The prevalence of strabismus types in strabismic Iranian patients

Abstract

PurposeTo determine the frequency of different types of strabismus and amblyopia in the patients of strabismus clinics from 2008 to 2014.MethodsThis retrospective cross-sectional study was conducted using data from the archives of Farabi Hospital in Tehran, Iran, from 2008 to 2014. The study consisted of using records of strabismic patients. From these, strabismus types and associated abnormalities, types of amblyopia and other ocular pathological findings were recorded.ResultsIn this study, 1174 strabismic patients were studied. Accommodative esotropia (ET) was the most prevalent type of strabismus accounting for 25.04% of all strabismic patients while intermittent exotropia (XT), nonaccommodative ET and partially accommodative ET, with 12.09%, 11.24% and 10.39%, respectively, were relatively common. Also, 63.03% of all strabismic patients had esodeviation with XT coming second accounting for 24.53% of patients. Other ocular pathologic findings in addition to strabismus were found in 236 (20.1%) patients. The most common association with those types of strabismus was inferior oblique over action accounting for 11.07% of all cases, and 88 patients had nystagmus in addition to strabismus. Significantly 45% of patients had no amblyopia and 37% of patients had a combined type of amblyopia which was the most common type of amblyopia found in strabismic patients.ConclusionThe prevalence of ET was two and a half times more than XT and almost half of strabismic patients suffer from amblyopia. This study suggests that strabismus screening of children could be useful in the early detection of strabismus, appropriate management of it and prevention of strabismic amblyopia.

Non-surgical management options of intermittent exotropia: A literature review

“… 5 6 7 8 About 48–92% of the exotropic patients have intermittent exotropia (IXT). 6 10 11 12 Jenkins reported that the prevalence of exodeviation was higher in countries near the Equator. 13 Its prevalence is also higher in subequatorial Africa, the Middle East, and East Asia (where there is plenty of sunshine) in comparison to the USA and Central Europe.…”

“…In many subtypes of IXT, the deviation is more obvious on distance vision, which is the reason why it is also referred to as intermittent distance exotropia. 12 13 17 18 Since the deviation usually manifests when the person is tired, sick, or daydreaming, it is also known as periodic or inattention exotropia. 19 The etiology of IXT is not clear, but many factors, including neuro-mechanical factors, 20 insufficient fusion, a high accommodative convergence to accommodation ratio (AC/A), 21 22 refractive errors, 23 and genetic factors 10 24 were cited in previous reports.…”

The effect of different amblyopia treatment protocols on axial length of non-amblyopic eyes in anisohyperopic patients

“…Amblyopia is a visual impairment that is characterized by a unilateral or bilateral reduction of visual acuity without an organic cause 1, 2, 3. With a prevalence of up to 3.5%, amblyopia is the most common cause of childhood vision loss4, 5, 6, 7, 8 that occurs in up to two-thirds of anisometropic and strabismic patients 9, 10, 11. Anisometropia is defined as the difference of refractive power between the two eyes, frequently caused by a difference in axial length (AL) 12 …”

“…Early diagnosis and timely treatment of anisometropic amblyopia are crucial in the successful treatment of this condition 13, 14, 15, 16. Treatment of amblyopic anisometropia usually involves correcting the refractive errors and covering the non-amblyopic eye using a patch, i.e., occlusion therapy 1, 6, 11, 16, 17. Although there is no consensus about the daily length of occlusion time that can result in the best treatment outcomes, some studies have shown that the daily duration of patching is an important factor in successful treatment of amblyopia in children 11, 18.…”

“…Treatment of amblyopic anisometropia usually involves correcting the refractive errors and covering the non-amblyopic eye using a patch, i.e., occlusion therapy 1, 6, 11, 16, 17. Although there is no consensus about the daily length of occlusion time that can result in the best treatment outcomes, some studies have shown that the daily duration of patching is an important factor in successful treatment of amblyopia in children 11, 18. While some studies suggest full-time occlusion therapy, others have documented improved success with part-time occlusion 1, 11, 19, 20…”