A STUDY ON THE VARIABLES OF STRAIGHT-EYED AMBLYOPIA WITH ANISOMETROPIA

Kritima Gurung, R R Sukul, A K Amitava, Abdul Waris*, Gargi Nagpal, Naheed Akhtar

ABSTRACT

Aims and objectives: The aim was to analyze the relationship of increasing magnitude of anisometropia with the depth of amblyopia and magnitude of its effect on binocularity, viz. fusion and steroacuity, also to determine the number of monofixators in anisometropic amblyopes and percentage of aniseikonia in anisometropic amblyopes. Magnitude of accommodation lag in amblyopes and assessment of inter-ocular accommodation differences in anisometropic amblyopes was also studied. Materials and methods: Visual acuity was measured with Snellen’s chart, retinoscopy was done with streak retinoscope, fusion was looked for with Worth’s 4 dot test and Bagolini’s striated glasses. Steroacuity at near was recorded with Titmus fly test. Aniseikonia was recorded using aniseikonia booklet. Monofixation sought for 4 pd base out test. Results: Anisometropic amblyopes in our study presented with moderate vision impairment. A strong correlation was found between degree of anisometropia and final visual acuity. Increasing anisometropia was found to be associated with decreasing stereoacuity. The mean log-MAR inter-ocular acuity difference (IOAD) of the anisohyperopic amblyopes was 0.6+(0.3), while that of anisomyopic amblyopes was 0.52+ (0.33). Conclusions: Anisometropia in the absence of strabismus is a known etiology of amblyopia. Hyperopic anisometropia was found to be more prevalent in our study population with increasing magnitude of anisometropia (>3D) having a strong association with higher grades of amblyopia. Increasing anisometropia and amblyopia also showed a significant correlation with impairment of binocular functions like stereoacuity. Timely detection of uncorrected refractive error and its correction is essential to prevent the development of amblyopia and associated impairment of binocular and accommodation function.

Keywords: Amblyopia, anisometropia,, steroacuity, anisomyopia, anisohyperopia.