Chan Colin C K, Boxer Wachler Brian S
Boxer Wachler Vision Institute, Beverly Hills, CA 90210, USA.
J Refract Surg. 2006 May;22(5):467-71. doi: 10.3928/1081-597X-20060501-08.
To analyze postoperative topographic centration when the coaxially sighted corneal light reflex was used for laser centration in hyperopic LASIK.
Centration photographs of 21 eyes (12 patients) that underwent hyperopic LASIK with centration over the coaxially sighted corneal light reflex were reviewed to determine the distance from the entrance pupil center to the coaxially sighted corneal light reflex. Postoperative ablation centration was determined topographically at day 1 and 3 months by four different methods. The difference between the actual decentration and the decentration that would have occurred had the ablation been centered over the entrance pupil center was calculated.
The mean deviation of the coaxially sighted corneal light reflex from the entrance pupil center preoperatively was 0.34 +/- 0.24 mm nasal or 4.5 +/- 3.0 degrees. At 1 day, the average decentration was 0.10 mm or 1.3 degrees temporal. The mean decentration that would have occurred if the ablation had been centered over the entrance pupil center was 0.44 mm or 5.5 degrees temporal. At 3 months, the average decentration was 0.07 mm or 0.25 degrees temporal. The mean decentration that would have occurred if the ablation had been centered over the entrance pupil center was 0.45 mm or 5.6 degrees temporal. Mean uncorrected visual acuity (logMAR) improved 3 lines from 0.54 +/- 0.14 (20/70) to 0.22 +/- 0.17 (20/32). No eye lost >2 lines of best spectacle-corrected visual acuity (BSCVA); 2 (10%) eyes lost 1 line of BSCVA at 3-month follow-up.
Excellent centration in hyperopic ablation is possible even in eyes with positive angle kappa when the ablation is centered over the corneal light reflex.
分析在远视性准分子激光原位角膜磨镶术（LASIK）中，使用同轴视轴角膜反光进行激光中心定位时的术后地形图中心定位情况。
回顾了21只眼（12例患者）接受远视性LASIK手术且以同轴视轴角膜反光进行中心定位的中心定位照片，以确定从入瞳中心到同轴视轴角膜反光的距离。在术后第1天和3个月，通过四种不同方法在地形图上确定消融中心定位情况。计算实际偏心与假设消融以入瞳中心为中心时本应出现的偏心之间的差值。
术前同轴视轴角膜反光相对于入瞳中心的平均偏移为鼻侧0.34±0.24mm或4.5±3.0度。在术后第1天，平均偏心为颞侧0.10mm或1.3度。假设消融以入瞳中心为中心时本应出现的平均偏心为颞侧0.44mm或5.5度。在术后3个月，平均偏心为颞侧0.07mm或0.25度。假设消融以入瞳中心为中心时本应出现的平均偏心为颞侧0.45mm或5.6度。平均未矫正视力（logMAR）从0.54±0.14（20/70）提高了3行至0.22±0.17（20/32）。没有眼睛最佳矫正视力（BSCVA）下降超过2行；2只眼（10%）在3个月随访时BSCVA下降了1行。
当消融以角膜反光为中心时，即使在具有正kappa角的眼中，远视性消融也可能实现极佳的中心定位。
