Prevalence of anisometropia and amblyopia in duane retraction syndrome of patients attened ibn Al-Haitham Teaching Eye Hospital

Abstract

uane’s Retraction Syndrome (DRS) is acongenital oculomotor anomaly thatpresents as globe retraction with simultaneousnarrowing of the palpebral fissure on attemptedadduction. To determine the prevalence of anisometropiaand amblyopia in Duane retraction syndrome in patientsreferred to tertiary eye center (Ibn Al-Haitham TeachingEye Hospital squint department). All recorded files of patientsattended to Ibn-Al Haitham Teaching Eye Hospitalbetween 2009 and 2015, were retrospectively reviewed,a total number of 5000 files, 120 patients with the diagnosisof Duane retraction syndrome were identified.The prevalence of the Duane retraction syndrome in ourstudy related to strabismus population was 2.4% (95%confidence interval [CI]: 1.4–1.9).Data collection regarding,clinical features , gender, age at diagnosis, lateralityand type of Duane retraction syndrome, abnormal headposture, amblyopia, Anisometropia (refractive errors), correctedvisual acuity, manifest and cycloplegic refraction,alternate cover test, ductions and version ocular movement,fundus examination, and slit lamp biomicroscopy.Amblyopia is a unilateral or, less commonly, bilateral reductionof best -corrected visual acuity that cannot be attributeddirectly to the effect of any structural abnormalityof the eye or visual pathways. Anisometropia dissimilar refractiveerrors in the 2 eyes cause the image on one retinato be chronically defocused. Levels of anisometropia thatcan lead to amblyopia are greater than 1.50 D of hyperopia,2.00 D of astigmatism, and 3.00 D of myopia. Higherlevels are associated with greater risk. 59 males (49.2%)and 61 females (50.8%) presented with age groups, below2yrs 48 cases (40.0%), 2-5yrs 54 cases (45.0%) andmore than 5yrs 18 cases(15.0%). 120 Duane RetractionSyndrome, the unilateral cases were 104 (86.7%) comparedto bilateral cases were 16 (13.3%), in unilateralcases, left eye was involved in 90 cases (75.0%) and theright eye 14 cases (11.7%) type I were 108 eyes (90.0%)type II were 7 eyes (5.8%)type III were 3 eyes (2.5%). Inbilateral cases type I for right eye &II for left eye was 1case (0.8%), type I for right eye &III for left eye was 1 case(0.8%), type I for right & left eyes were 14 cases (99.2%).11 cases with abnormal Head Posture recorded (9.2%).Total number of eyes with higher refractive error (Anisometropia)in Duane retraction syndrome was found in 37cases, unilateral Duane eyes 29 cases 78.4%and bilateralDuane eyes 8cases 21.6%. Total number of eyes withamblyopia in Duane retraction syndrome were 43 cases,unilateral Duane eye 33 cases 76.75% (29 of them dueto anisometropia and 4 cases due to Duane per se) whilein bilateral Duane eye 10cases 23.25% (8 of them dueanisometropia and 2 cases due to Duane per se). Each ofDRS and anisometropia independently causing amblyopia.But Amblyopia due to Anisometropia found to be moresignificant association.