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Clinical Examination in Neuro-Ophthalmology
Published in Vivek Lal, A Clinical Approach to Neuro-Ophthalmic Disorders, 2023
Selvakumar Ambika, Krishnakumar Padmalakshmi
Cover-uncover test in patients with ocular misalignment along with prism bar cover test/Krimsky helps to characterize and quantify the deviation. Prism bar cover test—A prism is placed in front of deviating eye (apex of the prism toward the deviation). An alternate cover test is performed by alternately occluding one eye and observing the uncovered eye. The movement of eye behind the prism is watched as it takes up fixation. The prism strength is increased until there is no movement to take up fixation. Thus, the angle of deviation measured as the strength of the prism.Modified Krimsky test—Prism bar is placed before the normal eye. Examiner observer the position of the corneal reflex as the patient fixates on a light source and prism strength is increased until the corneal reflex appears symmetrical, thus neutralizing the deviation.
Screening Programs
Published in Ching-Yu Cheng, Tien Yin Wong, Ophthalmic Epidemiology, 2022
Jakob Grauslund, Malin Lundberg Rasmussen
Strabismus or squint can be tested by lightning reflex test, where a light source is aimed at the nose of the child and the reflex on the cornea is assessed. The reflex should fall mirrored on the same place in both eyes. If not, non-parallel eyes should be suspected. Another test for strabismus is the cover test, in which the movement of one eye in the covering of the other eye reveals a pretest squint. This movement can sometimes be more easily seen compared to the light reflex in younger, restless children. Furthermore, stereopsis can be measured by Lang stereopsis test in older pre-school children. If it is not possible to measure visual acuity or to fully examine children, great attention must be paid to the parents’ suspicions and observations and the child should be referred for expert evaluation by an ophthalmologist.
Strabismus
Published in Mostafa Khalil, Omar Kouli, The Duke Elder Exam of Ophthalmology, 2019
Ahmed Hassane, Rizwan Malik, Obaid Kousha
Abnormal alignment of the eye, also known as a manifest squint. Can be tested using the cover test. Esotropia: Convergent squintExotropia: Divergent squint
Delayed Diagnosis of Amblyopia in Children of Lower Socioeconomic Families: The Hong Kong Children Eye Study
Published in Ophthalmic Epidemiology, 2022
Xiu Juan Zhang, Posey Po-Yin Wong, Emily S Wong, Ka Wai Kam, Benjamin Hon Kei Yip, Yuzhou Zhang, Wei Zhang, Alvin L. Young, Li Jia Chen, Patrick Ip, Clement C. Tham, Chi Pui Pang, Jason C. Yam
Ocular alignment was assessed by an ophthalmologist using the cover/uncover test, with a fixation target at both near (30 cm) and distant (6 m) ranges. The prism cover test was performed to measure the degree of eye misalignment. Refractive status was measured before and after cycloplegia for each child using an auto-refractor (Nidek ARK-510A, Gamagori, Japan). Two cycles of 1% cyclopentolate (Cyclogyl, Alcon-Convreur, Rijksweg, Belgium) and 1% tropicamide (Santen, Osaka, Japan) were each given 10 minutes apart. A third cycle of cyclopentolate and tropicamide drops was administered 30 minutes later if pupillary light reflex was still present or the pupil size was less than 6.0 mm. Finally, an ophthalmologist examined in detail the anterior segment using a slit-lamp (Haag-Streit, Koeniz, Switzerland) and the retina through an indirect ophthalmoscope with a 20D lens (Volk, Houston, TX).
Vision Abnormalities in Children and Young Adults With Cerebral Palsy; A Systematic Review
Published in Seminars in Ophthalmology, 2022
Samira Heydarian, Marziye Moradi Abbasabadi, Mehdi Khabazkhoob, Hosein Hoseini-Yazdi, Masoud Gharib
Esotropia was the most prevalent type of strabismus, followed by exotropia, with vertical deviations being the least common. Amongst the total of 1404 individuals with CP examined across 15 studies,17,18,26,27,29–31,33–40 420 cases (30%) were esotropic and 292 (21%) were exotropic. Even though the total number of esotropic cases was higher than exotropic ones across the entire CP population studied, however, a higher prevalence of exotropia compared to esotropia was reported in 3 out of the 17 selected studies.18,35,36 The cover test was employed in most studies to diagnose strabismus; however, the angle of ocular deviation was reported in only one study. Although strabismus is reportedly the most common oculomotor disorder among the CP patients (overall affecting approximately 48% of the evaluated population), CP is also associated with other oculomotor impairments including nystagmus, and deficits in the saccadic, pursuit and fixational eye movements. Among the oculomotor abnormalities, the second most common reported problem was nystagmus, ranging from 2% to 22% in the evaluated studies. However, the type of nystagmus and its frequency and amplitude were not reported in the studies.17,26,28–40
Objective excyclotorsion in age-related distance esotropia
Published in Strabismus, 2022
A retrospective chart review of consecutive patients with ARDE who underwent fundus photography between August 2010 and April 2021 was performed. The inclusion criteria for ARDE in this study were as follows: (1) intermittent or constant horizontal uncrossed diplopia at a distance and no diplopia at near; (2) deviation of esotropia with distance fixation was less than 30 prism diopter (PD) and was greater than that with near fixation; (3) age of onset (diplopia) was over 55 years; and (4) the patient showed full ocular versions and ductions with normal saccadic eye movements. The exclusion criteria were as follows: (1) a history of paretic or non-paretic strabismus, (2) the presence of incomitance in esodeviation on lateral gaze or of slow abducting saccade, (3) presence of significant vertical strabismus (>4 PD), and (4) association with high myopia (refraction exceeding 9 diopter or axial length longer than 27 mm). Clinical characteristics were collected by routine ophthalmologic examination of strabismus. These included the alternate prism cover test at distance and near gaze, major amblyoscopic examinations, and Hess screen test. Eye dominance was determined with the hole-in-the-card method.