The Assessment of Suppression in Anisometropia

Anisometropia is dissimilarity between the power between the two eyes that occurs in one or both principal meridian.^[1] This becomes clinically significant when its magnitude reaches approximately 1D in either or both of the principal meridians.^[3] When two eyes forms two non uniform images due to differences in power of both eye which leads to retinal rivalry. Suppression is an active inhibitory mechanism from the brain to reduce retinal rivalry.^[18] Total 50 subjects of age groups 5-19 yrs were undergone both objective and subjective refraction with anterior and posterior segment evaluation. After that worth four dot test was done on each patient from near to far. (40cm- 4m). For evaluation Log Marchart, Heine retinoscope, worth four- dot torch,slit-lamp was used. Analysis of subjects showed that suppression is lesser in myopic group than hyperopic. The degree of suppression in anisometropia, their mean and SD in NA(0.57±0.62) and AA(1.2±1.18) respectively (P<0.01) be statistically significant .The mean and SD of angle of suppression in hyperopia (1±0.9), myopia (1.02±1.25) degree respectively(p>0.001) was statistically non significant. The mean and SD of differences in refractive error (DRE) in hyperopia (3.1±1.23),myopia (-2.72±1.03) and angle of suppression in each groups hyperopic(0.99±.91) and myopic groups (1.04±1.24) respectively (p<0.001) was statistically significant. However suppression is found in Amblyopia cases with greater visual acuity than refractive error. Difference in refractive power show Statistical significance in suppression as their degree of anisometropia increases.