Structural and Biomechanical Corneal Differences between Type 2 Diabetic and Nondiabetic Patients

Abstract

Purpose. To analyze and compare corneal structural and biomechanical properties, characterized by corneal hysteresis (CH) and resistance factor (CRF), between patients with and without type 2 diabetes mellitus (DM), and determine the main ocular variables that influence them. Methods. Sixty diabetic and 48 age- and sex-matched non-DM patients were enrolled in this cross-sectional study. The DM group was analyzed according to DM duration (<or ≥ 10 years), HbA1c levels (<or ≥ 7%), and presence of retinopathy. CH and CRF were evaluated using the Ocular Response Analyzer® (ORA). Central corneal thickness (CCT) was determined by Scheimpflug tomography (Pentacam® HR). Intraocular pressure was obtained with ORA (IOPcc) and Goldmann applanation tonometry (IOP-GAT). Univariate and multivariate linear regression analyses were performed to evaluate the relationship between demographical, clinical, and ocular variables with the biomechanical properties. Results. There were no statistically significant differences in the CH and the CRF between DM and non-DM groups (p=0.637 and p=0.439, respectively). Also, there was no statistical difference between groups for the CCT, IOPcc, or IOP-GAT. Multivariate linear regression analysis showed that CH was positively associated with CCT (p<0.001) and negatively associated with IOPcc (p<0.001), while CRF was positively associated with CCT (p<0.001) and IOPcc (p=0.014). Conclusion. The CCT and IOPcc were found to be the main parameters that affect corneal biomechanical properties both in diabetics and controls. In this study, there was no significant effect of DM type 2 on corneal biomechanics.

Intraocular Pressure and Anterior Segment Morphometry Changes after Uneventful Phacoemulsification in Type 2 Diabetic and Nondiabetic Patients

“…Full inclusion criteria are described elsewhere [16]. The exclusion criteria included prior eye surgery or trauma; any eye corneal, retinal or optic nerve pathology except DR; mature cataracts (brown/white) [17]; Goldmann applanation tonometry (IOP-GAT) > 25 mmHg; preoperative ACA in Scheimpflug tomography <20°; pseudoexfoliation syndrome; and current treatment with any form of steroids.…”

“…Diabetic patients were excluded from the analysis if they had severe nonproliferative diabetic retinopathy (NPDR), proliferative DR (PDR), or diabetic macular edema (DME). No cases of intraoperative complications or use of adjunctive procedures (e.g., adjuvant intravitreal treatment with anti-VEGF or steroids) were included [16].…”

“…Measurements were repeated as necessary until high-quality images were obtained. All measurements were performed by an experienced operator (JB) under standard dim light conditions, without cyclopegia, and the patients were told to blink immediately before each examination [16].…”

<p>Evaluation of Corneal Structure and Endothelial Morphological Characteristics in Type 2 Diabetic and Non-Diabetic Patients</p>

“…Caucasian type 2 diabetic patients and controls, aged 50 or older, scheduled for cataract surgery between September 2015 and March 2016 were invited to participate. Full selection criteria are described elsewhere; 17 but in short, DM diagnosis was confirmed by medical history and glycated hemoglobin (HbA1c) levels ≥ 6.5%. The exclusion criteria included the presence of any ocular disease, except cataract and DR (however, patients with eyes with uncontrolled complications of proliferative DR and/or white/brown cataracts were excluded); prior eye surgery (except for intravitreal treatment > 120 days or laser photocoagulation > 90 days before surgery of diabetics); axial length [AL] > 26 mm or refractive error > 6 diopters of spherical equivalent; wearing of contact lenses; pseudoexfoliation syndrome; systemic connective tissue diseases; and current treatment with glucocorticoids.…”

Visual Outcomes, Quality of Life and Satisfaction After Phacoemulsification in Patients With Type 2 Diabetes Mellitus and Patients Without Diabetes

“…Caucasian patients with type 2 DM and controls, aged 50 or older, were included. Full selection criteria are described elsewhere (11); succinctly, DM diagnosis was con rmed by medical history and glycated hemoglobin (HbA1c) levels ≥ 6.5% . The exclusion criteria included the presence of any ocular disease, except cataract and DR (however, patients were excluded if presented white/brown cataracts and/or uncontrolled complications of proliferative DR, such as, neovascular glaucoma, vitreous hemorrhage or tractional retinal detachment); prior ocular surgery (except for intravitreal treatment ≥ 120 days or laser photocoagulation ≥ 90 days before surgery); and current treatment with glucocorticoids.…”