Topographic and Biomechanical Characteristics of Cornea in Patients with Angioid Streaks

Purpose: To evaluate corneal biomechanics obtained with Corvis ST and topographic characteristics of the cornea measured with Pentacam topography in individuals with angioid streaks and to compare them with healthy subjects. Methods Thirty-six eyes of 18 patients with angioid streaks (study group) and 46 eyes of 23 healthy subjects (control group) were included in the study. Corneal topography with Pentacam was performed and the parameters obtained were as follows; flattest keratometry, steepest keratometry, mean keratometry, maximum keratometry, topographic cylinder value, central corneal thickness, and total deviation value of Belin-Ambrósio enhanced ectasia display. The biomechanical parameters, IOP with non-contact tonometer (IOPnct), and biomechanical corrected IOP (bIOP) were measured with Corvis ST. Results All topographic parameters were comparable between the study and control groups (all P > 0.05). Corneal ectasia was not observed in any patient. In patients with angioid streaks, statistically significant longer applanation 1 (A1) time, lower A2 velocity, lower deformation amplitude (DA) and DA ratio (2 mm), higher stiffness parameter A1, and lower Corvis biomechanical index (CBI) values indicated higher corneal stiffness compared to the control group (all P < 0.05). IOPcnt value was significantly increased in the study group, while the bIOP value was similar in both groups (P = 0.041, and P = 0.075, respectively). Conclusions Normal corneal topographic properties and increased corneal stiffness have been demonstrated in eyes with angioid streaks. These findings may be crucial in patients with angioid streaks when planning corneal refractive surgery or when precise IOP measurement is needed for the diagnosis or follow-up of glaucoma.