Shetty Rohit, Pahuja Natasha, Roshan Thimmarayappa, Deshmukh Rashmi, Francis Mathew, Ghosh Arkasubhra, Sinha Roy Abhijit
J Refract Surg. 2017 Oct 1;33(10):676-682. doi: 10.3928/1081597X-20170621-07.
To evaluate the performance of different customized corneal cross-linking (CXL) methods.
This was a single-center interventional, prospective, longitudinal case series. Four different customized CXL methods were evaluated in keratoconic eyes: (1) uniform (uniform intensity ultraviolet-A [UVA] beam [9 mW/cm] for 10 minutes) (n = 12 eyes); (2) sector axial map (sector-based UVA irradiation) (n = 12 eyes); (3) ring axial map (concentric rings of UVA beam intensity centered at the steepest curvature of the anterior axial map) (n = 12 eyes); and ring tangential map (same as the ring axial map but centered at the steepest curvature of the anterior tangential map) (n = 14 eyes). Peak UVA energy density in the sector and ring axial map (and ring tangential map) protocols did not exceed 15.0 and 10.8 J/cm, respectively. A 0.1% riboflavin solution was applied after epithelium removal. Corneal tomography and visual acuity were assessed before and 6 months after CXL.
Average and peak energy density was lowest in the ring tangential protocol and highest in the sector axial map group (P < .001). Treated area was lowest in the ring tangential map group and highest in the uniform group (P < .001). Decrease in curvature was similar among the uniform, sector axial map, and ring axial map groups (P < .05). The ring tangential map group had the greatest decrease in curvature per unit energy dose to the cornea (P < .05). Improvement in uncorrected (0.081 ± 0.056 logMAR) and corrected (0.041 ± 0.026 logMAR) distance visual acuity per unit energy density was greatest in the ring tangential map group (P > .05).
When normalized to the average energy density, the ring tangential map protocol appeared to provide maximum flattening and improvement in visual acuity. Further studies with larger sample sizes are needed to validate the findings of this pilot study. [J Refract Surg. 2017;33(10):676-682.].
评估不同定制角膜交联（CXL）方法的性能。
这是一项单中心干预性、前瞻性、纵向病例系列研究。在圆锥角膜眼中评估了四种不同的定制CXL方法：（1）均匀照射（均匀强度的紫外线A [UVA]光束[9 mW/cm]照射10分钟）（n = 12只眼）；（2）扇形轴向图（基于扇形的UVA照射）（n = 12只眼）；（3）环形轴向图（以轴向地形图最陡曲率为中心的UVA光束强度同心圆）（n = 12只眼）；以及环形切线图（与环形轴向图相同，但以前切线图最陡曲率为中心）（n = 14只眼）。扇形和环形轴向图（以及环形切线图）方案中的峰值UVA能量密度分别不超过15.0和10.8 J/cm²。去除上皮后应用0.1%核黄素溶液。在CXL术前和术后6个月评估角膜地形图和视力。
环形切线方案中的平均和峰值能量密度最低，扇形轴向图组最高（P <.001）。治疗面积在环形切线图组中最低，在均匀照射组中最高（P <.001）。均匀照射组、扇形轴向图组和环形轴向图组的曲率降低相似（P <.05）。环形切线图组每单位角膜能量剂量的曲率降低最大（P <.05）。每单位能量密度下，环形切线图组的未矫正（0.081±0.056 logMAR）和矫正（0.041±0.026 logMAR）远视力改善最大（P>.05）。
以平均能量密度归一化后，环形切线图方案似乎能提供最大的角膜变平和视力改善。需要更大样本量的进一步研究来验证这项初步研究的结果。[《屈光手术杂志》。2017；33（10）：676 - 682。]
