Fuchs endothelial corneal dystrophy and small eyes
Aim: To determine whether there is an association between Fuchs endothelial corneal dystrophy (FECD) and shorter axial length (AL), shallower anterior chamber depth (ACD) and higher spherical equivalent (SE). In addition, to evaluate whether there is a correlation between AL and severity of corneal decompensation in FECD, using corneal thickness as a proxy.
Design: Retrospective cohort study.
Methods: This was a single-centre study conducted in a cornea clinic in Sydney, Australia. Detailed clinical measurements of 91 eyes of 50 FECD patients were compared with 110 eyes of 55 controls. Main outcome measures included AL, ACD and SE. Other outcome measures included central corneal thickness, visual acuity, intraocular pressure and keratometry.
Results: Mean AL of FECD patients was 23.6 mm (standard deviation [SD] ±0.9 mm), compared with 24.7 mm (SD ±1.8 mm) for controls (1.1 mm difference [95% confidence interval [CI] 0.5-1.6], p < 0.001, independent sample t-test); corresponding means for ACD were 3.0 and 3.3 mm (0.32 mm difference [95%CI 0.2-0.5], p < 0.001, independent t-test). Eleven out of the 22 FECD patients with available refraction data had hypermetropic refraction compared with 16 out of 36 controls (p = 0.68, chi-squared test). The mean SE of FECD patients (+0.10D) was higher than controls (−1.33D) (1.4D difference [0.1-2.8], p = 0.04, independent t-test). No statistically significant correlation was found between AL and corneal thickness (p = 0.28, linear regression).
Conclusion: In this retrospective cohort study, a strong association was established between FECD and small eyes, with shorter AL and shallower ACD, compared with controls. These results have important implications for surgical planning, as shorter AL and ACD in FECD patients likely contribute to their high risk of corneal decompensation following cataract surgery.