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1 Chapter 1 : Strabismus Causes - American Academy of Ophthalmology Clinical Management of Strabismus [Elizabeth E. Caloroso, Michael W. Rouse] on blog.quintoapp.com *FREE* shipping on qualifying offers. One of the most challenging aspects of vision care is the establishment of clear single binocular vision in patients with strabismus and its associated conditions. Go to Academy Store Learn more and Purchase. Is a single eye crossed or deviated outward? Which eye is involved? Was the onset gradual or sudden, and has the problem occurred before? Is the problem stable, improving, or getting worse? Does the patient have diplopia, asthenopia, headaches, or other symptoms? Are there associated signs or symptoms such as ptosis or variability that might suggest myasthenia gravis? Are there any neurologic concerns? Finally, an understanding of the influence of the condition on activities of daily living is important in helping to counsel the patient regarding treatment recommendations and prognosis. Key areas of discussion may include effect on work, driving, relationships, social life, feeling of well-being, and concern for the future Table 1. Review of prior treatment records can be helpful, though records from childhood are often not available. Lack of availability of previous records should not preclude treatment, including surgery. A comprehensive eye examination, with special emphasis on the ocular motility examination, is indicated for any adult patient for whom strabismus surgery is planned. Examination needs will vary from patient to patient and a one-size-fits-all approach is not appropriate. Ocular motility evaluation should include assessment of binocular alignment in the primary position at distance and near, and evaluation of ocular versions at a minimum. For patients with incomitant strabismus, such as that due to a cranial nerve palsy or restrictive strabismus, assessment of ocular alignment in the secondary and tertiary positions of gaze may be helpful. The ophthalmologist should be aware of the presence of primary and secondary deviations in patients with paralytic or restrictive strabismus Figure 1. The specific techniques of ocular motility evaluation are well known to practicing ophthalmologists, and the reader is referred to standard texts for this information. The presence of monocular diplopia should be ruled out in any patient who reports diplopia. Monocular diplopia can occur in patients with or without strabismus and can coexist with strabismic diplopia. Potential causes of monocular diplopia are listed in Table 2. Ancillary Testing Numerous ancillary studies can be performed on a patient with strabismus. This section covers some of the more common tests that are readily available in most ophthalmology offices. Sensory Testing It is often useful to determine if a patient has the potential to fuse, especially if surgery is anticipated. This can be determined with prism correction of the deviation or with an amblyoscope. In a patient with an intermittent deviation or a small-to-moderate deviation, sensory testing may be particularly helpful. In the standard clinical setting, this most commonly consists of stereopsis testing with the Titmus fly test or Randot stereoacuity test. In patients who do not have stereopsis, evaluation with the Worth 4-dot test may be useful to demonstrate the presence of some level of binocular peripheral cooperation. Patients who can achieve binocular peripheral cooperation or stereopsis are more likely to sustain optimal ocular alignment following surgical intervention, and demonstration of this ability prior to surgery may aid in preoperative planning and patient education. However, the absence of ability to fuse is not a contraindication to strabismus surgery. Motor Fusional Amplitudes Evaluation of motor fusional amplitudes can be helpful in selected patients. Patients with good motor fusional amplitudes are more likely to be able to fuse following surgery. Testing for Cyclotorsion Each of the cyclovertical muscles has a complex set of primary and secondary actions including torsional ocular movements. Therefore, testing for the presence of a concurrent cyclotropia is important in the management of a patient with vertical strabismus. Cyclotorsion can be estimated objectively by evaluation of the fundus for evidence of cyclotorsion Figure 2 and can be measured subjectively with double Maddox rods. For the test, vertically oriented Maddox rods are placed in trial frames. With the room lights dimmed, the patient rotates the Maddox rod before each eye while viewing a light source, such as a muscle light, until the linear image of the light created by the Maddox rods in each eye is parallel with the horizon. The size and direction of cyclodeviation present in each eye can be quantified in degrees using the scale on the trial frame. Use of Double Maddox Rod Test to Assess Cyclotropia Binocular Visual Field Testing This test can be useful in quantifying the size and location of the field of single binocular Page 1

2 vision in a patient who is able to achieve fusion in some positions of gaze. For the test, the patient is seated at the Goldmann perimeter with both eyes open and is asked to follow a target from the binocular to the diplopia field in several meridians Figure 3. The patient reports when diplopia is noted in each meridian. The treatment plan should seek to expand the field of single binocular vision and maximize this field around the primary and reading positions. Binocular Visual Field Assessment Using a Goldmann Perimeter Evaluation of Limited Ductions When evaluating a patient with limited ocular ductions, the ophthalmologist must determine if the duction limitation is due to restriction of the antagonist or to paresis of the agonist muscle. Clinical evaluation of saccadic velocity can often help the examiner make this distinction. An attempted saccade by a muscle that is markedly paretic will be characterized by a slow, floating saccade, with most or all of the movement due to relaxation of the antagonist, rather than contraction of the weak agonist muscle. It may be difficult to distinguish a more subtle paresis from a restriction through observation alone. Forced duction testing and force generation testing can be useful in this setting. Forced duction testing can be performed in the office with the patient awake or in the operating room prior to the start of surgery. For the test, the conjunctiva is grasped firmly with forceps following administration of topical anesthesia in an awake patient approximately 2 mm from the limbus and the eye is gently rotated along its normal arc of rotation. A full passive duction is not possible when a restriction of the antagonist is present. As a general rule, resection procedures are avoided on muscles that exhibit significant restriction. If there is no limitation to passive ductions, a paresis must be the cause of the duction limitation. Force generation testing can be performed to grossly quantify the degree of weakness of a paretic muscle. The patient is asked to look in the direction of the agonist while the ophthalmologist palpates the amount of force generated by the muscle. With experience, the ophthalmologist is able to detect the presence of a mild, marked, or severe paresis. In the presence of a total paralysis or a severely paretic muscle, saccadic velocity testing is often distinctly abnormal, precluding the need for force generation testing. Page 2

3 Chapter 2 : Clinical Management of Strabismus, Elizabeth E. Caloroso. (Paperback ) Clinical Management of Strabismus By Elizabeth R. Caloroso & Michael W. Rouse. One of the most challenging aspects of vision care is the establishment of clear single binocular vision in patients with strabismus and its associated conditions. Pathophysiology[ edit ] The extraocular muscles control the position of the eyes. Thus, a problem with the muscles or the nerves controlling them can cause paralytic strabismus. An impairment of cranial nerve III causes the associated eye to deviate down and out and may or may not affect the size of the pupil. Impairment of cranial nerve IV, which can be congenital, causes the eye to drift up and perhaps slightly inward. Sixth nerve palsy causes the eyes to deviate inward and has many causes due to the relatively long path of the nerve. Increased cranial pressure can compress the nerve as it runs between the clivus and brain stem. Strabismus may cause amblyopia due to the brain ignoring one eye. Amblyopia is the failure of one or both eyes to achieve normal visual acuity despite normal structural health. During the first seven to eight years of life, the brain learns how to interpret the signals that come from an eye through a process called visual development. Development may be interrupted by strabismus if the child always fixates with one eye and rarely or never fixates with the other. To avoid double vision, the signal from the deviated eye is suppressed, and the constant suppression of one eye causes a failure of the visual development in that eye. If a great difference in clarity occurs between the images from the right and left eyes, input may be insufficient to correctly reposition the eyes. Other causes of a visual difference between right and left eyes, such as asymmetrical cataracts, refractive error, or other eye disease, can also cause or worsen strabismus. Due to the near triad, when a patient engages accommodation to focus on a near object, an increase in the signal sent by cranial nerve III to the medial rectus muscles results, drawing the eyes inward; this is called the accommodation reflex. If the accommodation needed is more than the usual amount, such as with people with significant hyperopia, the extra convergence can cause the eyes to cross. Retinal birefringence scanning can be used for screening of young children for eye misaligments. Several classifications are made when diagnosing strabismus. This section does not cite any sources. May Learn how and when to remove this template message Strabismus can be manifest -tropia or latent -phoria. A manifest deviation, or heterotropia which may be eso-, exo-, hyper-, hypo-, cyclotropia or a combination of these, is present while the patient views a target binocularly, with no occlusion of either eye. The patient is unable to align the gaze of each eye to achieve fusion. A latent deviation, or heterophoria eso-, exo-, hyper-, hypo-, cyclophoria or a combination of these, is only present after binocular vision has been interrupted, typically by covering one eye. This type of patient can typically maintain fusion despite the misalignment that occurs when the positioning system is relaxed. Intermittent strabismus is a combination of both of these types, where the patient can achieve fusion, but occasionally or frequently falters to the point of a manifest deviation. Onset[ edit ] Strabismus may also be classified based on time of onset, either congenital, acquired, or secondary to another pathological process. Many infants are born with their eyes slightly misaligned, and this is typically outgrown by six to 12 months of age. The onset of accommodative esotropia, an overconvergence of the eyes due to the effort of accommodation, is mostly in early childhood. Acquired non-accommodative strabismus and secondary strabismus are developed after normal binocular vision has developed. In adults with previously normal alignment, the onset of strabismus usually results in double vision. Sensory strabismus is strabismus due to vision loss or impairment, leading to horizontal, vertical or torsional misalignment or to a combination thereof, with the eye with poorer vision drifting slightly over time. Most often, the outcome is horizontal misalignment. Its direction depends on the patient age at which the damage occurs: This last is typically the case when strabismus is present since early childhood. Alternation of the strabismus may occur spontaneously, with or without subjective awareness of the alternation. Alternation may also be triggered by various tests during an eye exam. May Learn how and when to remove this template message Horizontal deviations are classified into two varieties. Eso describes inward or convergent deviations towards the midline. Exo describes outward or divergent misalignment. Vertical deviations are also classified into two varieties. Hyper is the term for an eye whose gaze is directed Page 3

4 higher than the fellow eye while hypo refers to an eye whose gaze is directed lower. Cyclo refers to torsional strabismus, which occurs when the eyes rotate around the anterior-posterior axis to become misaligned and is quite rare. May Learn how and when to remove this template message The directional prefixes are combined with -tropia and -phoria to describe various types of strabismus. A patient with a mild exophoria can maintain fusion during normal circumstances, but when the system is disrupted, the relaxed posture of the eyes is slightly divergent. Strabismus can be further classified as follows: Paretic strabismus is due to paralysis of one or several extraocular muscles. Nonparetic strabismus is not due to paralysis of extraocular muscles. Comitant or concomitant strabismus is a deviation that is the same magnitude regardless of gaze position. Noncomitant or incomitant strabismus has a magnitude that varies as the patient shifts his or her gaze up, down, or to the sides. Nonparetic strabismus is generally concomitant. Incomitant strabismus is almost always caused by a limitation of ocular rotations that is due to a restriction of extraocular eye movement ocular restriction or due to extraocular muscle paresis. These letters of the alphabet denote ocular motility pattern that have a similarity to the respective letter: Duane syndrome, horizontal gaze palsy, and congenital fibrosis of the extraocular muscles. Less severe eye turns are called small-angle strabismus. The degree of strabismus can vary based on whether the patient is viewing a distant or near target. Strabismus that sets in after eye alignment had been surgically corrected is called consecutive strabismus. May Learn how and when to remove this template message Pseudostrabismus is the false appearance of strabismus. It generally occurs in infants and toddlers whose bridge of the nose is wide and flat, causing the appearance of esotropia due to less sclera being visible nasally. Retinoblastoma may also result in abnormal light reflection from the eye. Management of strabismus Surgery to correct strabismus on an eight-month-old infant As with other binocular vision disorders, the primary goal is comfortable, single, clear, normal binocular vision at all distances and directions of gaze. Glasses[ edit ] In cases of accommodative esotropia, the eyes turn inward due to the effort of focusing far-sighted eyes, and the treatment of this type of strabismus necessarily involves refractive correction, which is usually done via corrective glasses or contact lenses, and in these cases surgical alignment is considered only if such correction does not resolve the eye turn. In case of strong anisometropia, contact lenses may be preferable to spectacles because they avoid the problem of visual disparities due to size differences aniseikonia which is otherwise caused by spectacles in which the refractive power is very different for the two eyes. In a few cases of strabismic children with anisometropic amblyopia, a balancing of the refractive error eyes via refractive surgery has been performed before strabismus surgery was undertaken. However, a review of randomized controlled trials concluded that the use of corrective glasses to prevent strabismus is not supported by existing research. Eyes that remain misaligned can still develop visual problems. Although not a cure for strabismus, prism lenses can also be used to provide some temporary comfort and to prevent double vision from occurring. Surgery[ edit ] Strabismus surgery does not remove the need for a child to wear glasses. Currently it is unknown whether there are any differences for completing strabismus surgery before or after amblyopia therapy in children. The procedure can typically be performed in about an hour, and requires about six to eight weeks for recovery. Adjustable sutures may be used to permit refinement of the eye alignment in the early postoperative period. Prisms change the way light, and therefore images, strike the eye, simulating a change in the eye position. The treatment may need to be repeated three to four months later once the paralysis wears off. Common side effects are double vision, droopy eyelid, overcorrection, and no effect. The side effects typically resolve also within three to four months. Botulinum toxin therapy has been reported to be similarly successful as strabismus surgery for people with binocular vision and less successful than surgery for those who have no binocular vision. Even with therapy for amblyopia, stereoblindness may occur. The appearance of strabismus may also be a cosmetic problem. Page 4

5 Chapter 3 : Strabismus - Wikipedia Clinical management of strabismus by Elizabeth E. Caloroso,, Butterworth-Heinemann edition, in English. Coverage includes the most common non-strabismic binocular vision disorders, including accommodative and eye movement disorders as well as amblyopia. Coverage of each diagnostic category includes background information, symptoms, case analysis, and management options. Case studies appear at the end of each chapter. This edition includes three new chapters on primary care of binocular vision, accommodative and eye movement disorders; myopia control; and binocular vision problems associated with refractive surgery. The thoroughly revised chapters on vision therapy procedures and instrumentation describe the latest equipment and computer software. The chapters on advanced diagnostic and management issues have been updated with the latest research. Clinical Ocular Pharmacology, Second Edition covers the diagnostic and therapeutic clinical procedures in the administration of drugs to the eye. This book is organized into five parts encompassing 35 chapters that evaluate the basic pharmacologic principles that govern the different types of ophthalmic drugs. It addresses the pharmacologic agents useful in the diagnosis and treatment of ocular diseases. Some of the topics covered in the book are the basic science of ocular pharmacology; clinical administration of ocular drugs; drugs affecting the autonomic nervous system; types of local anesthetics; review of anti-inflammatory drugs; and examination of inhibitors of aqueous formation. Other parts deal with the development of contact lens solution in clinical practice and the pharmacologic management of strabismus. These topics are followed by discussions of the legal basis of using drugs in optometry and the systemic effects of ocular drugs. The concluding part is devoted to the diseases of the optic nerve. The book can provide useful information to doctors, optometrists, pediatricians, students, and researchers. Leonard A Levin Language: Elsevier Health Sciences Format Available: Levin and Daniel M. The concise chapter structure features liberal use of colorâ with full-color line artworks, call-out boxes, summaries, and schematics for easy navigation and understanding. This comprehensive resource provides you with a better and more practical understanding of the science behind eye disease and its relation to treatment. Covers all areas of disease in ophthalmology including retina, cornea, cataract, glaucoma, and uveitis for the comprehensive information you need for managing clinical cases. Presents a unique and pragmatic blend of necessary basic science and clinical application to serve as a clinical guide to understanding the cause and rational management of ocular disease. Features full-color line artworks that translate difficult concepts and discussions into concise schematics for improved understanding and comprehension. Provides the expert advice of internationally recognized editors with over 40 years of experience together with a group of world class contributors in basic science and clinical ophthalmology. Find Your ebooks Hereâ. Chapter 4 : Ebook Clinical Strabismus Management as PDF Download Portable Document Format Focusing on clinical management, this text puts into perspective modern diagnostic tests, and discusses the range of treatments available once a case of strabismus has been evaluated. Covers both standard and innovative surgical techniques through the use of color intraoperative photographs. Chapter 5 : CLINICAL MANAGEMENT OF STRABISMUS Optometric Extension Program Foundation Features a step-by-step approach to strabismus management. Clinically-oriented, this text offers problem-solving techniques, numerous case studies, and treatment flow charts to aid the reader in patient management. Chapter 6 : Strabismus surgery Clinical Gate This bar-code number lets you verify that you're getting exactly the right version or edition of a book. The digit and digit formats both work. Page 5

6 Chapter 7 : Curriculum Baylor College of Medicine Houston, Texas Caloroso, Elizabeth E. and Rouse, Michael W., Clinical Management of Strabismus, Butterworth- Heinemann,, pp, Â, ISBN 0 X John S. Elston British Journal of Visual Impairment. Chapter 8 : Adult Strabismus: Clinical Evaluation Clinical Approach to Ocular Motility: Characteristics and Orthoptic Management of Strabismus, Second Edition, is available for sale in print and ebook formats on Amazon. Proceeds from sales will benefit the Ida Lucy Iacobucci Orthoptic Clinic at the University of Michigan. Chapter 9 : clinical management of strabismus Download ebook PDF/EPUB Clinical Management of Strabismus Author: Elizabeth E. Caloroso One of the most challenging aspects of vision care is the establishment of clear single binocular vision in patients with strabismus and its associated conditions. Page 6