Topographic, tomographic and biomechanical corneal changes during pregnancy in patients with keratoconus: a cohort study

PurposeThis study aimed at evaluating the effect of pregnancy on topographic, tomographic and biomechanical parameters of patients with keratoconus (KC) in comparison with non-pregnant patients with KC. MethodIn a cohort study, patients with KC, whose disease was stable for at least 2years, were evaluated before pregnancy, at their third trimester of pregnancy (34th week of pregnancy) and 6months after pregnancy. As the control group, an equivalent number of age- and severity-matched non-pregnant female patients with KC were evaluated at the corresponding times. All subjects were evaluated with respect to central and thinnest corneal thickness (CCT and TCT), keratometry values, and maximum anterior and posterior elevation measurements (AE and PE) by Pentacam. Furthermore, corneal biomechanical properties including corneal hysteresis (CH) and corneal resistance factor (CRF) were measured using the ocular response analyser. ResultsTwenty-two eyes of 11 patients were equally enrolled in each group. The results revealed that there was a statistically significant difference between the means of all measurements during the course of study (p<0.001, repeated measures analysis of variance). The values of CCT, TCT, CH, CRF, IOPg and IOPcc were significantly decreased; however, keratometry values, AE, PE and refraction measurements were significantly increased during the study period (p<0.001). In contrast, no significant differences were observed regarding the study variables in the control group (p>0.05). According to the Amsler-Krumeich classification, severity of KC increased during the pregnancy and postpregnancy periods (p=0.038). ConclusionThe obtained results revealed that KC progressed during the pregnancy period and continued to the post-partum period, indicating that pregnancy may be a risk factor for KC progression. Patients with KC, who intend to become pregnant, may consider corneal cross-linking treatment in an attempt to stop KC progression.