Prevalence of Corneal Astigmatism and Anterior Segmental Biometry Characteristics Before Surgery in Chinese Congenital Cataract Patients

Abstract

The prevalence and the distribution characteristics of corneal astigmatism (CA) and anterior segment biometry before surgery in Chinese congenital cataract (CC) patients are not completely understood. This study involved 400 CC patients from the Zhongshan Ophthalmic Center enrolled from February 2011 to August 2015. Data on CA, keratometry, central corneal thickness (CCT) and anterior chamber depth (ACD) were measured by the Pentacam Scheimpflug System. The mean age of patients was 54.27 months, and the ratio of boys to girls was 1.53:1. The mean CA was 2.03 diopters (D), and 39.25% of subjects had CA values ≥2 D. The most frequent (71.8%) diagnosis was with-the-rule astigmatism. Oblique astigmatism was present in 16.2% of cases, and 12% of cases had against-the-rule astigmatism. The mean keratometry measurement of cataractous eyes in bilateral patients was significantly larger than that in unilateral patients. Girls had a larger mean keratometry but a thinner CCT than did boys. The CA, CCT, and ACD of cataractous eyes were significantly larger than those of non-cataractous eyes in unilateral patients. The CA, mean keratometry, CCT, and ACD in CC patients varied with age, gender, and laterality. Fully understanding these characteristics may help inform guidelines and treatment decisions in CC patients.

Figure 1. Distribution of corneal astigmatism in CC patients.

Corneal astigmatism in CC patients largely (78.5%, 314/400) fell between 0.5 and 3 D. CC: congenital cataract; D: diopters.

Figure 2. Constitution of the type of corneal astigmatism in CC patients.

With-the-rule corneal astigmatism predominated among pediatric CC patients. CC: congenital cataract.

Figure 3. Scatterplots of age versus the mean keratometry value of all eyes.

Panel (A) The trend line shows a linear decline in mean keratometry during the first 6 months of life. Panel (B) No significant change was found in the keratometry value with increasing age beyond 6 months. D: diopters.

Figure 4. Scatterplots of mean keratometry, CA, CCT, and ACD in relation to age.

Panel (A) (mean keratometry versus age), Panel (B) (CA versus age) and Panel (C) (CCT versus age) show little relationship between the respective variables and age. Panel (D) illustrates a logarithmic relationship between ACD and age. D: diopters; CA: anterior corneal astigmatism; CCT: central corneal thickness; ACD: anterior chamber depth.