| ObjectiveTo evaluate the safety and efficacy of epi-off accelerated corneal cross-linking(UVA parameters:30mW/cm2 × 4min,7.2J/cm2)for progressive keratoconus.MethodsThis was a prospective,uncontrolled,interventional case series.60 eyes of 46 patients from September 2016 to September 2017 who received A-CXL in our center were recruited in this study.The visual acuity including UCVA and BCVA,diopter of spherical power(SD),diopter of cylindrical power(CD),endothelial cell count,corneal topography parameters,and corneal biomechanical parameters were examined preoperatively and postoperative 1 week,1,3,6,12 months,respectively.Anterior Segment Optical Coherence Tomography(AS-OCT)was performed 1 month postoperatively.ResultsThis study involved 35 patients(48 eyes)who completed thorough reviews,including 24 males(68.57%)and 11 females(31.43%).Male:female>2.whereas the remaining 11 patients(12 eyes)were not included due to the inability of regular reviews.The pre-operative and post-operative 1 week,1,3,6 and 12 month uncorrected visual acuity(LogMAR)were 0.70±0.20,0.73±0.20,0.64±0.19,0.63±0.21,0.57±0.20 and 0.56±0.20,respectively(P<0.01),the best corrected visual acuity(LogMAR)were 0.38±0.23,0.34±0.20,0.31±0.18,0.23±0.14,0.21±0.14,and 0.16±0.09,respectively(P<0.01).The SD at 1 week,1 month and 3 months after surgery were smaller than that before operation,but there was no statistical difference(P>0.05).The median of preoperative spherical power diopter(SD)was-5.00D,and it were-5.00D?-5.00D?-5.13D?-5.00D and-5.13D at 1 week,1 month,3 months,6 months and 12 months after surgery,respectively.The SD at 1 week,1 month and 3 months after surgery were smaller than that before operation,but there was no statistical difference(P>0.05).However,the SD at post-operative 6 months and 12 months were significantly lower than that before surgery(P<0.01).The median of cylindrical power diopter(CD)before operation was-5.63D,and it decreased to-5.00D,-4.75D,-5.00D,-4.87D and-4.50D at 1 week,1 months 3 months,6 months and 12 months after operation,respectively(P<0.01).The median of thinnest corneal thickness(TCT)before operation was 450.50?m,which decreased to 444.50?m at 1 month,445.50?m at 3 months and 447.00?m at 6 months after surgery,respectively(P<0.01).The median of maximum corneal curvature(Kmax)was 56.95D before operation.Post-operative median of Kmax values decreased to 55.70D,55.65D,55.20D,55.10D and 55.20D at 1 week,1 month,3 month,6 month and 12 month,respectively(P<0.01).No considerably differences were observed in corneal endothelial cell counts(P>0.05).Comparative analyses showed a rise of corneal stiffness demonstrated by a significant increase of Stiffness Parameter Applanation 1(SP-A1)and significant decreases of both Inverse Concave Radius(1/R)and Deformation Amplitude Ratio(DA Ratio)(P<0.05).40 eyes(83.33%)showed transient irritation after surgery.Five eyes(10.42%)showed mild corneal haze.No serious intraoperative and postoperative complications were observed.ConclusionsThe A-CXL protocol can enhance vision acuity and reduce corneal curvature,as well as improving biomechanical stability for progressive keratoconus with great safety and efficacy.Further observation is needed for long term effectiveness. |
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