Original Article

Evaluation of Macular Thickness and Retinal Nerve Fiber Layer by Optical Coherence Tomography in Cases with Strabismic and Anisometropic Amblyopia

10.4274/tjo.41.74046

  • Gülizar Soyugelen
  • Nihal Onursever
  • Basak Bostanci Ceran
  • Izzet Can

Received Date: 17.01.2011 Accepted Date: 10.05.2011 Turk J Ophthalmol 2011;41(5):318-324

Pur­po­se:

To measure the macular and retinal nerve fiber layer (RNFL) thicknesses using optical coherence tomography (OCT) in amblyopic eyes of unilateral strabismic and anisometropic patients and to compare the results with those of their normal eyes and with a control group.

Ma­te­ri­al and Met­hod:

30 strabismic and 30 anisometropic amblyopic patients who were followed by Atatürk Training and Research Hospital Strabismus section between September 2009 and February 2010 and 30 healthy children who were examined in the out-patient clinic were included in the study. The amblyopic eyes of the amblyopic patients were compared with their normal eyes and with the right eyes of the healthy patients. After detailed ophthalmologic examination, macular thickness, central foveal, parafoveal and perifoveal volumes and RNFL thickness of the cases were measured with OCT and compared statistically. A p-value of less than 0.05 was accepted as statistically significant.

Re­sults:

Foveal volume of the amblyopic eyes of strabismic and anisometropic amblyopic cases (0.20mm3; 0.21mm3, respectively) was statistically higher than in the control group (0.19 mm3) (p=0.002).As the level of amblyopia increased, there was an increase in foveal volume. Central foveal thickness (CFT) of the amblyopic eyes of strabismic and amblyopic patients (258 µm and 260 µm, respectively) was higher than in the control group (244 µm), which was statistically significant difference (p=0.010). Similarly, as the level of amblyopia increased, there was an increase in CFT. When strabismic and amblyopic cases were compared, no statistical difference was observed between foveal volumes (central-parafoveal-perifoveal) and CFT results (p>0.05). There was no difference in RNFL thickness of strabismic, anisometropic and control cases (p>0.05). In addition, no significant difference was detected between the normal eyes of the amblyopic patients and the control group (p>0.05).

Dis­cus­si­on:

Although the primary site of deficit is in the visual cortex in amblyopia, secondary changes occur in the retina as well. While RNFL thickness does not differ from that in normal eyes, the thickness and volume of the fovea of amblyopic eyes are higher than in normal individuals. As a result, amblyopia not only affects the visual cortex, but gives rise to secondary changes at retinal level. (Turk J Ophthalmol 2011; 41: 318-24)

Keywords: Strabismic amblyopia, anisometropic amblyopia, optical coherence tomography, macular thickness, foveal volume, retina nerve fiber layer thickness

Full Text (Turkish)