REPEATABILITY OF CHOROIDAL THICKNESS MEASUREMENTS ASSESSED WITH SWEPT-SOURCE OPTICAL COHERENCE TOMOGRAPHY IN HEALTHY AND DIABETIC INDIVIDUALS.

PURPOSE: To assess the intrasession repeatability of choroidal thickness measurements obtained using swept-source optical coherence tomography in Type 2 diabetic (T2D) patients and healthy controls. METHODS: This was a single-center, prospective, observational, cross-sectional study with consecutive inclusion of 33 healthy subjects and 43 T2D patients. Subjects underwent three consecutive swept-source optical coherence tomography scans in a single session. After automatic delineation of the choroid, subfoveal choroidal thickness, and thickness at 500-µm intervals up to 2,500 µm nasal and temporal from the fovea were measured using the software caliper by the same operator. Intraclass correlation coefficients (ICCs), coefficients of variation, and test-retest variability were calculated. RESULTS: Mean subfoveal choroidal thickness in healthy subjects and in T2D patients was 229.97 ± 79.9 and 192.67 ± 74.3 µm, respectively (P = 0.013). All intrasession intraclass correlation coefficients were higher than 0.95 and 0.99, respectively. Coefficients of variations were less than 4.4% and 1.8%, respectively. Test-retest variability ranged from 0.76 µm to 11.12 µm and 0.64 µm to 6.29 µm, respectively. No significant differences were found in the intrasession repeatability of any choroidal measurement between healthy subjects and T2D patients. CONCLUSION: Swept-source optical coherence tomography provided excellent intrasession repeatability of choroidal thickness measurements in healthy subjects and T2D patients.

Influence of inflammatory plasma biomarkers on choroidal thickness in type 2 diabetes mellitus.

PURPOSE: To assess the influence of inflammatory plasma biomarkers on choroidal thickness (CT) in patients with type 2 diabetes (T2D). METHODS: Cross-sectional study enrolling T2D patients and age-matched healthy controls (>55 years of age, Caucasian, axial length <26 mm, no macular edema, and naïve). Patients were examined with swept-source OCT Triton, obtaining automatic measurements. CT was analyzed using the ETDRS grid and the recently proposed choroidal division. A blood analysis was commanded: general biochemical profile, liver status, T2D status, thyroid and parathyroid activity, coagulation, general immunological profile, and inflammatory biomarkers. RESULTS: 124 eyes of 124 patients with a mean age between 66 and 68 years were examined. The new choroidal division showed differences between groups (p < 0.05) in more sectors than the ETDRS grid, and more biomarkers influenced these new sectors. T2D patients had higher levels of IL-8, TNF-α, MCP1, adiponectin and L-selectin. CT was influenced by TNF-α, IL-17, leukocytes and erythrocyte sedimentation rate, as well as by HDL cholesterol, albumin, liver function biomarkers, and TSH. HbA1c showed little influence on CT. CONCLUSIONS: T2D patients present increased plasma inflammatory biomarkers, exhibiting an influence on CT. IL-17 is related to a thicker choroid but TNF-α is related to a thinner choroid. HbA1c has little influence on CT. The recently proposed choroidal division is more sensitive to CT changes than the ETDRS grid. Some sectors are more sensitive to plasma biomarkers.

Mapping choroidal thickness in patients with type 2 diabetes.

OBJECTIVE: To determine and compare topographic features of the choroidal thickness (CT) between patients with type 2 diabetes (T2D) and age-matched healthy controls based on swept source-optical coherence tomography (SS-OCT). DESIGN: Cross-sectional study. PARTICIPANTS: 96 T2D patients and 33 healthy individuals aged above 18 years and with an axial length (AL) lower than 26 mm were included. METHODS: A macular 6 × 6 mm cube, comprising 900 200 × 200 µm cubes, was scanned with SS-OCT. The choroid was automatically segmented using the segmentation algorithm. Three-dimensional maps were created to represent the choroid. The scanned area was divided into different zones based on CT, and equivalent zones were compared between groups. RESULTS: Mean age (standard deviation) in the control group was 66.83 (7.3) years, and that of the T2D group was 67.94 (7.9) years (p = 0.48). Both groups were similar regarding AL and spherical equivalent. Overall, CT was significantly thinner in the T2D group; it was 203.78 (53.40) in healthy individuals and 169.98 (63.22) in T2D patients (p = 0.01). Outside the fovea, the mean CT was thicker in the superior hemiretina and decreased inferiorly, temporally, and nasally, with minimum thickness in the most distant points from the fovea. CONCLUSIONS: Choroidal thickness follows an ellipsoid pattern in both nondiabetic and diabetic eyes, with diabetic eyes showing thinner measurements diffusely. Understanding these differences is important for future studies aimed at understanding the pathophysiological underpinnings of diabetic retinopathy.

Choroidal thickness measured using swept-source optical coherence tomography is reduced in patients with type 2 diabetes.

OBJECTIVE: To compare choroidal thickness between patients with type 2 diabetes (T2D) and healthy controls measured using swept-source optical coherence tomography (SS-OCT). METHODS: The sample comprised 157 eyes of 94 T2D patients, 48 eyes of which had diabetic macular edema (DME), and 71 normal eyes of 38 healthy patients. Subfoveal (SF) choroidal thickness, and choroidal thickness at 500-µm intervals up to 2500 µm nasal and temporal from the fovea were measured using the SS-OCT. Choroidal thicknesses were compared between groups using Student's t-test. Additionally, Pearson correlations were calculated between diabetes duration, glycosylated hemoglobin (HbA1c) levels, and choroidal thickness. RESULTS: Mean diabetes duration was 16.6±9.5 years, while mean glycosylated hemoglobin was 7.7±1.3%. Overall, the choroid was significantly thinner in T2D patients. Individuals with DME had reduced choroidal thickness in all measurements, except at 2000 and 2500-µm nasal positions, compared to healthy controls. There was a moderate correlation between choroidal thickness and HbA1c levels in DME patients (SF: r = 0.342; p = 0.017). Diabetes duration did not correlate significantly with choroidal thickness. CONCLUSION: SS-OCT measurements revealed that the choroid was significantly thinner in T2D patients, moderate non-proliferative diabetic retinopathy patients, and DME patients than in healthy individuals. Further studies are needed to clarify the effect of diabetes on this layer and the relationship between choroidal thickness and DME.

Clinical Applications of Dexamethasone for Aged Eyes.

The risk of severe eye problems has been found to increase significantly with age, particularly between the fifth and sixth decades of life. Cataracts, dry eye, neovascular age-related macular degeneration, diabetic retinopathy and retinal vein occlusion (RVO) are very common and very different age-related ocular diseases that reduce the patient's quality of life. The rationale for using corticosteroids to treat anterior and posterior ocular segment diseases is driven by inflammation. Dexamethasone, one of the most powerful corticosteroids available, is widely used for topical or intravitreal administration. Topical dexamethasone has proven efficacy for the management of postoperative inflammation in the anterior segment after cataract surgery and symptom relief in dry-eye disease. A new sustained-release 700 µg dexamethasone intravitreal implant (DEX) was recently approved for the treatment of macular edema following RVO, diabetic macular edema, or non-infectious uveitis, and its use is increasing, especially when other therapeutic agents have failed. The most common side effects are increased intraocular pressure and cataract formation. The potency of DEX, alone or in combination with other agents, makes DEX a promising option for treating several retinal diseases.

Diabetic Macular Edema: Options for Adjunct Therapy.

Diabetes mellitus (DM) is a chronic disease that affects 387 million people worldwide. Diabetic retinopathy (DR), a common complication of DM, is the main cause of blindness in the active population. Diabetic macular edema (DME) may occur at any stage of DR, and is characterized by vascular hyperpermeability accompanied by hard exudates within the macula. Medical and surgical therapies have dramatically reduced the progression of DR, and timely intervention can reduce the risk of severe vision loss by more than 90 %. In 2012, intravitreal ranibizumab became the first antivascular endothelial growth factor (anti-VEGF) agent approved for DME and, since then, many reports of the use of ranibizumab for DME have been promising. Randomized, prospective, multicenter clinical trials-most notably, RESOLVE, READ-2, RISE/RIDE, RESTORE, DRCR.net protocol I, and RETAIN-reported improvements in best-corrected visual acuity and decreased central retinal thickness as measured with optical coherence tomography in patients with DME. Similar treatment benefits have also been noted in clinical trials evaluating intravitreal aflibercept and bevacizumab (DAVINCI, VISTA/VIVID, and BOLT) and more recently DRCR.net protocol T. Intravitreal steroids (dexamethasone intravitreal implant and fluocinolone acetonide), particularly in refractory cases, also play a significant role in the management of DME (MEAD/CHAMPLAIN and FAMOUS/FAME studies). In summary, over the last 5 years, blocking VEGF and inflammation has been shown to improve visual outcomes in patients with macular edema due to DM, revolutionizing the treatment of center-involved DME and establishing a new standard of care.