Correlation between corneal refractive power and anterior chamber morphology in age-related cataract patients with shallow anterior chambers

Abstract

Objective: To investigate the relationship between corneal refractive power and anterior chamber parameters in age-related cataract patients with normal axial lengths and shallow anterior chambers. Methods: Retrospective case series study. Clinical data of 627 age-related cataract patients (627 eyes) with axial lengths between 22 mm and 24 mm and anterior chamber depths less than 2.20 mm treated in the Department of Ophthalmology of Peking University International Hospital from June 2018 to October 2021 were selected. There were 215 male patients and 412 female patients, with an average age of (75±10) years. According to the average corneal refractive power, eyes were divided into groups of keratometry (K)<42 diopters (D) (50 eyes), 42 D ≤K<45 D (398 eyes) and K ≥45 D (179 eyes). Axial length, anterior chamber depth, corneal diameter, anterior chamber volume and anterior chamber angle of 3 groups were recorded, and Spearman correlation analysis was used to analyze the correlation between parameters. The differences of parameters among different groups were compared by one-way analysis of variance or Kruskal-Wallis test, and multiple or pairwise comparisons using LSD-t test or Mann-Whitney U test. Results: There was a negative correlation between axial length and corneal refractive power in 627 eyes (r=-0.62, P<0.001). Corneal refractive power was positively correlated with anterior chamber depth (r=0.26, P=0.006), while in the K≥45 D group, corneal refractive power was also positively correlated with anterior chamber depth (r=0.23, P=0.025). Anterior chamber depth [M (Q1,Q3)] was 1.77 (1.64, 1.90) mm in the K<42 D group, 1.85 (1.70, 2.14) mm in the 42 D≤K<45 D group and 2.02 (1.81, 2.18) mm in the K≥45 D group. Multiple comparisons showed that there were significant differences in anterior chamber depth between the K<42 D group and the K≥45 D group, between the 42 D≤K<45 D group and the K≥45 D group (U=14 372.00, 18 226.00; both P<0.05). There was a negative correlation between corneal refractive power and corneal diameter in 627 eyes (r=-0.52,P<0.001), while in the 42 D≤K<45 D group and the K≥45 D group, corneal refractive power were also negatively correlated with corneal diameter (r=-0.20, -0.28; both P<0.05). Corneal diameter was (11.77±0.43) mm in the K<42 D group, (11.24±0.35) mm in the 42 D≤K<45 D group and (10.90±0.33) mm in the K≥45 D group, while there were significant differences in multiple comparisons (t=1.92, 2.96, 2.01; all P<0.05). There was no correlation between corneal refractive power and anterior chamber volume, or between corneal refractive power and anterior chamber angle in 627 eyes (all P>0.05). There was no significant difference both in anterior chamber volume and in anterior chamber angle among 3 groups (all P>0.05). Conclusion: For age-related cataract patients with normal axial lengths and shallow anterior chambers, the anterior chamber depth increase and the corneal diameter decrease with the increase of corneal refractive power, but there is no significant change in anterior chamber volume and anterior chamber angle.