Modelling ocular ageing in adults with well-controlled type I diabetes

To develop a paraxial eye model based on a previously collected cohort of adults with well-controlled type 1 diabetes mellitus (DM1) and a limited range of refractive errors.

The study used the previously published biometric data of 72 participants (Age: 41.5 ​± ​12.4 years) with DM1. Measurements included objective refraction, anterior and posterior corneal radii of curvatures, and internal distances. Moreover, phakometry was used to determine the lens radii of curvature and lens equivalent indices, from which the lens powers were calculated. A multivariate linear regression was performed for each biometric parameter with respect to current age (Age), the time since the onset of diabetes (T_db), and current levels of glycated hemoglobin (HbA1c). The vitreous chamber depth was determined from other distances, and lens equivalent index was chosen to balance the models. These were compared with an existing model for non-diabetic eyes.

Some dependent parameters were not affected by the independent variables (spherical equivalent, anterior corneal radius of curvature, central corneal thickness), some were affected by time since onset (the lens radii of curvatures, anterior chamber depth) and others were affected by both age and time since onset (posterior corneal radius of curvature, lens thickness, axial length). None of the dependent parameters were affected by current levels of HbA1c.

The proposed model accurately describes the age-related changes in the eyes of people with DM1. In this description the age of diabetes onset plays an important role, especially if the diabetes onset occurred during childhood.