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Binocular vision problems after refractive surgery
Published in Jan-Tjeerd de Faber, 28th European Strabismological Association Meeting, 2020
D.J.M. Godts, M.J. Tassignon, L. Gobin
Dominance problems can occur when the dominant eye is undercorrected after surgery (Jain et al 1996), what happened in all our patients. Disturbing the ocular dominance in this way resulted in a decompensation of the heterophoria in patient I and II. In patient I even the non-dominant eye was treated instead of the dominant eye for mono vision.
Discussions (D)
Published in Terence R. Anthoney, Neuroanatomy and the Neurologic Exam, 2017
“Strabismus” is defined basically as improper alignment of the visual axes of the two eyes (e.g., DeJ, p. 142). Several authors equate heterotropia with strabismus, meaning manifest strabismus (e.g., Hensyl, 1982, p. 647; DeJ, p. 142; Ruch and Patton, 1979, p. 459). Heterophoria, On the Other hand, is usually equated with latent strabismus (e.g., Hensyl, 1982, p. 646, DeJ, p. 142), in which no deviation is present when both eyes are open simultaneously and visual fixation is occurring. Some authors use the words “phoria” and “tropia,” without prefixes, as synonymous with “heterophoria” and “heterotropia,” respectively (e.g., A&V, p. 200; T&D, p. 92–93). At variance with most other authors, Gouras seems to use the term “heterotropia” to mean latent strabismus, which he distinguishes from “strabismus, or squint” (in K&S, p. 578).
Disorders of Sensation, Motion, and Body Schema
Published in Rolland S. Parker, Concussive Brain Trauma, 2016
Vertical oculomotor deviations vary in magnitude by gaze position and time of day. In addition, patients may report impaired binocular depth perception and headaches (Kapoor & Ciuffreda, 2005). For other deviations of maintaining fixation (heterotropia, heterophoria), see Miller and Newman (1999, pp. 501–504).
Horizontal Heterophoria Modifications by Means of Thin Proprioceptive Stimulations Applied on the Foot Sole: A Randomised Study
Published in Journal of Motor Behavior, 2022
Heterophoria is a latent deviation of the visual axis which becomes evident only when the normal fusion mechanisms are disrupted (Mestre et al., 2018). These ocular dysfunctions seem to be related to different symptoms, in fact, several authors pointed out different symptoms related to the presence of the heterophoria, and horizontal heterophoria in particular, such as cervical pain, symptoms of asthenopia, diplopia, dizziness, limited attention span, headaches, apparent movement and distortion of text, eye strain, frequent loss of place when reading and difficulty in concentration (Fraix et al., 2021; O'Colmain et al., 2014; Przekoracka-Krawczyk et al., 2019; Sánchez-González et al., 2019; Scheiman et al., 2020). Besides, we know that this particular ocular dysfunction can be corrected with orthoptic exercises both in children, adolescents and adults (Birnbaum et al., 1999; Dawidowsky et al., 2019; Rucker & Phillips, 2018) but we do not know if it can be affected by other postural structures, such as the feet.
Binocular vision disorders in a geriatric population
Published in Clinical and Experimental Optometry, 2022
Hassan Hashemi, Payam Nabovati, Abbas Ali Yekta, Mohammadreza Agha Mirsalim, Shokoofeh Rafati, Hadi Ostadimoghaddam, Mehdi Khabazkhoob
Binocular vision disorders are a group of visual system abnormalities that impair visual performance by affecting clear single binocular vision.1 Various studies have reported a considerable prevalence of heterophoria in children and pre-presbyopic young adults. Accordingly, the prevalence of heterophoria has been reported in a wide range from 9.9 to 61.4% (median prevalence: 22.6%)2–15 this variability is mainly due to differences in diagnostic criteria and testing methods.1 According to a recent review in which the studies were also mostly related to children and young adults, the estimated global pooled prevalence of strabismus was 1.9%; 1.8% in subjects below 20 years and 3.3% in subjects above 20 years.16 Age-related changes in binocular vision status and the prevalence of binocular vision disorders in the elderly have received less attention.17
Vergence Profile and Prevalance of Non-Strabismic Vergence Anomalies Among School Children in Abia State, Nigeria
Published in Ophthalmic Epidemiology, 2019
Uchenna C. Atowa, Samuel O. Wajuihian, Rekha Hansraj
The binocular vision function included horizontal phoria, near point of convergence (NPC), fusional vergence range (FV), vergence facility (VF), accommodative amplitude (AA), accommodative response (AR), accommodative facility (AF), and AC/A ratio. Horizontal heterophoria was assessed with the Howell phoria card20 and the gradient AC/A ratio was determined by measuring heterophoria through plus and minus 2D lenses, with the target at 33 cm. Near fusional vergence ranges were determined in free space using horizontal prism bars (B-16 horizontal prism bars-Gulden Ophthalmics, Elkins Park, PA, USA), with a 6/9 equivalent accommodative target held at 40 cm. Considering the age of the participants and the difficulty in reporting blur experience, the fusional reserve was taken as the break point instead of the blur point.11,20 The NPC (break and recovery) was measured using the Royal Air Force (RAF) rule, with a vertical line as the target point.11 The amplitude of accommodation was measured monocularly and binocularly using the Donder’s push-up method with a RAF rule and a 6/9 row of letters as the target. The target was moved slowly towards the participants until a sustained blur was reported, with three readings being taken and averaged. The accommodative response was assessed using the monocular estimation method (MEM), with dynamic retinoscopy at 40 cm. Owing to the varying ability of the children to understand some complex tests, not all participants examined completed all binocular vision tests.