Strabismus PDF

STRABISMUS Assistant professor Dr Arif younis Baletey Ian surreens Eye specialist make University of Duhok Time  n s...

STRABISMUS Assistant professor Dr Arif younis Baletey Ian surreens Eye specialist make University of Duhok Time  n s STRABISMUS 6 extra ocular muscles insert on the sclera of each eye They move both eyes simultaneously in a harmonious way The image of the object formed by each eye will lay on the fovea (macula) 4 recti & 2 oblique's  STRABISMUS Strabismuseyes misalignmentof Misalignment of both eyes The image of the object seen does not fall on the fovea of both eyes simultaneously 2- 5% of population Leads to visual impairment Cosmetic & social impact Test the corneal light reflection Cover test / alternating cover – uncover test EEE  RISK FACTORS family history—if relatives have strabismus, a person is more likely to develop it refractive errors—extreme farsightedness (hyperopia) can develop strabismus due to the amount of eye focusing necessary to keep vision clear A lot of accommodation → convergence medical conditions—people with Down syndrome or cerebral palsy and people who have suffered a stroke or head injury are at higher risk for developing strabismus from: Strabismus.com  TYPES OF STRABISMUS Esotropia (Endotropia)—inward turning of the eye Exotropia—outward turning of the eye Hypertropia—upward turning of the eye Hypotropia—downward turning of the eye from: American Optometric Association ESOTROPIA ENDOTROPIA The left eye is turned inward—note that the light reflection in the eyes is not symmetric EXOTROPIA The right eye is turned outward—again, note the light reflection in the eyes is not symmetrical HYPERTROPIA The right eye is turned upward—light reflection not symmetrical HYPOTROPIA The right eye is turned downward-light reflection in eyes is not symmetric  ADDITIONAL CLASSIFICATIONS constant or intermittent—with which frequency does it occur ?! Bilateral—both eyes converge or diverge at the same time Unilateral—if it always involves the same eye Alternating—when the turning is sometimes the right and other times the left eye  WHEN DOES IT OCCUR? Congenital—developing during infancy; children are born with squint Acquired—developing in adulthood  Strabismus vs amblyopia Strabismus is NOT the same as Amblyopia!! Amblyopia is also called “lazy eye” and is a normally during childhood a condition where vision does not develop Child may have one weak eye with poor vision and the other totally normal Amblyopia DOES occur commonly with Strabismus Types of amblyopia: Strabismic (due to squint) Stimulus deprivation (opacity in visual pathway as cataract) Anisometropic (different refractive error between both eyes) Bilateral ametropic (bilateral high hyperopia) Meridional (uncorrected astigmatism)  DEVELOPMENT of squint IN INFANTS It is not normal for an infant’s eyes to cross constantly By the end of the fourth month of age, the infant should be able to focus on objects and eyes should be straight, with no turning 30-50% of children with strabismus develop secondary vision loss (amblyopia) The onset of strabismus is most common in children at 18 months to 6 If parents notice any misalignment (inward , outward, crossed, or the child is not focusing on objects ! They have to approach an eye specialist  DEVELOPMENT IN ADULTS Most likely develops as a result of injury or disease Adult will experience double vision, eye fatigue, blurred images, a pulling sensation around the eyes, difficulty with reading If loss of vision occurs, it is typically due to exotropia rather than amblyopia Pseudostrabismus Hypertelorism ,telecanthus  DIAGNOSIS o Comprehensive ocular examination patient history— detailed history is necessary to assess symptoms, health problems, and medications visual acuity—measurements are taken to assess extent to which vision is affected refraction—conducted to determine the lens power necessary to compensate for any refractive error alignment and focusing—assessing how well both eyes focus, move, and work together ! eye health exam—assessing the structures of the eye to rule out any disease !  TREATMENT Eye Patch The normal eye is patched to force the brain to interpret images from the strabismic eye. Eye patches will not change the angle of the strabismus. Typically, eye patching is used only if amblyopia is Duration depend on severity (mild, moderate present. and deep amblyopia) and age of patient.  TREATMENT Eyeglasses or Contact lenses Eyeglasses or Contacts are used to improve the positioning of the eye(s) by modifying the patient’s reaction to focus. Eyeglasses and Contacts can also redirect the line of sight, which can help straighten the eye.  TREATMENT Prisms Prisms are used to modify the way light and images hit the eye. The lenses provide comfort and can help prevent double vision from developing.  TREATMENT 2 types of surgery: Resection (strengthening the muscle) Muscle Surgery Recession (weakening the muscle) Surgery may be necessary in an attempt to align the eyes by modifying one or more muscles in the eye. During surgery, the muscle positions will be changed or the length of the muscles will be changed. Surgery may follow a period of eye patching and then eyeglasses may be used after surgery to help treat strabismus. The goal of treatment is to help the patient to achieve binocular vision in Surgery on medial rectus muscle of the all directions of gaze and at all left eye. distances  TREATMENT Botox Therapy Used as an alternative to eye muscle surgery. The idea is that the drug will temporarily relax the eye muscle, which will allow the opposite eye to tighten and straighten. The effects are short-term—about 3 weeks. Eye muscle exercises and eyeglasses may also be used to help strengthen the eye.