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Diabetes Mellitus, Obesity, Lipoprotein Disorders and other Metabolic Diseases
Published in John S. Axford, Chris A. O'Callaghan, Medicine for Finals and Beyond, 2023
This is background diabetic retinopathy of the macula area and there may be associated retinal oedema. Macular oedema is difficult to detect with direct ophthalmoscopy and can cause permanent central visual loss if not treated.
An Approach to Visual Loss in a Child
Published in Vivek Lal, A Clinical Approach to Neuro-Ophthalmic Disorders, 2023
Muhammad Hassaan Ali, Stacy L. Pineles
Examination of the posterior segment of the eye should be performed after adequate pupillary dilatation. Tropicamide, phenylephrine, cyclopentolate, and atropine drops can be used to dilate the pupils depending upon the color and pigmentation of the iris. Fundus examination is essential to rule out any underlying cause of vision loss including life-threatening conditions like retinoblastoma. The examination can be made relatively easy if the parents are asked to hold and simultaneously feed the baby. Young infants can be examined by wrapping them in a sheet and getting an assistant hold the head of the baby steady. Parents should be counseled that the examination is not painful so they need not worry if the child cries during the examination. Fundus examination if usually performed using 28D or 30D lenses with indirect ophthalmoscope. If any lesion is found on the optic nerve head or macula, a magnified view can be obtained using direct ophthalmoscope. While examining the fundus always comment on the status of the optic disc, macula, periphery and retinal vasculature. Optic disc pit, foveal hypoplasia, macular scarring, abnormal macular pigmentation, bone spicule pigmentation, arteriolar attenuation and optic disc pallor can be seen in various pathologies which produce visual loss in children.
Preclinical Toxicology/Safety Considerations in the Development of Ophthalmic Drugs and Devices
Published in David W. Hobson, Dermal and Ocular Toxicology, 2020
Robert B. Hackett, Michael E. Stern
Although binocular viewing of the optic nerve head and retina may be performed with a biomicroscope and the use of a specialized contact lens, ophthalmoscopy is the technique routinely used for evaluation of the fundus. In the albino rabbit, the retinal and choroidal vessels are readily observable and changes to the optic nerve head may be assessed by determination of the cup:disc ratio at appropriate intervals. In pigmented animals, the choroidal vessels are obscured. Changes to the macula and fovea in primates as well as changes to the optic nerve head and retinal vasculature are critical in assessing a drug’s potential for ocular toxicity. Generally, ophthalmoscopic evaluations should be performed prior to the initiation of treatment, following 1 month of treatment and every 3 months thereafter for the duration of the study. There are two types of ophthalmoscopes: direct and indirect. Direct ophthalmoscopy provides high magnification of the fundus and generally may be performed without the use of mydriatics. The main disadvantage of direct ophthalmoscopy is the limited viewing area. Indirect ophthalmoscopy, by contrast, is stereoscopic providing a wide area of view, thereby allowing better evaluation of the peripheral retina, and greater illumination. Unlike direct ophthalmoscopy however, indirect ophthalmoscopy requires the use of mydriatics to retard the constriction of the pupil due to the bright illumination producing an inverted image of the fundus. A fundus camera may be used to maintain a photographic record.
Prevalence of Positive QuantiFERON-TB Test among Sarcoid Uveitis Patients and its Clinical Implications in a Country Non-endemic for Tuberculosis
Published in Ocular Immunology and Inflammation, 2023
Etienne Garneret, Yvan Jamilloux, Mathieu Gerfaud-Valentin, Laurent Kodjikian, Salim Trad, Pascal Sève
A complete ophthalmologic examination was performed for all patients, and included slit-lamp examination, tonometry, laser flare meter testing, and indirect ophthalmoscopy. Further ophthalmologic examinations were performed according to the clinical presentation (optical coherence tomography, fluoresceine or indocyanine angiography). We used the Standardization of Uveitis Nomenclature (SUN) criteria to classify uveitis.8 A persistent ocular inflammation was retained if inflammatory activity persisted at the last ophthalmological visit. Signs of inflammatory activity were: anterior chamber cellularity (tyndall), vitreous haze or hyalitis, active retinal focus on fundus, vasculitis on angiography. The minimal work-up before the diagnosis of sarcoid uveitis consisted in chest X-ray, complete blood count, C-reactive protein level determination, syphilis serology, and the search for TB by either a tuberculin skin test (TST) or a QFT. Were not included patients with a positive syphilis serology. The retrospective review of computerized medical records allowed to collect the QuantiFERON-TB value (and if available TB1 and TB2, see below), the serum angiotensin-converting enzyme (sACE) level, and lymphocyte count. Our laboratory reference value was used to define an elevated sACE level (>62 UI/L), and lymphopenia was defined as <1.5 G/L.9
A Review to Populate A Proposed Cost-Effectiveness Analysis of Glaucoma Screening in Sub-Saharan Africa
Published in Ophthalmic Epidemiology, 2022
Olusola Olawoye, Augusto Azuara-Blanco, Ving Fai Chan, Prabhath Piyasena, Grainne E. Crealey, Ciaran O’Neill, Nathan Congdon
Ophthalmoscopy (Direct): Direct ophthalmoscope is often used to examine the optic nerve head with or without dilation of the pupil. An advantage of the direct ophthalmoscope is its portability and use of batteries instead of electrical current, access to which may be problematic in remote areas. The main disadvantage, however, is its inability to give a stereoscopic view of the nerve. Harper et al.68 reported a sensitivity of 81% (95% CI 69–89%) and a specificity of 90% (95% CI 84–95%) with the use of the instrument, when compared to a gold standard of stereophotography in the evaluation of the narrowest rim width for glaucoma screening.68 Cook et al.69 reported that the use of the direct ophthalmoscope using a cut-off of 0.7 for the vertical cup to disc ratio, in addition to the testing for afferent pupil defect, could give an accuracy of up to 90% for the case detection of glaucoma.
The utility of a direct ophthalmoscope in estimating the magnitude of refractive error using a modification of the Brückner test
Published in Expert Review of Ophthalmology, 2021
Praveena S. Kumar, Yogish Subraya Kamath
Refractive errors are the second major cause of blindness in India [1]. Refractive errors in children are often missed due to challenges in evaluation, and may result in amblyopia if left untreated. Poor vision also hinders academic performance and the child’s over all development [2]. These events can be prevented by the early detection of advanced refractive errors, which can ensure timely management with spectacles. Various devices like automated refractometers and photo screeners have been developed for detection of refractive errors, but are not in widespread use as they are expensive and inaccessible in rural areas [3,4]. Simpler techniques like retinoscopy are time consuming and require personnel trained in Ophthalmology [3]. The direct ophthalmoscope is an instrument that is frequently used by Pediatricians and Internists, for viewing the ocular fundus. The utility of this device in estimation of the refractive error would help in early detection and referral of individuals with higher refractive errors.