Nguyen Lan Chi, Hastings Gareth D, Kauffman Matthew J, Applegate Raymond A, Marsack Jason D
Visual Optics Institute, College of Optometry, University of Houston, 4901 Calhoun Rd, Houston, TX 77204 USA.
Cont Lens Anterior Eye. 2020 Dec;43(6):613-616. doi: 10.1016/j.clae.2020.02.006. Epub 2020 Mar 4.
To demonstrate the necessity of aligning a wavefront-guided scleral lens (WGSL) optical correction to the eye's effective pupil, with misalignments leading to reduced performance.
A 34 year old subject with a history of failed LASIK in the left eye, leading to penetrating keratoplasty, extracapsular extraction of the crystalline lens and neodymium:yttrium-aluminum-garnet (Nd:YAG) laser posterior capsulotomy, enrolled in a study examining WGSL performance. Habitual logMAR acuity OS (aided with a scleral lens) was +0.04. Residual higher order root mean square (HORMS) wavefront error (WFE) was 0.28 μm (Φ =4.75 mm, mean age-matched norm =0.17 μm), and objective over-refraction was -0.30 -0.54 × 008. When a WGSL (targeting aberrations up to the 5 th radial order) was manufactured with the wavefront-guided optics aligned to the center of the dilated pupil, logMAR acuity worsened to +0.15, residual HORMS WFE worsened to 0.44 μm (Φ =4.75 mm), and objective over-refraction increased to +1.19 -0.30 × 122. Slit lamp imagery revealed that the effective pupil was no longer defined by the iris of the eye, but rather the capsular opening created by the capsulotomy. When the WGSL was redesigned to align the wavefront-guided optics to the center of the capsular opening, logMAR acuity improved to -0.14, residual HORMS WFE reduced to 0.17 μm (Φ =4.75 mm) and objective over-refraction reduced to +0.20 -0.15 × 111.
WGSLs are an emerging option for patients with highly aberrated, ectatic and post-surgical corneas whose visual symptoms cannot be alleviated with conventional corrections. However, alignment of the optics of the WGSL to the underlying optics of the eye over the effective pupil is critical in achieving good optical and visual performance.
证明将波前引导巩膜镜(WGSL)的光学矫正与眼睛的有效瞳孔对齐的必要性,因为未对齐会导致性能下降。
一名34岁的受试者,左眼有准分子激光原位角膜磨镶术(LASIK)失败史,导致穿透性角膜移植术、晶状体囊外摘除术和钕:钇铝石榴石(Nd:YAG)激光后囊切开术,参与了一项研究WGSL性能的试验。其左眼习惯对数最小分辨角视力(借助巩膜镜)为+0.04。残余高阶均方根(HORMS)波前像差(WFE)为0.28μm(Φ = 4.75mm,年龄匹配的正常均值 = 0.17μm),客观验光为 -0.30 -0.54×008。当制造一个波前引导光学系统与散瞳中心对齐的WGSL(针对高达5阶径向像差)时,对数最小分辨角视力恶化至+0.15,残余HORMS WFE恶化至0.44μm(Φ = 4.75mm),客观验光增加至+1.19 -0.30×122。裂隙灯图像显示,有效瞳孔不再由眼睛的虹膜界定,而是由囊切开术形成的囊膜开口界定。当重新设计WGSL以使波前引导光学系统与囊膜开口中心对齐时,对数最小分辨角视力改善至 -0.14,残余HORMS WFE降至0.17μm(Φ = 4.75mm),客观验光降至+0.20 -0.15×111。
对于角膜高度像差、扩张性和术后角膜且常规矫正无法缓解视觉症状的患者,WGSL是一种新兴的选择。然而,将WGSL的光学系统与眼睛在有效瞳孔上的基础光学系统对齐对于实现良好的光学和视觉性能至关重要。