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
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.
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