Exophoria is a type of heterophoria characterized by a tendency for outward deviation of the eyes from the standard visual axis. In the majority of cases, it arises due to convergence insufficiency or inability to maintain proper eye alignment at near vision and the cause is unknown.
Apart from visual observation of the tendency of the eyes to drift outward, symptoms are frequently absent , but when it is a constitutive feature of convergence insufficiency (CI), defined as inability to preserve normal eye alignment at near, it can present with symptoms such as eye fatigue, headaches, and double vision when attempting to perform activities that require near sight, for e.g. reading  . CI, apart from exophoria, can be accompanied by a remote near point of convergence or decreased positive fusional vergence  . Other symptoms that are reported in patients suffering from exophoria are the frequent loss of place when reading, print moving on the page, difficulty concentrating and a short attention span . In some cases, hyperphoria - a permanent upward deviation of the visual axis of the eye, was described as well . Some authors consider that severe exophoria progressively leads to intermittent exophoria, a type of strabismus and that it may develop as early as infancy .
Eye disease : Pathology of the eye ( H00–H59 360–379) Adnexa Eyelid Inflammation Stye Chalazion Blepharitis Entropion Ectropion Lagophthalmos Blepharochalasis Ptosis Blepharophimosis Xanthelasma Eyelash Trichiasis Madarosis Lacrimal apparatus Dacryoadenitis [worldlibrary.org]
Enophthalmos Orbital cellulitis Orbital lymphoma Periorbital cellulitis Conjunctiva Conjunctivitis allergic Pterygium Pinguecula Subconjunctival hemorrhage Globe Fibrous tunic Sclera Scleritis Episcleritis Cornea Keratitis herpetic acanthamoebic fungal Corneal ulcer [worldlibrary.org]
H50.61 Brown's sheath syndrome H50.69 Other mechanical strabismus H50.8 Other specified strabismus Reimbursement claims with a date of service on or after October 1, 2015 require the use of ICD-10-CM codes. [icd10data.com]
This form of strabismus is easily detected through an eye examination, and we pediatric ophthalmologists actively screen for it in our patients. For some people this strabismus is merely an incidental eye finding, and there are no symptoms. [hutchdoc.com]
Abraham Spierer, Ayelet Priel and Dan Sachs, Strabismus in Senile Cataract Patients, Journal of American Association for Pediatric Ophthalmology and Strabismus, 9, 5, (422), (2005). R. Jiménez, M. A. Pérez, J. A. García and M. D. [doi.org]
scotoma Pupil Anisocoria Argyll Robertson pupil Marcus Gunn pupil Adie syndrome Miosis Mydriasis Cycloplegia Parinaud's syndrome Other Nystagmus Childhood blindness Infections Trachoma Onchocerciasis Index of the eye Description Phenomena Disease Treatment [worldlibrary.org]
Photokeratitis Thygeson's superficial punctate keratopathy Corneal dystrophy Fuchs' Meesmann Corneal ectasia Keratoconus Pellucid marginal degeneration (PMD) Keratoglobus Terrien's marginal degeneration Keratoconjunctivitis sicca Corneal neovascularization Kayser–Fleischer [worldlibrary.org]
senilis Band keratopathy Vascular tunic Iris Ciliary body Uveitis Intermediate uveitis Hyphema Rubeosis iridis Persistent pupillary membrane Iridodialysis Synechia Choroid Choroideremia Choroiditis Chorioretinitis Lens Cataract Congenital cataract Childhood [worldlibrary.org]
iridis Persistent pupillary membrane Iridodialysis Synechia Choroid Choroideremia Choroiditis Chorioretinitis Lens Cataract Congenital cataract Childhood cataract Aphakia Ectopia lentis Retina Retinitis Chorioretinitis Cytomegalovirus retinitis Retinal [worldlibrary.org]
Physicians can make a preliminary diagnosis just by close inspection of the eyes during the physical examination, while patient history can reveal signs and symptoms that indicate problems with near vision. Some tests, however, may be employed to confirm exophoria as the cause of symptoms. Firstly, simple cover testing and evaluation of accommodation can be performed, which will provoke the outward movement of the eye in virtually all cases. The Snellen chart should not be used as a sole diagnostic method, since it may reveal completely normal findings in patients suffering from exophoria. The severity of prism diopter (PD) deviation should be examined by skilled ophthalmologists, in order to evaluate the need for correction .
- Jung JW, Lee SY. A Comparison of the Clinical Characteristics of Intermittent Exotropia in Children and Adults. Korean J Ophthalmol. 2010;24(2):96–100.
- Saunte JP, Holmes JM. Sustained improvement of reading symptoms following botulinum toxin A injection for convergence insufficiency. Strabismus. 2014;22(3):95-99.
- Bade A, Boas M, Gallaway M, et al. Relationship between Clinical Signs and Symptoms of Convergence Insufficiency. Optom Vis Sci. 2013;90(9):988-995.
- Scheiman M, Gwiazda J, Li T. Non-surgical interventions for convergence insufficiency. Cochrane Database Syst Rev. 2011;(3):CD006768.
- Gupta NC, Narang RK, Khurana AK, Parmar IP, Ahluwalia BK. Exophoria and refractive errors-evaluation of 250 cases. Indian J Ophthalmol. 1987;35(4):204-206.