Choroidal Assessment in Patients with Type 2 Diabetes Mellitus and Non-Proliferative Diabetic Retinopathy by Swept-Source Ocular Coherence Tomography and Image Binarization

Background and Objectives: The aim of this study was to evaluate choroidal structure and vascularity indices in patients with non-proliferative diabetic retinopathy (NPDR). Materials and Methods: Sixty-three eyes from sixty-three patients were evaluated: 21 from healthy subjects, 20 with diabetes mellitus (DM) and no diabetic retinopathy (DR), and 22 with DM and non-proliferative diabetic retinopathy without diabetic macular edema (DME). Each patient underwent ocular examination, macular swept-source ocular coherence tomography (SS-OCT) imaging, glycemic control, and systemic high blood pressure (HBP) evaluation. Subfoveal choroidal thickness (SF-CT) was manually assessed on a line scan. Line scan OCT images were exported to ImageJ program. The areas under a 1.5, 3 and 6 mm horizontal line centered on the fovea were assessed by converting the OCT images to binary images, and total choroidal area (TCA), luminal area (LA), stromal area (SA), LA:SA ratio, and choroidal vascularity index (CVI) were evaluated. SF-CT and choroidal parameters were compared between groups, and correlations with ocular and systemic factors were analyzed. Results: SF-CT, TCA, LA, and SA were similar between groups. CVIs were significantly different between groups for all three studied areas (CVI-1.5: 66.21% vs. 66.06% vs. 63.74%, p = 0.003; CVI-3: 65.88% vs. 66.46% vs. 63.79%, p = 0.008; CVI-6: 64.79% vs. 65.40% vs. 63.61%, p = 0.032). NPDR patients had significantly lower CVIs compared to DM patients (p < 0.05). No association of choroidal parameters with glycemic control, DM duration and HBP was found significant (p < 0.05). Conclusions: Choroidal assessment by SS-OCT and image binarization in healthy subjects, subjects with DM without DR, and subjects with DM and NPDR indicated that CVI changes were identifiable and significant in early DR. The lack of association with ocular and systemic factors suggest that CVIs are reliable assessment parameters of choroidal vascular structure

Assessing Changes in Diabetic Retinopathy Caused by Diabetes Mellitus and Glaucoma Using Support Vector Machines in Combination with Differential Evolution Algorithm

The aim of this study is to evaluate the changes related to diabetic retinopathy (DR) (no changes, small or moderate changes) in patients with glaucoma and diabetes using artificial intelligence instruments: Support Vector Machines (SVM) in combination with a powerful optimization algorithm—Differential Evolution (DE). In order to classify the DR changes and to make predictions in various situations, an approach including SVM optimized with DE was applied. The role of the optimizer was to automatically determine the SVM parameters that lead to the lowest classification error. The study was conducted on a sample of 52 patients: particularly, 101 eyes with glaucoma and diabetes mellitus, in the Ophthalmology Clinic I of the “St. Spiridon” Clinical Hospital of Iaşi. The criteria considered in the modelling action were normal or hypertensive open-angle glaucoma, intraocular hypertension and associated diabetes. The patients with other types of glaucoma pseudoexfoliation, pigment, cortisone, neovascular and primitive angle-closure, and those without associated diabetes, were excluded. The assessment of diabetic retinopathy changes were carried out with Volk lens and Fundus Camera Zeiss retinal photography on the dilated pupil, inspecting all quadrants. The criteria for classifying the DR (early treatment diabetic retinopathy study—ETDRS) changes were: without changes (absence of DR), mild forma nonproliferative diabetic retinopathy (the presence of a single micro aneurysm), moderate form (micro aneurysms, hemorrhages in 2–3 quadrants, venous dilatations and soft exudates in a quadrant), severe form (micro aneurysms, hemorrhages in all quadrants, venous dilatation in 2–3 quadrants) and proliferative diabetic retinopathy (disk and retinal neovascularization in different quadrants). Any new clinical element that occurred in subsequent checks, which led to their inclusion in severe nonproliferative or proliferative forms of diabetic retinopathy, was considered to be the result of the progression of diabetic retinopathy. The results obtained were very good; in the testing phase, a 95.23% accuracy has been obtained, only one sample being wrongly classified. The effectiveness of the classification algorithm (SVM), developed in optimal form with DE, and used in predictions of retinal changes related to diabetes, was demonstrated

Clinical Study on the Ocular Manifestations in Patients with Obstructive Sleep Apnea Syndrome—Preliminary Results

Obstructive sleep apnea syndrome is a multisystemic disorder associated with a series of side effects. Obstructive sleep apnea syndrome (OSAS) includes hypoxemia and is correlated with an increased incidence for various neuronal conditions, including glaucoma, strokes, reduced mental ability, depressive disorders, peripheral neuropathy, and non-arteritic ischemic optic neuropathy. This study’s aims are the evaluation of the degree of ocular surface damage in obstructive sleep apnea patients (in the absence of the continuous positive airway pressure treatment) and the structural changes in the optic nerve, and to establish correlation between the degree of damage to the ocular surface (eye dryness by Schirmer test) and corneal biomechanics by ocular response analyzer. The subjects included in the study will be grouped as follows: a group of patients with glaucoma and obstructive sleep apnea syndrome that will be compared to patients with glaucoma only as well as identifying the evolution of structural changes in patients with glaucoma and sleep apnea syndrome. A prospective study included 65 eyes from 65 subjects diagnosed with obstructive sleep apnea (45 eyes of 45 subjects with glaucoma and OSAS as well as 20 subjects, 20 eyes with dry-eye syndrome and OSAS) who did not follow the continuous positive airway pressure treatment. The control group consisted of 45 subjects (45 eyes) with (mild or moderate) primary open-angle treated glaucoma without obstructive sleep apnea. All patients had ophthalmologic evaluations according to a standardized protocol. Moreover, respiratory functional parameters (apnea–hypopnea index—AHI) and the body mass index were recorded. Within the studied group, patients with mild or moderate primary open-angle glaucoma, with moderate or severe dry-eye syndrome, patients with floppy-eyelid syndrome, with optical non-arteritis ischemic neuropathy, and a patient with retinal central vein occlusion were identified. The increased rate of the apnea syndrome during sleep produces a severe disorder of the ocular surface and a retinal neuro-degenerative disorder. The eyes of patients with sleep apnea syndrome (SAS) and glaucoma have lower mean intraocular pressure than eyes with glaucoma without SAS. However, the mean C/D ratio in eyes with glaucoma correlates with the severity of SAS. There is a positive correlation between the severity of the apnea and the ocular disorder’s degree similar to the studies in the literature review. The joint cooperation between the sleep specialists and ophthalmologists can lead to the improvement of the vascular and ocular status for the obstructive sleep apnea patients