Tran Tu M, Mittal Aman, Naik Vihar, Chhadva Priyanka, Wade Matthew, Garg Sumit
Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN, United States.
Dean McGee Eye Institute, University of Oklahoma, Oklahoma, OK, United States.
Front Ophthalmol (Lausanne). 2023 Sep 20;3:1269439. doi: 10.3389/fopht.2023.1269439. eCollection 2023.
To determine the prevalence of subclinical keratoconus (SKCN) among individuals undergoing routine, uncomplicated age-related cataract surgery and its impact on visual and refractive outcomes.
At a major academic ophthalmology department in the United States, we reviewed records of patients aged 50 years and older who underwent surgery from January 2011 to June 2022. We excluded patients who had poor-quality or unreliable tomographic data, previous corneal surgery, keratorefractive procedures, and significant vision-limiting ocular pathology. We defined SKCN if an eye had a Belin-Ambrósio enhanced ectasia index (BAD-D) ≥1.7, which was based on the results of a meta-analysis of large studies. In addition to the BAD-D cutoff, the eye had to deviate significantly on at least one of seven additional parameters: 1) posterior elevation at thinnest point, 2) index of vertical asymmetry, 3) index of surface variation, 4) total front higher order aberrations, 5) front vertical coma, 6) front secondary vertical coma, 7) back vertical coma. An individual had SKCN if at least one eye met the tomography-based classification and did not have manifest KCN in either eye. Visual and refractive outcomes data were acquired from patients of one experienced cataract surgeon with cases done from July 2021 to June 2022. Statistical significance was set at p < 0.05.
Among 5592 eyes from 3828 individuals, the prevalence of SKCN was 24.7% (95% CI, 23.4 - 26.1, 945 individuals), and the prevalence of KCN was 1.9% (95% CI, 1.6 - 2.4, 87 individuals). The prevalence of SKCN did not increase with age and was more prevalent among females and non-white races. Median post-operative month one distance-corrected visual acuity (DCVA) and proportion of eyes with improvement in DCVA were similar between normal and SKCN eyes. The proportion of eyes reaching ±0.5 and ±1.0 diopter within the refractive target were similar between normal and SKCN eyes.
SKCN is highly prevalent and should be detected but is unlikely to have a significant deleterious effect on outcomes in routine, uncomplicated cataract surgery.
确定在接受常规、无并发症的年龄相关性白内障手术的个体中亚临床圆锥角膜（SKCN）的患病率及其对视力和屈光结果的影响。
在美国一家主要的学术眼科部门，我们回顾了2011年1月至2022年6月期间接受手术的50岁及以上患者的记录。我们排除了那些断层扫描数据质量差或不可靠、既往有角膜手术、角膜屈光手术以及有严重视力受限眼部病变的患者。如果一只眼睛的贝林 - 安布罗西奥增强扩张指数（BAD - D）≥1.7，我们将其定义为SKCN，这是基于对大型研究的荟萃分析结果。除了BAD - D临界值外，该眼睛还必须在另外七个参数中的至少一个上有显著偏差：1）最薄点处的后表面高度；2）垂直不对称指数；3）表面变化指数；4）总前高阶像差；5）前垂直彗差；6）前二级垂直彗差；7）后垂直彗差。如果至少一只眼睛符合基于断层扫描的分类且两只眼睛均无明显圆锥角膜（KCN），则个体患有SKCN。视力和屈光结果数据来自一位经验丰富的白内障外科医生在2021年7月至2022年6月期间完成的病例。统计学显著性设定为p < 0.05。
在来自3828名个体的5592只眼中，SKCN的患病率为24.7%（95%置信区间，23.4 - 26.1，945名个体），KCN的患病率为1.9%（95%置信区间，1.6 - 2.4，87名个体）。SKCN的患病率不随年龄增加，在女性和非白人种族中更为普遍。正常眼和SKCN眼术后第1个月的中位距离矫正视力（DCVA）以及DCVA改善的眼比例相似。正常眼和SKCN眼在屈光目标范围内达到±0.5和±1.0屈光度的眼比例相似。
SKCN非常普遍，应该被检测出来，但在常规、无并发症的白内障手术中不太可能对结果产生显著的有害影响。
