a prospective observational study of adult strabismus

Conditions: Convergence Insufficiency; Divergence Insufficiency; Hypertropia

Summary: the purpose of this study is to describe clinical characteristics, treatments, and one-year outcomes of adults with convergence insufficiency, divergence insufficiency, or small angle hypertropia.

the purpose of this study is to describe clinical characteristics, treatments, and one-year outcomes of adults with convergence insufficiency, divergence insufficiency, or small angle hypertropia. treatment comparisons within the studied conditions will also be done to help develop future studies.

Eligibility criteria:
eligibility criteria for convergence insufficiency (ci) group: the following inclusion criteria must be met for the subject to be enrolled into the study: * adults ≥18 years of age (adult onset of ci not required) * no strabismus surgery within the past 10 years * ci symptom survey score ≥21 points * near exodeviation of ≥4∆ and at least 4∆ larger than at distance by pact * distance exodeviation ≤15∆ by pact * vertical deviation ≤2∆ at distance and near by pact * no constant exotropia at distance or near * reduced positive fusional vergence (pfv) at near (\<20∆ or fails sheard's criterion that the pfv measures less than twice the magnitude of the near phoria) * near point of convergence (npc) of ≥6 cm break * visual acuity 20/50 or better in both eyes by etdrs or snellen * no paralytic strabismus (e.g., 3rd, 4th, or 6th cranial nerve palsies, skew deviation, duane syndrome) * no restrictive strabismus (e.g., blowout fracture, thyroid eye disease, post scleral buckle, brown syndrome) * no monocular diplopia * no paretic strabismus, thyroid eye disease, myasthenia gravis, chronic progressive external ophthalmoplegia, or eye movement abnormalities associated with known neurological disease. patients with parkinson's disease can be enrolled if non-paretic deviation. * no inferior or superior oblique overaction defined as 2+ or greater * ability to fuse with prism in space (see section 2.4.1) * ability to understand and complete a survey * investigator is initiating treatment with prism, orthoptic exercises, botulinum toxin injection or surgery * if initiating treatment with botulinum toxin or surgery, planned injection or surgery to be within 60 days of enrollment * single treatment modality is planned (e.g., no combined prism and orthoptic exercises) * treatment to be initiated has not been used within the past one year eligibility criteria for divergence insufficiency (di) group: the following inclusion criteria must be met for the subject to be enrolled into the study: * adults ≥18 years of age * adult-onset di (at ≥18 years of age) * no prior strabismus surgery * symptoms of diplopia at distance with a frequency of sometimes or worse in primary position (in current glasses if wearing glasses) * distance esodeviation of 2∆ to 30∆ and at least 50% larger than at near by pact * no more than 5∆ difference between right and left gaze by pact * no more than 10∆ difference between the primary position at distance and either upgaze or downgaze ≤10∆ by pact * any coexisting vertical deviation must be less than distance esodeviation and ≤10∆ by pact * visual acuity 20/50 or better in both eyes by etdrs or snellen * no paralytic strabismus (e.g., 3rd, 4th, or 6th cranial nerve palsies, skew deviation, duane syndrome) * no restrictive strabismus (e.g., blowout fracture, thyroid eye disease, post scleral buckle, brown syndrome) * no monocular diplopia * no paretic strabismus, thyroid eye disease, myasthenia gravis, chronic progressive external ophthalmoplegia, or eye movement abnormalities associated with known neurological disease. patients with parkinson's disease can be enrolled if non-paretic deviation * no inferior or superior oblique overaction defined as 2+ or greater * ability to fuse with prism in space (see section 2.4.2) * ability to understand and complete a survey * investigator is initiating treatment with prism, orthoptic exercises, botulinum toxin injection or surgery * if initiating treatment with botulinum toxin or surgery, planned injection or surgery to be within 60 days of enrollment * single treatment modality planned (e.g., no combined prism and orthoptic exercises) * treatment to be initiated has not been used within the past one year eligibility criteria for small-angle hypertropia (ht) group: the following inclusion criteria must be met for the subject to be enrolled into the study: * adults ≥18 years of age * adult-onset ht (at ≥18 years of age) * no prior strabismus surgery * symptoms of diplopia at distance or near with a frequency of sometimes or worse in primary or reading position (in current glasses if wearing glasses) * vertical deviation ≥1∆ to ≤10∆ at distance and near by pact * no more than 4∆ difference from the primary in any gaze position by pact * any coexisting esodeviation must be less than the vertical deviation * any coexisting exodeviation ≤10∆ by pact * no convergence insufficiency as defined in section 2.2.1 * visual acuity 20/50 or better in both eyes by etdrs or snellen * no paralytic strabismus (e.g., 3rd, 4th, or 6th cranial nerve palsies, skew deviation, duane syndrome) * no restrictive strabismus (e.g., blowout fracture, thyroid eye disease, post scleral buckle, brown syndrome) * no monocular diplopia * no paretic strabismus, thyroid eye disease, myasthenia gravis, chronic progressive external ophthalmoplegia, or eye movement abnormalities associated with known neurological disease. patients with parkinson's disease can be enrolled if non-paretic deviation. * no inferior or superior oblique overaction defined as 2+ or greater * ability to fuse with prism in space (see section 2.4.3) * ability to understand and complete a survey * investigator is initiating treatment with prism, orthoptic exercises, botulinum toxin injection or surgery * if initiating treatment with botulinum toxin or surgery, planned injection or surgery to be within 60 days of enrollment * single treatment modality planned (e.g., no combined prism and orthoptic exercises) * treatment to be initiated has not been used within the past one year exclusion criteria for convergence insufficiency (ci) group: the following criteria exclude a subject from enrollment into the study: * strabismus surgery within the past 10 years * ci symptom survey score ≥21 points * near exodeviation of ≤4∆ and at least 4∆ larger than at distance by pact * distance exodeviation ≥15∆ by pact * vertical deviation ≥2∆ at distance and near by pact * constant exotropia at distance or near * near point of convergence (npc) of ≤6 cm break * visual acuity worse than 20/50 either eye by etdrs or snellen * paralytic strabismus (e.g., 3rd, 4th, or 6th cranial nerve palsies, skew deviation, duane syndrome) * restrictive strabismus (e.g., blowout fracture, thyroid eye disease, post scleral buckle, brown syndrome) * monocular diplopia * paretic strabismus, thyroid eye disease, myasthenia gravis, chronic progressive external ophthalmoplegia, or eye movement abnormalities associated with known neurological disease. patients with parkinson's disease can be enrolled if non-paretic deviation. * inferior or superior oblique overaction defined as 2+ or greater * inability to fuse with prism in space (see section 2.4.1) * inability to understand and complete a survey * treatment to be initiated has already been used within the past one year exclusion criteria for divergence insufficiency (di) group: the following criteria exclude a subject from enrollment into the study: * no adult-onset di (at ≥18 years of age) * prior strabismus surgery * distance esodeviation outside the range of 2∆ to 30∆ and less than 50% larger than at near by pact * more than 5∆ difference between right and left gaze by pact * more than 10∆ difference between the primary position at distance * any coexisting vertical deviation more than distance esodeviation and ≥10∆ by pact * visual acuity worse than 20/50 in either eye by etdrs or snellen * paralytic strabismus (e.g., 3rd, 4th, or 6th cranial nerve palsies, skew deviation, duane syndrome) * restrictive strabismus (e.g., blowout fracture, thyroid eye disease, post scleral buckle, brown syndrome) * monocular diplopia * paretic strabismus, thyroid eye disease, myasthenia gravis, chronic progressive external ophthalmoplegia, or eye movement abnormalities associated with known neurological disease. * inferior or superior oblique overaction defined as 2+ or greater * inability to fuse with prism in space (see section 2.4.2) * inability to understand and complete a survey * treatment to be initiated has already been used within the past one year exclusion criteria for small-angle hypertropia (ht) group: the following criteria exclude a subject from enrollment into the study: * no adult-onset ht (at ≥18 years of age) * prior strabismus surgery * vertical deviation ≤1∆ or ≥10∆ at distance and near by pact * more than 4∆ difference from the primary in any gaze position by pact * coexisting esodeviation must not be less than the vertical deviation * coexisting exodeviation ≥10∆ by pact * convergence insufficiency as defined in section 2.2.1 * visual acuity worse than 20/50 in either eye by etdrs or snellen * paralytic strabismus (e.g., 3rd, 4th, or 6th cranial nerve palsies, skew deviation, duane syndrome) * restrictive strabismus (e.g., blowout fracture, thyroid eye disease, post scleral buckle, brown syndrome) * monocular diplopia * paretic strabismus, thyroid eye disease, myasthenia gravis, chronic progressive external ophthalmoplegia, or eye movement abnormalities associated with known neurological disease. * inferior or superior oblique overaction defined as 2+ or greater * inability to fuse with prism in space (see section 2.4.3) * inability to understand and complete a survey * treatment to be initiated has already been used within the past one year

Keywords: convergence insufficiency divergence insufficiency small-angle hypertropia strabismus