Lisa C, Fernández-Vega Cueto L, Poo-López A, Madrid-Costa D, Alfonso José F
*Instituto Universitario Fernández-Vega, Fundación de Investigación Oftalmológica, Universidad de Oviedo, Oviedo, Spain; and †Optics II Department, Faculty of Optics and Optometry, Universidad Complutense de Madrid, Madrid, Spain.
Cornea. 2017 Nov;36(11):1325-1330. doi: 10.1097/ICO.0000000000001339.
To assess the long-term outcomes of implanting intrastromal corneal ring segments (ICRSs) to correct central keratoconus with a high corneal asphericity value.
Forty-three eyes with central keratoconus with a corneal asphericity value ≥-1.00 were evaluated before and after implanting an inferior 210-degree arc-length Ferrara-type AFR5 ICRS (AJL Ophthalmic, Spain). Logarithm of the minimum angle of resolution uncorrected (UDVA) and best-corrected (CDVA) distance visual acuity, corneal asphericity, root mean square for coma-like aberrations [computed for the Zernike terms Z (3, 1) and Z (3, -1)], and residual refractive errors analyzed using vector analysis were recorded before and at all follow-up visits. The postoperative follow-up duration was 3 years in all cases.
Mean UDVA (logarithm of the minimum angle of resolution scale) rose from 1.18 ± 0.59 to a postoperative 0.53 ± 0.39 after ICRS implantation (P < 0.0001). Mean CDVA varied in turn from 0.36 ± 0.18 to 0.17 ± 0.10 (P < 0.0001). CDVA remained unchanged or improved in all eyes after surgery. Both UDVA and CDVA were stable over the postoperative period (P > 0.05). The spherical equivalent declined steeply after ICRS implantation (P < 0.0001). Both spherical equivalent and refractive cylinder were stable over the postoperative period. The corneal asphericity and root mean square values for coma-like aberrations exhibited statistically significant decreases 6 months after ICRS implantation (P < 0.0001) and were also stable over postoperative follow-up (P > 0.05).
These results suggest that implanting a single, inferior, 210-degree arc-length Ferrara-type ICRS is a safe, effective, and stable procedure for treating patients with central hyperprolate keratoconus.
评估植入基质内角膜环片（ICRS）矫正具有高角膜非球面性值的中央圆锥角膜的长期效果。
对43只中央圆锥角膜且角膜非球面性值≥ -1.00的眼睛，在植入下方210度弧长的费拉拉型AFR5 ICRS（AJL Ophthalmic，西班牙）前后进行评估。记录未矫正的最小分辨角对数（UDVA）和最佳矫正的距离视力（CDVA）、角膜非球面性、类彗差的均方根[针对泽尼克项Z(3, 1)和Z(3, -1)计算]，以及在所有随访时使用矢量分析的残余屈光不正。所有病例的术后随访时间为3年。
ICRS植入后，平均UDVA（最小分辨角对数尺度）从1.18 ± 0.59提高到术后的0.53 ± 0.39（P < 0.0001）。平均CDVA依次从0.36 ± 0.18变为0.17 ± 0.10（P < 0.0001）。术后所有眼睛的CDVA保持不变或有所改善。术后期间UDVA和CDVA均稳定（P > 0.05）。ICRS植入后等效球镜急剧下降（P < 0.0001）。等效球镜和屈光柱镜在术后期间均稳定。ICRS植入后6个月，角膜非球面性和类彗差的均方根值呈现统计学上的显著下降（P < 0.0001），并且在术后随访期间也稳定（P > 0.05）。
这些结果表明，植入单个下方210度弧长的费拉拉型ICRS是治疗中央高前突圆锥角膜患者的一种安全、有效且稳定的方法。
