The modified surgery technique of canaloplasty with suprachoroidal drainage yields the opportunity to optimize the IOP-lowering effect of canaloplasty as a non-penetrating surgical procedure while still offering a more favourable safety profile than trabeculectomy. The suprachoroidal access facilitates the most complicated step of the canaloplasty surgery: the localization of Schlemm's canal.
Background/AimsThe classification of retinal detachment is currently still based on many objective criteria such as duration of symptoms and funduscopic macular status, which leaves some important questions unanswered. The most important factor is the macular status, which is determined using direct or indirect ophthalmoscopy. Optical coherence tomography (OCT) has become a standard tool in clinical practice and enables detecting the exact extent of subretinal fluid in macula-off/on retinal detachment. We introduce a new and simple OCT-based grading system for macular detachment to provide a basis for further investigations to determine the optimal timing for surgery.MethodsWe retrospectively included 155 patients who were treated for retinal detachment. We defined the extent of the macular detachment in six stages based on the Early Treatment Diabetic Retinopathy Study (ETDRS) grid of the OCT scan.The outermost ring of the ETDRS grid was defined as zone 1, the middle ring as zone 2 and the inner ring as zone 3. Only zone 3 differed in the retinal detachment height grades (grade a <250 µm vs grade b >250 µm). Retinal detachment heights that could not be measured were considered grade 4 (ungradable) detachments.ResultsForty-seven patients had no macular involvement (grade 0). Regarding macular detachment, 14 patients had grade 1, 20 had grade 2, 9 had grade 3a, 29 had grade 3b and 36 had grade 4.ConclusionThe newly developed OCT grading system for macular involvement following retinal detachment is a crucial tool to objectively classify a retinal detachment in order to be able to make better statements in the future, like for defining the optimal time for surgical intervention. A secondary benefit of this grading system would be that it improves predicting postoperative visual acuity.
Purpose To demonstrate that the diagnostic efficacy of pseudoisochromatic plates is reduced by oversized and by undersized angles of observation. Methods Pseudoisochromatic “C” and “E” plates accounting for equal demands on color vision in repeated exams were presented to 7 daltonian and 10 normal observers. An illuminant D 65 source (Unity Color Light2go) rendered 170 cd/m2 of luminance. The standard viewing time was 3 s, the viewing angles were 33.4°, 7.4° and 1.8°. Results Daltonians failed to recognize the plates at 7.4° of visual angle which correspondes to the recommended standard viewing distance. At a viewing angle of 33.4° the plates were recognized by 4 of 7 Daltonians. At a viewing angle of 1.8° the plates were recognized by 3 of 7 Daltonians. With 1.8° of viewing angle, normal observers claimed fusion of i) those various pseudoisochromatic picture elements which are on the red side of yellow, and of ii) those various elements which are on the green side. Conclusion A standardized observation distance (0,7 m) is necessary for pseudoisochromatic plates, as recommended by Ishihara and Velhagen. At small viewing angle, antagonistic processing of colored picture elements is impaired, causing loss of optotype camouflage. At large viewing angle, individual elements may activate weak color opponent mechanisms in a daltonian retina where green cones or red cones are scarce but not entirely lacking. Poster visitors may observe spatial tuning within their own color vision. Commercial interest
Purpose Effects of viewing time on the recognition of red/green and blue/green pseudoisochromatic plates were evaluated to improve clinical application. Methods Special pseudoisochromatic “C” or “E” plates (in following referred to as “spic‐plates”) allow repeated exams with identical demands on color vision. The study included 5 daltonian subjects with a best corrected visual acuity BCVA of 1.0, 5 diabetic patients with non proliferative diabetic retinopathy NPDR, BCVA 0.8 or better, and 10 normal observers. Under standard illumination and viewing distance, the viewing time was 1 s, 3 s, or unrestricted until the subject had arrived at his or her final estimate. Results Daltonian subjects were unable to recognize the red / green spic‐plates during a viewing time of 1 s or 3 s. Under unrestricted observation, 3 of 5 daltonian subjects deciphered the red/ green spic plates. Blue/green spic‐plate results in the daltonian subjects matched those of normal observers. 3 of 5 diabetic patients failed in the blue/green spic plate at 1 s, one at 3 s of viewing time. With one exception at 1 s, the diabetic patients passed the red/green spic plates, as normal observers did. Conclusion Besides the angle of observation and the level and spectral composition of illumination, the viewing time has an influnence on the results of color vision testing by pseudoisochromatic plates. In clinical application, viewing time should be considered e.g. following Ishihara’s advice of 3 s Commercial interest
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.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.