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Perceptual Impairments
Published in Julie A. Jacko, The Human–Computer Interaction Handbook, 2012
Julie A. Jacko, V. Kathlene Leonard, Molly A. McClellan, Ingrid U. Scott
Proliferative diabetic retinopathy is characterized by extraretinal fibrovascular proliferation; that is, fibrovascular changes that extend beyond the confines of the retina and into the vitreous cavity. Fibrovascular proliferation in proliferative diabetic retinopathy may lead to tractional retinal detachment and vitreous hemorrhage. High-risk proliferative diabetic retinopathy is defined by any combination of three of the four following retinopathy risk factors: (1) presence of vitreous or preretinal hemorrhage; (2) presence of new vessels; (3) location of new vessels on or near the optic disc; and (4) moderate to severe extent of new vessels (Diabetic Retinopathy Study Research Group 1979).
Recent developments in imaging and surgical vision technologies currently available for improving vitreoretinal surgery: a narrative review
Published in Expert Review of Medical Devices, 2023
Elham Sadeghi, Sashwanthi Mohan, Danilo Iannetta, Jay Chhablani
Nowadays, most light sources for endo-illumination in vitreoretinal surgeries consist of multiple light filters. The Photon (Synergetics) light source contains a 485 nm cutoff filter which limits the yellow wavelength. The Xenon Brightstar (DORC) has 435, 475, and 515 nm cutoffs filter to reduce yellow wave. Bausch and Lomb Inc. applied three filters on Stellaris PC: a green filter for improving illumination and visualization and a yellow and amber filter for both safety advantages and enhanced illumination. The amber filter may reduce glare during internal limiting membrane (ILM) removal with Brilliant Blue dye and air-fluid exchange, while the green filter is the preferred filter to use with other dyes. The red-free filter is used to better visualize the ischemic retina in vitreous hemorrhage and to distinguish the tissues during scleral buckling. The main downside to light filters is the reduced color contrast (Figure 5) [86,145].
Comparative analysis of measurements of the anterior segment and the axial length parameters of the eyeball obtained with optical and ultrasound technique
Published in Expert Review of Medical Devices, 2021
Robert Mazur, Adam Wylegala, Edward Wylegala, Dariusz Dobrowolski
Patients qualified for cataract surgery at the Chair and Clinical Department of Ophthalmology, Division of Medical Science in Zabrze, were consecutively included in the study. This prospective study complied with the requirements of the Declaration of Helsinki and was approved by the bioethics committee of the Silesian Medical University (Commission approval number KNW/0022/KB1/128/18/19, dated 08/01/2019). All participants signed informed consent and received a leaflet explaining the nature of the study. Patients referred for cataract surgery as the sole indication for surgery were eligible for the study. Minors and pregnant women did not participate in the study. Prior to measurements, the patients underwent a complete ophthalmic examination with the best correction of visual acuity, slit-lamp non-contact tonometry, and fundus examination. A total of 194 eyes of patients qualified for cataract surgery were examined consecutively on the day before surgery. There were 84 females and 66 males examined. The mean age was 68 years, with a range of 46 to 85 years. Participants with eye diseases that may lead to unreliable AL values, such as retinal detachment, vitreous hemorrhage, central retinal lesions such as DME, AMD with CNV, and the diseases or lesions affecting the cornea listed further were excluded from the study. Patients in whom measurement by all methods was not feasible due to cataract advancement were also not included. Patients with comorbidities such as keratoconus and other ectasias, corneal dystrophies, keratitis, previous refractive surgery, and keratoplasty were excluded to reduce the instability of K1, K2, CCT, ACD measurements.
Recent advances in imaging technologies for assessment of retinal diseases
Published in Expert Review of Medical Devices, 2020
Taha Soomro, Neil Shah, Magdalena Niestrata-Ortiz, Timothy Yap, Eduardo M. Normando, M. Francesca Cordeiro
cSLO has allowed imaging through undilated pupils and opaque media such as cataracts using infrared light, unlike traditional fundus photography (see Figure 3.A the retina is still visible through a right eye vitreous hemorrhage).