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Chemosensory Disorders and Nutrition
Published in Alan R. Hirsch, Nutrition and Sensation, 2023
Carl M. Wahlstrom, Alan R. Hirsch, Bradley W. Whitman
Thus, variability of olfactory ability is a continuum. Such a heterogeneous condition is highlighted in the concept of normal olfaction. An example in another sensory system can be observed in vision. Visual acuity is relatively homogenous in the general population, where 20/20 is defined as the normal value. On the other hand, two standard deviations from the population mean, the definition of normal olfactory ability, is so widespread, that two individuals can still be considered in the normal range, even though one individual’s olfactory ability may be one thousand times better than the other. Hence, identification tests of olfactory ability may be classified as normosmia, but the previously nasute individual would perceive as severely reduced (Hirsch 1995a). This is much more complex due to the lack of a few pure odors (like only three colors), but rather the presence of a virtual aromatic kaleidoscope continuously bombarding the proboscis—a literal universe of kippage at the tip of the nose. Moreover, odors blend and diffuse together, with a normosmic normal able to detect over one trillion unique odors (Keller, Dushdid, Magnasco, and Vosshall 2014).
Screening Programs
Published in Ching-Yu Cheng, Tien Yin Wong, Ophthalmic Epidemiology, 2022
Jakob Grauslund, Malin Lundberg Rasmussen
Visual acuity is measured using the Snellen, E chart, or similar charts. It can be easily tested by minimally trained personnel. In most children, visual acuity can be examined at the age of 4 or 5 or even younger. If any suspicion of visual impairment arises, patients should be referred to an ophthalmologist, where more detailed visual acuity can be measured.
Cranial Neuropathies II, III, IV, and VI
Published in Philip B. Gorelick, Fernando D. Testai, Graeme J. Hankey, Joanna M. Wardlaw, Hankey's Clinical Neurology, 2020
Tanyatuth Padungkiatsagul, Heather E. Moss
Optic nerve sheath meningiomas classically present with unilateral insidious visual loss. Bilateral and multifocal cases are associated with neurofibromatosis type 2 (NF-2). Visual acuity is usually within the 20/40 to 20/200 range and can be normal. The appearance of the optic nerve is almost always abnormal either atrophic or swollen. Optociliary shunt vessels are visible on the optic nerve head in up to 33% of patients.40 Mass effect can also lead to proptosis, ophthalmoplegia, and diplopia.
Dropped Nucleus during Cataract Surgery in South India: Incidence, Risk Factors, and Outcomes
Published in Ophthalmic Epidemiology, 2022
Stephanie B. Engelhard, Aravind Haripriya, Sathvik Namburar, Maxwell Pistilli, Ebenezer Daniel, John H. Kempen
In our study, 51.9% of eyes with DN achieved a visual acuity of 20/40 or better at 1 month. Almost all the eyes with DN underwent vitrectomy (97.7%) within 1 month to achieve this result, which is similar to a large report from the United Kingdom.25 This number is in line with prior studies, which report 44–85% of cases achieving 20/40 or better visual acuity.25 It is possible that our number is artificially low because the follow-up period was only 1 month. Visual acuity in some patients may have improved more further out from surgery. Additionally, 23.4% of patients with DN were lost to follow up (nearly all after receiving vitrectomy treatment), which possibly also artificially decreases visual outcome given that patients, particularly from the outreach camp, may not see the necessity of follow up if they had no ongoing problems or visual complaints. Only seven DN patients (5.3%) had visual acuity worse than 20/200 at 1 month.
Pediatric Uveitis in a Referral Center in North Part of Turkey
Published in Ocular Immunology and Inflammation, 2021
Hilal Eser-Ozturk, Yuksel Sullu
The decreased visual acuity was associated with chronicity, granulomatous appearance, and infectious etiology. However, visual acuity improved in 54 (34.6%) eyes at final visit. The improvement in visual acuity can be associated with rapid and adequate systemic treatment. Visual acuity decreased in only nine (5.8%) eyes during follow-up. Of these nine patients, four had anterior uveitis, four had intermediate uveitis and one had panuveitis. In 87.2% of our patients, final visual acuity <0.3 LogMAR. In the literature, this rate varies between 60-93%.4,9,13 In a study that was examining patients with low visual acuity as a result of uveitis, Hettinga et al.15 reported that 76% of the patients had posterior uveitis, and 74% of them had infectious etiology.15 It was reported that mostly posterior uveitis caused visual loss.4,8,30
Superior ophthalmic vein thrombosis post manual carotid compression for indirect carotid-cavernous fistula
Published in Orbit, 2021
Shebin Salim, Kirthi Koka, Swatee Halbe, Sonam Poonam Nisar, Parinita Singh, Bipasha Mukherjee
All the patients presented with a decrease in vision, worsening of prominence, and chemosis. The other presenting symptoms were worsening of redness in 2 patients and periocular swelling in one. (Figures 1d and 2a) The mean visual acuity at presentation was 0.89 (range: 0.18–1.5) in the logMAR scale. The causes of reduced visual acuity were venous stasis retinopathy (n = 4) and compressive optic neuropathy (n = 1). The clinical signs documented were worsening of proptosis and venous stasis retinopathy in all patients, an increase in conjunctival chemosis in 4, extraocular motility restriction in 3, relative afferent pupillary defect in 2, eyelid edema, ptosis, and choroidal detachment in one patient each. Intraocular pressure (IOP) by Goldmann applanation tonometry was found to be raised in 4 patients and the mean IOP in the affected eyes was found to be 28.2 mm Hg (range: 20–38 mm Hg) which was controlled with topical antiglaucoma medications. Cystoid macular edema (CME) occurred in 2 patients and compressive optic neuropathy in one patient during the course of SOVT. The diagnosis of SOVT was made based on clinical and imaging findings. MRI confirmed the diagnosis in all patients and revealed a classical enlarged superior ophthalmic vein (SOV) with loss of flow void on plain MRI-scan (T2 weighted images) and filling defects on contrast-enhanced MRI-scan. (Figures 1e and 2c,d) In two patients, DSA revealed the conversion of type D CCF to type B as the external carotid feeder vessels were obliterated with an enlarged SOV without any significant outflow. (Figure 1f)