Keratoconus: a potential risk factor for osteoarthritis

This study was undertaken to compare the distal femoral cartilage thickness in patients with keratoconus (KC) with that of age- and sex-matched healthy controls, in order to identify a potential risk factor for early osteoarthritis in patients with KC and to allow initiation of early rehabilitation.

Thirty-six KC patients between 18 and 35 years of age and 36 healthy controls were included in this study. Keratometry readings (K1, K2), central corneal thickness (CCT), anterior chamber depth (ACD), iridocorneal angle (ICA), and corneal volumes (CV) were measured using a Sirius imaging system (Costruzioni Strumenti Oftalmici, Italy). Also, the distal femoral cartilage thickness (DFCT) was assessed bilaterally using ultrasound by the same physiatrist. Lateral femoral condyle (LFC), intercondylar area (ICA), medial femoral condyle (MFC), and body mass index (BMI) values were recorded.

Patient and control groups were comparable in terms of age, gender, and BMI. On the other hand, patients with KC had a significant reduction in right LFC, MFC thickness and left ICA, MFC as compared to controls (p < 0.05). In the corneal topographic evaluation of the groups, it was observed that K₁, K₂, CCT, and ACD values differed significantly.

Detection of thinner DFCT in KC patients suggests that these patients may be future candidates of osteoarthritis.