Purpose: We present the design of a new low-cost optical coherence tomography (OCT) system and compare its retinal imaging capabilities to a standard commercial system through a clinical study. Methods: A spectral-domain OCT system was designed using various cost-reduction techniques to be low-cost, highly portable, and completely stand-alone. Clinical imaging was performed on 120 eyes of 60 patients (60 eyes of normal volunteers and 60 eyes with retinal disease) using both the low-cost OCT and a Heidelberg Engineering Spectralis OCT. Contrast-to-noise ratio (CNR) was measured from resulting images to determine system performance. Results: The low-cost OCT system was successfully applied to clinical imaging of the retina. The system offers an axial resolution of 8.0 lm, a lateral resolution of 19.6 lm, and an imaging depth of 2.7 mm for a 6.6-mm field of view in the X and Y directions. Total cost is $5037, a significant size reduction compared to current commercial higher performance systems. Mean CNR value of low-cost OCT images is only 5.6% lower compared to the Heidelberg Spectralis. Conclusions: The images captured with the low-cost OCT were of adequate resolution and allowed for clinical diagnostics. It offers comparable performance as a retinal screening tool at a fraction of the cost of current commercial systems.
Background Subacute thyroiditis (SAT) is a rare inflammatory disease that presents diagnostic challenges. The underlying pathophysiology and prediction of outcomes are elusive. We investigated the long-term follow-up of SAT for up to 30 years and determined predictors for later hypothyroidism.
Methods SAT outcome data from 127 patients (age: 47.6 ± 11.0 yrs., BMI: 24.7±4.8 kg/m²) were analyzed retrospectively. Patients with pre-existing and known causes of hypothyroidism unrelated to SAT were excluded. We also excluded patients without an accelerated erythrocyte sedimentation rate. SAT outcome parameters included anterior neck pain or tenderness of the thyroid, inflammation markers, hypoechoic areas in thyroid ultrasound, hyperthyroidism, fine-needle aspiration, and thyroid scan. Pre-treatment TSH-levels, gender, age, ultrasound findings, anti-thyroid antibodies and markers of inflammation were considered as possible predictors of SAT outcome.
Results More than 26.8% of SAT patients developed permanent hypothyroidism within 3 years of treatment. The patient groups later developing hypothyroidism did not differ in age, BMI, pre-treatment TSH levels or initial dosage of prednisolone treatment. However, high cumulative doses of prednisolone were associated with a higher prevalence of hypothyroidism. Also, women were more likely to develop hypothyroidism (OR: 3.18 (95% CI: 1.14–8.65); p=0.0176).
Conclusions Our study suggests that one-quarter of patients with SAT develop hypothyroidism in the long-term. Hypothyroidism was predicted by high cumulative doses of prednisolone treatment and female gender. The reported lower prevalence of hypothyroidism in other countries may represent the faster establishment of diagnosis, different treatment protocols, or lower susceptibility to loss of thyroid function. Swift establishment of the diagnosis and rapid tapering of steroids may result in a higher proportion of patients with euthyroidism.
Purpose: To assess components of the fibrinolytic system in the vitreous humour and serum of patients with vitreoretinal disorders.
Methods: Forty‐three samples of vitreous humour and plasma of 43 patients undergoing pars plana vitrectomy for macular hole, macular pucker, retinal detachment or proliferative vitreoretinopathy were evaluated for their content of plasminogen, a2‐antiplasmin, plasminogen‐activator‐inhibitor 1, plasmin‐a2‐antiplasmin‐complex, tissue plasminogen activator, total protein, albumin, d‐dimer. Patient groups were compared with each other using the U‐test (Mann and Whitney) for non‐parametric testing of two independent samples.
Results: The groups of retinal detachment and proliferative vitreoretinopathy had elevated vitreal levels of plasminogen‐activator‐inhibitor 1 (352.5 and 370.7 ng/mL vs. 1.86 and 56.6 ng/mL, P = non‐significant), plasmin‐a2‐antiplasmin‐complex (2416.5 and 1836.2 µg/L vs. 124.2 and 133.4 µg/L, P < 0.001), albumin (0.08 and 0.15 g/dL vs. 0.03 and 0.07 g/dL, P < 0.05) and d‐dimer (4.76 and 1.64 µg/mL vs. 0.40 and 0.48 µg/mL, P = non‐significant) when compared with patients with macular hole and macular pucker.
Conclusions: There are significant differences in the vitreal concentration of components of the fibrinolytic system in patients with vitreoretinal disorders. Breakdown of the blood–retinal barrier and complex disease‐specific mechanisms are thought to be responsible for an increase of components of the fibrinolytic system in the vitreous.
These data suggest that decreases in plasma free-VEGF levels are greater after treatment with aflibercept or bevacizumab compared with ranibizumab at 4 weeks. At 52 and 104 weeks, a greater decrease was observed in bevacizumab versus ranibizumab. Results from 2 subgroups of participants who did not receive injections within at least 1 month and 2 months before collection suggest similar changes in VEGF levels after stopping injections. It is unknown whether VEGF levels return to normal as the drug is cleared from the system or whether the presence of the drug affects the assay's ability to accurately measure free VEGF. No significant associations between VEGF concentration and systemic factors were noted.
Bilateral vascular abnormalities are more common in Coats disease than previously reported. This observation supports a systemic and/or genetic association with Coats disease. Patients with Coats disease should have careful evaluation of the periphery of the less affected eye, preferably with fluorescein angiography, to identify vascular changes not visible clinically. Both eyes warrant surveillance over the lifetime of the patient for potential progression to exudative disease that would warrant treatment.
During routine vitreous surgery, the vitreous cavity and retina are cooled to much lower temperatures than those used in therapeutic hypothermia. Rapid rewarming occurs within the eye once the infusion line is closed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.