Original Article

Is the 'sound ' eye of amblyopic patients really healthy? - Original Article

  • Fatma Yülel
  • Hüseyin Simavli
  • Ayse Gül Koçak Altintas
  • Derya Dal
  • Hasan Basri Çakmak
  • Saban Simsek

Turk J Ophthalmol 2009;39(4):283-287

Aim:

Comparing the contrast sensitivity of healthy “sound” eye and amblyopic eyes of patients with amblyopia with the contrast sensitivity of eyes of normal healthy subjects.

Material and Methods:

Twenty three patients with anisometropic amblyopia and 22 subjects of an age and sex matched control group (C) with visual acuity of 1 on Snellen chart were included in the study. Best corrected visual acuities (BCVA) on Snellen chart and contrast sensitivities (CS) [at spatial frequencies of 3, 6, 12 and 18 cyles/degree (cpd)of CV 1000 test] of the ‘sound’ eye (G1) and amblyopic eye (G2) of patients with amblyopia and eyes of healthy subjects in the control group (C) were measured. Contrast sensitivity values were compared by Kruskall Wallis test.

Results:

The cylindrical refractive errors of G1 and C were significantly different (p=0.003). There were no differences between groups at 3 cpd (p=0.23). There a significant difference between groups at higher spatial frequencies (p value for 6 cpd is 0.003, the p values for 12 cd and 18 cd are both 0.001). The eyes in G1 and G2 were significantly different ( p value for 6 cpd=0.012, for 12 cpd= 0.010, and for 18 cpd p=0.001). The eyes in G2 and the eyes in C were significantly different at all frequencies (p=0.001 for all of them. The eyes in G1 and the eyes in C were significantly different at only 12 cpd ( p=0.001).

Discussion:

There is a statistically significant decrease in contrast sensitivity at moderately high spatial frequencies in ‘sound ’eyes of patients with amblyopia in comparison to control group eyes. Evaluation of these eyes, thought to be healthy, with other tests of visual function like contrast sensitivity may be important for follow up of these patients.

Keywords: Amblyopia, contrast sensitivity, anisometropia