Marsack Jason D, Parker Katrina E, Pesudovs Konrad, Donnelly William J, Applegate Raymond A
Visual Optics Institute, College of Optometry, University of Houston, Houston, TX 77204, USA.
Optom Vis Sci. 2007 Jun;84(6):463-70. doi: 10.1097/OPX.0b013e31802e64f0.
To examine the relationship between uncorrected residual wavefront error and visual performance (VP) in rigid gas permeable (RGP) contact lens-wearing keratoconic eyes.
Seven eyes from six subjects (six moderate, one severe) were studied (mean +/- SD age: 42.71 +/- 11.38 years). Significant corneal scarring was an exclusion criterion. Measurements were taken with RGP lenses in place. After pupil dilation, the VP measures of high contrast logMAR visual acuity (VA) and Pelli-Robson contrast sensitivity (PRCS) were measured through a 5-mm artificial pupil. Wavefront error was measured using a Shack-Hartmann wavefront sensor and calculated over 5 mm. For both VP and wavefront error, comparisons were made to previously collected normal values by calculating the interval encompassing 95% of normals, then reporting how many of the seven keratoconic eyes fell outside the normal interval. Additionally, second to sixth order aberrations were processed into four previously reported image quality metrics: root mean square of the wavefront (RMSw), root mean square of the slope (RMSs), average blur strength (Bave) and diameter containing 50% light energy (D50) and regressed against VP measures.
Five of seven keratoconic eyes fell outside the normal interval (-0.23 to 0.09) for VA and two of seven fell outside the normal interval (1.59 to 2.03) for PRCS. Five of seven keratoconic eyes fell outside the normal interval (0.07 to 0.35 microm) for total higher order RMS. Linear regressions demonstrated relationships between both VA and PRCS and the image quality metrics RMSw, D50, RMSs, and Bave with R values for VA = 0.30, 0.30, 0.47, 0.62, and PRCS = 0.21, 0.15, 0.45, 0.75 respectively.
VP in RGP-wearing keratoconic eyes is reduced and higher order wavefront aberrations are elevated compared to normals. Metrics of retinal image quality demonstrate a relationship between keratoconic VP and residual wavefront aberrations. This relationship suggests developing corrections that more completely correct aberrations may improve visual performance in keratoconus.
研究佩戴硬性透气性（RGP）隐形眼镜的圆锥角膜眼中未矫正的残余波前像差与视觉性能（VP）之间的关系。
对6名受试者（6例中度，1例重度）的7只眼睛进行研究（平均±标准差年龄：42.71±11.38岁）。显著的角膜瘢痕是排除标准。在佩戴RGP镜片的情况下进行测量。瞳孔散大后，通过5毫米人工瞳孔测量高对比度对数最小分辨角视力（VA）和佩利-罗布森对比敏感度（PRCS）的VP指标。使用夏克-哈特曼波前传感器测量波前像差，并计算5毫米范围内的数值。对于VP和波前像差，通过计算包含95%正常范围的区间，然后报告7只圆锥角膜眼中有多少只超出正常区间，与先前收集的正常值进行比较。此外，将二阶至六阶像差处理为四个先前报道的图像质量指标：波前均方根（RMSw）、斜率均方根（RMSs）、平均模糊强度（Bave）和包含50%光能的直径（D50），并与VP指标进行回归分析。
7只圆锥角膜眼中，5只的VA超出正常区间（-0.23至0.09），7只中的2只PRCS超出正常区间（1.59至2.03）。7只圆锥角膜眼中，5只的总高阶RMS超出正常区间（0.07至0.35微米）。线性回归显示VA和PRCS与图像质量指标RMSw、D50、RMSs和Bave之间存在关系，VA的R值分别为0.30、0.30、0.47、0.62，PRCS的R值分别为0.21、0.15、0.45、0.75。
与正常人相比，佩戴RGP的圆锥角膜眼的VP降低，高阶波前像差升高。视网膜图像质量指标显示圆锥角膜VP与残余波前像差之间存在关系。这种关系表明，开发能更完全矫正像差的矫正方法可能会改善圆锥角膜的视觉性能。
