Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, 200031, China.
NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, 83 Fenyang Road, Shanghai, 200031, China.
BMC Ophthalmol. 2024 Oct 18;24(1):458. doi: 10.1186/s12886-024-03695-0.
To compare the characteristics of the quantitative contrast sensitivity function (qCSF) in eyes with early keratoconus (Early-KC) and normal control (NC) eyes and investigate the associated factors.
A cross-sectional study.
This study included 43 eyes of 43 patients with Early-KC (including subclinical keratoconus [SKC] and forme fruste keratoconus [FFKC]) and 77 NC eyes of 77 participants with corrected distance visual acuity (CDVA) all ≥ 20/20. Contrast sensitivity (CS) was assessed using the qCSF tests. Subgroup analysis was performed according to keratoconus type(SKC and FFKC) and astigmatism(cylindrical refraction >-1.0D or ≤-1.0D).
Sex ratio, spherical refraction, and spherical equivalent (SE) varied significantly between the two groups (all P < 0.01). The area under log CSF (AULCSF), CSF Acuity, and CS at low (1.0 and 1.5 cycles per degree [cpd]) and high (12.0 and 18.0 cpd) spatial frequencies decreased significantly in the Early-KC group than that in the NC group (all P < 0.05). The subgroup analysis revealed a similar decrease in the SKC group (all P < 0.05). AULCSF, CSF Acuity, and CS at high spatial frequencies of patients with cylindrical refraction ≤-1.0D in the Early-KC group decreased significantly (all P < 0.05) than those in the NC group. The index of vertical asymmetry and index of height decentration correlated negatively with CS at 1.5 cpd (r= -0.321 and -0.306; both P < 0.05).
CS decreased significantly at low and high spatial frequencies in Early-KC, though with normal CDVA. The qCSF test can sensitively reflect visual performance in early keratoconus.
比较早期圆锥角膜（早期 KC）患者和正常对照（NC）患者定量对比敏感度函数（qCSF）的特征，并探讨相关因素。
横断面研究。
本研究纳入 43 例（43 只眼）早期 KC 患者（包括亚临床型圆锥角膜[SKC]和顿挫型圆锥角膜[FFKC]）和 77 例 NC 患者（77 只眼），所有患者的矫正远视力（CDVA）均≥20/20。使用 qCSF 测试评估对比敏感度（CS）。根据圆锥角膜类型（SKC 和 FFKC）和散光（散光值>-1.0D 或≤-1.0D）进行亚组分析。
两组患者的性别比例、球镜屈光度和等效球镜（SE）差异均有统计学意义（均 P < 0.01）。早期 KC 组的对数 CSF 曲线下面积（AULCSF）、CS 敏锐度和低空间频率（1.0 和 1.5 周/度）及高空间频率（12.0 和 18.0 周/度）的 CS 均显著低于 NC 组（均 P < 0.05）。亚组分析显示 SKC 组也存在类似的下降（均 P < 0.05）。早期 KC 组中散光值≤-1.0D 的患者的 AULCSF、CS 敏锐度和高空间频率的 CS 均显著降低（均 P < 0.05）。垂直不对称指数和高度偏心指数与 1.5 cpd 的 CS 呈负相关（r= -0.321 和 -0.306；均 P < 0.05）。
尽管 CDVA 正常，但早期 KC 患者的低空间频率和高空间频率的 CS 显著降低。qCSF 测试可敏感地反映早期圆锥角膜患者的视觉表现。
