-Off CXL treatment for the management of early progressive corneal ectasia,and thus optimize clinic workflow.展开更多
文摘Keratoconus is an ectatic condition characterized by gradual corneal thinning,corneal protrusion,progressive irregular astigmatism,corneal fibrosis,and visual impairment.The therapeutic options regarding improvement of visual function include glasses or soft contact lenses correction for initial stages,gas-permeable rigid contact lenses,scleral lenses,implantation of intrastromal corneal ring or corneal transplants for most advanced stages.In keratoconus cases showing disease progression corneal collagen crosslinking(CXL)has been proven to be an effective,minimally invasive and safe procedure.CXL consists of a photochemical reaction of corneal collagen by riboflavin stimulation with ultraviolet A radiation,resulting in stromal crosslinks formation.The aim of this review is to carry out an examination of CXL methods based on theoretical basis and mathematical models,from the original Dresden protocol to the most recent developments in the technique,reporting the changes proposed in the last 15y and examining the advantages and disadvantages of the various treatment protocols.Finally,the limits of non-standardized methods and the perspectives offered by a customization of the treatment are highlighted.
文摘Purpose:To assess clinical results of the 9 mW/5.4 J/cm^(2) accelerated crosslinking(ACXL)in the treatment of progressive keratoconus(KC)over a span of 5 years.Methods:The prospective open non-randomized interventional study(Siena Eye-Cross Study 2)included 156 eyes of 112 patients with early progressive KC undergoing the Epi-Off 9 mW/5.4 J/cm^(2) ACXL at the Siena Crosslinking Centre,Italy.The mean age was 18.05±5.6 years.The 20-min treatments were performed using the New KXL I(Avedro,Waltham,USA),10 min of 0.1%HPMC Riboflavin soaking(VibeX Rapid,Avedro,Waltham,USA)and 10 min of continuous-light UV-A irradiation.Uncorrected distance visual acuity(UDVA),corrected distance visual acuity(CDVA),Kmax,coma,minimum corneal thickness(MCT),surface asymmetry index(SAI),endothelial cell count(ECC)were measured,and corneal OCT performed.Results:UDVA and CDVA improved significantly at the 3rd(P=0.028),Δ+0.17 Snellen lines and 6th postoperative month,respectively(P<0.001),Δ+0.23 Snellen lines.Kmax improved at the 6th postoperative month(P=0.03),Δ−1.49 diopters from the baseline value.Also,coma aberration value improved significantly(P=0.004).A mild temporary haze was recorded in 14.77%of patients without affecting visual acuity and without persistent complications.Corneal OCT revealed a mean demarcation line depth at 332.6±33.6μm.Conclusion:The 5-year results of Epi-Off 9 mW/5.4 J/cm^(2) ACXL demonstrated statistically significant improvements in UCVA and CDVA,corneal curvature and corneal higher-order aberrations which confers a long-term stability for progressive ectasia.Based on the results of the Siena Eye-Cross Study 2,the 9 mW/5.4 J/cm^(2) ACXL is a candidate to be the natural evolution of Epi-Off CXL treatment for the management of early progressive corneal ectasia,and thus optimize clinic workflow.
